
<PAGE>   1
                                CREDIT AGREEMENT







                         Dated: As of November 25, 1996



























                        This Instrument Prepared by:


                        Dean A. Stiffle, Esq.
                        Battle Fowler LLP
                        75 East 55th Street
                        New York, New York  10022
<PAGE>   2
                                TABLE OF CONTENTS

                                                                           Page
                                                                           ----
1.  Definitions............................................................  1

2.  Credit Facility........................................................  1

3.  Letter of Credit.......................................................  3

4.  Drafts Under the Letter of Credit......................................  4

5.  Letter of Credit Fee...................................................  4

6.  Letter of Credit Provisions............................................  4

7.  Maturity Date..........................................................  7

8.  Use of Proceeds and Maximum Amount Available...........................  7

9.  Advances under the Credit Facility.....................................  9

10. Condition to Advances..................................................  9

11. Readvances............................................................. 10

12. Additional Properties.................................................. 11

13. Loan to Value Requirement.............................................. 12

14. Updated Appraisals..................................................... 12

15. Collateral............................................................. 12

16. Sale of Property....................................................... 13

17. New Debt or Equity Offering............................................ 14

18. Restrictions on Transfer and Further Encumbrance....................... 14

19. Commitment Fee......................................................... 15

20. Administrative Fees.................................................... 15

21. Fee on Unused Portion of Credit Facility............................... 15

22. Representations and Warranties......................................... 15

23. Covenants.............................................................. 22

24. Recourse Obligations................................................... 35

25. Syndication of Credit Facility......................................... 35

26. Interest Rate Protection Agreements.................................... 37

27. Right of Entry......................................................... 38

28. Books and Records...................................................... 38

29. Taxes.................................................................. 39

30. Insurance Coverage..................................................... 40

31. Condemnation........................................................... 44

32. Environmental Provisions............................................... 45

33. Estoppel Certificates.................................................. 48
<PAGE>   3
                                                                           Page
                                                                           ----

34. Non-Waiver............................................................. 48

35. Sole Discretion........................................................ 49

36. Absolute and Unconditional Obligation.................................. 49

37. Relationship........................................................... 49

38. Anti-Forfeiture........................................................ 49

39. Deposits............................................................... 50

40. Submission to Jurisdiction............................................. 50

41. Retention of Counsel and Consultants................................... 51

42. Waiver of Notice....................................................... 51

43. Events of Default...................................................... 51

44. Application of Moneys.................................................. 54

45. Right to Cure Defaults................................................. 55

46. Further Assurances..................................................... 55

47. Costs and Expenses..................................................... 55

48. Indemnification of Agent and Co-Lenders................................ 55

49. Construction of Agreement.............................................. 55

50. Parties Bound, etc..................................................... 56

51. Complete Agreement..................................................... 56

52. Governing Law.......................................................... 56

53. Severability........................................................... 56

54. Notices................................................................ 56

55. Modification........................................................... 57

56. Waivers................................................................ 57

57. WAIVER OF TRIAL BY JURY................................................ 57

58. Borrowers' Reliance on Agent's Authority............................... 57

59. Authorized Representatives of BRT...................................... 58

60. Exculpation............................................................ 58


Exhibit A        Definitions
Exhibit B        Credit Facility Payment Provisions
Exhibit C        Form of Credit Facility Note
Exhibit D        Form of Request for Advance under Credit Facility
Exhibit E        Conditions for Inclusion of Additional Properties
Exhibit F        Initial Properties
Exhibit G        Form of Mortgage
Exhibit H        Form of Deed of Trust
Exhibit I        Form of Assignment of Leases and Rents


                                      -ii-
<PAGE>   4
Exhibit J        Form of Guaranty of Payment
Exhibit K        Form of Hazardous Material Guaranty and Indemnification
                 Agreement
Exhibit L        Form of Co-Lenders Certificate
Exhibit M        Form of Operating Statements
Exhibit N        Form of Financial Statements
Exhibit O        Form of Operating Budgets
Exhibit P        Quarterly Individual and Consolidated Operating Statements
Exhibit Q        Insurance Requirements


Schedule 1       Litigation
Schedule 2       Space Leases
Schedule 3       Other Leases
Schedule 4       Immediate Repairs
Schedule 5       Environmental Reports for Initial Properties


                                    -iii-
<PAGE>   5
                           REVOLVING CREDIT AGREEMENT


            THIS REVOLVING CREDIT AGREEMENT made as of the 25th day of November,
1996, among SMITH BARNEY MORTGAGE CAPITAL GROUP, INC. ("Smith Barney"), a
Delaware corporation having an office at 390 Greenwich Street, New York, New
York; NATIONSBANK, N.A. ("NationsBank"), a national banking corporation having
an office at 8300 Greensboro Drive, McLean, Virginia, acting in its individual
capacity (Smith Barney and NationsBank are hereinafter collectively referred to
as "Initial Co-Lenders"); BRANDYWINE REALTY TRUST ("BRT"), a Maryland real
estate investment trust having an office at Newtown Square Corporate Campus, 16
Campus Boulevard, Suite 150, Newtown Square, Pennsylvania; BRANDYWINE OPERATING
PARTNERSHIP, L.P. ("BOP"), a Delaware limited partnership having an office at
Newtown Square Corporate Campus, 16 Campus Boulevard, Suite 150, Newtown Square,
Pennsylvania; LC/N HORSHAM LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a Pennsylvania limited
partnership; NICHOLS LANSDALE LIMITED PARTNERSHIP III, a Pennsylvania limited
partnership; NEWTECH III LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania limited partnership;
C/N OAKLANDS LIMITED PARTNERSHIP I, a Pennsylvania limited partnership; FIFTEEN
HORSHAM, L.P., a Pennsylvania limited partnership; C/N LEEDOM LIMITED
PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN LIMITED
PARTNERSHIP III, a Pennsylvania limited partnership; all having offices c/o
Brandywine Realty Trust, Newtown Square Corporate Campus, 16 Campus Boulevard,
Suite 150, Newtown Square, Pennsylvania (collectively, the BRT/BOP Limited
Partnerships) (BRT, BOP and the BRT/BOP Limited Partnership are hereinafter
collectively referred to as "Borrowers"); and NATIONSBANK, N.A., a national
banking association having an office at 8300 Greensboro Drive, McLean, Virginia,
acting in its capacity as administrative and documentation agent (NationsBank,
N.A., acting in its capacity as administrative and documentation agent, or any
successor administrative and documentation agent being so designated being
hereinafter referred to as "Agent").

                              PRELIMINARY STATEMENT

            Co-Lenders have agreed on the terms, covenants and provisions of
this Agreement hereinafter set forth to extend to Borrowers a revolving credit
facility in the principal sum of up to, but not in excess of, $80,000,000 (the
"Credit Facility").

            NOW, THEREFORE, in consideration of Ten Dollars ($10.00) and other
good and valuable consideration, the receipt of which is hereby acknowledged,
and to induce Co-Lenders to extend the Credit Facility, Borrowers hereby
represent and warrant to and covenant and agree with Co-Lenders as follows:

            1.  Definitions.  All capitalized terms as used in this Agreement
shall, unless otherwise defined in this Agreement, have the meanings given to
such terms in EXHIBIT A attached hereto.

            2.  Credit Facility.  The Credit Facility shall be advanced and
readvanced by Co-Lenders to Borrowers in accordance with the provisions of
this Agreement hereinafter set forth, and shall be evidenced by, and payable,
together with interest thereon, in accordance with the provisions of the
<PAGE>   6
Credit Facility Notes and EXHIBIT B attached hereto. Except as specifically
provided for to the contrary in the Co-Lenders Agreement from time to time, the
Credit Facility Notes (the basic form of which is attached hereto as EXHIBIT C)
shall be secured on a pari passu basis with each other inter alia by the
Mortgages and the Assignments of Leases and Rents. Payments under the Credit
Facility must be received by Agent prior to 12:00 noon, Charlotte, North
Carolina time, for Borrowers to receive credit for such payment that day. The
respective undivided percentage interests (the "Credit Facility Percentage
Interests") held by each Co-Lender in the Credit Facility (inclusive of risk
participations in any Letter of Credit which is issued and is outstanding under
the Credit Facility) on the date of this Agreement are as follows:

<TABLE>
<CAPTION>
                                      Amount    Percentage Interest
                                    ----------- -------------------
<S>                                 <C>               <C>
            Smith Barney            $40,000,000       50%
            NationsBank             $40,000,000       50%
</TABLE>

Each Co-Lender shall be obligated to fund a portion of each advance made under
the Credit Facility in accordance with the provisions of this Agreement which is
equal to the amount of each such advance multiplied by such Co-Lender's
undivided Credit Facility Percentage Interest. Borrowers expressly acknowledge
and agree that (i) each Co-Lender directly assumes the obligation to fund, and
shall have the sole obligation to fund, its Credit Facility Percentage Interest
in each advance of the Credit Facility which is made, or required to be made, by
Co-Lenders in accordance with the provisions of this Agreement, (ii) the
obligations and liabilities of Co-Lenders in respect of the Credit Facility are
several obligations and liabilities and not joint and several obligations and
liabilities of Co-Lenders, (iii) Borrowers shall not have the right under any
fact or circumstance to look to any other party, including, without limitation,
any other Co-Lender, for the funding of the portion of the Credit Facility which
is required to be funded by a particular Co-Lender in accordance with the
provisions of this Agreement if such Co-Lender shall default in doing so, all
risk of such default being assumed in all respects by Borrowers, (iv) the
respective rights and obligations of Co-Lenders vis-a-vis one another
(including, without limitation, voting and approval rights), shall be as set
forth in the Co-Lenders Agreement, and (v) Borrowers shall not have the right to
examine or receive a copy of the Co-Lenders Agreement. Subject to the terms and
provisions contained therein, the Co-Lenders Agreement provides, among other
things, that (A) without the unanimous consent of Co-Lenders, (i) no Collateral
may be released other than in accordance with the express provisions of the
Credit Facility Documents, (ii) neither Borrowers nor any Guarantor may be
released from liability under the Credit Facility Documents, (iii) neither the
interest rate nor any other fees or charges payable under the Credit Facility
Documents may be changed or modified and (iv) no Credit Facility Documents may
be modified, (B) the acceptance of Additional Property for inclusion in the
collateral pool for the Credit Facility requires the unanimous approval of
Co-Lenders, and (C) Agent has (i) the authority to authorize releases of
Collateral in accordance with the express provisions of the Credit Agreement,
and (ii) the authority to authorize the making of advances and the issuance of
Letters of Credit in accordance, and upon compliance by Borrowers, with the
provisions of the Credit Agreement pertaining thereto. Borrowers acknowledge and
agree that (i) the voting and approval rights of Co-Lenders and the authority of
Agent described in the preceding sentence are for illustrative purposes only and
do not constitute a complete or exhaustive list of decisions upon which
Co-Lenders may exercise voting and approval rights, or of the authority of
Agent, in respect of the Credit Facility; provided, however, that Borrowers
shall have the right to rely on the advice of Agent as to any action taken or
not taken by Co-Lenders or as to any approval given or not given by Co-Lenders
or as to the authority of Agent, all as more particularly set forth in paragraph
58 of this Agreement, (ii) the aforesaid voting and approval rights of
Co-Lenders and authority of Agent may at any time subsequent to the closing


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<PAGE>   7
of the Credit Facility (and without prior notice to or approval by Borrowers) be
modified by Co-Lenders either (x) in accordance with the provisions of the
Co-Lenders Agreement, or (y) otherwise in the sole and absolute discretion of
Co-Lenders, and to the extent pertaining to Agent, with the approval of Agent,
and (iii) Borrowers shall in no event or under any circumstances have any right
to review, approve or consent to any modification or amendment to the Co-Lenders
Agreement, all of which may be made without any notice to or approval by
Borrowers, in the sole and absolute discretion of Co-Lenders. Agent shall
promptly inform Borrowers of any such change in the voting and approval rights
of Co-Lenders or in the authority of Agent, it being agreed that (i) any failure
by Agent to so notify Borrowers shall not prevent any such change in voting and
approval rights of Co-Lenders or in the authority of Agent from becoming
effective, and (ii) neither Agent nor Co-Lenders shall in any event have any
liability of any nature whatsoever to Borrowers for any failure by Agent to so
notify Borrowers. Borrowers acknowledge that it is Smith Barney's intention (in
consultation with NationsBank) to effect a further syndication of direct
interest in the portion of the Credit Facility held by Smith Barney and
NationsBank on the date of this Agreement pursuant to and in the manner
contemplated by paragraph 25 of this Agreement, and acknowledge that the
undivided Credit Facility Percentage Interest held by Smith Barney and
NationsBank on the date of this Agreement, and the provisions of this Agreement,
will be appropriately adjusted in accordance with the provisions of paragraph 25
of this Agreement to reflect any such further syndication of direct interests in
the Credit Facility which is concluded by Smith Barney after the date of this
Agreement, and to include the party to whom any such direct interest in the
Credit Facility is so transferred by Smith Barney as a Co-Lender under this
Agreement, all with the same force and effect as if such party was an original
Co-Lender under this Agreement.

            3. Letter of Credit. Contemporaneously with the closing of the
Credit Facility, NationsBank ("L/C Issuer") has extended for the account of
Borrowers a letter of credit facility (the "Letter of Credit Facility"), which
the Letter of Credit Facility is being extended under, and as a component of,
the Credit Facility and is included within, and is not in addition to, the
$80,000,000 maximum amount available under the Credit Facility. Each Co-Lender
shall have an undivided interest in each Letter of Credit which is issued under
the Letter of Credit Facility and in the obligation thereunder equal to its
Credit Facility Percentage Interest. Borrowers shall have the right, from time
to time, to request L/C Issuer to issue one or more unconditional and
irrevocable letters of credit for Borrowers' account (each a "Letter of
Credit"), subject to the terms and conditions of this paragraph hereinafter set
forth:

                        (i) Each request for the issuance of a Letter of Credit
            shall be in writing, shall state the requested date of issuance of
            the Letter(s) of Credit (which shall be at least five (5) business
            days after the request is received by L/C Issuer), shall state the
            requested amount of the Letters(s) of Credit and the purposes for
            which the Letter(s) of Credit are requested (which purposes shall be
            limited to the purposes set forth in clause (vi) of the first
            sentence of paragraph 8 of this Agreement), shall indicate the
            beneficiary of the Letter(s) of Credit, and shall specify the terms
            of the Letter(s) of Credit (which terms shall be satisfactory to L/C
            Issuer), it being agreed that in no event or under any circumstances
            shall L/C Issuer be obligated or required to issue under the Letter
            of Credit Facility a so-called "evergreen letter of credit" or any
            letter of credit which is subject to any form of automatic renewal.

                        (ii)  Each Letter of Credit shall be in an amount of
            not less than $100,000.


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<PAGE>   8
                        (iii) At no time during the term of the Credit Facility
            shall there be more than five (5) Letters of Credit in the aggregate
            outstanding, unless otherwise agreed to by L/C Issuer in its sole
            discretion.

                        (iv) No Letter of Credit shall have an expiration date
            beyond November 15, 1998.

                        (v) In no event shall the aggregate of the Principal
            Balance outstanding under the Credit Facility pursuant to the
            clauses (iv) and (v) of the first sentence of paragraph 8 of this
            Agreement, and the amount available for draw under outstanding
            Letter of Credit at any time during the term of the Credit Facility
            exceed $10,000,000.

                        (vi) L/C Issuer shall have the sole obligation to issue
            Letter(s) of Credit under this Agreement, and Borrowers shall not
            have the right under any fact or circumstance to look to any other
            party, including, without limitation, any other Co-Lender, for the
            issuance of the Letter(s) of Credit if L/C Issuer defaults in doing
            so, all such risk of default being assumed by Borrowers.

            4. Drafts Under the Letter of Credit. Any draw honored by L/C Issuer
under a Letter of Credit shall constitute an automatic advance under the Credit
Facility and shall be evidenced by and payable, together with interest thereon,
in accordance with the provisions of the Credit Facility Notes and EXHIBIT B
attached hereto. Upon request of L/C Issuer, each of the other Co-Lenders will
fund their respective undivided Credit Facility Percentage Interests in each
such advance under the Credit Facility which is made as a result of a draw under
a Letter of Credit.

            5. Letter of Credit Fee. Borrowers shall pay to L/C Issuer a letter
of credit fee (the "Letter of Credit Fee") calculated and payable in the manner
hereinafter set forth in this paragraph. The Letter of Credit Fee payable by
Borrowers to L/C Issuer with respect to any Letter of Credit which is issued
under the Letter of Credit Facility shall be paid in full on the date of
issuance of such Letter of Credit and as a condition precedent to issuance of
such Letter of Credit, shall be deemed earned in full on payment and shall not
be subject to refund in whole or in part, and shall be equal to (1.875%)
multiplied by (a fraction, the numerator of which shall be equal to the actual
number of days from and including the date of issuance of such Letter of Credit
to, but not including, the stated expiration date of such Letter of Credit, and
the denominator of which shall be 360). Any extension or renewal of a Letter of
Credit shall be deemed the issuance of a new Letter of Credit. L/C Issuer shall
be entitled to retain for its own account, in its capacity as L/C Issuer, 6.667%
of the Letter of Credit Fee payable with respect to each Letter of Credit which
is issued under the Letter of Credit Facility, and shall cause Agent to
distribute the remaining 93.333% of each such Letter of Credit Fee to each
Co-Lender (inclusive of NationsBank) ratably in accordance with their respective
Credit Facility Percentage Interests. The obligation of Borrowers to pay the
Letter of Credit Fee to L/C Issuer pursuant to the provisions of this paragraph
shall be secured by the Mortgages. The Letter of Credit Fee shall constitute
part of the Debt.

            6.  Letter of Credit Provisions.  Borrowers agree with L/C Issuer
that the following provisions of this paragraph shall be in effect with
respect to the Letter(s) of Credit:

                        (a) It is understood that the cost to L/C Issuer of
            maintaining its commitments under the Letter(s) of Credit may
            fluctuate as a result of the implementation, or subsequent


                                        4
<PAGE>   9
            increase, of reserve requirements on the Letter(s) of Credit by the
            Board of Governors of the Federal Reserve System of the United
            States, including, but not limited to, reserve requirements under
            Regulation D of such Board of Governors as now and from time to time
            in effect ("Regulation D"). Borrowers agree to pay to L/C Issuer,
            from time to time as hereinafter provided, such amounts as shall be
            necessary to compensate L/C Issuer for the portion of the cost
            actually incurred by L/C Issuer in maintaining its commitments under
            the Letter(s) of Credit resulting from the imposition, or any
            subsequent increase, in either case after the date of this
            Agreement, of such reserve requirements on the Letter(s) of Credit,
            it being understood that the Letter of Credit Fees and other sums
            payable by Borrowers in connection with the issuance of the
            Letter(s) of Credit have been determined on the basis of existing
            reserve requirements. In the event that any change in applicable
            law, regulation, condition, directive or interpretation thereof
            (including any request, guideline or policy whether or not having
            the force of law and including, without limitation, Regulation D) by
            any authority charged with the administration or interpretation
            thereof occurs after the date of this Agreement which:

                        (i) subjects L/C Issuer to any tax with respect to its
                  commitments under the Letter(s) of Credit (other than any tax
                  measured by or based upon the overall net income of L/C
                  Issuer); or

                        (ii) changes the basis of taxation of any amount paid or
                  payable to L/C Issuer in connection with the Letter(s) of
                  Credit (other than any tax measured by or based upon the
                  overall net income of L/C Issuer); or

                        (iii) imposes, modifies, increases or deems applicable
                  any reserve requirements with respect to the Letter(s) of
                  Credit; or

                        (iv) imposes upon L/C Issuer any other condition with
                  respect to any amount paid or payable to L/C Issuer in
                  connection with the Letter(s) of Credit; and the result of any
                  of the foregoing is to actually increase the cost to L/C
                  Issuer of maintaining its commitments under the Letter of
                  Credit, or to actually reduce the amount of any payment
                  receivable by L/C Issuer with respect to the Letter(s) of
                  Credit, or to actually require L/C Issuer to make any payment
                  on or calculated by reference to the gross amount of any sum
                  received by it with respect to the Letter(s) of Credit, in
                  each case by an amount which L/C Issuer in its sole judgment
                  deems material, then and in any such case:

                              (1)  L/C Issuer shall promptly notify Borrowers
                        in writing of the happening of such event;

                              (2) L/C Issuer shall promptly deliver to Borrowers
                        a certificate stating the change which has occurred or
                        the reserve requirements or other conditions which have
                        been imposed on L/C Issuer or the request, direction or
                        requirement with which it has complied, together with
                        the date thereof, the amount of such actual increased
                        cost, reduction or payment and the way in which such
                        amount has been calculated; and


                                        5
<PAGE>   10
                              (3) Borrowers shall pay to L/C Issuer, within ten
                        (10) days after delivery of the certificate referred to
                        in clause (2) above, such amount or amounts as will
                        compensate L/C Issuer for such additional cost,
                        reduction or payment.

The certificate of L/C Issuer as to any additional amount or amounts payable by
Borrowers pursuant to this subparagraph, which shall be calculated in a good
faith, nondiscriminatory manner, shall be conclusive evidence of the amount
thereof, absent manifest error. The protection of this subparagraph shall be
available to L/C Issuer regardless of any possible contention of invalidity or
inapplicability of the law, regulation or condition which has been imposed. In
no event or under any circumstance shall L/C Issuer be obligated to reduce the
Letter of Credit Fees or other sums payable hereunder as a result of any
reduction after the date hereof in the costs incurred by L/C Issuer in
maintaining its commitments under the Letter(s) of Credit (including, without
limitation, any reduction in applicable reserve requirements).

                        (b) It is understood that L/C Issuer's commitment to the
            beneficiary under the Letter(s) of Credit are obligations separate
            and distinct from such beneficiary's obligations, if any, to
            Borrowers. Accordingly, should Borrowers obtain an injunction,
            attachment or other order or decree from any court which prohibits
            L/C Issuer from honoring draws made under any Letter of Credit, or
            otherwise reimbursing itself for payments made under any Letter of
            Credit, Borrowers shall pay any and all expenses which L/C Issuer
            may incur on account of such Letter of Credit (including reasonable
            attorneys' fees), or otherwise reimbursing itself for payments made
            under such Letter of Credit, together with interest thereon at the
            Default Rate. This right shall be in addition to any other rights
            L/C Issuer may have at law or in equity.

                        (c) L/C Issuer shall exercise the standard of care in
            dealing with the Letter(s) of Credit as is set forth in the Uniform
            Customs and Practice for Documentary Credits (1993 Revision),
            International Chamber of Commerce Publication No. 500. Borrowers
            agrees that any action taken or not taken by L/C Issuer or by any
            correspondent of L/C Issuer under or in connection with the
            Letter(s) of Credit consistent with the standards set forth in such
            Publication, shall be binding on Borrowers and shall not put L/C
            Issuer or its correspondents under any resulting liability to
            Borrowers.

                        (d) In case of any variation between the documents
            called for by the Letter(s) of Credit or Borrowers' instructions and
            documents accepted by L/C Issuer, Borrowers shall be conclusively
            deemed to have waived any right to object to such variation with
            respect to any action of L/C Issuer relating to such documents, and
            to have ratified and approved such action as having been taken at
            Borrowers' direction, unless promptly after receipt of such
            documents or acquisition of actual knowledge of such variation (but
            in no event later than five (5) business days after receipt or
            acquisition of actual knowledge), Borrowers files written objection
            with L/C Issuer.

                        (e) Borrowers agree to indemnify L/C Issuer and to hold
            L/C Issuer harmless from and against any and all claims, damages,
            losses, liabilities, costs or expenses of any nature whatsoever
            which L/C Issuer may incur or suffer by reason of or in connection
            with the execution and delivery of or payment under any Letter of
            Credit other than any such claims, damages, losses,


                                        6
<PAGE>   11
            liabilities, costs or expenses caused by (i) the willful misconduct
            or gross negligence of L/C Issuer in performing its obligations
            under this Agreement and the Letter(s) of Credit, (ii) L/C Issuer's
            making payment against any draft presented under a Letter of Credit
            which do not strictly comply with the terms of such Letter of
            Credit, or (iii) L/C Issuer's failure to make timely payment against
            any draft presented under a Letter of Credit in compliance with the
            terms of such Letter of Credit, it being agreed that in making
            payment under a Letter of Credit L/C Issuer's exclusive reliance
            (absent willful misconduct or gross negligence) on the documents
            presented to L/C Issuer in accordance with the provisions of such
            Letter of Credit as to any and all matters set forth therein,
            whether or not any statement or any document presented pursuant to
            any such Letter of Credit proves to be forged, fraudulent, invalid
            or insufficient in any respect or any statement therein proves to be
            untrue or inaccurate in any respect whatsoever shall not relieve
            Borrowers of their obligations to indemnify L/C Issuer pursuant to
            this subparagraph. Borrowers shall, upon demand by L/C Issuer,
            reimburse L/C Issuer for any expenses incurred by L/C Issuer in
            connection with investigating or defending against any of the
            foregoing (including reasonable legal fees) except if the same is
            due to L/C Issuer's gross negligence or willful misconduct. The
            indemnities contained in this subparagraph shall, notwithstanding
            anything to the contrary contained in this Agreement, survive (i)
            the expiration of the Letter(s) of Credit and (ii) the payment of
            the Debt in full. Nothing contained in this subparagraph (e) shall
            be deemed to constitute a waiver by Borrowers of any rights or
            remedies Borrowers shall have at law, in equity or otherwise as a
            result of L/C Issuer's willful misconduct or gross negligence.

                        (f) Upon the occurrence of an Event of Default and for
            so long as such Event of Default shall continue, Co-Lenders or Agent
            shall have the absolute and unconditional right to demand that
            Borrowers deposit, in a non-interest bearing cash collateral account
            with Agent an amount equal to the face amount of all outstanding
            Letter(s) of Credit, and Borrowers upon such demand shall
            immediately make such deposit, it being expressly understood that
            the obligation of Borrowers to make such deposit is secured by the
            Mortgages and the other Credit Facility Documents, and Co-Lenders
            shall have the absolute right to enforce its remedies under the
            Mortgages and the other Credit Facility Documents, including,
            without limitation, foreclosure of the Mortgages to enforce the
            performance of Borrowers's obligation hereunder. All sums deposited
            by Borrowers pursuant to the provisions of this subparagraph shall
            not bear interest and shall constitute additional security for the
            payment of the Debt. The balance, if any, of any such deposit
            remaining after payment in full of the Debt shall be paid to
            Borrowers or as may otherwise be directed by a court of competent
            jurisdiction.

            7. Maturity Date. The Credit Facility shall mature and shall be
payable in full on December 1, 1998 (the "Maturity Date"). Co-Lenders shall have
no obligation to make any advance under the Credit Facility subsequent to
November 15, 1998, and L/C Issuer shall have no obligation to issue any Letter
of Credit subsequent to September 1, 1998.

            8. Use of Proceeds and Maximum Amount Available. The Credit Facility
shall be available (i) to refinance Additional Properties which are from time to
time added to the collateral pool for the Credit Facility in accordance with the
provisions of this paragraph and paragraph 11 of this Agreement, (ii) to finance
the acquisition by Borrowers of Additional


                                        7
<PAGE>   12
Properties, (iii) to finance in accordance with the provisions of this Agreement
the Development and the further Development of unimproved land and improved
properties owned and/or controlled either directly or indirectly by Borrowers
(irrespective of whether constituting part of the collateral pool for the Credit
Facility), provided that (x) Borrowers retain at all times in the opinion of
Co-Lenders sufficient availability under the Credit Facility to fund all costs
remaining to be paid in connection with the completion and stabilization of the
improvements which are the subject of all such Developments from time to time,
which availability under the Credit Facility will be reserved to cover the
payment of such costs and will not be advanced for any other purpose until such
costs have been paid in full, (y) Borrowers shall prior to the commencement of
any such Development submit a comprehensive description and budget therefor to
Co-Lenders, which budget and the nature and scope of such Development shall be
subject to approval by Co-Lenders prior to the commencement of such Development,
(iv) to finance the Renovation of, and capital improvements required with
respect to, properties owned and/or controlled either directly or indirectly by
Borrowers (irrespective of whether constituting part of collateral pool for the
Credit Facility), (v) for general trust, corporate and partnership purposes of
Borrowers, and (vi) for the issuance of Letters of Credit required by Borrowers
in the course of their general operation and business, provided, however, that
(A) the aggregate of the Principal Balance outstanding under the Credit Facility
pursuant to clauses (iv) and (v) of this sentence, and the amount available for
draw under outstanding Letter of Credit shall at no time during the term of
Credit Facility exceed $10,000,000, and (B) the aggregate of the Principal
Balance outstanding under the Credit Facility, and the amount available for draw
under outstanding Letter of Credit shall at no time during the term of the
Credit Facility exceed the maximum amount available under the Credit Facility
from time to time in accordance with the provisions of this Agreement (the
aggregate of the Principal Balance outstanding from time to time under the
Credit Facility, and the amount available for draw under outstanding Letters of
Credit from time to time is herein referred to as the "Credit Facility
Outstanding"). Any draw made under an outstanding Letter of Credit shall
constitute an automatic and mandatory advance under the Credit Facility which
shall be evidenced by the Credit Facility Notes and secured inter alia by the
Mortgages and the Assignments of Leases and Rents. The inclusion of Additional
Properties in the collateral pool for the Credit Facility shall be at the option
of Borrowers, and the acceptance of the same for inclusion in the Credit
Facility shall be subject to satisfaction of the conditions set forth in
paragraph 11 of this Agreement. Each time there is a change in the maximum
amount available under the Credit Facility as a result of the satisfaction of
the appraisal requirements pertaining to an Initial Property pursuant to
paragraph 10(iv) of this Agreement, the acceptance and inclusion of an
Additional Property as part of the collateral pool for the Credit Facility in
accordance with the provision of paragraph 12 of this Agreement, the release of
a Property constituting part of the collateral pool for the Credit Facility in
accordance with the provisions of paragraph 16 of this Agreement upon the sale
thereof, a reduction in the outstanding Principal Balance of the Credit Facility
in order to restore compliance with one or more of the financial covenants set
forth in paragraph 13 and paragraph 23 of this Agreement, or as a result of any
other fact or circumstance or the application of any other provisions set forth
in this Agreement or the other Credit Facility Documents, Agent shall prepare
(on behalf of Co-Lenders) and shall deliver to Co-Lenders and Borrowers a
statement setting forth the change in the maximum amount available under the
Credit Facility and the manner in which such change and such adjusted maximum
amount available under the Credit Facility were calculated, which statement
shall be promptly acknowledged and confirmed by Borrowers and Co-Lenders, shall
be conclusive and binding upon Borrowers absent manifest error, and shall remain
in effect until the next such statement is prepared and circulated by Agent.


                                        8
<PAGE>   13
            9. Advances under the Credit Facility. Co-Lenders shall not be
obligated to make an advance under the Credit Facility unless Co-Lenders are
satisfied that the conditions precedent for the making of such advance under the
Credit Facility as set forth in this Agreement and the other Credit Facility
Documents have been satisfied. Borrowers shall not have the right (other than as
provided in the next sentence) to obtain more than one advance per month under
the Credit Facility. Notwithstanding the foregoing, Borrowers shall have the
right to obtain more than one advance under the Credit Facility per month if
such additional advance is being made solely in connection with the acquisition
of an Additional Property. Each request by Borrowers for an advance under the
Credit Facility shall be in writing to Agent, shall specify the purposes for
which such advance is requested (which purposes shall be limited to the
permitted purposes set forth in paragraph 8 of this Agreement), shall in each
case be signed by a duly authorized representative of Borrowers and shall be in
the form attached hereto as EXHIBIT D (a "Request for Advance"). Each Request
for Advance shall be delivered to Agent not less than five (5) business days
prior to the date upon which such advance is requested. Co-Lenders shall not be
obligated to make an advance under the Credit Facility unless Borrowers have
delivered, or caused to be delivered, to Agent a Request for Advance at least
five (5) business days prior to the date upon which such advance is requested.
The issuance of a Letter of Credit in accordance with the provisions of this
Agreement shall be deemed to constitute an advance under the Credit Facility for
the purposes of this Agreement.

            10.  Condition to Advances.  Co-Lenders' obligation to make each
advance under the Credit Facility shall be subject to satisfaction of each of
the following additional conditions:

                        (i) No default shall have occurred and shall be
            continuing under the Credit Facility Documents.

                        (ii) All affirmative and negative covenants and
            representations and warranties contained in this Agreement and the
            other Credit Facility Documents and all of the other terms,
            covenants and conditions contained in the Credit Facility Documents
            shall continue to be complied with both before and after the making
            of each advance under the Credit Facility.

                        (iii) Agent shall be satisfied that each of the title
            insurance policies insuring the respective liens of the Mortgages
            will subsequent to the making of each advance under the Credit
            Facility (inclusive of the issuance of any Letters of Credit)
            continue to insure the respective liens of the Mortgages as first
            liens (subject only to the Permitted Title Exceptions) on each of
            the Properties constituting part of the collateral pool for the
            Credit Facility for an amount equal to the Credit Facility
            Outstanding after the making of each such advance under the Credit
            Facility, it being the intent that the respective liens of the
            Mortgages will at all times be insured as first liens on the
            Properties from time to time constituting part of the collateral
            pool for the Credit Facility for an amount which is at all times at
            least equal to the Credit Facility Outstanding from time to time and
            subject only to the Permitted Title Exceptions. In this regard,
            Borrowers shall be obligated as a condition precedent to each
            advance under the Credit Facility to deliver to Agent such
            continuations of title and endorsement to the title insurance
            policies insuring the respective liens of the Mortgages as may be
            reasonably required by Co-Lenders to evidence compliance with the
            provisions of this subparagraph. In making their determination as to
            the necessity of requiring such continuations of title and
            endorsements to the title insurance policies insuring the liens of
            the Mortgages, Co-Lenders will take into account the laws of the


                                        9
<PAGE>   14
            jurisdiction in which the Properties are located insofar as they
            pertain to the priority of the liens of Mortgages securing revolving
            credit loans over intervening liens, and whether such title policies
            as originally issued have acceptable revolving credit endorsements
            which insure the priority of future advances under the Credit
            Facility over intervening liens. Co-Lenders acknowledge that the
            title policies insuring the respective liens of the Mortgages
            covering the Initial Properties contain satisfactory revolving
            credit endorsements, and that in the absence of a change in
            applicable law or the occurrence in the opinion of Co-Lenders of any
            other material circumstance or event, Co-Lenders will not require
            date down endorsements with respect to these title insurance
            policies as a condition precedent to the making of advances under
            the Credit Facility, but do reserve the right to require
            continuation of title as a condition precedent to making such
            advance.

                        (iv) Borrowers acknowledge and agree that as of the date
            of this Agreement, Co-Lenders have not received final appraisals
            with respect to any of the Initial Properties, and, as a result,
            Co-Lenders are not obligated to make any advances under the Credit
            Facility in accordance with the provisions of this Agreement.
            Borrowers shall cause to be delivered to Co-Lenders not later than
            December 31, 1996, final "as is" appraisals with respect to the
            Properties in conformity with the requirements concerning appraisals
            generally, as set forth in paragraph 1(m) of EXHIBIT E attached
            hereto. As the appraised values of the Initial Properties, as set
            forth in such appraisals are approved by Co-Lenders (with or without
            downward adjustment, as the case may be) the amount available under
            the Credit Facility will be adjusted upward to reflect those of the
            Initial Properties with respect to which appraised values have been
            approved by Co-Lenders from time to time (with or without downward
            adjustment, as the case may be).


                        (v) All of the other terms and conditions set forth in
            this Agreement and the other Credit Facility Documents pertaining to
            advances of the Credit Facility shall have been satisfied.

            11. Readvances. The Credit Facility is intended to be a revolving
credit facility. In this regard, it is understood that Borrowers shall have the
right upon compliance with the conditions of this Agreement and the other Credit
Facility Documents which pertain to the making of advances under the Credit
Facility (including, without limitation, the requirement that all advances be
evidenced and secured by the Credit Facility Documents and insured under
acceptable title insurance policies) to obtain readvances of amounts from time
to time applied to the reduction of the outstanding Principal Balance of the
Credit Facility pursuant to the provisions of paragraphs 16, 17, 30 or 31 of
this Agreement, or otherwise required or permitted to be applied in reduction of
the outstanding Principal Balance of the Credit Facility in accordance with the
provisions of this Agreement or the other Credit Facility Documents (including,
without limitation, any portion of the outstanding Principal Balance of the
Credit Facility which is prepaid in accordance with the provisions of the Credit
Facility Notes and paragraph 10 of EXHIBIT B attached hereto). All sums which
are applied from time to time in reduction of the outstanding Principal Balance
of the Credit Facility in accordance with the provisions of this Agreement of
any of the other Credit Facility Documents shall (unless otherwise agreed to the
contrary by Borrowers) be deemed to have been applied first in reduction of
advances of the Credit Facility made pursuant to clauses (iv) and (v) of
paragraph 8 of this Agreement.


                                       10
<PAGE>   15
             12. Additional Properties. From time to time after the date hereof,
Borrowers shall have the right to request that one or more Additional Properties
be included in the collateral pool for the Credit Facility. If Borrowers wish to
submit an Additional Property for inclusion in the collateral pool for the
Credit Facility, Borrowers shall notify Agent in writing of their desire to do
so at least forty five (45) days prior to the date upon which Borrowers wish to
include such Additional Property in the collateral pool for the Credit Facility,
and shall at Borrowers' sole cost and expense cause all of the terms and
conditions of the Commitment which pertained to the inclusion of the Initial
Properties in the original collateral pool for the Credit Facility to be
satisfied with respect to the Additional Property, all with the same force and
effect as if the Additional Property had constituted part of the original
collateral pool for the Credit Facility (including, without limitation, the
terms and conditions more particularly set forth in EXHIBIT E attached hereto).
An Additional Property shall not be included in the collateral pool for the
Credit Facility unless (i) all of the aforesaid terms and conditions are met to
the satisfaction of Co-Lenders, (ii) the Additional Property shall in the
opinion of Co-Lenders be at least comparable in quality to the Initial
Properties constituting part of the original collateral pool for the Credit
Facility, (iii) all of the affirmative and negative covenants and all of the
representations and warranties contained in this Agreement and the other Credit
Facility Documents and all of the other terms, covenants and provisions of the
Credit Facility Documents shall continue to be complied with after the inclusion
of the Additional Property in the collateral pool for the Credit Facility, and
(iv) the inclusion of the Additional Property in the collateral pool for the
Credit Facility is otherwise approved by Co-Lenders holding in the aggregate not
less than 100% of the undivided Total Credit Facility Percentage Interests, it
being agreed that Co-Lenders shall in no event or under any circumstance have
any liability to Borrowers or any other person, party or entity as the result of
their decision not to accept an Additional Property for inclusion in the
collateral pool for the Credit Facility. In addition to the foregoing, if
Borrowers' interest in an Additional Property is a leasehold, such Additional
Property will not be accepted for inclusion in the collateral pool for the
Credit Facility unless the ground lease creating such leasehold estate is, in
the opinion of Co-Lenders, financeable and the terms of such ground lease shall
otherwise be approved by Co-Lenders. Agent shall inform Borrowers within fifteen
(15) days after submission by Borrowers of all of the Required Due Diligence
Materials for an Additional Property as to whether the Additional Property has
been approved for inclusion in the collateral pool for the Credit Facility by
Co-Lenders holding in the aggregate not less than 100% of the undivided Total
Credit Facility Percentage Interests. If an Additional Property is so approved
for inclusion in the collateral pool for the Credit Facility, the Appraised
Value of such Additional Property will be equal to the appraised value of the
Additional Property, as set forth in the appraisal obtained with respect to such
Additional Property pursuant to the provisions of paragraph 1(m) of EXHIBIT E
attached to this Agreement, if the fair market value of such Additional
Property, as set forth in such appraisal, is approved without adjustment by
Co-Lenders holding in the aggregate not less than two thirds (2/3) of the
undivided Total Credit Facility Percentage Interests. If the fair market value
of such Additional Property as set forth in such appraisal is approved with
downward adjustment in value by Co-Lenders holding in excess of one third (1/3)
of the undivided Total Credit Facility Percentage Interests, the Appraised Value
of such Additional Property shall be the Weighted Average Adjusted Appraised
Value of such Additional Property. The "Weighted Average Adjusted Appraised
Value" of such Additional Property shall be determined by Agent and shall be
equal to the weighted average (i.e., on the basis of the respective undivided
Total Credit Facility Percentage Interest held by each Co-Lender) of the fair
market value of such Additional Property, as respectively approved (with or
without adjustment, as the case may be) by each individual Co-Lender.


                                       11
<PAGE>   16
            13. Loan to Value Requirement. In no event will the aggregate Credit
Facility Outstanding at any given time during the term of the Credit Facility
exceed sixty percent (60%) of the aggregate Approved Value of the Properties
from time to time constituting part of the collateral for the Credit Facility
(the "Loan to Value Requirement"). The "Approved Value" of a particular Property
constituting part of the collateral pool for the Credit Facility (A) shall
during the first year of the inclusion of such Property in the collateral pool
for the Credit Facility be equal to the Appraised Value of such Property, as
determined by appraisal in accordance with the provisions of this Agreement, and
(B) shall subsequent to the first anniversary of the date of the inclusion of
such Property in the collateral pool for the Credit Facility be equal to the
Capitalization Rate Value of such Property. The "Capitalization Rate Value" of a
Property constituting part of the collateral pool for the Credit Facility shall
be equal to the aggregate Cash Flow of such Property for the four calendar
quarters preceding the date of each determination of the Capitalization Rate
Value of such Property divided by a capitalization rate of 10.5%. "Cash Flow" of
a particular Property constituting part of the collateral pool for the Credit
Facility for any given four calendar quarters shall mean the earnings (i.e.,
gross revenues less expenses) of such Property (based upon GAAP) for such four
calendar quarters before depreciation, amortization, interest expense and income
taxes less an annual capital and leasing reserve of fifty cents ($.50) per
square foot, it being understood that in determining the expenses of such
Property the management fees for such Property shall be deemed for the purposes
of this calculation to be the higher of actual management fees for such period
of time or three percent (3%) of the gross revenues of such Property for such
four calendar quarters. If at any time the Loan to Value Requirement shall cease
to be satisfied, Borrowers shall within ten (10) business days after demand by
Agent either (i) pay the outstanding Principal Balance of the Credit Facility
down by an amount sufficient to restore compliance with the Loan to Value
Requirement, or (ii) deliver to Agent additional collateral for the Credit
Facility consisting of unencumbered improved property which is satisfactory in
all respects to Co-Lenders and sufficient in the opinion of Co-Lenders to
restore compliance with the Loan to Value Requirement.

            14. Updated Appraisals. Co-Lenders shall have the right in their
discretion to commission updated appraisals or interim valuations with respect
to the Properties from time to time constituting part of the collateral pool for
the Credit Facility (i) with respect to a particular Property, if Co-Lenders, in
the exercise of their sole and absolute discretion, believes that there has been
a material reduction in the value of such Property (including, without
limitation, by reason of fire or other casualty or by reason of condemnation)
and (ii) upon the occurrence of an Event of Default and for so long as any such
Event of Default shall continue. All costs incurred in connection with any
updated appraisal or interim valuation required under this paragraph shall be
borne by Borrowers, shall be paid by Borrowers within ten (10) days after
request by Agent, and shall constitute part of the Debt. The obligation of
Borrowers to pay the aforementioned appraisal costs pursuant to this paragraph
shall be secured by the Mortgages and the other Credit Facility Documents.

            15. Collateral. The Credit Facility Notes shall be secured on a pari
passu basis with each other inter alia by the Mortgages and the Assignments of
Leases and Rents. Each Mortgage shall be substantially in the form of the
mortgage or deed of trust attached hereto as EXHIBITS G and H respectively, and
each Assignment of Leases and Rents shall be substantially in the form attached
hereto as EXHIBIT I, with such changes therein as may be necessary (i) to
reflect the interests in the Property or other Collateral to be encumbered
thereby and the ownership thereof, (ii) to adapt the same to the laws of the
particular jurisdiction in which the Property or other Collateral to be
encumbered thereby is located, and (iii) to reflect the specific terms and
conditions which are applicable thereto, including, without limitation,


                                       12
<PAGE>   17
any necessary changes as may be reasonably required by Co-Lenders.
Notwithstanding anything to the contrary contained in this Agreement, it is
understood that the portion of the principal balance of the Credit Facility
secured by a Mortgage covering a Property which is located in a state with a
substantial mortgage recording, stamp, documentary, intangible or other
comparable tax (and which does not permit allocation of debt secured by blanket
mortgages and deeds of trust in multi-state transactions) will be limited to an
amount equal to 125% of the Appraised Value of such Property. Any Mortgage which
is limited in principal amount secured in accordance with the provisions of the
preceding sentence shall otherwise secure one hundred (100%) percent of all
interest and sums (other than principal) which may or shall become due and
payable in respect of the Credit Facility in accordance with the provisions of
the Credit Facility Documents. In addition to the foregoing, and as a condition
precedent to the closing of the Credit Facility, (i) Guarantors shall execute
and deliver the Guaranty of Payment in the form of EXHIBIT J attached hereto,
and (ii) Borrowers and Guarantors shall execute and deliver the Hazardous
Material Guaranty and Indemnification Agreement in the form of EXHIBIT K
attached hereto.

            16. Sale of Property. A Property constituting part of the collateral
for the Credit Facility and other property owned by Borrowers and not
constituting part of the collateral pool for the Credit Facility may be sold
with the prior approval of Co-Lenders, which approval will not be unreasonably
withheld or delayed, provided that (i) such sale is an arms length bona fide
sale, (ii) no default has occurred and is continuing under the Credit Facility
Documents, (iii) the Loan to Value Requirement, the Minimum Debt Service
Coverage Ratio, the Supplemental Debt Service Coverage Ratio, the Fixed Charge
Coverage Ratio and the Debt-to-Tangible Net Worth Requirement shall continue to
be maintained and satisfied after any such release, (iv) if the property being
sold is a Property constituting part of the collateral pool for the Credit
Facility, the outstanding Principal Balance of the Credit Facility shall be
reduced by an amount equal to greater of (x) 100% of the net proceeds (i.e,
gross sales proceeds less usual and ordinary arms-length third party costs and
expenses actually incurred by Borrowers in connection with such sale, as
substantiated by evidence reasonably satisfactory to Co-Lenders) realized on the
sale of such Property, and (y) 60% of the Approved Value of such Property as of
the date upon which a binding contract for the sale of such Property has been
entered into (so long as such sale occurs within 180 days after such contract is
entered into, it being agreed that if such sale occurs more than 180 days after
such contract is entered into the Approved Value of such Property as of the date
of sale shall be utilized), (v) if property being sold does not constitute part
of the collateral pool for the Credit Facility, 100% of the net proceeds (i.e,
gross sales proceeds less usual and ordinary arms-length third party costs and
expenses actually incurred by Borrowers in connection with such sale, as
substantiated by evidence reasonably satisfactory to Co-Lenders) realized on the
sale of such property shall be applied first to the payment of the Other Secured
Debt, if any, encumbering such property and which is payable to unrelated third
parties, and next to the reduction of the outstanding Principal Balance of the
Credit Facility before being used for any other purpose, (vi) Co-Lenders shall
be of the reasonable opinion that the sale of any such Property constituting
part of the collateral pool for the Credit Facility will not have a material
adverse effect on the value, quality, composition or character of the remaining
Properties in collateral pool for the Credit Facility, and (vii) all of the
terms, covenants, conditions, representations and warranties contained in the
Credit Facility Documents shall continue to be complied with after any such
sale. If a Property constituting part of the collateral pool for the Credit
Facility is sold in compliance with the provisions of this paragraph, Co-Lenders
shall authorize Agent to release such Property from the lien of the Mortgage and
other Credit Facility Documents encumbering such Property contemporaneously with
the sale of such Property.


                                       13
<PAGE>   18
            17. New Debt or Equity Offering. The net cash proceeds of any new
debt or equity offering by Borrowers or their respective subsidiaries or
Affiliates shall (unless otherwise agreed to by Co-Lenders in the exercise of
their sole and absolute discretion) be applied first to the reduction of the
outstanding Principal Balance of the Credit Facility before being used for any
other purpose. The net proceeds of any new debt or equity offering by BRT may
first be contributed by BRT to BOP so long as the full amount of such net
proceeds shall immediately upon receipt by BOP be applied in accordance with the
preceding sentence.

            18. Restrictions on Transfer and Further Encumbrance. Except as
otherwise expressly provided to the contrary in the Credit Facility Documents,
no part of the Properties nor any interest of any nature whatsoever therein
(whether legal or beneficial or whether held directly or indirectly), nor any
interest of any nature whatsoever in Borrowers (whether partnership, stock,
equity, beneficial, profit, loss or otherwise or whether held directly or
indirectly, other than stock of BRT and limited partnership interests in BOP
issued to transferring persons, parties or entities as partial or total
consideration for the transfer of properties to BOP and irrespective of whether
constituting part of the collateral pool for the Credit Facility), shall in any
manner be further encumbered, sold, transferred, assigned or conveyed, or
permitted to be further encumbered, sold, transferred, assigned or conveyed
without the prior consent of Co-Lenders, which consent in any and all
circumstances may be withheld in the sole and absolute discretion of Co-Lenders.
The provisions of the foregoing sentence of this paragraph shall apply to each
and every such further encumbrance, sale, transfer, assignment or conveyance,
regardless of whether or not Co-Lenders have consented to, or waived by their
action or inaction their rights hereunder with respect to, any such previous
further encumbrance, sale, transfer, assignment or conveyance, and irrespective
of whether such further encumbrance, sale, transfer, assignment or conveyance is
voluntary, by reason of operation of law or is otherwise made. Until the Debt
has been paid in full, and unless otherwise consented to the contrary by
Co-Lenders in the exercise of their sole and absolute discretion, (i) not less
than a 75% interest in BOP shall at all times be owned and controlled by BRT,
and which interest shall at all times remain unencumbered other than by the
Credit Facility Documents, (ii) the sole general partner of BOP shall at all
times be BRT and BRT shall not encumber, sell, transfer, assign or convey its
general partner interest in the BOP, other than by the Credit Facility
Documents, (iii) not less than the present interest held either directly or
indirectly by BRT and/or BOP in each BRT/BOP Limited Partnership which owns an
Initial Property shall at all times continue to be owned and controlled by BRT
and/or BOP, which interest in each such BRT/BOP Limited Partnership shall at all
times remain unencumbered except by the Credit Facility Documents, and (iv) the
management and day to day operations of BRT, BOP and each BRT/BOP Limited
Partnership shall at all times be under the active control of BRSC, or another
management company of comparable experience and credentials and which is
otherwise reasonably acceptable to Co-Lenders. Nothing contained in this
paragraph or elsewhere in this Agreement or the other Credit Facility Documents
shall be deemed or construed to restrict in any manner whatsoever BRT's ability
to issue any common stock or beneficial shares of beneficial interests in BRT,
or the transferability of shares in BRT or limited partnership units in BOP, or
BOP's ability to issue additional limited partnership units in accordance with
the provisions of its agreement of limited partnership, it being agreed that
additional partnership units in BOP will only be issued as consideration in
whole or in part for properties being acquired by Borrowers in compliance with
the provisions of this Agreement. In addition, and upon prior notice to
Co-Lenders, WOP and the ownership of its assets may be consolidated into BOP
and/or any one or more of the BRT/BOP Limited Partnerships and the ownership of
their respective assets may be consolidated into BOP, in each case pursuant to
documents and procedures which are in form and substance reasonably satisfactory
to Co-Lenders.


                                       14
<PAGE>   19
            19. Commitment Fee. In consideration of Co-Lenders extending to
Borrowers the Credit Facility in accordance with the provisions of the Credit
Facility Documents, Borrowers shall pay to Co-Lenders on the date of execution
and delivery of this Agreement, and as a condition precedent to the first
advance of the Credit Facility, a commitment fee (the "Commitment Fee") of
$600,000, which Commitment Fee shall be divided pro rata between Co-Lenders,
shall be deemed earned in full by Co-Lenders upon payment by Borrowers, and
shall in no event be refundable in whole or in part.

            20. Administrative Fees. In consideration of the administration and
maintenance of the Credit Facility, Borrowers shall pay to (i) Agent an annual
administration fee for the Credit Facility equal to $35,000 per annum (the
"Credit Facility Administration Fee"), which Credit Facility Administration Fee
shall be payable by Borrowers, in advance, on the date of execution and delivery
of this Agreement and on the first anniversary date thereof and shall be deemed
earned in full by Agent upon payment. The Credit Facility Administration Fee
shall constitute part of the Debt and the obligation of Borrowers to pay the
Credit Facility Administration Fee pursuant to this paragraph shall be secured
by the Mortgages and the other Credit Facility Documents.

            21. Fee on Unused Portion of Credit Facility. Borrowers shall pay a
fee (the "Unused Facility Fee") on the Unused Portion of the Credit Facility,
which Unused Facility Fee shall be payable quarterly in arrears, shall be
calculated separately for each calendar quarter or portion thereof during the
term of the Credit Facility on the basis of the actual number of days elapsed
over a 360 day year and on the basis of the daily weighted average of the Unused
Portion of the Credit Facility, and shall equal 1/8% per annum from the date of
this Agreement to and including March 31, 1997, and shall, effective April 1,
1997, and thereafter equal 1/4% per annum. The Unused Facility Fee shall be
payable to Agent and shall be distributed by Agent to the Co-Lenders in
accordance with their respective daily weighted average Credit Facility
Percentage Interests during the calendar quarter or portion thereof with respect
to which the same is payable. The Unused Facility Fee shall constitute part of
the Debt and the obligation of Borrowers to pay the Unused Facility Fee pursuant
to this paragraph shall be secured by the Mortgages and the other Credit
Facility Documents.

            22.  Representations and Warranties.  Borrowers hereby represent
and warrant to Co-Lenders as follows:

                        (a) BOP is and will continue to be a limited partnership
            duly organized, validly existing and in good standing under the laws
            of the State of Delaware; BRT is and will continue to be a real
            estate investment trust duly organized, validly existing and in good
            standing under the laws of the State of Maryland and is and will at
            all times continue to maintain its tax status as a REIT under
            Section 856 of the Internal Revenue Code; each BRT/BOP Limited
            Partnership is and will continue to be a limited partnership duly
            formed, validly existing and in good standing under the laws of the
            Commonwealth of Pennsylvania; WOP is and will continue to be a
            limited partnership duly formed, validly existing and in good
            standing under the laws of the State of Delaware; BRP is and will
            continue to be a general partnership duly formed, validly existing
            and in good standing under the laws of the Commonwealth of
            Pennsylvania; BRC and BHI are and will continue to be corporations
            duly organized, validly existing and in good standing under the laws
            of the Commonwealth of Pennsylvania; each Borrower and each
            Guarantor is and will continue to be duly licensed and qualified as
            a foreign partnership, corporation or otherwise in each jurisdiction
            in which a Property is located or failure to be qualified or
            licensed


                                       15
<PAGE>   20
            would have a materially adverse effect on any Borrower, any
            Guarantor, any Property or other Collateral or on the business,
            assets, operations, property or financial or other condition of any
            Borrower or Guarantor; each Borrower has and will continue to have
            all requisite power and authority to borrow under the Credit
            Facility and to execute and deliver, and to observe and perform all
            of its obligations under, this Agreement and the other Credit
            Facility Documents; each Guarantor has and will continue to have all
            requisite power and authority to execute and deliver, and to observe
            and perform all of its obligations under the Credit Facility
            Documents; BRT has and will continue to have all requisite power and
            authority to be the sole general partner of BOP and a general
            partner of BRP (unless and until such general partnership interest
            is transferred by BRT to BOP) and to execute and deliver on behalf
            of BOP, as its sole general partner, and on behalf of BRP, as one of
            its general partners, all of the Credit Facility Documents, and to
            observe and perform all of its obligations, as the sole general
            partner of the BOP and as one of the general partners of BRP (unless
            and until such general partnership interest is transferred by BRT to
            BOP), under the Credit Facility Documents; BHI has and will continue
            to have all requisite power and authority to be the sole general
            partner of WOP and to execute and deliver on behalf of WOP, as its
            sole general partner, all of the Credit Facility Documents, and to
            observe all of its obligations, as the sole general partner of WOP
            under the Credit Facility Documents, BOP has and will continue to
            have all requisite power and authority to be the sole general
            partner of those of the BRT/BOP Limited Partnership in which it is
            currently the sole general partner (i.e., C/N Leedom Limited
            Partnership II and C/N Iron Run Limited Partnership III) and to
            execute and deliver on behalf of each such BRT/BOP Limited
            Partnership, as its sole general partner, all of the Credit Facility
            Documents, and to observe and perform all of its obligations, as the
            sole general partner of each such BRT/BOP Limited Partnership, under
            the Credit Facility Documents; WOP has and will continue to have all
            requisite power and authority to be the sole general partner of
            those of the BRT/BOP Limited Partnership in which it is currently
            the sole general partner (i.e., LC/N Horsham Limited Partnership,
            LC/N Keith Valley Limited Partnership I, Nichols Lansdale Limited
            Partnership III, Newtech III Limited Partnership, Newtech IV Limited
            Partnership, C/N Oaklands Limited Partnership I and Fifteen Horsham,
            L.P.) and to execute and deliver on behalf of each such BRT/BOP
            Limited Partnership, as its sole general partner, all of the Credit
            Facility Documents, and to observe and perform all of its
            obligations, as the sole general partner of each such BRT/BOP
            Limited Partnership, under the Credit Facility Documents; and each
            Borrower and each Guarantor has and will continue to have all
            requisite power and authority to own their respective assets and
            property and to carry on the business in which they are engaged.

                        (b) The execution, delivery and performance by Borrowers
            of this Agreement and the other Credit Facility Document, the
            borrowings by the Borrowers under the Agreement and the other Credit
            Facility Documents, and the execution, delivery and performance by
            Borrowers, and by BRT, individually and as the sole general partner
            of BOP and as a general partner of BRP, and by BHI, as the sole
            general partner of WOP, and by BOP, individually and as the sole
            general partner of those of the BRT/BOP Limited Partnership in which
            it is the sole general partner (i.e., C/N Leedom Limited Partnership
            II and C/N Iron Run Limited Partnership III), and by WOP
            individually, and as the sole


                                       16
<PAGE>   21
            general partner of the BRT/BOP Limited Partnership in which it is
            the sole general partner (i.e., LC/N Horsham Limited Partnership,
            LC/N Keith Valley Limited Partnership I, Nichols Lansdale Limited
            Partnership III, Newtech III Limited Partnership, Newtech IV Limited
            Partnership, C/N Oaklands Limited Partnership I and Fifteen Horsham,
            L.P., and by Guarantors of all other agreements and instruments (not
            mentioned above) to be executed and delivered by them pursuant
            hereto or thereto or in connection herewith or therewith, have been
            or will be duly authorized by all necessary corporate action
            (including any necessary stockholder action), partnership action or
            other action on the part of each of them, and do not and will not
            (i) violate (A) any provision of any law, rule, regulation, order,
            writ, judgment, decree, determination or award presently in effect
            having applicability to any Borrower or Guarantor of any of the
            organizational documents of any Borrower or Guarantor, or (B) any
            indenture, agreement or other instrument to which any Borrower or
            Guarantor is a party, or by which any Borrower or Guarantor or any
            of their respective property or assets is bound, except in cases
            where such violation will not have a materially adverse effect on
            any Property, any other Collateral or on the business, assets,
            operations, property or financial or other condition of any
            Borrowers or Guarantor, or (ii) be in conflict with, result in a
            breach of or constitute (with due notice or lapse of time or both) a
            default under any such indenture, agreement or other instrument,
            except in cases where such conflict, breach or default will not have
            a materially adverse effect on any Property, any other Collateral or
            on the business, assets, operations, property or financial or other
            condition of any Borrower or Guarantor, or (iii) result in or
            require (except as specifically contemplated by this Agreement) the
            creation or imposition of any lien of any nature upon any of the
            assets or property of any Borrower or Guarantor. This Agreement has
            been duly executed and constitutes, and (when executed and delivered
            by Borrowers and/or Guarantors, as applicable) each other Credit
            Facility Document now or hereafter executed and delivered by
            Borrowers and/or the Guarantors pursuant hereto or thereto or in
            connection herewith, or therewith, will each constitute the legal,
            valid and binding obligation of Borrowers and/or Guarantors
            respectively, enforceable against them in accordance with their
            terms, except as enforcement may be limited by bankruptcy,
            insolvency and other similar laws affecting the enforcement of
            creditors' rights generally and by moratorium laws from time to time
            in effect. No authorization, consent, approval, license or formal
            exemption from, nor any filing, declaration or registration with,
            any court, governmental agency or regulatory authority (Federal,
            state, local or foreign), including, without limitation, the
            Securities and Exchange Commission, or with any securities exchange,
            is required by Borrowers or Guarantor in connection with the making
            and performance by Borrowers of this Agreement or the Facility Notes
            or with respect to the borrowings hereunder or for the execution,
            delivery and performance by Borrowers and Guarantors of the other
            Credit Facility Documents, except for those already obtained or
            completed.

                        (c) When duly recorded or filed in the appropriate
            public records, the Mortgages and the Financing Statements shall
            each create in the Co-Lenders, valid and perfected first liens upon
            the property subject thereto and no further action will be required
            to perfect such liens. The representations in this subparagraph are
            limited to Borrowers' review of the title


                                       17
<PAGE>   22
            policies insuring the respective liens of the Mortgages and their
            own actual knowledge.

                        (d) The December 31, 1995, audited consolidated
            financial statements and the December 31, 1995 annual unaudited
            consolidating financial statements of Borrowers previously delivered
            by Borrowers to Co-Lenders are correct in all material respects and
            fairly set forth the financial condition of Borrowers, respectively,
            as of December 31, 1995, and the results of Borrowers' respective
            operations and changes in respective financial position for the
            period then ended, all in accordance with GAAP. Since December 31,
            1995, there has not occurred any material adverse change in the
            business, assets, operations, property or financial or other
            condition of Borrowers.

                        (e) All quarterly consolidated and consolidating
            unaudited financial statements for the calendar quarter ending
            September 30, 1996 of Borrowers previously delivered by Borrowers to
            Co-Lenders are correct in all material respects and fairly set forth
            the financial condition of Borrowers, as of the dates set forth
            therein, and the results of Borrowers' operations and changes in
            Borrowers' respective financial position for the period then ended,
            all in accordance with GAAP. Since the date of such statements
            delivered by Borrowers, there has not occurred any material adverse
            change in the business, assets, operations, property or financial or
            other condition of Borrowers.

                        (f) All quarterly unaudited individual and consolidated
            operating statements and all annual individual and consolidated
            operating statements previously delivered by Borrowers to Co-Lenders
            with respect to the Initial Properties are correct in all material
            respects and fairly set forth the operating results of the Initial
            Properties as of the dates set forth therein, and the results of
            each Initial Property's respective operations and changes in each
            Initial Property's operating activities for the period then ended.
            Since the date of such statements, there has not occurred any
            material adverse change in the operations of any Initial Property.

                        (g) Except as set forth on Schedule 1 attached to this
            Agreement, there are no actions, suits or proceedings pending or, to
            the best knowledge of Borrowers, threatened against any Borrower,
            any Guarantor or any of their respective properties or assets by or
            before any court or any Federal, state, local, foreign or other
            governmental agency or regulatory authority which, in the reasonable
            judgment of Borrowers, after consultation with counsel, would have
            or could reasonably be expected to have a materially adverse effect
            on any Property or any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor or would or could reasonably be expected to materially
            impair the ability of any Borrower or Guarantor to perform their
            respective obligations under this Agreement, the Facility Notes and
            the other Credit Facility Documents, or would otherwise be required
            to be reported under applicable Federal or state securities laws.

                        (h) Borrowers own fee title to, or a leasehold estate
            in, or other title or ownership interest in all their respective
            properties and assets including, without limitation, the properties
            and assets reflected on the audited consolidated financial
            statements referred to in subparagraph (d) above and assets and
            properties acquired since December 31, 1995.


                                       18
<PAGE>   23
                        (i) Borrowers own fee title to all of the Initial
            Properties (other than Delaware Corporate Center with respect to
            which BOP's interest is a leasehold estate). The fee title to and
            leasehold estates in the Properties are and will continue to be
            owned and held by Borrowers free and clear of all liens and monetary
            encumbrances of any nature whatsoever (except for the Permitted
            Title Exceptions). For those Properties with respect to which
            Borrowers holds leasehold estates, the Ground Leases are in full
            force and effect and no event has occurred, which but for the
            passage of time or notice, or both, would constitute a default under
            any Ground Lease, and no action has commenced and no notice has been
            given or received for the purposes of terminating any Ground Lease.
            All non-monetary encumbrances affecting the Properties will either
            benefit the Properties or will enhance the integrated use, operation
            and management of the Properties or will not otherwise have a
            materially adverse effect on the title, ownership, value, use or
            operation of any of the Properties.

                        (j) Each Borrower and Guarantor has filed or caused to
            be filed all United States and state income tax returns which are
            required to be filed and has paid or caused to be paid all taxes
            shown on such returns or on any assessment made against it, except
            in cases where such a failure to file or to pay would not have a
            materially adverse effect on any Property, any other Collateral or
            on the business, assets, operations, property or financial or other
            condition of any Borrower or Guarantor. Each Borrower and Guarantor
            has filed or caused to be filed all United States, state, local and
            foreign tax returns (other than income tax returns) which are
            required to be filed and has paid or caused to be paid all taxes
            shown on such returns or on any assessment made against it and all
            other taxes, fees or other charges imposed on it by any governmental
            authority, agency or instrumentality which have become due and
            payable (other than taxes, assessments, fees and other charges the
            validity or amount of which is being contested in good faith by
            appropriate proceeding [and otherwise in compliance with the general
            requirements for contesting Taxes, as more specifically set forth in
            paragraph 29 of this Agreement] or the failure to pay which would
            not have a materially adverse effect on any Property, any other
            Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor). No tax
            liens have been filed against any Borrower or Guarantor or against
            their respective assets and property (other than those the validity
            or amount of which is being contested in good faith by appropriate
            proceedings [and otherwise in compliance with the general
            requirements for contesting Taxes, as more specifically set forth in
            paragraph 29 of this Agreement] or the foreclosure of which would
            not have a materially adverse effect on any Property, any other
            Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor), and no
            material claims are being asserted in respect of any taxes (other
            than those being contested as aforesaid or those that are not
            material as aforesaid).

                        (k) Neither any Borrower, nor any Guarantor is in
            default in any respect under or in respect of any contract,
            agreement or other instrument to which it is a party or by which it
            or its property or assets may be bound, except in cases where such
            default has no materially adverse effect on any Property, any other
            Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor. No Event
            of Default described in paragraph 43 hereof has occurred and


                                       19
<PAGE>   24
            is continuing and no event has occurred which but for notice, lapse
            of time, or both, would constitute an Event of Default. Neither any
            Borrower, nor any Guarantor is in default under any order, judgment,
            award or decree of any court, arbitrator or other governmental
            authority binding upon or affecting it or by which any of its
            property or assets may be bound or affected, except in cases where
            such default has no materially adverse effect on any Property, any
            other Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor, and no
            such order, judgment, award or decree materially adversely affects
            the ability of any Borrower or Guarantor to carry on its business as
            now conducted or the ability of any Borrower or Guarantor to perform
            their respective obligations under this Agreement, the Facility
            Notes and the other Credit Facility Documents.

                        (l) Each Borrower and Guarantor maintains with
            financially sound and reputable insurance companies, with premiums
            at all times currently paid, property and casualty insurance upon
            fixed assets and inventories, public liability insurance, fidelity
            bond coverage, business interruption insurance, and all insurance
            required by law, all in form and amounts required by law and
            customary to the respective natures of their businesses and
            properties, and including, without limitation, the Insurance
            Policies required pursuant to paragraph 30 of this Agreement, except
            in cases where failure to maintain such insurance will not have or
            potentially have a materially adverse effect on any Property, any
            other Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor.

                        (m) Neither this Agreement, any other Credit Facility
            Document nor any document, financial statement, report, notice,
            schedule, certificate, statement or other writing furnished to or to
            be furnished to Co-Lender by any Borrower or Guarantor in connection
            with the Credit Facility or otherwise in connection with the
            transaction contemplated hereby, contains or will contain any untrue
            or misleading statement of, or omission of, any material fact as of
            the date upon which the same is so furnished.

                        (n) All of the Properties and their use comply and will
            continue to comply in all material respects with all applicable
            zoning resolutions, building codes, fire safety, subdivision and
            other applicable laws, rules and regulations including, without
            limitation, and to the best knowledge of Borrowers (which knowledge
            is based solely upon reports of the inspecting engineers who have
            prepared structural and engineering reports with respect to
            Properties) the Americans with Disabilities Act.

                        (o) No portion of any Property nor any improvements
            located on any Premises which are material to the operation, use or
            value of a Property are damaged or injured in any material respect
            as a result of any fire, explosion, accident, flood or other
            casualty.

                        (p) Except for the Ground Leases, the Leases described
            on Schedule 2 attached to this Agreement and the other leases
            described on Schedule 3 attached to this Agreement, there are no
            other leases, management and/or leasing agreements for, concerning
            or with respect to any of the Properties or any portions thereof,
            including any personal property located thereon.


                                       20
<PAGE>   25
                        (q) No condemnation or eminent domain proceeding has
            been commenced or to the knowledge of Borrowers is threatened
            against any Property.

                        (r) Borrowers have no knowledge of any notices of any
            violation of Federal law or municipal ordinances or orders or
            requirements of the States in which the Properties are located or
            any municipal department or other governmental authority which
            remain uncured.

                        (s) There exists no default by any Borrower under any
            deed of trust, mortgage, pledge or other security agreement
            affecting any Property or any other Collateral, or any portion
            thereof, or under any Material Agreement pertaining to any Property,
            or by which any portion of any of the Properties or the other
            Collateral may be bound, except where such default does not and will
            not have a material adverse effect on any Property, or any other
            Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor.

                        (t) Neither any Borrower nor any Guarantor is engaged in
            the business of extending credit for the purpose of purchasing or
            carrying any margin stock (within the meaning of Regulation G or U
            of the Board of Governors of the Federal Reserve System of the
            United States). No part of the proceeds of any advance made under
            the Credit Facility will be used to purchase or carry any such
            margin stock or to extend credit to others for the purpose of
            purchasing or carrying any such margin stock or for the purpose of
            repaying any loan the proceeds of which were used for such purpose.
            If requested by Agent, Borrowers will furnish to Agent a statement
            in conformity with the requirements of Federal Reserve Form U-1
            referred to in said Regulation U. No part of the proceeds of any
            advance made under the Credit Facility will be used for any purpose
            that violates, or which is inconsistent with, the provisions of
            Regulation G, T, U or X or any other regulation of the Board of
            Governors of the Federal Reserve System of the United States.

                        (u) Neither any Borrower nor any Guarantor has taken any
            action which would cause it to become an "employee benefit plan" as
            defined in Section 3(3) of the Employee Retirement Income Security
            Act of 1974, as amended from time to time ("ERISA"), or a
            "governmental plan" as defined in Section 3(32) of ERISA, or a
            "plan" as defined in Section 4975(e)(1) of the Internal Revenue
            Code, or which would cause its assets to become "plan assets" as
            defined in 29 C.F.R. Section 2510.3-101.

                        (v) The proceeds of any and all advances under the
            Credit Facility shall be used for the purposes set forth in
            paragraph 8 of this Agreement and for no other purposes.

                        (w) BRT and BOP taken as a whole are each, and after
            giving effect to all of the transactions contemplated by this
            Agreement and the other Credit Facility Documents, will each
            continue to be, in a solvent condition. As used herein, "solvent"
            means, when used with respect to any Person, that (i) the present
            fair saleable value of such Person's assets is in excess of the
            total amount of its liabilities (including contingent liabilities);
            (ii) such Person is able to pay its debts as they become due; and
            (iii) such Person does not have unreasonably small


                                       21
<PAGE>   26
            capital to carry on such Person's business as theretofore operated
            and all businesses in which such Person is about to engage.

                        (x) Each Borrower is not, and will by such acts as may
            be necessary, continue not to be, an investment company within the
            meaning of the Investment Company Act of 1940.

                        (y) No Borrower is a "holding company" or a "subsidiary
            company" of a "holding company," or an "affiliate" of a "holding
            company," or of a "subsidiary company" of a "holding company,"
            within the definitions of the Public Utility Holding Company Act of
            1935, as amended.

                        (z) Borrowers have dealt with no brokers in connection
            with the Credit Facility, and no brokerage fees or commissions are
            payable by or to any Person in connection with this Agreement or the
            Credit Facility. Co-Lenders shall not be responsible for the payment
            of any fees or commissions to any broker and Borrowers shall
            indemnify, defend and hold Co-Lenders harmless from and against any
            claims, liabilities, obligations, damages, costs and expenses
            (including reasonable attorneys' fees and disbursements) made
            against or incurred by Co-Lenders as a result of claims made or
            actions instituted by any broker or Person claiming by, through or
            under Borrowers in connection with the Credit Facility.

                        (aa) No aspect of any of the transactions contemplated
            herein violate or will violate any usury laws or laws regarding the
            validity of agreements to pay interest in effect on the date hereof.

                        (bb) No Borrower is a "foreign person" within the
            meaning of Section 1445 or 7701 of the Internal Revenue Code.

                        (cc) No Borrower uses a trade name and no Borrower has
            conducted or presently conducts business under any name other than
            its actual name set forth herein. The principal place of business of
            each Borrower is as stated in the recitals hereto.

The representations and warranties of Borrowers under this paragraph shall be
deemed to be continuing representations and warranties which may at all times
during the term of the Credit Facility be relied upon by Co-Lenders (and each
Participant) unless Agent shall have been informed by Borrowers of any change in
fact or circumstance which would affect the continuing accuracy of the
representations and warranties set forth in this paragraph. Borrowers shall
promptly inform Agent (but in no event later than five (5) business days after
Borrowers shall have actual knowledge thereof) of the occurrence of any fact,
circumstance or event which would change or materially affect in any way the
continuing accuracy of the representations and warranties set forth in this
paragraph or which would render any such representation or warranty inaccurate
or false in any material respect.

            23. Covenants. Borrowers shall observe and perform and shall cause
Guarantors to observe and perform, as applicable, at all times during the term
of the Credit Facility the following covenants:

                        (a) BRT and BOP shall at all times during the term of
            the Credit Facility maintain a net worth (i.e. value of total assets
            less total liabilities, as determined on the basis of generally
            accepted accounting principles consistently applied) of at least the
            aggregate of $100,000,000 plus ninety (90%) percent of the net
            proceeds (i.e., after the expenses incurred in


                                       22
<PAGE>   27
            connection with such offerings) of all equity offerings by BRT or
            BOP after the date of this Agreement. In determining the aforesaid
            net worth, Co-Lenders shall give credit to the issued and
            outstanding Series A Convertible Preferred Stock held by the Voting
            Trust dated November 6, 1996 for the benefit of the Commonwealth of
            Pennsylvania State Employes Retirement System.

                        (b) In the case of BRT, do or cause to be done all
            things necessary to preserve, renew and keep in full force and
            effect its existence as a real estate investment trust and its tax
            status as a REIT under Section 856 of the Internal Revenue Code.

                        (c) Comply in all material respects with, and do or
            cause to be done all things necessary to preserve, renew and keep in
            full force and effect, its material rights, licenses, permits and
            franchises and the rights and franchises, pertaining to or
            comprising part of the Properties or the other Collateral unless the
            failure to do so does not have a material adverse effect on any
            Property or any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor; comply with all laws, rules and regulations applicable
            to it except where the failure to do so does not have a material
            adverse effect on any Property or any other Collateral or on the
            business, assets, operations, property or financial or other
            condition of any Borrower or Guarantor; at all times maintain and
            preserve all property used or useful in the conduct of its business
            and keep the same in good repair, working order and condition, and
            from time to time make, or cause to be made, all repairs, renewals
            and replacements thereto, so that the business carried on in
            connection therewith may be properly conducted at all times except
            where the failure to do so does not have a material adverse effect
            on any Property or any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor;

                        (d) Keep its insurable properties adequately insured at
            all times; maintain such other insurance, to such extent and against
            such risks, including fire and other risks insured against by
            extended coverage, as is customary with companies in the same or
            similar businesses; maintain in full force and effect public
            liability insurance against claims for personal injury or death or
            property damage occurring upon, in, about or in connection with the
            use of any properties owned, occupied or controlled by it in such
            amount as it shall reasonably deem necessary; and maintain such
            other insurance as may be required by law.

                        (e) Borrowers (i) shall comply in all material respects
            with the requirements of, and to the extent within Borrowers'
            control, maintain, preserve, enforce and renew rights of way,
            easements, grants, privileges, licenses and restrictive covenants
            which from time to time affect or pertain to the whole or any
            portion of a Property, (ii) shall not modify, amend or terminate any
            rights of way, easements, grants, privileges, licenses or
            restrictive covenants which from time to time affect or pertain to
            the whole or any portion of a Property, and (iii) shall not without
            obtaining the prior consent of Co-Lenders (which consent shall not
            be unreasonably withheld or delayed) modify, amend or terminate, or
            surrender any of its rights under, any of such rights of way,
            easements, grants, privileges, licenses or restrictive covenants,
            unless, with respect to a modification or amendment referred to in
            clauses (ii) and (iii) only, such modification or amendment would
            not have an adverse effect on any


                                       23
<PAGE>   28
            Property, any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor.

                        (f) Borrowers shall at all times comply with and shall
            cause the Properties to continue to comply with all existing and
            future governmental laws, orders, ordinances, rules and regulations
            affecting the Properties, or any portion thereof or the use thereof,
            except where the failure to do so does not have a material adverse
            effect on any Property or any other Collateral or on the business
            assets, operations, property, financial or other condition of any
            Borrower or Guarantor.

                        (g) Promptly repair, replace or rebuild any part of a
            Property which may be damaged or destroyed by fire or other property
            hazard or casualty (including any fire or other property hazard or
            casualty for which insurance was not obtained or obtainable) or
            which may be affected by any taking by any public or quasi-public
            authority through eminent domain or otherwise, and shall complete
            and pay for, within a reasonable time, any portion of any Property
            which is at any time in the process of renovation or repair.

                        (h) Observe and perform each and every term to be
            observed or performed by Borrowers pursuant to the terms of any
            agreement or recorded instrument affecting or pertaining to the
            Properties, except where the failure to do so does not have a
            material adverse effect on any Property or any other Collateral or
            on the business, assets, operations, property or financial or other
            condition of any Borrower or any Guarantor.

                        (i) Observe and perform, and cause to be observed and
            performed, all of the terms, covenants and provisions contained in
            the Credit Facility Documents.

                        (j) Borrowers will not, without obtaining the prior
            consent of Co-Lenders, initiate, join in or consent to any private
            restrictive covenant, zoning ordinance, or other public or private
            restrictions, limiting or adversely affecting the uses which may be
            made of the Properties or any part thereof.

                        (k) Pay all of its indebtedness and obligations promptly
            and in accordance with their terms (other than such indebtedness and
            obligations, the validity or amount of which is being contested in
            good faith by appropriate proceeding [and otherwise in compliance
            with the general requirements for contesting Taxes, as more
            specifically set forth in paragraph 29 of this Agreement] or where
            the failure to pay would not have a materially adverse effect on any
            Property, any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor; and pay and discharge promptly all taxes, assessments
            and governmental charges or levies imposed upon it or upon its
            income or profits or in respect of its property, before the same
            shall become in default, as well as all lawful claims for labor,
            materials and supplies or otherwise which, if unpaid, might become a
            lien upon such properties or any part thereof (except for such
            taxes, assessments, governmental charges or levies, or such claims,
            the validity or amount of which is being contested in good faith by
            appropriate proceeding [and otherwise in compliance with the general
            requirements for contesting Taxes, as more specifically set forth in
            paragraph 29 of this Agreement] or where the failure


                                       24
<PAGE>   29
            to pay would not have a materially adverse effect on any Property,
            any other Collateral or on the business, assets, operations,
            property or financial or other condition of any Borrower or
            Guarantor).

                        (l) Furnish to Co-Lenders all financial statements and
            information required pursuant to the provisions of this Agreement
            and the other Credit Facility Documents, it being understood that
            such financial information shall be delivered by Borrowers to Agent
            for distribution by Agent to Co-Lenders.

                        (m) Give Agent prompt written notice of (i) the
            occurrence and nature of any Event of Default; (ii) the occurrence
            and nature of any event which has resulted in, or which Borrowers
            believes will result in, a materially adverse change in any Property
            or any other Collateral or in the condition or operations of any
            Property or in the financial condition or operations of any Borrower
            or Guarantor; or (iii) any matter (other than those specified above
            as to which Co-Lenders have received due notice) which has resulted
            in, or which Borrowers reasonably believe will result in, a
            materially adverse change in any Property or any Collateral or in
            the condition or operations of any Property or in the financial
            condition or operations of any Borrower or Guarantor.

                        (n) Unless Co-Lenders shall have previously consented in
            writing, neither any Borrower nor any Guarantor (i) will take any
            action which would cause it to become an "employee benefit plan" as
            defined in Section 3(3) of ERISA, or a "governmental plan" as
            defined in Section 3(32) of ERISA, or a "plan" as defined in Section
            4975(e)(1) of the Internal Revenue Code, or its assets to become
            "plan assets" as defined in 29 C.F.R. Section 2510.3-101, or (ii)
            will sell, assign or transfer its respective property, or any
            portion thereof or interest therein (other than a lease entered into
            in conformity with the provisions of this Agreement), to any
            transferee which does not execute and deliver to Co-Lenders its
            written assumption of the obligations of this covenant, it being
            understood that nothing contained herein shall be construed to make
            the obligations of this covenant applicable to any transferee of a
            Property insofar as the Mortgage encumbering such Property is being
            released in accordance with the provisions of paragraph 15 of this
            Agreement immediately prior to or simultaneously with such transfer.
            Each Borrower further covenants and agrees to protect, defend,
            indemnify and hold Co-Lenders harmless from and against all loss,
            cost, damage and expense (including without limitation, all excise
            taxes, costs of correcting any prohibited transaction or obtaining
            an appropriate exemption and reasonable attorneys' fees) which
            Co-Lenders may incur as a result of breach of this covenant by any
            Borrowers or Guarantor. This indemnity shall survive the repayment
            or retirement of the Credit Facility.

                        (o) Borrowers shall not without the prior consent and
            approval of Co-Lenders enter into, modify, amend or terminate (in
            whole or in part) any Lease covering 20,000 square feet or more of
            space located in any Property from time to time constituting part of
            the collateral pool for the Credit Facility. Borrowers shall not
            enter into any Lease covering less than 20,000 square feet of space
            located in the Improvements unless such Lease is in a form approved
            by Co-Lenders (with such changes therein as may be consistent with
            normal and prudent business practices pertaining to comparable
            leases of space in properties which are similar to


                                       25
<PAGE>   30
            the Property in question and otherwise consistent with Borrowers
            usual business practices), and at rents and otherwise on terms which
            are consistent with prevailing market conditions, as reasonably
            determined by Borrowers, and Borrowers shall not terminate any such
            Leases other than in accordance with normal and prudent business
            practices. Co-Lenders shall within ten (10) business days after
            delivery by Borrowers to Agent of a term sheet setting forth in
            detail the proposed terms for any Lease in excess of 20,000 square
            feet indicate to Borrowers whether such terms have been approved
            (subject to review and approval of the final draft of such Lease by
            Co-Lenders). Co-Lenders shall indicate to Borrowers within ten (10)
            business days after delivery by Borrowers to Agent of the final
            draft of any Lease covering in excess of 10,000 square feet (and
            irrespective of whether a term sheet has first been submitted to
            Co-Lenders for approval with respect thereto) whether Co-Lenders
            have approved such Lease, such approval not to be unreasonably
            withheld or delayed. If Co-Lenders do not indicate to Borrowers
            within ten (10) business days after receipt by Agent of any such
            term sheet or any such Lease pursuant to the provisions of this
            subparagraph, as the case may be, either their approval or
            disapproval of the same, such approval shall be deemed to have been
            granted so long as the request for such approval indicates in bold
            type that failure to approve or disapprove such term sheet or Lease,
            as the case may be, within ten (10) business days after receipt
            shall be deemed to constitute the approval of Co-Lenders. Borrowers
            shall enforce the obligation of the tenants under the Leases and
            shall observe and perform the terms, covenants and provisions of the
            Leases on Borrowers' respective parts to be observed and performed.

                        (p) Cause all taxes, assessments, water rates, sewer
            rates and other charges with respect to the Properties to be paid
            prior to the date upon which any fine, penalty, interest or cost may
            be added thereto or imposed by law for the non-payment thereof
            (other than those the validity or amount of which is being contested
            in good faith by appropriate proceedings [and otherwise in
            compliance with the general requirements for contesting Taxes, as
            more specifically set forth in paragraph 29 of this Agreement] or
            the non-payment of which would not have a materially adverse effect
            on any Property, any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor).

                        (q) Cause all income taxes, corporate franchise taxes
            and other fees payable by each Borrower and Guarantor or otherwise
            pertaining to the Properties or the Collateral to be paid as and
            when the same become due and payable (other than those the validity
            or amount of which is being contested in good faith by appropriate
            proceedings [and otherwise in compliance with the general
            requirements for contesting Taxes, as more specifically set forth in
            paragraph 29 of this Agreement] or the non-payment of which would
            not have a materially adverse effect on any Property, any other
            Collateral or on the business, assets, operations, property or
            financial or other condition of any Borrower or Guarantor).

                        (r) Cause to be observed and performed each and every
            term, covenant and provision of any partnership agreement, joint
            venture agreement, tenancy-in-common agreement, condominium
            agreement, Ground Lease, Lease and property agreement relating to
            any Property or any other Collateral on the part of a Borrower, a
            Guarantor or any Person under their control to be observed and


                                       26
<PAGE>   31
            performed and cause to be taken all steps (short of the termination
            of any Lease) necessary to enforce their respective rights
            thereunder. No such partnership agreement, joint venture or
            tenancy-in-common agreement, condominium agreement or property
            agreement shall be in any manner modified, amended or terminated
            without the prior consent of Co-Lenders unless such agreement would
            not have a materially adverse effect on any Property, any other
            Collateral or on the business assets, operations, property or
            financial or other condition of any Borrower or any Guarantor.
            Notwithstanding the provisions of the foregoing sentence, no such
            partnership agreement pertaining to BOP, BRP or WOP and no Ground
            Lease shall be modified, amended or terminated in any respect
            without the prior consent of Co-Lenders in each and every case.

                        (s) Each request for an advance under the Credit
            Facility without further act or instrument shall constitute a
            reaffirmation by Borrowers, of each of the representations and
            warranties set forth in this Agreement and in each of the other
            Credit Facility Documents, which reaffirmation shall be a condition
            precedent to Co-Lenders' obligation to make advances under the
            Credit Facility.

                        (t) Take all necessary action to maintain the Properties
            and the other Collateral in good condition and repair and will not
            commit or suffer to be committed any waste with respect thereto. The
            failure of Borrowers to pay any Taxes or any installment thereof
            (other than those the validity or amount of which is being contested
            in good faith by appropriate proceedings [and otherwise in
            compliance with the general requirements for contesting Taxes, as
            more specifically set forth in paragraph 29 of this Agreement] or
            the non-payment of which would not have a materially adverse effect
            on any Property, any other Collateral or on the business, assets,
            operations, property or financial or other condition of any Borrower
            or Guarantor), or any Insurance Premiums payable with respect to any
            of the Insurance Policies covering the Properties or any portion
            thereof, or to use and apply the Rents strictly in accordance with
            the provisions of the Credit Facility Documents, shall be deemed for
            all purposes to constitute waste, regardless of whether the same
            would, in the absence of this provision, otherwise constitute waste
            under applicable law.

                        (u) Except as expressly permitted in accordance with the
            provisions of this Agreement or the other Credit Facility Documents,
            neither the Properties nor the other Collateral nor any portion
            thereof nor any interest therein or in any Borrower shall in any
            manner be further encumbered, sold, transferred or conveyed or
            permitted to be further encumbered, sold, transferred or conveyed
            without the prior consent of Co-Lenders, which consent may be
            withheld in the sole and absolute discretion of Co-Lenders;
            provided, however, that nothing contained herein shall prohibit the
            issuance of partnership interests in BOP or equity shares in BRT
            (subject to the provisions of paragraph 18 of this Agreement) to an
            entity which conveys a Property to Borrowers as partial or total
            consideration for the conveyance of such Property.

                        (v) Cause the Debt to be paid in accordance with the
            provisions of this Agreement and the other Credit Facility
            Documents.

                        (w) At all times continue to satisfy the Loan to Value
            Requirement.


                                       27
<PAGE>   32
                        (x) Neither any Borrowers nor any Guarantor nor any of
            their respective Affiliates or subsidiaries shall engage in any
            business or activity which is not directly related to the ownership,
            operation or management of the Properties constituting part of the
            Collateral for the Credit Facility or other properties not
            constituting part of the Collateral for the Credit Facility which
            are otherwise generally comparable in nature to the Properties
            constituting part of the Collateral for the Credit Facility.

                        (y) Neither Borrowers nor any of the respective
            Affiliates or subsidiaries of Borrowers will incur either directly
            or as a guarantor any liability (whether recourse or non-recourse)
            for the payment of any indebtedness other than the Debt and Other
            Permitted Debt. In addition to outstandings under the Credit
            Facility, (A) Borrowers shall be permitted after the date hereof to
            retain currently existing non-recourse secured debt, to retain
            and/or assume from other guarantors up to, but not in excess of,
            $10,458,000 of secured debt which has recourse, and of which
            $8,775,000 is held by First Union Bank and encumbers Oakland 45 and
            50, and 6575 Snowdrift Road, and of which $1,583,000 is held by PNC
            Bank (formerly known as Midlantic Bank) and encumbers 110 Summit
            Drive, it being agreed that no such existing recourse secured debt
            will be extended, renewed or refinanced in whole or in part other
            than on a non-recourse basis (subject to the usual and customary
            exculpation carveouts of institutional lenders) and otherwise in
            compliance with the provisions of this paragraph hereinafter set
            forth, and to incur other non-recourse secured debt (all such
            secured debt whether existing on the date of the closing of the
            Credit Facility or incurred thereafter is herein collectively
            referred to as "Other Secured Debt"), provided that (i) the net
            proceeds (i.e., the gross proceeds of any such Other Secured Debt
            less the usual and ordinary arms-length third party costs and
            expenses incurred by Borrowers in obtaining the same as
            substantiated by evidence reasonably satisfactory to Co-Lenders) of
            any Other Secured Debt which is incurred after the date of the
            closing of the Credit Facility shall be used to reduce the
            outstanding Principal Balance of the Credit Facility before being
            used for any other purpose, (ii) the incurrence of such Other
            Secured Debt shall not cause a default or Event of Default to occur
            under the Credit Facility Documents, and (iii) each loan
            constituting Other Secured Debt and which closes after the date of
            the closing of the Credit Facility (inclusive of any existing
            secured non-recourse or existing secured recourse debt hereinabove
            referred to which is refinanced or extended after the date of the
            closing of the Credit Facility) shall bear interest at a market
            interest rate, shall have an initial maturity of not less than five
            (5) years after the date of its closing and funding, shall have a
            loan to value ratio of not LESS than fifty (50%), shall be
            non-recourse (subject to the usual and customary exculpation
            carveouts of institutional lenders) and shall otherwise be on terms
            and conditions which are generally applicable to comparable secured
            indebtedness, and (v) the conditions set forth in the following
            sentence of this paragraph shall otherwise be complied with, and (B)
            Borrowers shall be permitted to incur up to, but not in excess of
            $5,000,000 of unsecured recourse debt ("Other Unsecured Debt")
            provided that (i) the incurrence of such Other Unsecured Debt, shall
            not cause a default to occur under the Credit Facility Documents,
            and (ii) the conditions set forth in the following sentence of this
            paragraph shall otherwise be complied with. In addition to the
            conditions set forth in the preceding sentence, (i) no such Other
            Secured Debt or Other


                                       28
<PAGE>   33
            Unsecured Debt (collectively, "Other Debt") shall be secured in
            whole or in part by the Properties and any other Collateral, (ii)
            the Supplemental Debt Service Coverage Ratio, the Fixed Charge
            Coverage Ratio and the Debt-to-Tangible Net Worth Requirement shall
            continue to be complied with both before and after the incurring of
            any such Other Debt, (iii) Borrowers shall inform Agent in advance
            of their intention to incur any such Other Debt and shall provide to
            Co-Lenders with a term sheet setting forth the terms and conditions
            which will pertain to any such Other Debt, and such other
            information with respect thereto as shall be requested by
            Co-Lenders, (iv) all of the other affirmative and negative covenants
            and representations and warranties contained in the Credit Facility
            Documents shall continue to be complied with both before and after
            the incurring of any such Other Debt by Borrowers, and (v)
            Co-Lenders shall be satisfied that such Other Debt will not have a
            materially adverse effect on Borrowers, or their ability to perform
            their obligations under the Credit Facility Documents, or on
            collateral for the Credit Facility. Any Other Debt retained, assumed
            or incurred by Borrowers in compliance with the provisions of the
            preceding provisions of this subparagraph is herein referred to as
            "Other Permitted Debt". The incurrence of any Other Debt in
            contravention of the provisions of this subparagraph shall
            constitute an immediate "Event of Default" under this Agreement. It
            is also agreed that the earliest to occur of any one of the
            following events in respect of Other Permitted Debt shall constitute
            an immediate "Event of Default" under this Agreement:

                        (a) if any default shall occur and be continuing in
                  respect of any Other Permitted Debt and the holder thereof has
                  declared an "event of default" in respect thereof, or has
                  accelerated the payment thereof or has otherwise exercised any
                  right or remedy which it may have as a result of the
                  occurrence of such "event of default";

                        (b) if any default shall occur in respect of any Other
                  Permitted Debt, and irrespective of whether such default
                  constitutes, or would, but for notice or the lapse of time, or
                  both, constitute, an "event of default" in respect thereof,
                  and either (x) Borrowers shall fail to inform Co-Lenders of
                  the occurrence of such default within five (5) business days
                  after they have received notice of such default or otherwise
                  have actual knowledge that such default has occurred, or (y)
                  Borrowers shall fail in the case of any such default which can
                  be cured by the payment of a sum of money to effect a cure
                  thereof within five (5) days after the giving of such notice
                  to Co-Lenders, or (z) Borrowers shall fail in the case of any
                  such default which can not be cured by the payment of a sum of
                  money to effect a cure thereof with twenty (20) days after
                  giving such notice to Co-Lenders, provided, however, that if
                  such default can not in the exercise of due diligence
                  reasonably be cured within such twenty (20) day period, such
                  default shall not constitute an "Event of Default" under this
                  Agreement so long as Borrowers commence to cure such default
                  within such twenty (20) day period and thereafter diligently
                  take all steps to effect a cure thereof, as promptly as
                  possible, but in no event later than eighty (80) days after
                  the giving of such notice to Co-Lenders, failing which such
                  default shall constitute an immediate "Event of Default" under
                  this Agreement.


                                       29
<PAGE>   34
                        (z) At all times to maintain Cash Flow at a level
            sufficient to provide at least 1.65x debt service coverage on the
            Credit Facility Outstanding (the "Minimum Debt Service Coverage
            Ratio"). For the purpose of determining compliance with the "Minimum
            Debt Service Coverage Ratio"), the aggregate Cash Flow of the
            Properties in collateral pool for the Credit Facility shall (except
            as otherwise hereinafter specifically provided to the contrary in
            this paragraph) be determined on a trailing four (4) calendar
            quarter basis and on a Property by Property basis in the same manner
            as is set forth in paragraph 13 of this Agreement (except that for
            the purposes of this paragraph only the annual capital and leasing
            reserve of fifty cents ($.50) per square foot referred to in
            paragraph 13 of this Agreement will not be deducted from the
            respective earnings of such Properties as is the case for the
            purposes of paragraph 13 of this Agreement), which Property by
            Property determination will then be aggregated to determining total
            aggregate Cash Flow of the Properties, and annual debt service on
            the Credit Facility Outstanding shall insofar as the outstanding
            Principal Balance of Credit Facility is concerned be deemed to be
            equal to the greater of (x) the outstanding Principal Balance of the
            Credit Facility, as of the date of determination, multiplied by the
            weighted average interest rate applicable to the Credit Facility on
            the date of determination (which weighted average interest rate
            shall be determined on the basis of the interest rates applicable to
            the outstanding Principal Balance of the Credit Facility on the date
            of determination and the relative portions of such outstanding
            Principal Balance to which such interest rates apply), and (y) the
            annual debt service which would be payable on a 25 year fully
            amortizing loan closing on the date of determination in an amount
            equal the outstanding Principal Balance of the Credit Facility on
            such date and bearing interest at a per annum rate equal to 180
            basis points over prevailing rates on ten year U.S. Treasury
            Obligations on such date. If a Property constituting part of the
            collateral pool for the Credit Facility has on the date of any
            determination of compliance with the Minimum Debt Service Coverage
            Ratio been owned by Borrowers for less than a complete calendar
            quarter, the "Cash Flow" of such Property shall be determined by
            pro-forming on an annual basis the aggregate annual rents payable
            under Leases in effect at such Property as of the date of
            determination, and on the basis of actual expenses incurred during
            the partial calendar quarter in question, as annualized and
            appropriately adjusted to reflect expenses such as taxes and
            insurance premiums which are accrued in a manner satisfactory to
            Co-Lenders and otherwise consistent with the provisions of paragraph
            13 of this Agreement. If a Property has been owned for at least one
            full calendar quarter, but less than four calendar quarters, on the
            date of any determination of compliance with the Minimum Debt
            Service Coverage Ratio, the Cash Flow of such Property shall be
            determined by annualizing the actual earnings of such Property for
            the complete calendar quarters during which such Property has been
            owned, and on the basis of actual expenses incurred during such
            calendar quarters as annualized and appropriately adjusted to
            reflect annual expenses such as taxes and insurance premiums which
            are accrued in a manner satisfactory to Co-Lenders and otherwise in
            a manner consistent with the provisions of paragraph 13 of this
            Agreement. If at any time the Minimum Debt Service Coverage Ratio
            shall cease to be satisfied, Borrowers shall within ten (10)
            business days after demand by Agent either (a) reduce the
            outstanding Principal Balance of the Credit Facility by an amount
            sufficient to restore compliance with the Minimum Debt Service
            Coverage Ratio, or (b) deliver to Agent additional collateral for
            the Credit Facility


                                       30
<PAGE>   35
            consisting of unencumbered improved property which is satisfactory
            to Co-Lenders and sufficient in the opinion of Co-Lenders to restore
            compliance with the Minimum Debt Service Coverage Ratio.

                        (aa) At all times to maintain Total Earnings at a level
            sufficient to provide at least 2.0x debt service coverage on the
            Credit Facility Outstanding and on Other Permitted Debt (the
            "Supplemental Debt Service Coverage Ratio). For the purpose of
            determining compliance with the Supplemental Debt Service Coverage
            Ratio, Total Earnings shall (except as otherwise provided to the
            contrary in EXHIBIT A to this Agreement) be determined on a trailing
            four (4) calendar quarter basis, and annual debt service on the
            Credit Facility Outstanding and on Other Permitted Debt (A) shall
            insofar as the outstanding Principal Balance of Credit Facility is
            concerned be deemed to be equal to the greater of (x) the
            outstanding Principal Balance of the Credit Facility, as of the date
            of determination, multiplied by the weighted average interest rate
            applicable to the Credit Facility on the date of determination, and
            (y) the annual debt service which would be payable on a 25 year
            fully amortizing loan closing on the date of determination in an
            amount equal the outstanding Principal Balance of the Credit
            Facility on such date and bearing interest at a per annum rate equal
            to 180 basis points over prevailing rates on ten year U.S. Treasury
            Obligations on such date (which weighted average interest rate shall
            be determined on the basis of the interest rates applicable to the
            outstanding Principal Balance of the Credit Facility on the date of
            determination and the relative portions of such outstanding
            Principal Balance to which such interest rates apply), and (B) shall
            insofar as Other Permitted Debt is concerned be equal to the actual
            per annum debt service payable on Other Permitted Debt, as of the
            date of determination. If at any time the Supplemental Debt Service
            Coverage Ratio shall cease to be satisfied, Borrowers shall within
            ten (10) business days after demand by Agent reduce the outstanding
            principal balance of the Credit Facility by an amount sufficient to
            restore compliance with the Supplemental Debt Service Coverage
            Ratio.

                        (bb) At all times to maintain a fixed charge coverage
            ratio of at least 1.75x (the "Fixed Charge Coverage Ratio"). The
            Fixed Charge Coverage Ratio shall (except as otherwise provided to
            the contrary in EXHIBIT A in this Agreement) be determined on a
            trailing four (4) calendar quarter basis, and shall be equal to the
            Total Earnings for the period in question divided by the actual debt
            service (inclusive of interest, amortization payments and letter of
            credit fees) payable on the Credit Facility and all Other Permitted
            Debt during the period in question plus actual capital expenditures
            (with the exception of capital expenditures that are related to
            newly acquired properties irrespective of whether constituting part
            of the collateral pool for the Credit Facility and either (x)
            escrowed with another lender, the seller of such property, a title
            company or other independent third party escrow agent at the time of
            acquisition, or (y) expended within 90-days after such acquisition).
            If at any time the Fixed Charge Coverage Ratio shall cease to be
            satisfied, Borrowers shall within ten (10) business days after
            demand by Agent reduce the outstanding Principal Balance of the
            Credit Facility by an amount sufficient to restore compliance with
            the Fixed Charge Coverage Ratio. If Borrowers so reduce the
            outstanding Principal Balance of the Credit Facility, Co-Lenders
            shall on the date of such reduction confirm compliance with the
            Fixed Charge Coverage Ratio by retesting such compliance by dividing
            the Total Earnings for the period in question (i.e., the four (4)
            calendar quarters


                                       31
<PAGE>   36
            preceding the re-test date) by an amount equal to the aggregate of
            (i) the Principal Balance of the Credit Facility as so reduced
            multiplied by the weighted average interest rate applicable to the
            outstanding Principal Balance of the Credit Facility on the re-test
            date (as determined on the basis of the actual number of days
            elapsed [i.e., 365 days] over a 360 day year, and on the basis of
            the interest rates applicable to the outstanding Principal Balance
            of the Credit Facility on the date of determination and the relative
            portions of such outstanding Principal Balance to which such
            interest rates apply), (ii) the per annum debt service which is
            payable on all Other Permitted Debt, as of the re-test date, and
            (iii) the capital expenditures hereinabove referred to in the first
            sentence of this subparagraph and which were actually incurred
            during the four calendar quarters preceding the re-test date.

                        (cc) At all times to maintain a maximum debt-to-tangible
            net worth of 1.0x (the "Debt-to-Tangible Net Worth Requirement").
            The Debt-to-Tangible Net Worth Requirement shall be determined by
            dividing any and all of Borrowers' indebtedness (including, without
            limitation, the Credit Facility Outstanding, the Other Permitted
            Debt and contingent liabilities under any outstanding guarantees to
            which any of the Borrowers is a party) by the Tangible Net Worth of
            Borrowers. The "Tangible Net Worth" of Borrowers shall be determined
            in accordance with GAAP and shall include the value of all assets
            (other than intangible assets owned by Borrowers) minus the total
            liability of Borrowers (excluding provisions for deferred taxes). If
            at any time the Debt-to-Tangible Net Worth Requirement shall cease
            to be satisfied, Borrowers shall within ten (10) business days after
            demand by Agent reduce the outstanding Principal Balance of the
            Credit Facility by an amount sufficient to restore compliance with
            the Debt-to-Tangible Net Worth Requirement. Notwithstanding anything
            to the contrary contained in this Agreement, and for the purpose of
            determining compliance with the Debt-to-Tangible Net Worth
            Requirement and other financial covenants set forth in this
            Commitment, in determining the value of Borrowers' investment in any
            joint venture, partnership, limited liability company or other
            comparable entity which is not already consolidated into Borrowers'
            financial statements, such value shall be determined taking into
            account the total equity interest owned in such joint venture,
            partnership, limited liability company or other comparable entity
            and the portion of the debt (whether secured or unsecured)
            encumbering the assets of such joint venture, partnership, limited
            liability company or other comparable entity or otherwise incurred
            by such joint venture, partnership, limited liability company or
            other comparable entity which is allocable to Borrowers' equity
            interest in such joint venture, partnership, limited liability
            company or other comparable entity or which otherwise constitutes
            the recourse obligation of any one or more of the Borrowers.

                        (dd) Borrowers shall not acquire unimproved land unless
            each of the following conditions is satisfied: (i) if such
            unimproved land is adjacent to and contiguous with an improved
            property being acquired by Borrowers (irrespective of whether such
            improved property will constitute part of the collateral pool for
            the Credit Facility), the total purchase price being paid for such
            improved property and unimproved land after allocating 100% of the
            purchase price to the improved property and 0% of the purchase price
            to the adjacent and contiguous unimproved land shall be comparable
            to the purchase prices paid for comparable improved


                                       32
<PAGE>   37
            properties which have been acquired by Borrowers and/or third
            parties in the same market; (ii) if such land is not adjacent to and
            contiguous with an improved property being acquired by Borrowers,
            Borrowers shall represent to Co-Lenders that they are acquiring such
            unimproved land with the intention of commencing the Development
            thereof within six (6) months of acquisition thereof; (iii) in the
            case of unimproved land being acquired either pursuant to clause (i)
            or (ii), Borrowers shall have prepared a comprehensive plan for the
            Development of such unimproved land, which plan shall be subject to
            review and approved by Co-Lenders, which review and approval shall
            not be unreasonably withheld or delayed, and Co-Lenders shall be
            reasonably satisfied that Borrowers will remain in compliance with
            all of the terms, covenants and provisions of this Agreement after
            such unimproved land is acquired and upon the commencement, and
            during and after the completion of, construction of the Development
            of the same (including, without limitation, the financial covenants
            set forth in paragraph 13 and paragraph 23 of this Agreement, and
            the requirements of subparagraph (ee) below; and (iv) the
            acquisition of any such unimproved land is otherwise approved by
            Co-Lenders, which approval shall not be unreasonably withheld. Any
            unimproved land which is adjacent to a Property constituting part of
            the Collateral for the Credit Facility will, at the election of
            Co-Lenders, become part of the Collateral for the Credit Facility.
            The value of unimproved land will not be taken into account for the
            purpose of determining compliance with the Loan to Value
            Requirement.

                        (ee) Borrowers shall not at any time during the term of
            the Credit Facility have under Development or further Development
            unimproved land or improved properties (irrespective of whether
            constituting part of the collateral pool for the Credit Facility)
            for their account unless (i) the total cost which will be incurred
            upon completion of all such Development (inclusive of land costs)
            and whether under construction or contemplated or intended to be
            under construction in the future shall not at any given time during
            the term of Credit Facility more than $25,000,000, (ii) prior to the
            commencement of construction of each such Development, such
            Development shall be at least 50% pre-leased on generally accepted
            market terms and all required permits and approvals for such
            Development shall have been issued or obtained from the applicable
            governmental authorities, and (iv) each such Development shall
            otherwise be similar in type, quality and location to the existing
            portfolio of improved properties owned by Borrowers, it being
            understood that the purchase price paid for unimproved land which is
            acquired pursuant to clause (ii) of subparagraph (dd) above shall be
            included for the purpose of determining compliance with the
            $25,000,000 limitation set forth in clause (i) of this subparagraph
            (ee) irrespective of whether construction of the contemplated
            Development thereon has actually commenced, and that the acquisition
            of unimproved land which is not adjacent and contiguous to improved
            property being acquired by Borrowers shall be deemed in and of
            itself to be a Development in progress for the purpose of
            determining compliance with the $25,000,000 limitation set forth in
            clause (i) of this subparagraph (ee) irrespective of whether
            construction of the contemplated Development thereon has commenced.
            The cost of constructing a Development on unimproved land which is
            adjacent and contiguous to improved property acquired by Borrowers
            shall not be considered for the purposes of the $25,000,000
            limitation set forth in clause (i) of this subparagraph (ee) until
            construction of such Development actually commences.


                                       33
<PAGE>   38
                        (ff) BRT will at all times maintain (i) its REIT status
            under the Internal Revenue Code, and (ii) its status as a public
            company whose stock is listed on a nationally-recognized exchange or
            is a NASDAQ security.

                        (gg) The dividend payout ratio of BRT (dividends paid
            divided by funds from operations, as defined by NAREIT), and as
            determined on a trailing twelve month basis, shall at all times be
            less than 90%. Notwithstanding the foregoing, the actual dividend
            payout may exceed the foregoing dividend payout ratio restriction if
            required in order to maintain BRT's status as a REIT under the
            Internal Revenue Code.

                        (hh) From and after December 31, 1996, the aggregate
            Approved Value of all Properties from time to time constituting part
            of the collateral pool for the Credit Facility shall at all times be
            equal to or in excess of $75,000,000.

                        (ii) At no time during the term of the Credit Facility
            shall any individual Property constituting part of the collateral
            pool for the Credit Facility have an Approved Value in excess of 15%
            of the aggregate Approved Value of all Properties constituting part
            of the collateral pool for the Credit Facility.

                        (jj) Borrowers will not without the prior consent of
            Co-Lenders assume, guaranty, endorse or otherwise become directly or
            contingently liable for the debts or obligations of any other
            person, party or entity, except by reason of endorsement of
            negotiable instruments for deposit or collection in the ordinary
            course of business.

                        (kk) The average occupancy of all of the Properties
            constituting part of the collateral pool for the Credit Facility
            from time to time shall at no time during the term of the Credit
            Facility be less than 85% as of the last day of any two consecutive
            calendar quarters during the term of the Credit Facility, it being
            agreed that this covenant shall not be breached unless the average
            occupancy of all of the Properties constituting part of the
            collateral pool for the Credit Facility from time to time shall as
            of the last day of any two consecutive calendar quarters during the
            terms of the Credit Facility be less than 85%. Occupancy shall mean
            space in the Properties constituting part of the collateral pool for
            the Credit Facility which is occupied by tenants who in each case
            are not in default in the payment of rent under their respective
            leases. For the purpose of determining compliance with this covenant
            not more than 15,000 square feet in the aggregate of headquarters
            space in the Properties which is occupied by Borrowers or by the
            respective Affiliates or subsidiaries of Borrowers shall be
            considered to constitute occupied space in the Properties.

                        (ll) Borrowers shall pay all fees, commissions, costs,
            charges, taxes and other expenses incurred by Co-Lenders in the
            extension of the Credit Facility and in connection with the
            preparation, execution and delivery of this Agreement and the other
            Credit Facility Documents, including, without limitation, reasonable
            attorneys' fees, appraisal fees, fees and expenses incurred in
            accounting review and fees and expenses relating to examination of
            title, title insurance premiums, surveys, hazard insurance and
            mortgage recording, documentary, intangible, transfer or other
            similar taxes, revenue stamps and all recording fees and charges.
            Co-Lenders shall cooperate with Borrowers in an


                                       34
<PAGE>   39
            attempt to minimize the aforementioned costs and expenses, provided,
            however, that nothing contained herein shall require Co-Lenders to
            compromise their respective underwriting standards and requirements.

                        (mm) Co-Lenders shall not be required to pay any
            brokerage fees or commissions or other remuneration of any nature
            whatsoever arising from the extension of the Credit Facility or the
            funding of the Credit Facility and Borrowers agrees to defend,
            indemnify and hold Co-Lenders harmless, from and against any and all
            such claims in connection therewith which are asserted by any broker
            with whom Borrowers has or is alleged to have dealt in connection
            with the Credit Facility.

                        (nn) Borrowers shall not assign this Agreement by
            agreement, operation of law or otherwise, or the moneys to be
            advanced and disbursed hereunder without the prior written consent
            of Co-Lenders, which consent may be withheld by Co-Lenders in the
            exercise of their sole and absolute discretion.

                        (oo) Borrowers shall immediately commence (subject to
            the existence of materially adverse weather conditions), and shall
            complete or cause to be completed, within ninety (90) days from the
            date hereof (but in no event later than June 30, 1997 if the
            commencement date is extended due to the existence of materially
            adverse weather conditions), all "immediate repairs", if any set
            forth on Schedule 4 attached to this Agreement. Promptly after
            completion of all such "immediate repairs", Borrowers shall deliver
            evidence satisfactory to Agent substantiating compliance with the
            provisions of this subparagraph.

Continuing compliance with the covenants set forth in paragraph 13 of this
Agreement and in subparagraphs (a), (w), (y), (z), (aa), (bb), (cc), (ee), (gg),
(hh) and (kk) of this paragraph shall be subject to confirmation by Co-Lenders
at the end of each calendar quarter during the term of the Credit Facility, it
being agreed that Borrowers shall provide to Co-Lenders not later than forty
five (45) days after the end of each calendar quarter during the term of the
Credit Facility with such information and evidence as Co-Lenders shall
reasonably request in connection with the confirmation of such compliance,
together with a detailed calculation by Borrowers of the actual level of
compliance by Borrowers with each such covenant. In addition, Borrowers shall
furnish to Co-Lenders not later than forty five (45) following the end of each
calendar quarter during the term of the Credit Facility with a certificate
signed by the chief executive officer or chief financial officer of BRT
certifying to Co-Lenders that Borrowers are in compliance with all of the terms,
covenants and conditions set forth in the Credit Facility Documents (including,
without limitation, those set forth in this paragraph) and that the
representations and warranties set forth in this Agreement and the other Credit
Facility documents continues to be true and correct in all material respects
(other than as specifically disclosed to Co-Lenders to the contrary in writing
in accordance with the provisions of the last sentence of paragraph 22 of this
Agreement).

            24.  Recourse Obligations.  Borrowers' obligations in respect of
the Credit Facility shall constitute the full joint and several recourse
obligations of Borrowers.

            25. Syndication of Credit Facility. Borrowers acknowledge that (i)
Smith Barney intends after the date of this Agreement (and in consultation with
NationsBank) to sell and assign and/or transfer direct interests in the portion
of the Credit Facility held by Initial Co-Lenders to one or more domestic or
foreign banks, insurance companies, pension funds, trusts or other


                                       35
<PAGE>   40
institutional lenders as may be selected by Smith Barney and NationsBank in
their sole and absolute discretion (any such bank, insurance companies, pension
funds, trusts or other institutional lenders to whom a direct interest in the
Credit Facility is sold and assigned and/or transferred in accordance with the
foregoing provisions of this paragraph or in accordance with the provisions of
this paragraph hereinafter set forth is herein collectively referred to,
together with Initial Co-Lender, as Co-Lenders and individually as a Co-Lender,
and shall be treated in all respects as a Co-Lender under this Agreement and the
other Credit Facility Documents, all with the same force and effect as if an
original party thereto). Co-Lenders also reserve the right to sell and assign
conventional participation interests in the Credit Facility to such domestic or
foreign banks, insurance companies, pension funds, trusts or other institutional
lenders or other Persons or investors (including, but not limited to, grantor
trusts, owner trusts, special purpose corporations or other similar or
comparable investment vehicles, but specifically excluding REMICS, FASITs and
real estate investment trusts) as may be selected by Co-Lenders in their sole
and absolute discretion and on terms and conditions satisfactory to Co-Lenders
in their sole and absolute discretion (any such bank, insurance company, pension
fund, trust or other institutional lender or other Person or investor to whom a
conventional participation interest in the Credit Facility is so sold and
assigned being herein referred to as a "Participant"). Borrowers expressly
acknowledge and agree that (i) each Co-Lender holding a direct interest in the
Credit Facility shall directly assume the obligation to fund, and shall have the
sole responsibility to fund, its Credit Facility Percentage Interest in each
advance of the Credit Facility which is made, or required to be made, by
Co-Lenders in accordance with the provisions of this Agreement, (ii) the
obligation and liabilities of Co-Lenders are several obligations and liabilities
and not joint and several obligations and liabilities, (iii) Agent shall from
time to time issue to Borrowers a Co-Lenders certificate in the form of EXHIBIT
L attached hereto (the "Co-Lenders Certificate"), which Co-Lenders Certificate
shall set forth the identity of Co-Lenders from time to time and their
respective Credit Facility Percentage Interests, each of which Co-Lenders
Certificate shall be conclusive and binding upon Borrowers, (iv) Borrowers shall
not have the right under any fact or circumstance to look to any other party,
including, without limitation, any other Co-Lender, for the funding of the
portion of the Credit Facility which is required to be funded by a particular
Co-Lender in accordance with this Agreement and as set forth in the most recent
Co-Lenders Certificate if such Co-Lender shall default in doing so, all risk of
such loss being directly assumed in all respects by Borrowers. If a Co-Lender
shall sell a conventional participation interest in the portion of the Credit
Facility held by it, Borrowers shall have no obligation to look to any Person
other than such Co-Lender for the funding of any portion of the Credit Facility
in which such Co-Lender has sold and assigned to a Participant a conventional
participation interest, it being agreed that the provisions of the preceding
sentence of this paragraph shall not be applicable to any conventional
participation interest in the Credit Facility which is sold and assigned by a
Co-Lender to a Participant. Borrowers shall cooperate, and shall cause each
Guarantor, indemnitor and other Person associated or connected with the Credit
Facility or the Collateral therefor to cooperate, in all respects with
Co-Lenders in connection with the sale of direct interests and conventional
participation interests in the Credit Facility in the manner contemplated by
this paragraph, and shall, in connection therewith, execute and deliver such
estoppels, certificates, instruments and documents as may be requested by Smith
Barney, including, without limitation, substitute Credit Facility Notes to
evidence the respective portions of a Co-Lender's interest which is sold and
which is retained and such other documents and instruments as are required to
effect the assumption by each Co-Lender of the direct obligation to fund the
portion of the Credit Facility held by it. Co-Lenders shall return to Borrowers
any Credit Facility Note with respect to which substitute Credit Facility Notes
are executed by Borrowers in accordance with the preceding provisions of this
paragraph, which replaced Credit Facility


                                       36
<PAGE>   41
Note shall, prior to being returned to Borrowers, be marked "cancelled and
replaced pursuant to paragraph 25 the Credit Agreement". Borrowers grant to
Co-Lenders, and shall cause each Guarantor, indemnitor and other Person
associated or connected with the Credit Facility or the Collateral therefor to
grant to Co-Lenders, the right to distribute on a confidential basis financial
and other information concerning Borrowers, each Guarantor and each such
indemnitor and other Person and the Properties encumbered by the Mortgages and
other pertinent information with respect to the Credit Facility to any party who
has purchased a direct interest or conventional participation interest in the
Credit Facility or who has expressed a serious interest in purchasing a direct
interest or conventional participation interest in the Credit Facility. The
policies of title insurance insuring the respective liens of the Mortgages shall
be assignable by Co-Lenders and Agent in connection with any sale, assignment or
syndication of the Credit Facility, and Borrowers shall be obligated to pay any
additional insurance premiums which may become due as the result of the
assignment of the title insurance policies in connection with any such sale,
assignment or syndication of the Credit Facility (including, without limitation,
any premium which may become due as a result of any endorsement to the title
insurance policy naming the holder(s) of any interest therein subsequent to any
such sale, assignment or syndication as named insured(s) in the title insurance
policies). Borrowers shall reimburse Smith Barney upon demand for all costs
incurred by Smith Barney in connection with the syndication of the Credit
Facility (including reasonable attorneys' fees), it being understood that (i)
Smith Barney shall, unless otherwise agreed to by Smith Barney, have the
exclusive right to effect a syndication of direct interests in the Credit
Facility, and (ii) 100% of any such syndication by Smith Barney shall be
transferred on a pari passu basis from Initial Co-Lenders respective Credit
Facility Percentage Interests unless otherwise mutually agreed by Initial
Co-Lenders to the contrary. Smith Barney and NationsBank shall have the right at
any time in their sole and absolute discretion and without obtaining the prior
approval or consent of Borrowers to permit other Co-Lenders to sell and assign
and/or transfer direct interests in the Credit Facility on such terms and
conditions as shall be acceptable to Smith Barney and NationsBank, and otherwise
on the terms and conditions hereinabove set forth in this paragraph and in the
Co-Lenders Agreement and which are applicable in connection with any such sale
and assignment and/or transfer of a direct interest in the Credit Facility by
Smith Barney. If Borrowers shall default in the performance of its obligation as
set forth in this paragraph, and if such default shall not be remedied by
Borrowers within ten (10) days after notice by Smith Barney and NationsBank,
Smith Barney and NationsBank shall acting together have the absolute and
unconditional right to declare the Credit Facility immediately due and payable.
Notwithstanding anything to the contrary in this paragraph, (i) Smith Barney
and/or The Travelers Insurance Corporation, a Connecticut insurance corporation
and an affiliate of Smith Barney, shall at all times during the term of the
Credit Facility (and provided that no Event of Default has occurred and is
continuing) hold not less than a $15,000,000 direct interest in the maximum
committed amount of the Credit Facility, and (i) NationsBank and/or and an
affiliate of NationsBank, shall at all times during the term of the Credit
Facility (and provided that no Event of Default has occurred and is continuing)
hold not less than a $15,000,000 direct interest in the Credit Facility, it
being understood and agreed that nothing contained in this sentence shall be
deemed to restrict the ability of Smith Barney, The Travelers Insurance Company,
NationsBank or any such affiliate of NationsBank to assign conventional
participation interests in their respective retained direct interests in Credit
Facility. Agent shall use its best efforts to inform Borrowers of each sale of a
direct interest in the Credit Facility promptly after the same occurs, but shall
in no event have any liability for failing to do so.

            26. Interest Rate Protection Agreements. Borrowers shall be
permitted to enter into interest rate swap and cap agreements with respect to


                                       37
<PAGE>   42
the Credit Facility and with respect to Other Permitted Debt provided that (i)
Borrowers notifies Agent of its intention to do so prior to entering into any
such agreement, (ii) Co-Lenders shall be satisfied with the counter-party to any
such swap or cap agreement, (iii) any such agreement which has the effect of
fixing the interest rate, or setting a minimum and/or maximum interest rate,
with respect to the Credit Facility or with respect to Other Permitted Debt
shall be taken into account in determining compliance with the Minimum Debt
Service Coverage Ratio, the Supplemental Debt Service Coverage Ratio and the
Fixed Charge Coverage Requirement, (iv) no such agreement shall be secured by
any Property or any Collateral, and (v) each such agreement which pertains to
the Credit Facility shall be assigned by Borrowers to Agent as additional
Collateral for the Credit Facility.

            27. Right of Entry. Agent, Co-Lenders and their respective employees
and agents shall have the right, upon reasonable prior notice to Borrowers and
subject to the rights of lessee and tenants to enter and inspect the Properties
at all reasonable times.

            28. Books and Records. Borrowers will keep and maintain or will
cause to be kept and maintained on a fiscal year basis in accordance with
generally accepted accounting practices consistently applied proper and accurate
books, records and accounts reflecting all of the financial affairs of
Borrowers, and all items of income and expense in connection with the operation
of the Properties or in connection with any services, equipment or furnishings
provided in connection with the operation of the Properties, whether such income
or expense be realized by Borrowers or any other Person excepting lessees
unrelated to and unaffiliated with Borrowers who have leased from Borrowers
portions of any Properties for the purpose of occupying the same. Co-Lenders and
their respective employees and agents shall have the right from time to time
upon not less than one (1) business day's prior notice and at all times during
normal business hours to examine such books, records and accounts at the offices
of Borrowers or other Person maintaining such books, records and accounts and to
make copies or extracts thereof as Co-Lenders, or their respective employees or
agents shall desire. Co-Lenders shall also have the right upon reasonable notice
and during normal business hours to conduct an audit of the books and records of
Borrowers, which audit may be performed by an independent certified public
accountant selected and retained by Co-Lenders. If such audit is conducted by
Co-Lenders subsequent to the occurrence of a default under any of the Credit
Facility Documents or if the results of such audit discloses a material
discrepancy from the information previously provided by Borrowers irrespective
of whether or not such audit was conducted subsequent to the occurrence of a
default under the Credit Facility Documents, then the cost of such audit shall
be borne by Borrowers, shall be paid by the Borrowers within ten (10) days after
request by Agent and shall constitute part of the Debt. The obligation of
Borrowers to pay the aforementioned audit costs pursuant to this paragraph shall
be secured by the Mortgages and the other Credit Facility Documents. Except as
otherwise set forth in this paragraph, the cost of any audit conducted hereunder
shall be paid by Co-Lenders. Borrowers shall furnish or cause to be furnished to
each Co-Lender each of the following:

                        (i) annually, within ninety (90) days next following the
            end of each calendar year during the term of the Credit Facility,
            individual and consolidated unaudited financial and operating
            statements in the form attached hereto as EXHIBIT M covering the
            operation of each of the Properties from time to time constituting
            part of the Collateral for the Credit Facility for such calendar
            year, which financial and operating statements shall show the actual
            performance of each of the Properties from time to time constituting
            part of the Collateral for the Credit Facility for the immediately
            preceding calendar year and shall otherwise be in form and substance
            reasonably satisfactory to Co-Lenders.


                                       38
<PAGE>   43
                        (ii) annually, within ninety (90) days next following
            the end of each calendar year during the term of the Credit
            Facility, complete executed copies of annual audited consolidated
            and annual unaudited consolidating financial statements in the form
            attached hereto as EXHIBIT N for each Borrowers and Guarantors for
            such calendar year, and containing a fully itemized statement of
            profit and loss and of surplus and a balance sheet.

                        (iii) individual and consolidated operating and capital
            expenditure budgets for each calendar year during the term of Credit
            Facility pertaining in the form attached hereto as EXHIBIT O and
            covering each of the Properties from time to time constituting part
            of the Collateral for the Credit Facility. The 1997 budgets shall be
            submitted prior to January 31, 1997, and the budgets for subsequent
            calendar years shall be due not later than 30 days prior to
            beginning of such calendar year during the term of the Credit
            Facility.

                        (iv) quarterly (unless otherwise requested by Agent more
            frequently than quarterly, but in no event more frequently than
            monthly) not later than forty five (45) days after the end of each
            calendar quarter (or such shorter period of time if requested more
            frequently than quarterly) during the term of the Credit Facility,
            quarterly unaudited individual and consolidated operating statements
            in the form attached hereto as EXHIBIT P covering each of the
            Properties from time to time constituting part of the Collateral for
            the Credit Facility, reconciled on a quarterly basis to the then
            current annual individual and consolidated operating budgets for the
            Properties;

                        (v) copies of all other quarterly and annual filings of
            Borrowers with the Securities and Exchange Commission and other
            publicly released information concurrent with such filing or public
            releases.

                        (vi) Such other information with respect to Borrowers,
            Guarantors, the properties and assets owned by Borrowers
            (irrespective of whether constituting part of the collateral pool
            for the Credit Facility) and by Guarantors and the respective
            subsidiaries and Affiliates of Borrowers and Guarantors as may be
            reasonably requested by Co-Lenders.

All audited financial statements required to be prepared pursuant to the
provisions of this paragraph shall be prepared and certified by an independent
certified public accountant acceptable to Co-Lenders, shall be prepared in
accordance with GAAP, and shall be in form and substance satisfactory to
Co-Lenders. All unaudited financial statements delivered to Co-Lenders pursuant
to the provisions of this paragraph shall be certified to be true and correct in
all material respects by the chief financial officer or the chief executive
officer of BRT. Borrowers shall furnish to Co-Lenders within forty five (45)
days next following the end of each calendar quarter during the term of the
Credit Facility, a certificate signed by the chief financial officer or the
chief executive officer of BRT certifying on the date thereof either that there
does or does not exist an event which constitutes, or which upon notice or lapse
of time or both would constitute, a default or an Event of Default under any of
the Credit Facility Documents, and if such default or Event of Default exists,
the nature thereof and the period of time it has existed.

            29. Taxes. Borrowers shall pay, or cause to be paid, all taxes,
assessments, water rates, sewer rents and other charges, including vault charges
and license fees for the use of vaults, chutes and similar areas adjoining the
Premises, now or hereafter levied or assessed against the


                                       39
<PAGE>   44
Properties (the "Taxes") prior to the date upon which any fine, penalty,
interest or cost may be added thereto or imposed by law for non-payment thereof.
Borrowers shall deliver to Co-Lenders, upon request, receipted bills, cancelled
checks, and other evidence satisfactory to Co-Lenders evidencing the payment of
the Taxes prior to the date upon which any fine, penalty, interest or cost may
be added thereto or imposed by law for the non-payment thereof. Co-Lenders shall
have the right in their discretion to maintain a tax services contract with
respect to the Properties with a tax reporting agency satisfactory to
Co-Lenders. Borrowers shall reimburse Co-Lenders upon demand for the cost of
maintaining such tax service contract during the term of the Credit Facility.
After prior notice to Co-Lenders, in the case of any material item, Borrowers,
at its own expense, may contest by appropriate legal proceeding, promptly
initiated and conducted in good faith and with due diligence, the amount or
validity or application in whole or in part of any of the Taxes, provided that
(i) no default shall have occurred and shall be continuing under the Credit
Facility Notes, the Mortgages, this Agreement or any of the other Credit
Facility Documents, (ii) Borrowers is permitted to do so under the provisions of
the Ground Leases and any mortgage or deed of trust superior in lien to the
Mortgages, (iii) such proceeding shall suspend the collection of the contested
Taxes from Borrowers and from the Properties, (iv) such proceeding shall be
permitted under and be conducted in accordance with the provisions of any other
instrument to which Borrowers is, or the Properties are, subject and shall not
constitute a default thereunder, (v) neither the Properties nor any part thereof
nor any interest therein will in the opinion of Co-Lenders be in danger of being
sold, forfeited, terminated, cancelled or lost, and (vi) Borrowers shall have
set aside in a manner satisfactory to Co-Lenders adequate cash reserves for the
payment of the contested Taxes, together with all interest and penalties
thereon, or in the alternative Borrowers shall have furnished such security as
may be required in the proceeding, or as may otherwise be requested or required
by Co-Lenders to insure the payment of the contested Taxes, together with all
interest and penalties thereon.

            30. Insurance Coverage. Borrowers will insure the Properties and
other Collateral against such perils and hazards, and in such amounts and with
such limits, as Co-Lenders may from time to time reasonably require, and in any
event will continuously maintain with respect to each of the Properties and the
other Collateral, without cost to Co-Lenders, the insurance described in EXHIBIT
Q of this Agreement (collectively, the "Insurance Policies"). All Insurance
Policies shall be in form, issued by companies, in amounts and with deductibles
satisfactory to Co-Lenders from time to time and shall be maintained throughout
the term of the Credit Facility without cost to Co-Lenders. An insurance company
shall not be satisfactory unless such insurance company (a) has Best's general
policyholder rating of "A-" or better and a financial rating of "Class VIII" or
better; (b) is licensed in the State in which the insured Property is located;
(c) has actively been in business for at least five (5) years; (d) if it is a
mutual company, is a nonassessable company; and (e) does not provide insurance
on any one building in excess of ten (10%) percent of its policyholders' surplus
(including capital). All Insurance Policies insuring against casualty and
business interruption and other appropriate policies shall include
non-contributing mortgagee endorsements in favor of Co-Lenders with loss payable
to Co-Lenders, as well as standard waiver of subrogation endorsements, and shall
provide that the coverage shall not be terminated or modified, nor a risk
changed without thirty (30) days' advance written notice to Co-Lenders. A
verified copy of each Insurance Policy shall be delivered to Agent. If a blanket
policy is issued, a certified copy of said policy shall be furnished, together
with an endorsement indicating that Co-Lenders, and their respective affiliates,
subsidiaries, successors and assigns are additional insureds under such policy
in the designated amount. If any portion of the insured risks are reinsured, the
reinsurance policies shall contain "cut-through" endorsements in form
satisfactory to Co-Lenders. Commencing with the calendar quarter which


                                       40
<PAGE>   45
commences on January 1, 1997, Borrowers will deliver to Co-Lenders, not later
than January 10, 1997, and thereafter not later than fifteen (15) days after the
commencement of each subsequent calendar quarter during the term of the Credit
Facility, evidence satisfactory to Co-Lenders confirming that Borrowers have
prepaid all insurance premiums for the Insurance Policies (the "Insurance
Premiums") allocable to the calendar quarter in question. Borrowers will deliver
all Insurance Policies to Agent and, in case of Insurance Policies about to
expire, Borrowers will deliver renewal or replacement policies to Agent not less
than thirty (30) days prior to the date of expiration. The foregoing
requirements of this paragraph shall apply to any separate policies of insurance
taken out by Borrowers concurrent in form or contributing in the event of loss
with the Insurance Policies. If any Insurance Policy or part thereof shall
expire or be withdrawn or become void by reason of the failure or impairment of
the capital of any company in which the insurance shall be carried, or if at any
time Co-Lenders are not in receipt of written evidence that all insurance
required hereunder is in force and effect or if for any reason whatsoever the
insurance shall be unsatisfactory to Co-Lenders, Co-Lenders shall have the
absolute and unconditional right without prior notice to Borrowers to take such
action as Co-Lenders deems necessary to protect the interest of Co-Lenders in
the Properties and other Collateral, including without limitation, the obtaining
of such insurance coverage as Co-Lenders deem appropriate, and all expenses
incurred by Co-Lenders in connection with such action or by Co-Lenders in
obtaining such insurance and keeping it in effect shall be paid by Borrowers to
Co-Lenders upon demand together with interest thereon at the Default Rate.
Co-Lenders will promptly inform Borrowers of any such action so taken by
Co-Lenders. Borrowers shall at all times comply with and shall cause the
Properties, the other Collateral and the use, occupancy, operation, maintenance,
alteration, repair and restoration thereof to comply with the terms, conditions,
stipulations and requirements of the Insurance Policies. If a Property, or any
portion thereof, is located in a Federally designated "special flood hazard
area", in addition to the other Insurance Policies required under this
paragraph, a flood insurance policy shall be delivered by Borrowers to Agent
with respect thereto. If no portion of a Property is located in a Federally
designated "special flood hazard area" such fact shall be substantiated by a
certificate in form satisfactory to Agent from a licensed surveyor, appraiser or
professional engineer or other qualified individual. Except as hereinafter
specifically provided to the contrary in this paragraph, if any Property shall
be damaged or destroyed, in whole or in part, by fire or other property hazard
or casualty, Borrowers shall give prompt notice thereof to Co-Lenders and one
hundred (100%) percent of the net amount of all insurance proceeds received by
Co-Lenders or Borrowers as a result of such damage or destruction after
deduction of reasonable costs and expenses, if any, in collecting the same,
shall be applied in reduction of outstanding Principal Balance under the Credit
Facility. If a particular Property (a "Damaged Property") shall be damaged or
destroyed, in whole or in part, by fire or other casualty, Co-Lenders shall, in
accordance with the provisions of this paragraph hereinafter set forth, make the
net amount of all insurance proceeds received by Co-Lenders pursuant to the
provisions of this Agreement as a result of such damage or destruction after
deduction of their reasonable costs and expenses, if any, in collecting the same
(hereinafter referred to as the "Net Proceeds") available for the repair and
restoration of the Damaged Property, provided that (i) no default shall have
occurred and shall be continuing under the Credit Facility Documents, (ii)
Borrowers shall commence the repair and restoration of the Damaged Property, as
nearly as possible to the condition the Damaged Property were in immediately
prior to such fire or other casualty, with such alterations as may be approved
by Co-Lenders, as soon as reasonably practicable, and provided that Co-Lenders
have confirmed to Borrowers that the Net Proceeds will be made available
pursuant to the following provisions of this paragraph to cover the cost of such
repair and restoration, and shall diligently pursue the same to satisfactory
completion, (iii) Co-Lenders shall be satisfied that any operating deficits
which will be incurred with respect


                                       41
<PAGE>   46
to the Damaged Property as a result of the occurrence of any such fire or other
casualty will be covered out of the Net Proceeds or by Borrowers out-of-pocket
or with the proceeds, if any, of business interruption or rental interruption
insurance, (iv) Co-Lenders shall be satisfied that, upon the completion of such
repair and restoration of the Damaged Property, the gross cash flow and the net
cash flow of the Damaged Property will be restored to a level sufficient to
cover all carrying costs and operating expenses of the Damaged Property, (v)
Co-Lenders shall be satisfied that the repair and restoration of the Damaged
Property will be completed on or before the earlier to occur of (w) ninety (90)
days prior to the Maturity Date, or (x) the earliest date required for such
completion under the terms of the Ground Lease, if any, pertaining to the
Damaged Property or under the terms of any Leases which will or are required in
accordance with the provisions of this paragraph hereinafter set forth to remain
in effect subsequent to the occurrence of such fire or other casualty and the
completion of the repair and restoration of the Damaged Property, (vi)
Co-Lenders shall be satisfied that all of the terms, covenants and provisions of
this Agreement and the other Credit Facility Documents will continue to be
complied with during and subsequent to the completion of such repair and
restoration (including, without limitation, the financial covenants set forth in
paragraph 13 and paragraph 23 of this Agreement, and (vii) Borrowers and the
Guarantors shall execute and deliver to Co-Lenders a completion guaranty in form
and substance satisfactory to Co-Lenders pursuant to the provisions of which
Borrowers and Guarantors shall jointly and severally guaranty to Co-Lenders the
lien-free completion by Borrowers of the repair and restoration of the Damaged
Property in accordance with the provisions of this paragraph. Notwithstanding
anything to the contrary contained in this paragraph, Co-Lenders shall not be
obligated to make Net Proceeds available for the repair and restoration of the
Damaged Property in accordance with the provisions of this paragraph if more
than 30% of the Property in question has been damaged or destroyed by such fire
or other casualty (as measured by the cost of completing the repair and
restoration of the damaged portions of the Property in question verses the cost
of total replacement of the Property in question) or if Leases demising in the
aggregate more than 30% of the total office space in the Damaged Property which
has been demised under executed and delivered Leases in effect as of the date of
the occurrence of such fire or other casualty are terminated as a result of such
fire or other casualty, or will not remain in full force and effect during and
after the completion of the repair and restoration of the Damaged Property. The
Net Proceeds, shall be held by Co-Lenders in an interest bearing account, and
until disbursed in accordance with the provisions of this paragraph, shall
constitute additional security for the payment of the Debt. The Net Proceeds
together with interest earned thereon, shall be disbursed by Co-Lenders to, or
as directed by, Borrowers from time to time during the course of the repair and
restoration of the Damaged Property, upon receipt of evidence satisfactory to
Co-Lenders (which evidence shall in each instance and to the full extent
required by Co-Lenders include receipted bills, invoices, lien waivers and a
continuation and date down of title to the Damaged Property in form satisfactory
to Co-Lenders and issued by the title company insuring the lien of this Mortgage
or another title company satisfactory to Co-Lenders) that (i) all materials
installed and work and labor performed (except to the extent that they are to be
paid for out of the requested disbursement) in connection with the repair and
restoration of the Damaged Property have been paid for in full, and (ii) there
exist no notice of pendency, stop order, notice of intention to file mechanic's
or materialman's lien, mechanic's or materialman's lien or other lien or
encumbrance of any nature whatsoever on the Damaged Property arising out of the
repair and restoration of the Damaged Property which have not either been fully
bonded to the satisfaction of Co-Lenders and discharged of record or in the
alternative fully insured over to the satisfaction of Co-Lenders by the title
company insuring the lien of the Mortgage covering the Damaged Property. The
repair and restoration of the Damaged Property shall be done and completed by
Borrowers in an expeditious and diligent fashion and in compliance with all


                                       42
<PAGE>   47
applicable governmental laws, rules and regulations (including, without
limitation, all applicable Environmental Requirements), and all plans and
specifications required in connection with the repair and restoration of the
Damaged Property shall be subject to review and acceptance in all respects by
Co-Lenders and by an independent consulting engineer selected by Co-Lenders
(hereinafter referred to in this paragraph as the "Consultant"). Upon the
occurrence of an Event of Default, Co-Lenders shall have the use of such plan
and specifications and all permits, licenses and approvals required or obtained
in connection with the repair and restoration of the Damaged Property. The
identity of the contractors, subcontractors and materialmen engaged in the
repair and restoration of the Damaged Property, as well as the contracts under
which they have been engaged, shall be subject to approval, review and
acceptance by Co-Lenders and Consultant. All costs and expenses incurred by
Co-Lenders in connection with making the Net Proceeds available for the repair
and restoration of the Damaged Property including, without limitation,
reasonable counsel fees and the Consultant's fees, shall be paid by Borrowers.
In no event shall Co-Lenders be obligated to make disbursements of the Net
Proceeds in excess of an amount equal to the costs actually incurred from time
to time for work in place as part of the repair and restoration of the Damaged
Property, as certified by the Consultant, minus the Casualty Retainage. The term
"Casualty Retainage" as used in this paragraph shall mean an amount equal to 10%
of the costs actually incurred for work in place as part of the repair and
restoration of the Damaged Property, as certified by the Consultant. The
Casualty Retainage shall in no event, and notwithstanding anything to the
contrary hereinabove set forth in this paragraph, be less than the amount
actually held back by Borrowers from contractors, subcontractors and materialmen
engaged in the making of the repair and restoration of the Damaged Property.
Co-Lenders shall not be obligated to make disbursements of the Net Proceeds more
frequently than once every fifteen (15) days. The Casualty Retainage shall not
be released until the Consultant certifies to Co-Lenders that the repair and
restoration of the Damaged Property have been completed in accordance with the
provisions of this paragraph, and Co-Lenders receives evidence satisfactory to
Co-Lenders that the costs of the repair and restoration of the Damaged Property
have been paid in full or will be paid in full out of the Casualty Retainage,
provided, however, that Co-Lenders will release the portion of the Casualty
Retainage being held with respect to any contractor, subcontractor or
materialman engaged in the repair and restoration of the Damaged Property as of
the date upon which the Consultant certifies to Co-Lenders that such contractor,
subcontractor or materialman has satisfactorily completed all work and has
supplied all materials in accordance with the provisions of such contractor's,
subcontractor's or materialman's contract, and such contractor, subcontractor or
materialman delivers such lien waivers and evidence of payment in full of all
sums due to such contractor, subcontractor or materialman as may be reasonably
requested by Co-Lenders or by the title company insuring the lien of the
Mortgage covering the Damaged Property. If required by Co-Lenders, the release
of any such portion of the Casualty Retainage shall be approved by the surety
company, if any, which has issued a payment or performance bond with respect to
such contractor, subcontractor or materialman. Notwithstanding anything to the
contrary contained in this paragraph, if the Net Proceeds shall be less than
$250,000 and if the costs of completing the repair and restoration of the
Damaged Property shall be less than $250,000, the Net Proceeds will be disbursed
by Co-Lenders to Borrowers upon receipt, provided that no default shall have
occurred and shall be continuing under the Credit Facility Documents, and
Borrowers delivers to Co-Lenders a written undertaking to expeditiously commence
and to satisfactorily complete with due diligence the repair and restoration of
the Damaged Property. If at any time the Net Proceeds or the undisbursed balance
thereof shall not, in the opinion of Co-Lenders, be sufficient to pay in full
the balance of the costs which will be incurred in connection with the
completion of the repair and restoration of the Damaged Property, Borrowers
shall deposit the deficiency (hereinafter referred to as the "Net Proceeds
Deficiency") with Co-Lenders before any


                                       43
<PAGE>   48
further disbursement of the Net Proceeds shall be made, which Net Proceeds
Deficiency deposit shall be held by Co-Lenders in an interest bearing account,
shall be disbursed together with interest earned thereon, for costs actually
incurred in connection with the repair and restoration of the Damaged Property
on the same conditions applicable to the disbursement of the Net Proceeds, and
until so disbursed pursuant to this paragraph shall constitute additional
security for the payment of the Debt. Upon the occurrence of an Event of
Default, Co-Lenders shall have the right to apply the undisbursed balance of any
Net Proceeds Deficiency deposit, together with interest thereon, to the payment
of the Debt whether or not then due and payable in such order, priority and
proportions as Co-Lenders shall deem to be appropriate in its discretion. The
excess, if any, of the Net Proceeds and the remaining balance, if any, of the
Net Proceeds Deficiency deposit, together with interest thereon, after the
Consultant certifies to Co-Lenders that the repair and restoration of the
Damaged Property have been completed in accordance with the provisions of this
paragraph, and the receipt by Co-Lenders of evidence satisfactory to Co-Lenders
that all costs incurred in connection with the repair and restoration have been
paid in full, shall be applied to the reduction of the outstanding Principal
Balance of the Credit Facility. All costs of the repair and restoration of the
Damaged Property in excess of the Net Proceeds shall be paid for by Borrowers.
All insurance proceeds received by Co-Lenders and not required to be disbursed
for the repair and restoration of the Damaged Property pursuant to the
provisions of this paragraph hereinabove set forth may be retained and applied
by Co-Lenders toward the payment of the Debt whether or not then due and payable
in such order, priority and proportions as Co-Lenders in their discretion shall
deem proper or, at the discretion of Co-Lenders, the same may be paid, either in
whole or in part, to Borrowers for such purposes as Co-Lenders shall designate,
in their discretion. If Co-Lenders shall receive and retain insurance proceeds,
the lien of the Mortgages shall be reduced only by the amount thereof received
and retained by Co-Lenders and actually applied by Co-Lenders in reduction of
the Debt.

            31. Condemnation. Notwithstanding any taking by any public or
quasi-public authority through eminent domain or otherwise, Borrowers shall
continue to pay the Debt at the time and in the manner provided for its payment
in the Credit Facility Notes, this Agreement and the Mortgages and the Debt
shall not be reduced until any award or payment therefor shall have been
actually received and applied by Agent to the discharge of the Debt. Except as
hereinafter specifically provided to the contrary in this paragraph, if all or
any portion of a Property is taken by any public or quasi-public authority
through eminent domain or otherwise, one hundred (100%) percent of the aggregate
award or payment received by Co-Lenders or Borrowers as a result of such taking
after deduction of reasonable costs and expenses, if any, in collecting the same
shall be applied in reduction of outstanding Principal Balance under the Credit
Facility. If any Property is sold, through foreclosure or otherwise, prior to
the receipt by Co-Lenders of such award or payment, Co-Lenders shall have the
right, whether or not a deficiency judgment on the Credit Facility Notes shall
have been sought, recovered or denied, to receive such award or payment, or a
portion thereof sufficient to pay the Debt, whichever is less. Borrowers shall
file and prosecute its claim or claims for any such award or payment in good
faith and with due diligence and cause the same to be collected and paid over to
Co-Lenders. Borrowers hereby irrevocably authorize and empower Co-Lenders, in
the name of Borrowers or otherwise, to collect and receipt for any such award or
payment and, subsequent to the occurrence of a default beyond the expiration of
applicable notice and cure periods, if any under any of the Credit Facility
Documents and during the continuance thereof, to file and prosecute such claim
or claims. Although it is hereby expressly agreed that the same shall not be
necessary in any event, Borrowers shall, upon demand of Co-Lenders, make,
execute and deliver any and all assignments and other instruments sufficient for
the purpose of assigning any such award or payment to Co-Lenders, free and clear


                                       44
<PAGE>   49
of any encumbrances of any kind or nature whatsoever. Notwithstanding anything
to the contrary contained in this paragraph, if a non-material part of a
particular Property is taken through eminent domain or otherwise and if such
taking does not otherwise involve a physical taking of the buildings
constituting part of such Property, or any portion thereof, any award given as a
result of such taking may be retained by Borrowers, provided (i) such award is
not in excess of $100,000, (ii) no default shall have occurred and shall be
continuing under the Credit Facility Documents, (iii) Borrowers promptly
commence any necessary repair or restoration to such Property, (iv) Co-Lenders
are satisfied that neither the value, use nor operation of such Property will be
adversely affected in any material way as a result of such taking, and (v)
Co-Lenders are satisfied that all necessary repairs and restorations to such
Property will be diligently and satisfactorily completed by Borrowers within a
reasonable period of time taking into account the nature of the taking.

            32. Environmental Provisions. For the purposes of this paragraph the
following terms shall have the following meanings: (i) the term "Hazardous
Material" shall mean any material or substance that, whether by its nature or
use, is now or hereafter defined as a hazardous waste, hazardous substance,
pollutant or contaminant under any Environmental Requirement, or which is toxic,
explosive, corrosive, flammable, infectious, radioactive, carcinogenic,
mutagenic or otherwise hazardous and which is now or hereafter regulated under
any Environmental Requirement, or which is or contains petroleum, gasoline,
diesel fuel or another petroleum hydrocarbon product, (ii) the term
"Environmental Requirements" shall collectively mean all present and future
laws, statutes, ordinances, rules, regulations, orders, codes, licenses,
permits, decrees, judgments, directives or the equivalent of or by any
Governmental Authority and relating to or addressing the protection of the
environment or human health, and (iii) the term "Governmental Authority" shall
mean the Federal government, or any state or other political subdivision
thereof, or any agency, court or body of the Federal government, any state or
other political subdivision thereof, exercising executive, legislative,
judicial, regulatory or administrative functions. Borrowers hereby represents
and warrants to Co-Lenders that to the best of Borrowers's knowledge (i) no
Hazardous Material is currently located at, on, in, under or about any Property,
except as specifically set forth in the Environmental Reports, (ii) no Hazardous
Material is currently located at, in, on, under or about any Property in a
manner which violates any Environmental Requirement, or which requires cleanup
or corrective action of any kind under any Environmental Requirement, (iii) no
releasing, emitting, discharging, leaching, dumping or disposing of any
Hazardous Material from any Property onto or into any other property or from any
other property onto or into any Property has occurred or is occurring in
violation of any Environmental Requirement, (iv) no notice of violation, lien,
complaint, suit, order or other notice with respect to any Property is presently
outstanding under any Environmental Requirement, and (v) each Property and the
operation thereof are in compliance with all Environmental Requirements.
Borrowers shall comply, and shall cause all tenants or other occupants of the
Properties to comply, in all respects with all Environmental Requirements, and
will not generate, store, handle, process, dispose of or otherwise use, and will
not permit any tenant or other occupant of any Property to generate, store,
handle, process, dispose of or otherwise use, Hazardous Materials at, in, on,
under or about any Property in a manner that could lead or potentially lead to
the imposition on Borrowers, any Co-Lender or any Property of any liability or
lien of any nature whatsoever under any Environmental Requirement. Borrowers
shall notify Co-Lenders promptly in the event of any spill or other release of
any Hazardous Material at, in, on, under or about any Property which is required
to be reported to a Governmental Authority under any Environmental Requirement,
will promptly forward Agent copies of any notices received by Borrowers relating
to alleged violations of any Environmental Requirement and will promptly pay
when due any fine or assessment against any Co-Lender, any Borrowers or any
Property


                                       45
<PAGE>   50
relating to any Environmental Requirement. If at any time it is determined that
the operation or use of any Property violates any applicable Environmental
Requirement or that there are Hazardous Materials located at, in, on, under or
about any Property which, under any Environmental Requirement, require special
handling in collection, storage, treatment or disposal, or any other form of
cleanup or corrective action, Borrowers shall, within thirty (30) days after
receipt of notice thereof from any Governmental Authority or from Agent, take,
at its sole cost and expense, such actions as may be necessary to fully comply
in all respects with all Environmental Requirements, provided, however, that if
such compliance cannot reasonably be completed within such thirty (30) day
period, Borrowers shall commence such necessary action within such thirty (30)
day period and shall thereafter diligently and expeditiously proceed to fully
comply in all respects and in a timely fashion with all Environmental
Requirements. If Borrowers fails to timely take, or to diligently and
expeditiously proceed to complete in a timely fashion, any such action,
Co-Lenders may, in their sole and absolute discretion, make advances or payments
towards the performance or satisfaction of the same, but shall in no event be
under any obligation to do so. All sums so advanced or paid by Co-Lenders
(including, without limitation, consultant fees and expenses, investigation and
laboratory fees and expenses, and fines or other penalty payments and reasonable
legal fees) and all sums advanced or paid in connection with any judicial or
administrative investigation or proceeding relating thereto, will immediately,
upon demand, become due and payable from Borrowers and shall bear interest at
the Default Rate from the date any such sums are so advanced or paid by
Co-Lenders until the date any such sums are repaid by Borrowers to Co-Lenders.
Borrowers will execute and deliver, promptly upon request, such instruments as
Co-Lenders may deem useful or necessary to permit Co-Lenders to take any such
action, and such additional notes, as Co-Lenders may require to secure all sums
so advanced or paid by Co-Lenders. If a lien is filed against any Property by
any Governmental Authority resulting from the need to expend or the actual
expending of monies arising from an action or omission, whether intentional or
unintentional, of Borrowers or for which Borrowers is responsible, resulting in
the releasing, spilling, leaking, leaching, pumping, emitting, pouring, emptying
or dumping of any Hazardous Material into the waters or onto land located within
or without the State in which any Property is located, then Borrowers will,
within thirty (30) days from the date that Borrowers are first given notice that
such lien has been placed against such Property (or within such shorter period
of time as may be specified by Co-Lenders if such Governmental Authority has
commenced steps to cause such Property to be sold pursuant to such lien) either
(a) pay the claim and remove the lien, or (b) furnish a cash deposit, bond, or
such other security with respect thereto as is satisfactory in all respects to
Co-Lenders and is sufficient to effect a complete discharge of such lien on such
Property. Notwithstanding the foregoing, after prior notice to Agent, in the
case of any material item, Borrowers, at its own expense, may contest by
appropriate legal proceedings, promptly initiated and conducted in good faith
and with due diligence, the validity or enforceability, in whole or in part, of
any Environmental Requirement, provided that (i) no default shall have occurred
and be continuing under the Credit Facility Notes, the Mortgages, this Agreement
or any of the other Credit Facility Documents, (ii) Borrowers is permitted to do
so under the provisions of the Ground Leases, (iii) such proceeding shall
suspend the obligation of Borrowers to comply with any such Environmental
Requirement, (iv) such proceeding shall be permitted under and be conducted in
accordance with the provisions of any other instrument to which Borrowers is, or
the Properties are, subject and shall not constitute a default thereunder, (v)
failure to immediately comply with any such law, order, ordinance, rule or
regulation will not invalidate or vitiate any Insurance Policies, in whole or in
part, and will not in the opinion of Co-Lenders constitute a present danger to
the Properties or any portion thereof, or to the individuals using and entering
upon the Properties, (vi) neither the Properties nor any part thereof nor any
interest therein will in the opinion of Co-Lenders be in danger of


                                       46
<PAGE>   51
being sold, forfeited, confiscated, terminated, cancelled or lost, (vii)
Borrowers shall have furnished such security as may be required in the
proceeding, or as may otherwise be requested or required by Co-Lenders to insure
the payment by Borrowers of all costs of compliance, fines and penalties,
together with interest thereon, as may be incurred by Borrowers in the event of
a determination in such proceeding adverse to Borrowers, and (viii) neither
Borrowers, Agent nor any Co-Lender will in the opinion of Agent and Co-Lenders
be subject to any criminal or civil liability as the result of such contestment
by Borrowers. Co-Lenders may, at their option, at intervals of not less than one
year, or more frequently if Co-Lenders reasonably believe that a Hazardous
Material or other environmental condition violates or threatens to violate any
Environmental Requirement applicable to a Property, cause an environmental audit
of such Property to be conducted to confirm Borrowers's compliance with the
provisions of this paragraph in respect of such Property, and Borrowers shall
cooperate in all reasonable ways with Agent in connection with any such audit.
If such audit discloses that a violation of an Environmental Requirement exists,
Borrowers shall pay all costs and expenses incurred in connection with such
audit, otherwise, the costs and expenses of such audit shall, notwithstanding
anything to the contrary set forth in this paragraph, be paid by Co-Lenders. If
any of the Mortgages is foreclosed, or if any Property is sold pursuant to the
provisions of the Mortgages, or if Borrowers tenders a deed or assignment in
lieu of foreclosure or sale, Borrowers shall deliver such Properties to the
purchaser at foreclosure or sale or to Co-Lenders, their respective nominees, or
wholly owned subsidiaries, as the case may be, in a condition that complies in
all respects with all Environmental Requirements. Borrowers will defend,
indemnify, and hold harmless Agent, Co-Lenders, their respective employees,
agents, officers, and directors, from and against any and all claims, demands,
penalties, causes of action, fines, liabilities, settlements, damages, costs, or
expenses of whatever kind or nature, known or unknown, foreseen or unforeseen,
contingent or otherwise (including, without limitation, consultant fees and
expenses, investigation and laboratory fees and expenses, court costs,
litigation expenses and reasonable attorneys fees) arising out of, or in any way
related to, (i) any breach by Borrowers of any of the provisions of this
paragraph, (ii) the presence, disposal, spillage, discharge, emission, leakage,
release, or threatened release of any Hazardous Material which is at, in, on,
under, about, from or affecting any Property, including, without limitation, any
damage or injury resulting from any such Hazardous Material to or affecting any
Property or the soil, water, air, vegetation, buildings, personal property,
individuals or animals located on any Property or on any other property or
otherwise, (iii) any personal injury (including wrongful death) or property
damage (real or personal) arising out of or related to any such Hazardous
Material, (iv) any lawsuit brought or threatened, settlement reached, or order
or directive of or by any Governmental Authority relating to such Hazardous
Material, or (v) any violation of any Environmental Requirement. The aforesaid
indemnification shall in all events and under all circumstances constitute the
personal recourse undertakings, obligations and liabilities of Borrowers. The
indemnification by Borrowers in favor of Agent and Co-Lenders hereinabove set
forth in this paragraph shall not be applicable to any claim, demand, penalty,
cause of action, fine, liability, settlement, damage, cost or other expense of
any type whatsoever pertaining to a particular Property (i) occasioned, arising
and caused solely and directly as the result of the negligence or willful
misconduct of Agent, any Co-Lender, any nominee or any wholly owned subsidiary
of Agent or a Co-Lender or their respective employees or agents and irrespective
of whether occurring prior or subsequent to the date upon which any Co-Lender or
any nominee or any wholly owned subsidiary of any Co-Lender acquires possession
of such Property by foreclosure of the Mortgages, a sale of such Property
pursuant to the provisions of the Mortgages, acceptance of a deed or assignment
in lieu of foreclosure or sale or otherwise, or (ii) occasioned, arising and
caused solely and directly as the result of any act of any Person (other than
(A) an act of Borrowers, its employees or agents or Persons under the control of


                                       47
<PAGE>   52
Borrowers, or (B) an act of Agent, any Co-Lender, any nominee or any wholly
owned subsidiary of any Co-Lender or their respective employees or agents which
does not constitute negligence or willful misconduct, or (C) an act of any
Governmental Authority, including, without limitation, any change in any
Environmental Requirement) and occurring subsequent to the earlier to occur of
(x) the date of payment to Co-Lenders in cash of the entire Debt, and (y) the
date upon which any Co-Lender, any nominee or any wholly owned subsidiary of any
Co-Lender acquires possession of such Property by foreclosure of the Mortgages,
a sale of such Property pursuant to the provisions of the Mortgages, acceptance
of a deed or assignment in lieu of foreclosure or sale or otherwise. Except as
hereinabove specifically provided to the contrary in this paragraph, the
obligations and liabilities of Borrowers under this paragraph shall survive and
continue in full force and effect and shall not be terminated, discharged or
released, in whole or in part, irrespective of whether the Debt has been paid in
full and irrespective of any foreclosure of any of the Mortgages, sale of any
one or more of the Properties pursuant to the provisions of the Mortgages or
acceptance by Co-Lenders, their nominees or wholly owned subsidiaries of one or
more deeds or assignments in lieu of foreclosure or sale and irrespective of any
other fact or circumstance of any nature whatsoever.

            33. Estoppel Certificates. Borrowers, within ten (10) days after
request by Co-Lenders and at its expense, will furnish Co-Lenders with a
statement, duly certified, setting forth the amount of the Debt and the offsets
or defenses thereto, if any. Co-Lenders, within ten (10) days after request by
Borrowers and at Borrowers's expense, and provided that no Event of Default has
occurred and is continuing under the Credit Facility Documents, will furnish
Borrowers with a statement setting forth the then outstanding principal balance
of the Credit Facility Notes and the interest, if any, accrued and unpaid
thereon.

            34. Non-Waiver. The failure of Co-Lenders or Agent to insist upon
strict performance of any term of this Agreement shall not be deemed to be a
waiver of any term of this Agreement. Borrowers shall not be relieved of
Borrowers's obligation to pay the Debt at the time and in the manner provided
for its payment in the Credit Facility Notes, the Mortgages and this Agreement
by reason of (i) failure of Co-Lenders to comply with any request of Borrowers
to take any action to foreclose any one or more of the Mortgages or otherwise
enforce any of the provisions of this Agreement, the Mortgages, the Credit
Facility Notes or any of the other Credit Facility Documents, and (ii) the
release, regardless of consideration, of the whole or any part of the Properties
or any other Collateral or security for the Debt. Regardless of consideration,
and without the necessity for any notice to or consent by the holder of any
subordinate lien, encumbrance, right, title or interest in or to the Properties,
Co-Lenders may release any Person at any time liable for the payment of the Debt
or any portion thereof or any part of the security held for the Debt and may
extend the time of payment or otherwise modify the terms of the Credit Facility
Notes, the Mortgages, this Agreement or any of the other Credit Facility
Documents, including, without limitation, a modification of the interest rate
payable on the principal balance of the Credit Facility Notes, without in any
manner impairing or affecting the Mortgages or the respective liens thereof or
the priority of the Mortgages, as so extended and modified, as security for the
Debt over any such subordinate lien, encumbrance, right, title or interest.
Co-Lenders may resort for the payment of the Debt to any other security held by
Co-Lenders in such order and manner as Co-Lenders in their discretion, may
elect. Co-Lenders may take action to recover the Debt, or any portion thereof,
or to enforce any covenant hereof without prejudice to the right of Co-Lenders
thereafter to foreclose any one or more of the Mortgages. Co-Lenders shall not
be limited exclusively to the rights and remedies herein stated but shall be
entitled to every additional right and remedy set forth in the Credit Facility
Documents or now or hereafter afforded by law. The rights of Co-Lenders under
this Agreement and


                                       48
<PAGE>   53
the other Credit Facility Documents shall be separate, distinct and cumulative
and none shall be given effect to the exclusion of the others. No act of
Co-Lenders shall be construed as an election to proceed under any one provision
of this Agreement or of the other Credit Facility Documents to the exclusion of
any other provision set forth in this Agreement or the other Credit Facility
Documents.

            35. Sole Discretion. Except as may otherwise be expressly provided
to the contrary, wherever pursuant to the Credit Facility Notes, the Mortgages,
this Agreement, or any of the other Credit Facility Documents, Agent or any
Co-Lender exercises any right given to it to consent or not consent, or to
approve or disapprove, or any arrangement or term is to be satisfactory to Agent
or such Co-Lender the decision of Agent or such Co-Lender, as the case may be,
shall be in the sole and absolute discretion of Agent or such Co-Lender, as the
case may be, and shall be final and conclusive.

            36. Absolute and Unconditional Obligation. Borrowers acknowledges
that Borrowers' obligation to pay the Debt in accordance with the provisions of
the Credit Facility Notes, the Mortgages and this Agreement is and shall at all
times continue to be absolute and unconditional in all respects, and shall at
all times be valid and enforceable irrespective of any other agreements or
circumstances of any nature whatsoever which might otherwise constitute a
defense to the Credit Facility Notes, the Mortgages or this Agreement or the
obligation of Borrowers thereunder to pay the Debt or the obligations of any
other Person relating to the Credit Facility Notes, the Mortgages or this
Agreement or the obligations of Borrowers under the Credit Facility Notes, the
Mortgages or this Agreement or otherwise with respect to the Credit Facility,
and Borrowers absolutely, unconditionally and irrevocably waives any and all
right to assert any defense, setoff, counterclaim or crossclaim of any nature
whatsoever with respect to the obligation of Borrowers to pay the Debt in
accordance with the provisions of the Credit Facility Notes, the Mortgages and
this Agreement or the obligations of any other Person relating to the Credit
Facility Notes, the Mortgages or this Agreement or obligations of Borrowers
under the Facility Notes, the Mortgages or this Agreement or otherwise with
respect to the Credit Facility in any action, case or proceeding brought by
Agent or Co-Lenders to collect the Debt, or any portion thereof, or to enforce,
foreclose and realize upon the lien and security interest created by the
Mortgages or any other document or instrument securing repayment of the Debt, in
whole or in part (provided, however, that the foregoing provisions of this
sentence shall not be deemed a waiver of the right of Borrowers to assert any
compulsory counterclaim in any such action, case or proceeding brought by Agent
or Co-Lenders in any state court if such counterclaim is compelled under local
law or rule or procedure, or in any such action, case or proceeding brought by
Agent or Co-Lenders in a court of the United States, nor shall the foregoing
provisions of this sentence be deemed a waiver of the right of Borrowers to
assert any claim which would otherwise constitute a defense, setoff,
counterclaim or crossclaim of any nature whatsoever against Agent or Co-Lenders
in any separate action, case or proceeding brought by Borrowers against Agent or
Co-Lenders).

            37. Relationship. The relationship of Co-Lenders to Borrowers
hereunder is strictly and solely that of lender and borrower and nothing
contained in the Credit Facility Notes, the Mortgages, this Agreement or any of
the other Credit Facility Documents is intended to create, or shall in any event
or under any circumstance be construed as creating, a partnership, joint
venture, tenancy-in-common, joint tenancy or other relationship of any nature
whatsoever between Co-Lenders and Borrowers other than as lender and borrower.

            38. Anti-Forfeiture. Borrowers hereby covenant and agree not to
commit, permit or suffer to exist any act or omission affording the Federal
government or any state or local government the right of forfeiture under any


                                       49
<PAGE>   54
Federal or state RICO or similar law as against the Properties or any part
thereof or interest therein or any monies paid in performance of Borrowers'
obligations under this Agreement, the Mortgages, the Credit Facility Notes or
any of the other Credit Facility Documents. In furtherance thereof, Borrowers
hereby indemnify Agent and Co-Lenders and agree to defend and hold Agent and
Co-Lenders harmless from and against any loss, damage or injury by reason of the
breach of the covenants and agreements set forth in this paragraph, which
indemnity shall constitute the personal recourse obligation of Borrowers.
Without limiting the generality of the foregoing, the filing of formal charges
or the commencement of proceedings against Borrowers or against the Properties
or any part thereof or interest therein under any Federal or state law for which
forfeiture of the Properties or any part thereof or of any monies paid in
performance of Borrowers' obligations under the Credit Facility Documents is a
potential result, shall, at the election of Co-Lenders, but otherwise subject to
the immediately following sentence, constitute an Event of Default hereunder
without notice or opportunity to cure. Notwithstanding the foregoing, after
prior notice to Co-Lenders, Borrowers, at their own cost and expense, may
contest the validity of or application of any such law affording such
forfeiture, provided that (i) no default shall have occurred and shall be
continuing under the Credit Facility Notes, the Mortgages, this Agreement or any
of the other Credit Facility Documents, (ii) Borrowers are permitted to do so
under the provisions of the Ground Leases, (iii) such proceeding shall be
permitted under and be conducted in accordance with the provisions of any other
instrument to which Borrowers are or the Properties are subject and shall not
constitute a default thereunder, (iv) neither the Properties nor any portion
thereof nor any interest therein will in the opinion of Co-Lenders be in danger
of being sold, forfeited, terminated, cancelled or lost, and (iii) Borrowers
shall have deposited with Agent cash or other cash equivalent or letter of
credit satisfactory to Co-Lenders in an amount sufficient to discharge any lien
together with interest and penalties thereon arising out of such law.
Notwithstanding the foregoing, Borrowers shall not be required to make any
deposit with Agent pursuant to clause (iii) of the preceding sentence, if
Co-Lenders are reasonably satisfied that (a) the act or omission affording such
forfeiture was committed by a Person other than Borrowers or an Affiliate or
subsidiary of Borrowers, (b) Borrowers are diligently pursuing their rights and
remedies against such Person, (c) neither the Properties nor any portion thereof
or interest therein will be in danger of being sold, forfeited, terminated,
cancelled or lost, and (d) the respective liens and priorities of the Mortgages
will not be in danger of being primed, diminished or forfeited.

            39. Deposits. Whenever in this Agreement, Borrowers are required to
deposit monies with Agent or Co-Lenders to secure obligations of Borrowers under
this Agreement or as a condition precedent to Borrowers' right to contest
certain obligations, such monies shall (unless otherwise specifically provided
to the contrary in this Agreement) be held in an interest bearing account
selected by Agent or Co-Lenders, as the case may be. All such accrued interest
shall be held, disbursed and applied in accordance with the provisions
applicable to such deposits. In order to secure the payment of the Debt and the
performance by Borrowers of its obligations under the Credit Facility Documents,
Borrowers hereby grant and assign to Agent and Co-Lenders a security interest in
and to all monies from time to time on deposit in any such account. Upon the
occurrence of an Event of Default and for so long as such Event of Default shall
continue, Co-Lenders shall have the absolute right to apply all or any portion
of the balances held in any such accounts to the payment of the Debt whether or
not due and payable in such order, priority and proportions as Co-Lenders in
their discretion shall deem appropriate.

            40. Submission to Jurisdiction. Borrowers agrees to submit to
personal jurisdiction in the State of New York in any action, case or proceeding
arising out of the Credit Facility Notes, this Agreement or the other Credit
Facility Documents (other than the Mortgages and the Assignments


                                       50
<PAGE>   55
of Leases and Rents), and, in furtherance of such agreement, Borrowers hereby
agree and consent that without limiting other methods of obtaining jurisdiction,
personal jurisdiction over Borrowers in any such action, case or proceeding may
be obtained within or without the jurisdiction of any court located in the State
of New York and that any process or notice of motion or other application to any
such court in connection with any such action, case or proceeding may be served
upon Borrowers by registered or certified mail to or by personal service at the
last known address of Borrowers, as the case may be, whether such address be
within or without the jurisdiction of any such court. Borrowers also agree that
the venue of any litigation arising in connection with the Debt or in respect of
any of the obligations of Borrowers under the Credit Facility Notes, this
Agreement or the other Credit Facility Document (other than the Mortgages and
the Assignments of Leases and Rents) shall, to the extent permitted by law, be
in New York County, New York.

            41. Retention of Counsel and Consultants. If, subsequent to the
occurrence of a default under any of the Credit Facility Documents or otherwise
in connection with the protection, preservation, addition or release of
Collateral, Agent or Co-Lenders deem it to be in the best interest of Co-Lenders
to retain the assistance of any Person (including, but not limited to,
attorneys, title insurance companies, third party escrow agents, appraisers,
accountants engineers and surveyors) with respect to any request for consent or
approval by Agent or Co-Lenders under the Credit Facility Documents, Borrowers
shall reimburse Co-Lenders within ten (10) days of demand by Agent for all
reasonable costs incurred by Co-Lenders in connection with the employment of
such Persons.

            42. Waiver of Notice. Borrowers shall not be entitled to any notices
of any nature whatsoever from Agent or any Co-Lender except with respect to
matters for which this Agreement specifically and expressly provides for the
giving of notice by Agent or a Co-Lender to Borrowers, and Borrowers hereby
expressly waive (to the full extent Borrowers may lawfully do so) the right to
receive any notice from Agent or any Co-Lender with respect to any matter for
which this Agreement does not specifically and expressly provide for the giving
of notice by Agent or a Co-Lender to Borrowers.

            43. Events of Default. The Debt shall become due at the option of
Co-Lenders upon the occurrence of any one or more of the following events
(collectively, "Events of Default"):

                        (a) if any portion of the Debt is not paid when due;

                        (b) if any of the covenants contained in paragraph 18 of
            this Agreement shall be breached;

                        (c) if any fact, circumstance or event shall occur which
            is specifically characterized under any provision of any Credit
            Facility Document as an "Event of Default" within the meaning given
            to such term pursuant to the provisions of this Agreement;

                        (d) if any representation or warranty of any Borrower or
            any Guarantor made in this Agreement or any of the other Credit
            Facility Documents, or in any certificate, report, financial
            statement or other instrument furnished in connection with the
            making of the Credit Facility Notes, the Mortgages, this Agreement
            or any other Credit Facility Document or the extension of the Credit
            Facility by Co-Lenders to Borrowers, shall prove false or misleading
            in any material respect;

                        (e) if any Federal tax lien is filed against Borrowers,
            or any Property and the same is not discharged of


                                       51
<PAGE>   56
            record within thirty (30) days after the same is filed (unless the
            same is being contested in good faith by appropriate proceeding and
            otherwise in compliance with the general requirements for contesting
            Taxes, as more specifically set forth in paragraph 29 of this
            Agreement);

                        (f) if without the consent of Co-Lenders any FF&E
            (except for normal replacement of the FF&E) is removed, or if
            without the consent of Co-Lenders any Property is demolished or
            materially altered (other than for tenant improvements being made
            under Leases entered into in conformity with the provisions of this
            Agreement);

                        (g) if the Insurance Policies are not kept in full force
            and effect, or if the Insurance Policies are not delivered to Agent
            upon request;

                        (h) if without the consent of Co-Lenders any Lease is
            made, cancelled or modified (other than in compliance with the
            provisions of this Agreement and the other Credit Facility
            Documents) or if any portion of the Rents is paid for a period of
            more than one (1) month in advance or if any of the Rents are
            further assigned;

                        (i) if any Borrower shall default beyond the expiration
            of any applicable notice and cure periods in the observance or
            performance of any term, covenant or condition of any Ground Lease
            on the part of any Borrower, as ground lessee thereunder, to be
            observed or performed, unless any such observance or performance
            shall have been waived or not required in writing by the ground
            lessor under such Ground Lease, or if any one or more of the events
            referred to in such Ground Lease shall occur which would or may
            cause such Ground Lease to terminate without notice or action by the
            ground lessor thereunder or which would entitle the ground lessor
            under such Ground Lease to terminate such Ground Lease and the term
            thereof by giving notice to a Borrower, as ground lessee thereunder,
            or if the leasehold estate created by such Ground Lease shall be
            surrendered, in whole or in part, or if such Ground Lease shall be
            terminated or cancelled for any reason or under any circumstance
            whatsoever, or if any of the terms, covenants or conditions of such
            Ground Lease shall in any manner be modified, changed, supplemented,
            altered or amended without the consent of Co-Lenders;

                        (j) if any Borrower or other Person shall be in default
            (beyond any applicable grace and cure period) under any mortgage,
            deed of trust, pledge or other security agreement (including,
            without limitation, any such agreement now or hereafter held by
            Co-Lenders) affecting or relating to any Property, or any other
            Collateral or any portion thereof or under any Material Agreement
            affecting or relating to any Property or any other Collateral, or
            any portion thereof;

                        (k) if any Property shall become subject (i) to any tax
            lien, other than a lien for local real estate taxes and assessments
            not due and payable, or (ii) to any lis pendens, notice of pendency,
            stop order, notice of intention to file mechanic's or materialman's
            lien, mechanic's or materialman's lien or other lien of any nature
            whatsoever, and the same shall not either be discharged of record or
            in the alternative insured over to the satisfaction of Co-Lenders by
            the title company insuring the lien of the Mortgage pertaining to
            the Property in question


                                       52
<PAGE>   57
            within a period of forty five (45) days after the date upon which
            Borrower shall be notified, or shall otherwise have actual
            knowledge, that the same is filed or recorded, and irrespective of
            whether the same is superior or subordinate in lien or other
            priority to the lien of the Mortgages and irrespective of whether
            the same constitutes a perfected or inchoate lien or encumbrance on
            the Properties or any portion thereof or is only a matter of record
            or notice;

                        (l) if for any reason any of the covenants set forth in
            paragraph 13 or paragraph 23 of this Agreement shall at any time
            during the term of the Credit Facility cease to be satisfied and
            complied with in all respects or if any representation or warranty
            set forth in paragraph 22 of this Agreement or elsewhere in the
            Credit Facility Documents shall at any time cease to be true and
            accurate in all material respects;

                        (m) if any Borrower or Guarantor shall make an
            assignment for the benefit of creditors;

                        (n) (1) if a court of competent jurisdiction enters a
            decree or order for relief with respect to any Borrower or Guarantor
            under Title 11 of the United States Code as now constituted or
            hereafter amended or under any other applicable Federal or state
            bankruptcy, insolvency or other similar law, rule or regulation; or
            (2) if such court enters a decree or order appointing a receiver,
            liquidator, assignee, trustee, custodian, examiner, magistrate,
            arbitrator, sequestrator (or similar official) of any Borrowers or
            Guarantor or of any substantial part of their respective properties;
            or (3) if such court decrees or orders the winding up or liquidation
            of the affairs of any Borrower or Guarantor and such order or decree
            is not dismissed, discharged or vacated of record within sixty (60)
            days after the same has been entered;

                        (o) if any Borrower or Guarantor files a petition for
            relief or answer or consent seeking relief under Title 11 of the
            United States Code as now constituted or hereafter amended, or under
            any other applicable Federal or state bankruptcy, insolvency or
            other similar law, rule or regulation, or if any Borrower or
            Guarantor fails to diligently oppose or shall otherwise consent to
            the commencement or prosecution of an involuntary case under Title
            11 of the United States Code as now constituted or hereafter
            amended, or under any other applicable Federal or state bankruptcy,
            insolvency or similar law, rule or regulation, or to the appointment
            of or taking possession by a receiver, liquidator, assignee,
            trustee, custodian, examiner, magistrate, arbitrator, sequestrator
            (or other similar official) of any Borrower or Guarantor or of any
            substantial part of their respective properties, or if any Borrower
            or Guarantor fails generally to pay its respective debts as such
            debts become due, or if any Borrower or Guarantor takes any action
            in furtherance of any action described in this subparagraph;

                        (p) if any Borrower, Guarantor or other Person shall be
            in default beyond the expiration of any applicable notice and cure
            periods under the Facility Notes, the Mortgages, this Agreement or
            any other Credit Facility Document or any other document or
            instrument otherwise executed and delivered in connection therewith
            or in connection with the extension of the Credit Facility by
            Co-Lenders to Borrowers;


                                       53
<PAGE>   58
                        (q) if (except as otherwise specifically provided to the
            contrary in paragraph 18 of this Agreement with respect to WOP and
            the BRT/BOP Limited Partnerships) there shall occur a complete or
            partial suspension or liquidation of all or substantially all of any
            business of any Borrower or any Guarantor and such occurrence in the
            opinion of Co-Lenders has or may have a materially adverse impact on
            any Property or any other Collateral or on the business, assets,
            operations, property, financial or other condition of any Borrower
            or Guarantor;

                        (r) if Borrowers shall fail to furnish or cause to be
            furnished to each Co-Lender, any financial or other information
            required to be provided in accordance with the provisions of this
            Agreement or the other Credit Facility Documents or otherwise
            reasonably requested by Co-Lenders or shall fail to permit, or to
            arrange for, the inspection by Co-Lenders (or their respective
            employees and agents) of any books or records of Borrowers or any
            Guarantor and such default shall continue for twenty (20) days after
            notice by Agent to Borrowers; or

                        (s) if Borrowers shall continue to be in default under
            any of the other terms, covenants or conditions of this Agreement
            for five (5) days after notice from Agent in the case of any default
            which can be cured by the payment of a sum of money, or for twenty
            (20) days after notice from Agent in the case of any other default,
            provided that if such default cannot reasonably be cured within such
            twenty (20) day period and Borrowers, as the case may be, shall have
            commenced to cure such default within such twenty (20) day period
            and thereafter diligently and expeditiously proceeds to cure the
            same, such twenty (20) day period shall be extended for so long as
            it shall require Borrowers, as the case may be, in the exercise of
            due diligence to cure such default, it being agreed, however, that
            no such extension shall be for a period in excess of sixty (60)
            days.

Upon the occurrence of an Event of Default, and for so long as any such Event of
Default continues, Co-Lenders (subject to the terms and provisions of the
Co-Lenders Agreement) (i) shall have no obligation to make any further advances
under the Credit Facility, (ii) shall have the absolute and unconditional right
in their sole and absolute discretion to declare the Debt or any portion thereof
immediately due and payable, (iii) shall have the right to pursue any and all
remedies provided for in this Agreement, the Credit Facility Notes, the
Mortgages, or any of the other Credit Facility Documents or otherwise available
to Co-Lenders, at law or in equity or otherwise, and (iv) shall have the
absolute and unconditional right in their sole and absolute discretion to
terminate the Credit Facility and their obligations with respect thereto under
this Agreement. All remedies afforded to Co-Lenders under this Agreement or
under any of the other Credit Facility Documents are separate and cumulative
remedies and it is agreed that none of such remedies shall be deemed to be in
exclusion of any other remedies available to Co-Lenders and shall not in any
manner limit or prejudice any other legal or equitable remedies which Co-Lenders
may have.

            44. Application of Moneys. All moneys received or collected by
Co-Lenders in respect of the Credit Facility after an Event of Default shall be
applied by Co-Lenders first to the payment of all costs incurred in the
collection of such moneys (including reasonable attorneys' fees and legal
expenses) and second, to the payment of the Debt in such order, priority and
proportions as Co-Lenders may in its sole and absolute discretion determine. The
balance, if any, of such moneys remaining after payment in full of such costs
and the Debt shall be remitted to Borrowers or as otherwise directed by a court
of competent jurisdiction.


                                       54
<PAGE>   59
            45. Right to Cure Defaults. If default beyond any applicable notice
and cure period in the performance of any of the covenants of Borrowers, shall
occur, Co-Lenders may, at their discretion, remedy the same and for such purpose
shall have the right to enter upon the Properties or any portion thereof without
thereby being liable to Borrowers (except in connection with its gross
negligence or willful misconduct) or any Person in possession thereof holding
under Borrowers, and to pay all sums as may be necessary to cure any such
default (including, without limitation any default by Borrowers in the payment
of any Insurance Premiums or any Taxes or other liens or encumbrances covering
the Properties or any part thereof). If Co-Lenders shall remedy such a default
(including, without limitation, any default by Borrowers in the payment of any
Insurance Premiums or any Taxes or other liens or encumbrances covering the
Properties or any part thereof) or appear in, defend or bring any action or
proceeding to protect the interest of Co-Lenders in the Properties, or any
portion thereof, or to foreclose any of the Mortgages or collect the Debt, the
costs and expenses thereof (including reasonable attorneys' fees to the extent
permitted by law) with interest as provided in this paragraph, shall be paid by
Borrowers to Agent upon demand, and shall be added to and constitute part of the
Debt secured by the Mortgages. All such costs and expenses incurred by
Co-Lenders in remedying such default or in appearing in, defending or bringing
any such action or proceeding, shall be paid by Borrowers to Agent upon demand,
with interest at a rate per annum equal to the Default Rate.

            46. Further Assurances. Borrowers agrees to do or cause to be done
all such further reasonable acts and things, and to execute and deliver or cause
to be executed and delivered all such additional conveyances, assignments,
agreements and instruments as Co-Lenders may at any time reasonably request in
connection with the administration or enforcement of this Agreement and the
other Credit Facility Documents or in order better to assure, perfect and
confirm unto Co-Lenders their rights, powers and remedies under this Agreement
and under the other Credit Facility Documents. Nothing contained in this
paragraph shall be construed as obligating Borrowers to provide or to cause to
be provided any collateral or security for the Credit Facility other than as
expressly contemplated by the provisions of this Agreement and the other Credit
Facility Documents.

            47. Costs and Expenses. Borrowers shall pay, or cause to be paid, to
Co-Lenders all costs, fees, expenses and charges incurred by Co-Lenders in
connection with the enforcement of this Agreement and the other Credit Facility
Documents (including without limitation all reasonable fees and disbursements of
Agent's New York City and local legal counsel).

            48. Indemnification of Agent and Co-Lenders. Borrowers shall
indemnify Agent, Co-Lenders, their affiliates, subsidiaries, directors, officers
and employees against all losses, claims, damages, penalties, judgments,
liabilities and reasonable expenses (including, without limitation, all expenses
of litigation or preparation therefor whether or not Agent or Co-Lenders are a
party thereto) which any of them may pay or incur arising out of or relating to
this Agreement, the other Credit Facility Documents, the transactions
contemplated hereby or the direct or indirect application or proposed
application of the proceeds of any advance hereunder, provided, however, that
the aforesaid indemnification shall not apply to any such loss, claim, damage,
penalty, judgment, liability or expense which is incurred by Agent or a
Co-Lender as a result of its gross negligence or willful misconduct. The
obligations of Borrowers under this paragraph shall survive the termination of
this Agreement.

            49. Construction of Agreement. The titles and headings preceding the
paragraphs of this Agreement have been inserted for convenience of reference
only and are not intended to summarize or otherwise describe the


                                       55
<PAGE>   60
subject matter of such paragraphs and shall not be given any consideration in
the construction of this Agreement.

            50. Parties Bound, etc. All of the terms, covenants and provisions
of this Agreement shall be binding upon and inure to the benefit of Borrowers,
Co-Lenders and Agent and their respective successors and assigns. Borrowers
shall not have the right without the prior consent of Co-Lenders (which consent
may be withheld in the sole and absolute discretion of Co-Lenders) to assign or
transfer their respective rights under this Agreement or under any of the other
Credit Facility Documents, in whole or in part, by agreement, operation of law
or otherwise to any other Person, it being agreed that any such assignment or
transfer without the prior consent of Co-Lenders shall be void and of no force
and effect and shall constitute an immediate Event of Default under this
Agreement.

            51. Complete Agreement. NO STATEMENTS, AGREEMENTS OR
REPRESENTATIONS, ORAL OR WRITTEN, WHICH MAY HAVE BEEN MADE BY ANY CO-LENDER, OR
BY ANY EMPLOYEE, AGENT OR BROKER ACTING ON BEHALF OF ANY CO-LENDER, WITH RESPECT
TO THIS AGREEMENT OR THE CREDIT FACILITY SHALL BE OF ANY FURTHER FORCE OR
EFFECT, EXCEPT TO THE EXTENT SPECIFICALLY SET FORTH IN THIS AGREEMENT OR IN THE
OTHER CREDIT FACILITY DOCUMENTS, AND ALL PRIOR AGREEMENTS AND REPRESENTATIONS IN
RESPECT OF THIS AGREEMENT AND THE CREDIT FACILITY ARE MERGED IN THIS AGREEMENT
SO THAT THIS AGREEMENT SHALL CONSTITUTE THE ENTIRE AGREEMENT BETWEEN CO-LENDERS
AND BORROWERS WITH RESPECT TO THE CREDIT FACILITY.

            52. Governing Law. This Agreement shall in all respects be gov-
erned, construed, applied and enforced in accordance with the laws of the State
of New York.

            53. Severability. If any term, covenant, provision or condition of
this Agreement shall be held to be invalid, illegal or unenforceable in any
respect, this Agreement shall be construed without such term, covenant, provi-
sion or condition.

            54. Notices. Any notice, request, demand, statement, authorization,
direction, approval or consent made under this Agreement or under the other
Credit Facility Documents shall be in writing and shall be sent by Federal
Express or other reputable national courier service, or by postage prepaid
registered or certified mail, return receipt requested, and shall be deemed
given (i) when received at the following addresses if sent by Federal Express,
or other reputable national courier service, and (ii) three (3) business days
after being postmarked and addressed as follows if sent by postage prepaid
registered or certified mail, return receipt requested:

            If to Smith Barney:

            Smith Barney Mortgage Capital Group, Inc.
            390 Greenwich Street, 5th Floor
            New York, New York 10013
            Attention:  Clive Bull

            With a copy to:

            Battle Fowler LLP
            Park Avenue Tower
            75 East 55th Street
            New York, New York  10022
            Attention:  Dean A. Stiffle, Esq.


                                       56
<PAGE>   61
            If to NationsBank, in its individual capacity
            or as Agent:

            NationsBank, N.A.
            Real Estate Banking
            8300 Greensboro Drive
            McLean, Virginia 22102-3604
            Attention:  Gary P.F. Carr
                        Vice President

            With a copy to:

            Cadwalader, Wickersham & Taft
            201 South College Street, Suite 1510
            Charlotte, North Carolina 28244
            Attention:  James P. Carroll, Esq.

            If to Borrowers:

            c/o Brandywine Realty Trust
            Newtown Square Corporate Campus
            16 Campus Boulevard, Suite 150
            Newtown Square, Pennsylvania 19073
            Attention:  Gerard H. Sweeney
                        President and Chief Executive Officer

            With a copy to:

            Pepper, Hamilton & Scheetz
            3000 Two Logan Square
            Eighteenth and Arch Streets
            Philadelphia, Pennsylvania 19103-2799
            Attention:  Michael H. Friedman, Esq.

Each party may designate a change of address by notice to the other parties,
given at least fifteen (15) days before such change of address is to become
effective.

            55. Modification. This Agreement may not be modified, amended or
terminated, in whole or in part, except by an agreement in writing executed by
the parties hereto.

            56. Waivers. Co-Lenders may at any time and from time to time waive
any one or more of the terms, covenants, provisions or conditions contained in
this Agreement or in the other Credit Facility Documents, but any such waiver
shall be deemed made in pursuance hereof or thereof and not in modification
thereof, and any such waiver in any particular instance or circumstance shall in
no event or under any circumstance be considered a waiver of any such term,
covenant, provision or condition in any other instance or any other
circumstance.

            57. WAIVER OF TRIAL BY JURY. BORROWERS AND CO-LENDERS HEREBY
IRREVOCABLY AND UNCONDITIONALLY WAIVE ANY AND ALL RIGHTS TO TRIAL BY JURY IN ANY
ACTION, SUIT OR COUNTERCLAIM ARISING IN CONNECTION WITH, OUT OF OR OTHERWISE
RELATING TO THE CREDIT FACILITY NOTES, THE MORTGAGES, THIS AGREEMENT OR ANY
OTHER DOCUMENT OR INSTRUMENT NOW OR HEREAFTER EXECUTED AND DELIVERED IN
CONNECTION THEREWITH OR WITH THE CREDIT FACILITY.

            58. Borrowers' Reliance on Agent's Authority. Unless otherwise
notified by Co-Lenders to the contrary, Borrowers shall have the right to rely
upon any advice they receive from Agent as to any action taken or not taken by
Co-Lenders, or as to any consent or approval given or not given by Co-Lenders,


                                       57
<PAGE>   62
or as to any other action taken or not taken by Co-Lenders, or as to any
decision otherwise made by Co-Lenders, in respect of the Credit Facility or
under or pursuant to the provisions of the Credit Facility Documents, it being
understood that all communication between Borrowers and Co-Lenders in respect of
day to day matters concerning the Credit Facility shall be done through the
offices of Agent.

            59. Authorized Representatives of BRT. The Chief Financial Officer
or the Chief Executive Officer of BRT shall from time to time notify and advise
Agent and Co-Lenders in writing of the officers of BRT who are authorized and
designated to act on behalf of BRT in respect of the Credit Facility and under
and pursuant to the provisions of the Credit Facility Documents, which notice
and advise may be conclusively relied upon by Agent and Co-Lenders.

            60. Exculpation. No recourse shall be had for any obligation of BRT
under this Agreement or any of the other Credit Facility Documents or for any
claim based thereon or otherwise in respect thereof, against any past, present
or future trustee, shareholder, officer or employee of BRT, whether by virtue of
any statute or rule of law, or by the enforcement of any assessment or penalty
or otherwise, all such liability being expressly waived and released by each
other party to this Agreement and the other Credit Facility Documents.


                                       58
 
<PAGE>   63
            IN WITNESS WHEREOF, Initial Co-Lenders, Borrowers and Agent have
duly executed this Agreement as of the day and year first above written.

                              SMITH BARNEY MORTGAGE CAPITAL GROUP, INC.,
                              a Delaware corporation

                              By:   _________________________________
                                    Name:   Clive Bull
                                    Title:  Vice President

                              NATIONSBANK, N.A., a national banking
                              association, acting in its individual
                              capacity

                              By:   _________________________________
                                    Name:   Gary P.F. Carr
                                    Title:  Vice President

                              BRANDYWINE REALTY TRUST, a Maryland
                              real estate investment trust

                              By:   _________________________________
                                    Name:   Gerard H. Sweeney
                                    Title:  President and Chief
                                            Executive Officer

                              BRANDYWINE OPERATING PARTNERSHIP, L.P.

                              By:   Brandywine Realty Trust, a Maryland
                                    real estate investment trust, its
                                    general partner

                                    By:   ___________________________
                                          Name:   Gerard H. Sweeney
                                          Title:  President and Chief
                                                  Executive Officer

                              LC/N HORSHAM LIMITED PARTNERSHIP, a
                              Pennsylvania limited partnership
 
                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:_________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                       59
<PAGE>   64
                              LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              NICHOLS LANSDALE LIMITED PARTNERSHIP III,
                              a Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              NEWTECH III LIMITED PARTNERSHIP, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                       60
<PAGE>   65
                              NEWTECH IV LIMITED PARTNERSHIP, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              C/N OAKLANDS LIMITED PARTNERSHIP I, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              FIFTEEN HORSHAM, L.P., a Pennsylvania
                              limited partnership

                              By:   Witmer Operating Partnership I,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                       61
<PAGE>   66
                              C/N LEEDOM LIMITED PARTNERSHIP II, a
                              Pennsylvania limited partnership


                              By:   Brandywine Operating Partnership,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Realty Trust, a
                                          Maryland real estate
                                          investment trust, its general
                                          partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              C/N IRON RUN LIMITED PARTNERSHIP III, a
                              Pennsylvania limited partnership

                              By:   Brandywine Operating Partnership,
                                    L.P., a Delaware limited
                                    partnership, its general partner

                                    By:   Brandywine Realty Trust, a
                                          Maryland real estate
                                          investment trust, its general
                                          partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              NATIONSBANK, N.A., a national banking
                              association, acting in its capacity as
                              administrative and documentation agent

                              By: ________________________
                                    Name:   Gary P.F. Carr
                                    Title:  Vice President


                                       62
<PAGE>   67
                                    EXHIBIT A

                          (Definition of Certain Terms)


Additional Property: The term "Additional Property" as used in this Agreement
shall mean any property acquired by Borrowers subsequent to the date of this
Agreement.

Affiliate: The term "Affiliate" as used in this Agreement shall mean any Person
directly or indirectly controlling, controlled by or under direct or indirect
common control with any other Person. A Person shall be deemed to control
another Person if the controlling Person owns fifty-one (51%) percent or more of
any class of voting securities of the controlled Person or possesses, directly
or indirectly, the power to direct or cause the direction of the management or
policies of the controlled Person, whether through ownership of stock by
contract or otherwise.

Agent: The term "Agent" as used in this Agreement shall have the meaning given
to such term in the preamble to this Agreement.

Agreement: The term "Agreement" as used in this Agreement shall mean this
Agreement.

Alternate Credit Rate: The term "Alternate Credit Rate" as used in this
Agreement shall have the meaning given to such term in paragraph 1(ii) of
Exhibit B to this Agreement.

Appraised Value: The term "Appraised Value" as used in this Agreement shall mean
(i) with respect to each Initial Property, the "as is" appraised value of such
Initial Property, if and when approved by Initial Lenders in accordance with the
provisions of paragraph 10(iv) of the main body of this Agreement, and (ii) with
respect to any Additional Property, either (y) the "as is" appraised value of
such Additional Property, as set forth in the appraisal prepared in connection
with its inclusion in the collateral pool for the Credit Facility if the fair
market value of such Additional Property, as set forth in such appraisal is
approved without adjustment by Co-Lenders holding in the aggregate not less than
2/3 of the undivided Total Credit Facility Percentage Interests or (z) the
Weighted Average Adjusted Appraised Value of such Additional Property, if the
fair market value of such Additional Property as set forth in such appraisal is
approved with downward adjustment in value by Co-Lenders holding in excess of
1/3 of the undivided Total Credit Facility Percentage Interests, as the same may
be updated in accordance with the provisions of paragraph 14 of this Agreement.

Approved Value: The term "Approved Value" as used in this Agreement shall have
the meaning given to such term in paragraph 13 of the main body of this
Agreement.

Assignments of Leases and Rents: The term "Assignments of Leases and Rents" as
used in this Agreement shall mean the Assignments of Leases and Rents to be
given by Borrowers to Agent, as security for the payment of the Debt and
constituting a first lien on all of Borrowers's right, title and interest now
owned or hereafter acquired in and to all Leases and Rents pertaining to or
derived from the Properties, the form of which is attached to this Agreement as
Exhibit I.

Base LIBOR Rate: The term "Base LIBOR Rate" as used in this Agreement shall have
the meaning given to such term in paragraph 1(v) of Exhibit B to this Agreement.
<PAGE>   68
Borrowers:  The term "Borrowers" as used this Agreement shall have the meaning
given to such term in the preamble to this Agreement.

BOP: The term "BOP" as used in this Agreement shall have the meaning given to
such term in the preamble to the main body of this Agreement.

BRP:  The term "BRP" as used in this Agreement shall mean Brandywine Realty
Partners, a Pennsylvania general partnership.

BRSC: The term "BRSC" as used in this Agreement shall mean Brandywine Realty
Services Corporation, a Pennsylvania corporation.

BHI: The term "BHI" as used in this Agreement shall mean Brandywine Holdings I,
Inc., a Pennsylvania corporation.

BRT: The term "BRT" as used in this Agreement shall have the meaning given to
such term in the preamble to the main body of this Agreement.

business day: The term "business day" shall have the meaning given to such terms
in paragraph 1(ii) of Exhibit B to this Agreement.

Business Day: The term "Business Day" as used in this Agreement shall have the
meaning given to such term in paragraph 1(i) of Exhibit B to this Agreement.

Capitalization Rate Value: The term "Capitalization Rate Value" as used in this
Agreement shall have the meaning given to such term in paragraph 13 of the main
body of this Agreement.

Cash Flow: The term "Cash Flow" as used in this Agreement shall (as the context
requires) have the meaning given to such term in paragraph 13 and/or paragraph
23(z) of the main body of this Agreement.

Casualty Retainage: The term "Casualty Retainage" shall as used in this
Agreement shall have the meaning given to such term in paragraph 30 of the main
body of this Agreement.

Co-Lenders: The term "Co-Lenders" as used in this Agreement shall mean,
collectively, Initial Co-Lenders, and all other parties from time to time to
whom direct interests in the Credit Facility are sold, transferred and assigned
and who are as a result thereof designated as Co-Lenders, under and pursuant to
the provisions of this Agreement and the Co-Lenders Agreement.

Co-Lenders Agreement: The term "Co-Lenders Agreement" as used in this Agreement
shall mean that certain Co-Lender and Servicing Agreement dated the date hereof
by and among Smith Barney and NationsBank, in its individual capacity and as
Agent, as the same may be amended from time to time.

Co-Lenders Certificate: The term "Co-Lenders Certificate" as used in this
Agreement shall have the meaning given to such term in paragraph 25 of the main
body of this Agreement.

Collateral: The term "Collateral" as used in this Agreement shall mean all of
the now existing or hereafter acquired right, title and interest of Borrowers in
and to (a) the Initial Properties, (b) the Additional Properties which are
included in the collateral pool for the Credit Facility, (c) all Leases, Rents,
easements, options, personal property and other rights or property related to
the ownership or operation of the Properties which are included from time to
time in the collateral pool for the Credit Facility, (d) any other collateral
now or hereafter delivered to Co-Lenders pursuant to the provisions of this
Agreement or the other Credit Facility Document as collateral for the Credit
Facility and (e) all proceeds of the foregoing.


                                       A-2
<PAGE>   69
Commitment: The term "Commitment" as used in this Agreement shall mean that
certain Commitment Letter dated November 6, 1996 by and among Smith Barney,
NationsBank, BRT and BOP.

Commitment Fee: The term "Commitment" as used in this Agreement shall have the
meaning given to such term in paragraph 19 of the main body of this Agreement.

Consultant: The term "Consultant" as used in this Agreement shall have the
meaning given to such term in paragraph 30 of the main body of this Agreement.

Credit Facility: The term "Credit Facility" as used in this Agreement shall have
the meaning given to such term in the Preliminary Statement on the first page of
the main body of this Agreement.

Credit Facility Administration Fee: The term "Credit Facility Administration
Fee" as used in this Agreement shall have the meaning given to such term in
paragraph 20 of the main body of this Agreement.

Credit Facility Documents: The term "Credit Facility Documents" as used in this
Agreement shall collectively mean this Agreement, the Credit Facility Notes, the
Mortgages, the Assignments of Leases and Rents, the Guaranty of Payment, the
Hazardous Material Guaranty and Indemnification Agreement and all other
documents and instruments of any nature whatsoever now or hereafter executed and
delivered in connection with this Agreement or the Credit Facility, as any of
the same may from time to time be amended, modified, extended, supplemented,
renewed, replaced or restated.

Credit Facility Notes: The term "Credit Facility Notes" as used in this
Agreement shall mean, collectively, the following: (i) that certain Note dated
the date hereof in the original principal amount of $40,000,000.00 given by
Borrowers to Smith Barney, and (ii) that certain Note dated the date hereof in
the original principal amount of $40,000,000.00 given by Borrowers to
NationsBank, as such Notes may from time to time be amended, modified, extended,
supplemented, renewed, replaced or restated.

Credit Facility Outstanding: The term "Credit Facility Outstanding" as used in
this Agreement shall have the meaning given to such term in paragraph __ of the
main body of this Agreement.

Credit Facility Percentage Interests: The term "Credit Facility Percentage
Interests" as used in this Agreement shall have the meaning given to such term
in paragraph 2 of the main body of this Agreement.

Damaged Property: The term "Damaged Property" as used in this Agreement shall
have the meaning given to such term in paragraph 30 of the main body of this
Agreement.

Debt: The term "Debt" as used in this Agreement shall mean all principal,
interest, additional interest and other sums of any nature whatsoever which may
or shall become due and payable to Co-Lenders in accordance with the provisions
of the Credit Facility Documents.

Debt-to-Tangible Net Worth Requirement: The term "Debt-to-Tangible Net Worth
Requirement" as used in this Agreement shall have the meaning given to such term
in paragraph 23(cc) of the main body of this Agreement.

default: The term "default" as used in this Agreement shall mean the occurrence
of any default by Borrowers or any other Person in the observance or performance
of any of the terms, covenants or provisions of this Agreement, the Credit
Facility Notes, the Mortgages or the other Credit Facility Documents on the part
of Borrowers or such other Person to be observed or


                                       A-3
<PAGE>   70
performed without regard to whether such default constitutes or would upon
notice or lapse of time, or both, constitute an Event of Default under this
Agreement, the Credit Facility Notes, the Mortgages or the other Credit Facility
Documents.

Default Rate: The term "Default Rate" as used in this Agreement shall, to the
extent necessary, be determined on a daily basis and shall be equal to four (4%)
percent plus the greater on a daily basis of (i) the weighted average of the
LIBOR Rates, if any, from time to time, applicable to the Credit Facility Notes,
and (ii) the Floating Rate, provided, however, that the Default Rate shall in no
event exceed the maximum interest rate permitted by applicable law. The Default
Rate shall be calculated for the actual number of days elapsed on the basis of a
360-day calendar year.

Development: The term "Development" as used in this Agreement shall mean any
improvements which are to be constructed on any unimproved land owned and/or
controlled either directly or indirectly by Borrowers or to be acquired by
Borrowers, and any additions which are to be added to any improved property
owned and/or controlled either directly or indirectly by Borrowers (irrespective
of whether constituting part of the collateral pool for the Credit Facility) and
which additions will increase the square footage of the improvements (rentable
or otherwise) located on any such improved property.

Environmental Requirements: The term "Environmental Requirements" as used in
this Agreement shall have the meaning given to such term in paragraph 32 of the
main body of this Agreement.

Environmental Reports: The term "Environmental Reports" as used in this
Agreement (i) shall mean in respect of the Initial Properties, the environmental
reports listed on Schedule 5 attached hereto, and (ii) shall mean in respect of
any Additional Property which is added to the collateral pool for the Credit
Facility from time to time, the environmental reports delivered to and approved
by Co-Lenders, in accordance with the provisions of paragraph 1(1) of Exhibit E
attached hereto.

ERISA: The term "ERISA" as used in this Agreement shall have the meaning given
to such term in paragraph 22(u) of the main body of this Agreement.

Events of Default: The term "Events of Default" as used in this Agreement shall
have the meaning given to such term in paragraph 43 of the main body of this
Agreement.

Federal Funds Effective Rate: The term "Federal Funds Effective Rate" as used in
this Agreement shall have the meaning given to such term in paragraph 1(ii) of
Exhibit B to this Agreement.

FF&E: The term "FF&E" as used in this Agreement shall mean, collectively, all
goods (as such term is defined in the Uniform Commercial Code), now owned or
hereafter acquired by Borrowers, located at or used in connection with the
Properties and the operation of the Properties, including, without limitation,
(i) all furniture and furnishings and all other items of personal property
(including inventory now owned or hereafter acquired by Borrowers but excluding
inventory and personal property owned by Lessee or any Other Lessee) located on,
or used in connection with the operation of the Properties, together with all
replacements, modifications, alterations and additions thereto; and (ii) all
equipment, machinery, fixtures and other items of property required or
incidental to the use of the Properties, including all components thereof, now
and hereafter permanently affixed to or incorporated into the Properties,
including, without limitation, all furnaces, boilers, heaters, electrical
equipment, heating, plumbing, lighting, ventilating, refrigerating,
incineration, air and water pollution control, waste, disposal, air-cooling and
air conditioning systems and apparatus, sprinkler systems and


                                       A-4
<PAGE>   71
fire and theft protection equipment, all of which to the greatest extent
permitted by law are deemed by the parties hereto to constitute real estate,
together with all replacements, modifications, alterations and additions
thereto.

Financing Statements: The term "Financing Statements" as used in this Agreement
shall mean Uniform Commercial Code Financing Statements, in form and content
acceptable to Co-Lenders.

FIRREA: The term "FIRREA" as used in this Agreement shall mean the Financial
Institutions Reform, Recovery and Enforcement Act.

Fixed Charge Coverage Ratio: The term "Fixed Charge Coverage Ratio" as used in
this Agreement shall have the meaning given to such term in paragraph 23(bb) of
the main body of this Agreement.

Floating Rate: The term "Floating Rate" as used in this Agreement shall have the
meaning given to such term in paragraph 1(ii) of Exhibit B to this Agreement.

GAAP: The term "GAAP" shall mean generally accepted accounting practices
consistently applied.

Governmental Authority: The term "Governmental Authority" as used in this
Agreement shall have the meaning given to such term in paragraph 32 of the main
body of this Agreement.

Ground Leases: The term "Ground Leases" as used in this Agreement shall mean
collectively, (i) that certain Ground Lease dated as of May 31, 1988, between
Woodlawn Trustees, Incorporated, as ground lessor, and Donahoe Wilmington
Associates One Limited Partnership, as ground lessee, and recorded on June 3,
1988, in the Office of the Recorder of Deeds for New Castle County, Delaware in
Deed Book 711, page 34, the ground lessees interest in which (x) was assigned by
Michael P. Walsh, Sheriff of New Castle County, Delaware, to New York Life
Insurance and Annuity Corporation by Deed dated March 15, 1995, and recorded in
the aforesaid Recorder's Office in Deed Book 1895, page 253, (y) was further
assigned by New York Life Insurance and Annuity Corporation to KB Fund II by
Assignment and Assumption Agreement dated as of June 29, 1995, and recorded on
July 14, 1995, in the aforesaid Recorder's office in Deed Book 1949, page 301,
and (x) was further assigned by KB Fund II to BOP by Assignment and Assumption
of Ground Lease dated December 2, 1996, and intended to be duly recorded in the
aforesaid Recorder's office, and pursuant to which Ground Lease, as so assigned,
BOP holds a leasehold estate in the Initial Property commonly known as the
Delaware Corporate Center, New Castle County Delaware, and (ii) any other ground
lease pursuant to which Borrowers now or hereafter hold a leasehold estate in
any Property which is included from time to time in the collateral pool for the
Credit Facility.

Guarantor: The term "Guarantor" as used in this Agreement shall collectively
mean WOP, BRP and BRSC.

Guaranty of Payment: The term "Guaranty of Payment" as used in this Agreement
shall mean that certain Guaranty of Payment dated the date hereof given by
Guarantors to Agent, the form of which is attached hereto as Exhibit J.

Hazardous Material: The term "Hazardous Material" as used in this Agreement
shall have the meaning given to such term in paragraph 32 of the main body of
this Agreement.

Hazardous Material Guaranty and Indemnification Agreement: The term "Hazardous
Material Guaranty and Indemnification Agreement" as used in this Agreement shall
mean that certain Hazardous Material Guaranty and


                                       A-5
<PAGE>   72
Indemnification Agreement dated the date hereof given by Guarantors to Agent,
the form of which is attached hereto as Exhibit K.

Initial Lenders: The term "Initial Lenders" as used in this Agreement shall
collectively mean Smith Barney and NationsBank.

Initial Properties: The term "Initial Properties" as used in this Agreement
shall meaning those Properties constituting part of the original collateral pool
for the Credit Facility, as more particularly described in Exhibit F attached
hereto.

Insurance Policies: The term "Insurance Policies" as used in this Agreement
shall have the meaning given to such term in paragraph 30 of the main body of
this Agreement.

Insurance Premiums: The term "Insurance Premiums" as used in this Agreement
shall have the meaning given to such term in paragraph 30 of the main body of
this Agreement.

Interest Period: The term "Interest Period" as used in this Agreement shall have
the meaning given to such term in paragraph 1(iii) of Exhibit B to this
Agreement.

Internal Revenue Code: The term "Internal Revenue Code" as used in this
Agreement shall mean the Internal Revenue Code of 1986, as amended, or any
successor statute.

L/C Issuer: The term "L/C Issuer" as used in this Agreement shall have the
meaning given to such term in paragraph 3 of the main body of this Agreement.

Leases: The term "Leases" as used in this Agreement shall mean collectively mean
all leases, licenses and other agreements (other than the Ground Leases) now or
hereafter entered into and affecting or relating to the use or occupancy of the
Properties from time to time constituting part of the collateral pool for the
Credit Facility.

Letter of Credit: The term "Letter of Credit" as used in this Agreement shall
have the meaning given to such term in paragraph 3 of the main body of this
Agreement.

Letter of Credit Facility: The term "Letter of Credit Facility" as used in this
Agreement shall have the meaning given to such term in paragraph 3 of the main
body of this Agreement.

Letter of Credit Fee: The term "Letter of Credit Fee" as used in this Agreement
shall have the meaning given to such term in paragraph 5 of the main body of
this Agreement.

LIBOR Rate: The term "LIBOR Rate" as used in this Agreement shall have the
meaning given to such term in paragraph 1(iv) of Exhibit B to this Agreement.

Loan to Value Requirement: The term "Loan to Value Requirement" as used in this
Agreement shall have the meaning given to such term in paragraph 13 of the main
body of this Agreement.

Material Agreements: The term "Material Agreements" as used in this Agreement
shall mean all Ground Leases, REAs, condominium declarations and related
documents and all other agreements which in the judgment of Co-Lenders are
material to the value, use, operation or management of any Property from time to
time constituting part of the collateral pool for the Credit Facility, or the
modification, amendment or termination of which could or would in the judgment
of Co-Lenders have a material adverse effect on the value, use,


                                      A-6
<PAGE>   73
operation or management of any Property from time to time constituting part of
the collateral pool for the Credit Facility.

Maturity Date: The term "Maturity Date" shall have the meaning given to such
term in paragraph 7 of the main body of this Agreement.

Minimum Debt Service Coverage Ratio: The term "Minimum Debt Service Coverage
Ratio" as used in this Agreement shall have the meaning given to such term in
paragraph 23(z) of the main body of this Agreement.

Mortgages: The term "Mortgages" as used in this Agreement shall mean fully cross
defaulted and cross collateralized blanket mortgages and deeds of trust
constituting a first lien on the fee and leasehold estates of Borrowers in all
Properties constituting part of the collateral pool for the Credit Facility from
time to time to be executed and delivered by Borrowers to or for the benefit of
Agent and securing payment in full of the Debt, the forms of which are attached
hereto as Exhibits G (mortgage) and H (deed of trust).

NAREIT: The term "NAREIT" as used in this Agreement shall mean the National
Association of Real Estate Investment Trusts.

NationsBank: The term "NationsBank" as used in this Agreement shall have the
meaning given to such term in the preamble to the main body of this Agreement.

Net Proceeds: The term "Net Proceeds" as used in this Agreement shall have the
meaning given to such term in paragraph 30 of the main body of this Agreement.

Net Proceeds Deficiency: The term "Net Proceeds Deficiency" as used in this
Agreement shall have the meaning given to such term in paragraph 30 of the main
body of this Agreement.

Other Debt: The term "Other Debt" as used in this Agreement shall have the
meaning given to such term in paragraph 23(y) of the main body of this
Agreement.

Other Permitted Debt: The term "Other Permitted Debt" as used in this Agreement
shall have the meaning given to such term in paragraph 23(y) of this Agreement.

Other Secured Debt: The term "Other Secured Debt" as used in this Agreement
shall have the meaning given to such term in paragraph 23(y) of this Agreement.

Other Unsecured Debt: The term "Other Unsecured Debt" as used in this Agreement
shall have the meaning given to such term in paragraph 23(y) of this Agreement.

Participant: The term "Participant" as used in this Agreement shall have the
meaning given to such term in paragraph 25 of the main body of this Agreement.

Permitted Title Exceptions: The term "Permitted Title Exceptions" as used in
this Agreement shall mean those matters set forth in the title insurance
policies insuring the respective liens of the Mortgages on the date hereof and
those matters otherwise approved in writing by Co-Lenders.

Person: The term "Person" as used in this Agreement shall mean an individual, a
corporation, a firm, a limited or general partnership, an association, a joint
venture or any other entity or organization, including a governmental or
political subdivision or an agent or instrumentality thereof.


                                       A-7
<PAGE>   74
Properties: The term "Properties" as used in this Agreement shall mean the
properties (including, without limitation; the Initial Properties) from time to
time constitutes part of the collateral pool for the Credit Facility.

Prime Rate: The term "Prime Rate" as used in this Agreement shall have the
meaning given to such term in paragraph 1(ii) of Exhibit B to this Agreement.

Principal Balance: The term "Principal Balance" as used in this Agreement shall
have the meaning given to such term in paragraph 1(vi) of Exhibit B to this
Agreement.

REA: The term "REA" as used in this Agreement shall mean, with respect to any
individual Property, any executed and delivered comprehensive reciprocal
easement and operating agreement which encumbers a Property and which either
benefits such Property or will enhance the integrated use, operation and
management of such Property.

Regulation D: The term "Regulation D" as used in this Agreement shall have the
meaning given to such term in paragraph 6(a) of the main body of this Agreement.

Reinvestment Rate: The term "Reinvestment Rate" as used in this Agreement shall
have the meaning given to such term in paragraph 10 of Exhibit B to this
Agreement.

Renovation: The term "Renovation" as used in this Agreement shall mean any
renovation to an improved property owned and/or controlled either directly or
indirectly by Borrowers (irrespective of whether constituting part of the
collateral pool for the Credit Facility) which does not constitute an additional
Development of such property.

Rents: The term "Rents" as used in this Agreement shall mean all rents,
royalties, issues, profits, rent equivalent income, security deposits, insurance
proceeds, tax refunds, any other revenues, income benefits or proceeds of any
nature whatsoever generated by, arising from or otherwise relating to the
Properties.

Request for Advance: The term "Request for Advance" as used in this Agreement
shall have the meaning given to such term in paragraph 9 of the main body of
this Agreement.

Required Due Diligence Materials: The term "Required Due Diligence Materials" as
used in this Agreement shall mean all materials required by paragraph 1 of
Exhibit E of this Agreement.

Re-Set Date: The term "Re-Set Date" as used in this Agreement shall have the
meaning given to such term in paragraph 1(vii) of Exhibit B to this Agreement.

Roll Over Date: The term "Roll Over Date" as used in this Agreement shall have
the meaning given to such term in paragraph 1(viii) of Exhibit B to this
Agreement.

Smith Barney: The term "Smith Barney" as used in this Agreement shall have the
meaning given to such term in preamble to the main body of this Agreement.

Supplemental Debt Service Coverage Ratio: The term "Supplemental Debt Service
Coverage Ratio" as used in this Agreement shall have the meaning given to such
term in paragraph 23(aa) of the main body of this Agreement.

Tangible Net Worth: The term "Tangible Net Worth" as used in this Agreement
shall have the meaning given to such term in paragraph 23(uu) of the main body
of this Agreement.


                                       A-8
<PAGE>   75
Taxes: The term "Taxes" as used in this Agreement shall have the meaning given
to such term in paragraph 29 of the main body of this Agreement.

Telerate Page 3750: The term "Telerate Page 3750" as used in this Agreement
shall have the meaning given to such term in paragraph 1(iv) of Exhibit B to
this Agreement.

Title Company: The term "Title Company" as used in this Agreement shall mean
Commonwealth Land Title Insurance Company, a Pennsylvania corporation, or such
other title company as may be designated by Borrowers from time to time and
approved by Co-Lenders.

Total Credit Facility Percentage Interests: The term "Total Credit Facility
Percentage Interests" as used in this Agreement shall mean the respective
undivided percentage interests held by each Co-Lender in the entire Credit
Facility (inclusive of any risk participations in any Letter of Credit which is
issued and is outstanding under the Credit Facility), which on the date hereof
are as follows: Smith Barney - 50% and NationsBank 50%.

Total Earnings: The term "Total Earnings" as used in this Agreement shall mean
the consolidated earnings of Borrowers before minority interests, interest,
taxes, depreciation and amortization, as determined on a consolidated basis and
according to GAAP, for the period in question. Total Earnings will be calculated
on the basis of the four complete calendar quarters preceding the date of
determination, with the exception that during 1997, the calculation shall be
based on complete calendar quarters commencing with the calendar quarter
beginning on October 1, 1996.

Unused Facility Fee: The term "Unused Facility Fee" as used in this Agreement
shall have the meaning given to such term in paragraph 21 of the main body of
this Agreement.

Unused Portion: The term "Unused Portion" as used in this Agreement shall be
calculated on a daily basis and shall mean, $80,000,000 less the sum of (i) the
daily weighted average of the outstanding principal balance of the Credit
Facility Notes and (ii) the daily weighted average of the aggregate amount
available for draw under all outstanding Letters of Credit.

Weighted Average Adjusted Appraised Value: The term "Weighted Average Adjusted
Apprised Value" as used in this Agreement shall have the meaning given to such
term in paragraph 12 of the main body of this Agreement.

WOP:  The term "WOP" as used in this Agreement shall mean Witmer Operating
Partnership I, L.P., a Delaware limited partnership.


                                       A-9
<PAGE>   76
                                    EXHIBIT B

                      (Credit Facility Payment Provisions)


            1. The following terms as used in this Exhibit shall have the
following meanings:

            (i) The term "Business Day" shall mean any day on which Agent is
      open for business in the city in which its principal office is located and
      on which commercial banks in the City of London, England are open for
      dealings in U.S. dollar deposits in the London Interbank Market, provided,
      however, that during any period of time during which the entire Principal
      Balance is bearing interest at the Floating Rate in accordance with the
      provisions of this Note hereinafter set forth, the term "Business Day"
      shall mean any day on which Agent is open for business in the city in
      which its principal office is located.

           (ii) The term "Floating Rate" shall mean a rate per annum equal to 25
      basis points plus the greater on a daily basis of (a) the Prime Rate, or
      (b) the Alternate Credit Rate. The term "Prime Rate" shall mean such rate
      of interest as is publicly announced by NationsBank or other comparable
      bank designated by Agent at its principal office from time to time as its
      prime rate. Any change in the Prime Rate shall be effective on the date
      such change is announced by NationsBank or other comparable bank
      designated by Agent. The term "Alternate Credit Rate" shall mean a rate
      per annum equal to 50 basis points plus the Federal Funds Effective Rate
      from time to time. The "Federal Funds Effective Rate" shall to the extent
      necessary be determined by Agent separately for each day during the term
      of the Credit Facility and shall for each such day be a rate per annum
      equal to the weighted average of the rates on overnight Federal funds
      transactions with members of the Federal Reserve System arranged by
      Federal funds brokers, as published for each such day (or if any such day
      is not a business day, for the next immediately preceding business day) by
      the Federal Reserve Bank of New York, or if the weighted average of such
      rates is not so published for any such day which is a business day, the
      average of the quotations for any such day on such transactions received
      by Agent from three Federal funds brokers of recognized standing selected
      by Agent. The term "business day" as used in the preceding sentence of
      this subparagraph shall mean any day on which the Federal Reserve Bank of
      New York is open for business. Any change in the Floating Rate as a result
      of a change in the Prime Rate or the Federal Funds Effective Rate shall be
      effective on the effective date of any such change in the Prime Rate or
      the Federal Funds Effective Rate, as the case may be. If for any reason
      Agent shall have determined (which determination shall be conclusive and
      binding on Borrowers) that Agent is unable to ascertain the Federal Funds
      Effective Rate for any reason, including, without limitation, the
      inability or failure of Agent to obtain sufficient bids for the purposes
      of determining the Federal Funds Effective Rate in accordance with the
      provisions of this subparagraph, the Floating Rate shall be determined on
      the basis of the Prime Rate until the circumstances giving rise to such
      inability no longer exist. The Floating Rate shall be calculated for the
      actual number of days elapsed on the basis of a 360-day year. Each
      determination of the Floating Rate shall be made by Agent and shall be
      conclusive and binding upon Borrowers absent manifest error.

          (iii) The term "Interest Period" shall mean the period of time during
      which a particular LIBOR Rate will be applicable to all or any particular
      portion of the Principal Balance in accordance with the provisions of this
      Exhibit, it being agreed that (a) each Interest Period shall commence and
      shall terminate on a Re-Set Date, (b) each


                                       B-1
<PAGE>   77
      Interest Period shall be of a duration of either one month, two months or
      three months, (c) no Interest Period shall extend beyond the Maturity
      Date, and (d) the portion of the Principal Balance with respect to which a
      particular Interest Period is applicable will bear interest at the LIBOR
      Rate pertaining to such Interest Period from and including the first day
      of such Interest Period to, but not including, the last day of such
      Interest Period.

           (iv) The "LIBOR Rate" applicable to a particular Interest Period
      shall mean a rate per annum equal to 175 basis points plus the Base LIBOR
      Rate applicable to such Interest Period. The "Base LIBOR Rate" applicable
      to a particular Interest Period shall mean a rate per annum equal to the
      rate for U.S. dollar deposits with maturities comparable to such Interest
      Period which appears on Telerate Page 3750 as of 11:00 a.m., London time,
      two (2) Business Days prior to the commencement of such Interest Period,
      provided, however, that if such rate does not appear on Telerate Page
      3750, the "Base LIBOR Rate" applicable to such Interest Period shall mean
      a rate per annum equal to the rate at which U.S. dollar deposits in an
      amount approximately equal to the Principal Balance (or the portion
      thereof which will bear interest at a LIBOR Rate during the Interest
      Period to which such Base LIBOR Rate is applicable in accordance with the
      provisions of this Exhibit), and with maturities comparable to the last
      day of the Interest Period with respect to which such Base LIBOR Rate is
      applicable, are offered in immediately available funds in the London
      Interbank Market to the London office of NationsBank or other comparable
      bank designated by Agent by leading banks in the Eurodollar market at
      11:00 a.m., London time, two (2) Business Days prior to the commencement
      of the Interest Period to which such Base LIBOR Rate is applicable. The
      term "Telerate Page 3750" means the display designated as "Page 3750" on
      the Associated Press-Dow Jones Telerate Service (or such other page as may
      replace Page 3750 on the Associated Press-Dow Jones Telerate Service or
      such other service as may be nominated by the British Bankers' Association
      as the information vendor for the purpose of displaying British Bankers'
      Association interest settlement rates for U.S. dollar deposits). Any Base
      LIBOR Rate determined on the basis of the rate displayed on Telerate Page
      3750 in accordance with the foregoing provisions of this subparagraph
      shall be subject to corrections, if any, made in such rate and displayed
      by the Associated Press-Dow Jones Telerate Service within one hour of the
      time when such rate is first displayed by such Service. Each determination
      of the LIBOR Rate and the Base LIBOR Rate applicable to a particular
      Interest Period shall be made by Agent and shall be conclusive and binding
      upon Borrowers absent manifest error. Interest at the applicable LIBOR
      Rate from time to time shall be calculated for the actual number of days
      elapsed on the basis of a 360-day year.

            (v) The term "Maturity Date" shall mean December 1, 1998.

            (vi) The term "Principal Balance" shall mean the outstanding
      principal balance of the Credit Facility from time to time.

            (vii) The term "Re-Set Date" shall mean the first day of the first
      calendar month which is not less than three (3) Business Days after the
      first advance under the Credit Facility. Each subsequent Re-Set Date
      during the term of the Credit Facility shall be the date in each
      subsequent calendar month during the term of the Credit Facility which
      numerically corresponds to the first Re-Set Date during the term of the
      Credit Facility, provided, however, that if the numerically corresponding
      date in any such subsequent calendar month during the term of the Credit
      Facility shall not be a Business Day, the Re-Set Date for such calendar
      month shall be the next succeeding Business Day, unless the next such
      succeeding Business Day would fall in the next calendar


                                       B-2
<PAGE>   78
      month, in which event the Re-Set Date for such calendar month shall be the
      next preceding Business Day. For the purposes of this Exhibit the period
      of time between any two consecutive Re-Set Dates during the term of the
      Credit Facility shall be deemed to be a period of one month.

         (viii) The "Roll Over Date" applicable to a particular Interest Period
      shall mean the last day of such Interest Period, it being understood that
      each such Roll Over Date shall fall on a Re-Set.

            2. The Principal Balance or so much thereof may be advanced and
readvanced by Co-Lenders to Borrowers and be outstanding from time to time in
accordance with the provisions of this Agreement, with interest thereon from and
including the date of this Agreement to, but not including, the date the
Principal Balance is paid in full calculated in the manner hereinafter set
forth, as follows:

      (i) interest on the Principal Balance calculated in the manner hereinafter
set forth shall be due and payable in Federal funds or other immediately
available funds on each Re-Set Date during the term of the Credit Facility; and

      (ii) the entire Principal Balance, together with all interest accrued and
unpaid thereon calculated in the manner hereinafter set forth and all other sums
due in respect of the Credit Facility in accordance with the Credit Facility
Documents, shall be due and payable on the Maturity Date.

            3. All payment in respect of the Principal Balance, interest on the
Principal Balance and all other sums which may or shall become due and payable
in respect of the Credit Facility in accordance with the provisions of the
Credit Facility Notes, this Agreement and the other Credit Facility Documents
shall (except to the extent otherwise specifically provided to the contrary in
the Credit Facility Documents) be paid to Agent for the equal and ratable
benefit of Co-Lenders.

            4. From and including the date of the initial advance of the Credit
Facility pursuant to the provisions of this Agreement to, but not including, the
first Re-Set Date during the term of the Credit Facility, the entire Principal
Balance shall bear interest at the Floating Rate. From and including the first
Re-Set Date during the term of the Credit Facility to, but not including, the
last Re-Set Date during the term of the Credit Facility, the entire Principal
Balance shall, except as specifically provided to the contrary in this paragraph
and in paragraph 6 and paragraph 11 of this Exhibit, bear interest at one or
more of the available LIBOR Rates. The available LIBOR Rates shall consist of a
one-month LIBOR Rate, a two-month LIBOR Rate and a three-month LIBOR Rate
determined in accordance with the provisions of paragraph 1 (iv) and paragraph 6
of this Exhibit, it being agreed that (i) Borrowers shall have the right to
select the LIBOR Rate or Rates from time to time applicable to the Principal
Balance, (ii) Borrowers shall not have the right to select a two-month or a
three-month LIBOR Rate prior to June 1, 1997, unless shall otherwise agree to
the contrary by Initial Lenders in their sole and absolute discretion, and (iii)
each LIBOR Rate from time to time so selected by Borrowers shall take effect and
shall end on a ReSet Date. Except as hereinafter specifically provided to the
contrary in this paragraph, Borrowers shall not have the right to select more
than one LIBOR Rate to take effect on any given Re-Set Date. If Borrowers shall
not select a LIBOR Rate by written notice given to Agent at least three (3)
Business Days prior to a particular Re-Set Date, the LIBOR Rate for such Re-Set
Date shall be a one-month LIBOR Rate. The LIBOR Rate selected by Borrowers or
otherwise designated for a particular Re-Set Date in accordance with the
foregoing provisions of this paragraph, shall be in effect from and including
the first day of the Interest Period to which such LIBOR Rate pertains to, but
not


                                       B-3
<PAGE>   79
including, the Roll Over Date applicable to such Interest Period, and shall
(subject to the following provisions of this paragraph) be applicable to the
entire portion of the Principal Balance with respect to which a LIBOR Rate or
Rates are due to be re-set on such Re-Set Date, as well as to any portion of the
Principal Balance bearing interest at a Floating Rate and any advance of the
Credit Facility scheduled to be made on such Re-Set Date. Notwithstanding the
foregoing provisions of this paragraph, any advance or advances of the Credit
Facility which are drawn down and which in the aggregate are less than
$2,000,000, or which are drawn down other than on a Re-Set Date in accordance
with the provisions of paragraph 5 of this Exhibit, will bear interest at the
Floating Rate from and including the date upon which the same are drawn down to,
but not including, the earlier to occur of (i) the first Re-Set Date which is
five (5) Business Days or more after the date of such draw and on which a LIBOR
Rate applicable to the outstanding Principal Balance is due to be reset, or (ii)
the first Re-Set Date which is five (5) Business Days or more after the date of
such draw and on which the aggregate portion of the Principal Balance bearing
interest at the Floating Rate is equal to or is in excess of $2,000,000,
whereupon the interest rate applicable to such advance or advances or such
portion of the Principal Balance bearing interest at the Floating Rate will be
converted to a LIBOR Rate in accordance with the provisions of this paragraph.
From and after the date upon which the Principal Balance is equal to or in
excess of $4,000,000, and for so long as the Principal Balance is equal to or in
excess of $4,000,000, Borrowers shall have the right to select up to, but not in
excess of, two LIBOR Rates to take effect on any given Re-Set Date by written
notice given to Agent at least five (5) Business Days prior to the applicable
Re-Set Date in which Borrowers shall specify the two LIBOR Rates so selected by
Borrowers and the respective portions of the Principal Balance (inclusive of any
advance of the Credit Facility scheduled to be made on such Re-Set Date) to
which such LIBOR Rates are to respectively pertain, it being agreed that (i) the
minimum portion of the Principal Balance to which any such LIBOR Rate may
pertain shall be equal to at least $2,000,000, and (ii) each such LIBOR Rate so
selected by Borrowers shall be applicable to the portion of the Principal
Balance to which it pertains from and including the first day of the applicable
Interest Period to, but not including, the Roll Over Date applicable to such
Interest Period. If the Maturity Date is not a Re-Set Date, the entire Principal
Balance shall at the election of Co-Lenders either bear interest at the Floating
Rate or at a one month LIBOR Rate determined in accordance with the provisions
of paragraph 1(iv) and paragraph 6 of this Exhibit from and including the last
Re-Set Date prior to the Maturity Date to, but not including, the Maturity Date,
it being agreed that any such one-month LIBOR Rate shall be determined on the
basis of an assumed Interest Period of one month.

            5. Notwithstanding anything to the contrary contained in this
Agreement or the other Credit Facility Documents, Borrowers shall not have the
right (other than as provided in the next sentence) to obtain more than one
advance per month under the Credit Facility. Notwithstanding the foregoing,
Borrowers shall have the right to obtain more than one advance under the Credit
Facility per month if such additional advance is being made pursuant to this
Agreement in connection with the acquisition of an Additional Property in
accordance with the provisions of this Agreement. Any such advance which is not
made on a Re-Set Date shall bear interest at the Floating Rate until the next
occurring Re-Set Date, unless such next occurring Re-Set Date is less than five
(5) Business Days from the date of such advance in which event such advance
shall bear interest at the Floating Rate until the second Re-Set Date following
the date of such advance, at which time the interest rate applicable to such
advance shall, except as otherwise provided to the contrary in this Exhibit, be
converted to a LIBOR Rate.

            6. Agent shall, as soon as practicable after 9:30 a.m., Charlotte,
North Carolina time, two (2) Business Days prior to the commencement of a
particular Interest Period, determine the LIBOR Rate which


                                       B-4
<PAGE>   80
will be in effect during such Interest Period and inform Borrowers of the LIBOR
Rate so determined (which determination shall be conclusive and binding upon
Borrowers absent manifest error). In the event, and on each occasion, that on
the day two (2) Business Days prior to the commencement of a particular Interest
Period, Agent shall have determined in good faith (which determination shall be
conclusive and binding upon Borrowers) that U.S. dollar deposits in an amount
approximately equal to the portion of the Principal Balance which is to bear
interest at a particular LIBOR Rate during such particular Interest Period in
accordance with the provisions of this Exhibit are not generally available at
such time in the London Interbank Market, or reasonable means do not exist for
ascertaining a LIBOR Rate for such particular Interest Period, Agent shall so
notify Borrowers and the interest rate applicable to the portion of the
Principal Balance with respect to which such LIBOR Rate was to pertain shall
automatically be converted to the Floating Rate as of the next occurring Re-Set
Date, it being agreed that the Floating Rate shall remain in effect thereafter
with respect to such portion of the Principal Balance unless and until Agent
shall have determined in good faith (which determination shall be conclusive and
binding upon Borrowers) that the aforesaid circumstances no longer exist,
whereupon the interest rate applicable to such portion of the Principal Balance
shall be converted back to a LIBOR Rate determined in the manner hereinabove set
forth in this Exhibit effective as of the first Re-Set Date which occurs ten
(10) Business Days or more after such good faith determination by Agent. If any
change in any law or regulation or in the interpretation thereof by any
governmental authority charged with the administration or interpretation thereof
shall make it unlawful for any one or more of Co-Lenders to make or maintain
LIBOR Rates with respect to the Principal Balance or any portion thereof or to
fund the Principal Balance or any portion thereof at LIBOR Rates in the London
Interbank Market or to give effect to their respective obligations as
contemplated by this Exhibit, then, upon notice by Agent to Borrowers, the
interest rate applicable to the entire Principal Balance shall be automatically
converted to the Floating Rate, it being agreed that any notice given by Agent
to Borrowers pursuant to this sentence shall, if lawful, be effective insofar as
it pertains to any particular portion of the Principal Balance bearing interest
at a particular LIBOR Rate on the last day of the then existing Interest Period
pertaining to such particular portion of the Principal Balance, or if not
lawful, shall be effective immediately upon being given by Agent to Borrowers,
and that the Floating Rate shall remain in effect thereafter with respect to
such particular portion of the Principal Balance unless and until Agent shall
have determined in good faith (which determination shall be conclusive and
binding upon Borrowers) that the aforesaid circumstances no longer exist,
whereupon the interest rate applicable to such portion of the Principal Balance
shall be converted to a LIBOR Rate determined in the manner hereinabove set
forth in this Exhibit effective as of the first Re-Set Date which occurs ten
(10) Business Days or more after such good faith determination by Agent. If the
interest rate applicable to any particular portion of the Principal Balance is
converted from a LIBOR Rate to the Floating Rate on a date other than a Roll
Over Date in accordance with the provisions of the preceding sentence, Borrowers
shall pay to Agent on demand an amount equal to the prepayment premium, if any,
which would have been due pursuant to the provisions of this Exhibit hereinafter
set forth if the portion of the Principal Balance bearing interest at such LIBOR
Rate was prepaid in full on the date of such conversion.

            7. Borrowers recognize that the cost to Co-Lenders of making or
maintaining LIBOR Rates with respect to the Principal Balance or any portion
thereof may fluctuate and Borrowers agree to pay Agent within ten (10) days
after demand by Agent an additional amount or amounts as Agent shall reasonably
determine will compensate Co-Lenders for actual costs incurred by Co-Lenders in
maintaining LIBOR Rates on the Principal Balance or any portion thereof as a
result of:


                                       B-5
<PAGE>   81
      (i) the imposition after the date of this Agreement of, or changes after
the date of this Agreement in, or the actual maintenance after the date of this
Agreement by any Co-Lender of, reserves in accordance with the reserve
requirements now or hereafter promulgated by the Board of Governors of the
Federal Reserve System of the United States, including, but not limited to, any
reserve on Eurocurrency Liabilities as defined in Regulation D of the Board of
Governors of the Federal Reserve System of the United States at the ratios
provided in such Regulation from time to time, it being agreed that the portion
of the Principal Balance bearing interest at LIBOR Rates from time to time in
accordance with the provisions of this Exhibit shall be deemed to constitute
Eurocurrency Liabilities, as defined by such Regulation; or

     (ii) any change, after the date of this Agreement, in applicable law, rule
or regulation or in the interpretation or administration thereof by any domestic
or foreign governmental authority charged with the interpretation or
administration thereof (whether or not having the force of law) or by any
domestic or foreign court changing the basis of taxation of payments to any
Co-Lender of the Principal Balance or interest on the Principal Balance or any
portion thereof at a LIBOR Rate or any other fees or amounts payable in respect
of the Credit Facility pursuant to the provisions of the Credit Facility
Documents (other than taxes imposed on all or any portion of the overall net
income of any such Co-Lender by the Federal government or by the state or
country of incorporation or domicile of any such Co-Lender or by any political
subdivision or taxing authority of the Federal government or any such state or
country), or imposing, modifying or applying any reserve, special deposit or
similar requirement against assets of, deposits with or for the account of,
credit extended by, or any other acquisition of funds for loans by any such
Co-Lender or imposing on any such Co-Lender or on the London Interbank Market
any other condition affecting the Credit Facility, the Credit Facility Documents
or the portion of the Principal Balance bearing interest at LIBOR Rates so as to
increase the cost to any such Co-Lender of making or maintaining LIBOR Rates
with respect to the Principal Balance or any portion thereof or to reduce the
amount of any sum received or receivable by any such Co-Lender with respect to
the Credit Facility pursuant to the provisions of the Credit Facility Documents
(whether of principal, interest or otherwise), by an amount deemed by Agent in
good faith to be material, but without duplication for payments required under
subparagraph (i) above.

            Any amount or amounts payable by Borrowers to Co-Lenders pursuant to
subparagraph (i) or (ii) above shall be paid by Borrowers to Co-Lenders within
ten (10) days of receipt by Borrowers from Agent of a statement setting forth
the amount or amounts due and the basis for the determination from time to time
of such amount or amounts, which statement shall be conclusive and binding upon
Borrowers absent manifest error. Failure on the part of Co-Lenders to demand
compensation for any increased costs in any Interest Period shall not constitute
a waiver of Co-Lenders' right to demand compensation for any increased costs
incurred during any such Interest Period or in any other subsequent or prior
Interest Period. Failure on the part of Co-Lenders to demand compensation for
any increased costs in any Interest Period shall not constitute a waiver of
Agent's right to demand compensation for any increased costs incurred during any
such Interest Period or in any other subsequent or prior Interest Period,
provided, however, that if Agent shall fail to notify Borrowers of the
occurrence of any event described in subparagraph (i) or (ii) above within one
hundred eighty (180) days after the occurrence of such event, Borrowers'
liability for any increased costs incurred by any such Co-Lender, as the result
of the occurrence of such event shall be limited to increased costs attributable
to the period occurring subsequent to the date upon which Co-Lenders shall
actually notify Borrowers of the occurrence of such event.


                                       B-6
<PAGE>   82
            8. Borrowers shall indemnify each Co-Lender against any loss or
expense that any such Co-Lender may sustain or incur as a consequence of any
failure by Borrowers to take down all or any portion of any advance of the
Credit Facility (including, without limitation, the initial advance of the
Credit Facility) on the date Borrowers requested that such advance be made in
accordance with the provisions of this Agreement or as a consequence of any
default by Borrowers in the payment of any portion of the Principal Balance
bearing interest at a LIBOR Rate, or any part thereof or interest accrued
thereon at a LIBOR Rate, as and when due and payable, or the occurrence of any
Event of Default including, but not limited to, any loss or expense sustained or
incurred by any such Co-Lender in liquidating or reemploying deposits from third
parties acquired to effect or maintain a LIBOR Rate with respect to all or any
portion of the Principal Balance or any advance of the Credit Facility requested
or scheduled to be made pursuant to the provisions of this Agreement. Co-Lenders
shall provide to Borrowers a statement explaining the amount of any such loss or
expense, which statement shall be conclusive and binding upon Borrowers absent
manifest error.

            9. If after the date of this Agreement, Agent shall have determined
that the adoption after the date of this Agreement of any law, rule, regulation
or guideline regarding capital adequacy, or any change therein, or any change in
any of the foregoing or in the interpretation or administration of any of the
foregoing by any domestic or foreign governmental authority, central bank or
comparable agency charged with the interpretation or administration thereof, or
compliance by any Co-Lender (or any lending office of any Co-Lender) or by any
Co-Lender's holding company, as the case may be, with any request or directive
regarding capital adequacy (whether or not having the force of law) of any such
authority, central bank or comparable agency, has or would have the effect of
reducing the rate of return on any Co-Lender's capital or on the capital of any
Co-Lender's holding company, as the case may be, as a consequence of any
Co-Lender's obligations with respect to the Credit Facility under the terms of
the Credit Facility Documents to a level below that which any such Co-Lender or
any such Co-Lender's holding company, as the case may be, could have achieved
but for such adoption, change or compliance (taking into consideration any such
Co-Lender's or any such Co-Lender's holding company's policies, as the case may
be, with respect to capital adequacy) by an amount deemed by Agent to be
material, then from time to time, Borrowers shall pay to Agent such additional
amount or amounts as will compensate any such Co-Lender or any such Co-Lender's
holding company, as the case may be, for such reduction. Any amount or amounts
payable by Borrowers to Co-Lenders in accordance with the provisions of this
paragraph shall be paid by Borrowers to Agent within ten (10) days of receipt by
Borrowers from Agent of a statement setting forth the amount or amounts due and
the basis for the determination from time to time of such amount or amounts,
which statement shall be conclusive and binding upon Borrowers absent manifest
error.

            10. Subject to the following provisions of this paragraph, Borrowers
shall have the right to prepay the Principal Balance in whole, or in part, upon
not less than five (5) Business Days' prior written irrevocable notice to Agent
specifying the intended date of prepayment, which date of prepayment shall not
be more than fifteen (15) days after the date of such notice, and the amount to
be prepaid and upon payment of all interest and other sums then due and payable
pursuant to the provisions of the Credit Facility Documents. The portion of the
Principal Balance specified in any such irrevocable notice of prepayment shall,
notwithstanding anything to the contrary contained in the Credit Facility
Documents, be absolutely and unconditionally due and payable on the date
specified in such notice. No prepayment premium shall be payable if the portion
of the Principal Balance being prepaid is bearing interest on the date of
prepayment at the Floating Rate in accordance with the provisions of paragraph
11 of this Exhibit or otherwise in accordance with the provisions of this
Exhibit, or if such


                                       B-7
<PAGE>   83
prepayment occurs on the Roll Over Date pertaining to the portion of the
Principal Balance being prepaid. If any particular portion of the Principal
Balance being prepaid is bearing interest at a particular LIBOR Rate and such
prepayment does not occur on the Roll Over Date pertaining to the portion of the
Principal Balance being prepaid, Borrowers shall pay to Agent contemporaneously
with such prepayment a prepayment premium equal to the portion of the Principal
Balance being prepaid, multiplied by a per annum interest rate equal to the
difference between the Base LIBOR Rate applicable to the portion of the
Principal Balance being prepaid and the 360-day equivalent interest yield, as
adjusted to reflect interest payments on a monthly basis (hereinafter called the
"Reinvestment Rate"), on any U.S. Government Treasury Obligations selected by
Agent, in its sole and absolute discretion, in an aggregate amount comparable to
the portion of the Principal Balance being prepaid, and with maturities
comparable to the Roll Over Date applicable to the portion of the Principal
Balance being prepaid, calculated over a period of time from and including the
date of prepayment to, but not including, the Roll Over Date applicable to the
portion of the Principal balance being prepaid. If the Base LIBOR Rate
applicable to the portion of the Principal Balance being prepaid is equal to or
less than the Reinvestment Rate no prepayment premium shall be due. No
prepayment premium payable under this paragraph shall in any event or under any
circumstance be deemed or construed to be a penalty. If a portion of the
Principal Balance is bearing interest at a LIBOR Rate or Rates and a portion of
the Principal Balance is bearing interest at the Floating Rate in accordance
with the provisions of this Exhibit on the date of a partial prepayment of the
Principal Balance in accordance with the provisions of this paragraph, such
partial prepayment shall be applied to the respective portions of the Principal
Balance bearing interest at such LIBOR Rate or Rates and the Floating Rate in
such order and manner so as to minimize the prepayment premium due with respect
thereto as calculated pursuant to the provisions of this paragraph. Any payment
of the Principal Balance after the Debt shall have been declared to be
immediately due and payable in accordance with the provisions of the Credit
Facility Documents, or after a foreclosure of one or more of the Mortgages has
commenced as a result of the occurrence of an Event of Default, shall, to the
extent permitted by law, be deemed to be a voluntary prepayment for all purposes
of this paragraph and a prepayment premium calculated pursuant to the provisions
of this paragraph shall be payable with respect thereto based upon the Base
LIBOR Rate or Rates applicable to the Principal Balance immediately prior to
such default, declaration or commencement. Agent shall deliver to Borrowers a
statement setting forth the amount and basis of determination of the prepayment
premium, if any, due in connection with a prepayment of the Principal Balance in
accordance with the provisions of this paragraph, it being agreed that (a) the
calculation of such prepayment premium may be based on any U.S. Government
Treasury Obligations selected by Agent, in its sole and absolute discretion, (b)
Co-Lenders shall not be obligated or required to have actually reinvested the
prepaid portion of the Principal Balance in any such U.S. Government Treasury
Obligations as a condition precedent to Borrowers being obligated to pay a
prepayment premium calculated in accordance with the provisions of this
paragraph, and (c) Borrowers shall not have the right to question the
correctness of any such statement or the method of calculation set forth therein
in the absence of manifest error. Borrowers shall, upon receipt of such
statement and contemporaneously with any such prepayment of the Principal
Balance, remit to Agent the prepayment premium, if any, due in connection
therewith, as calculated pursuant to the provisions of this paragraph.
Co-Lenders shall not be obligated to accept any prepayment of the Principal
Balance unless it is accompanied by the prepayment premium, if any, due in
connection therewith as calculated pursuant to the provisions of this paragraph.
Any partial prepayment of the Principal Balance in accordance with the
provisions of this paragraph shall be in a minimum amount of at least $1,000,000
and shall be in even multiples of $100,000. The provisions of this paragraph
shall be applicable to any prepayment of the Principal Balance in whole or in
part, it being agreed that any payment of the Principal Balance,


                                       B-8
<PAGE>   84
in whole or in part, (i) in connection with sale of any Property in accordance
with the provisions of paragraph 16 of this Agreement, (ii) to maintain
compliance with the Loan to Value Requirement, the Minimum Debt Service Coverage
Ratio, the Supplemental Debt Service Coverage Ratio, the Fixed Charge Coverage
Ratio or the Debt-to-Tangible Net Worth Requirement, (iii) in connection with
any mandatory pay down of the Principal Balance pursuant to paragraph 17 of this
Agreement, or (iv) otherwise pursuant to or as required by the provisions of the
Credit Facility Documents, shall be deemed to be a voluntary prepayment for the
purposes of this paragraph and a prepayment premium calculated pursuant to the
provisions of this paragraph shall be payable with respect thereto.

            11. Borrowers shall have the option upon not less than fifteen (15)
Business Days' prior written notice to Agent given simultaneously and in
conjunction with an irrevocable notice of prepayment given by Borrowers to Payee
pursuant to paragraph 10 of this Exhibit, and provided that such prepayment is
being made in connection with an anticipated sale of a Property pursuant to
paragraph 16 of this Agreement or constitutes a mandatory prepayment of the
Principal Balance pursuant to paragraph 17 of this Agreement, to convert the
interest rate on the portion of the Principal Balance which is to be prepaid, as
set forth in such notice of prepayment, to a Floating Rate effective as of the
Re-Set Date occurring immediately prior to the designated date of prepayment, as
set forth in such notice of prepayment, it being agreed that (i) such Re-Set
Date must be ten (10) Business Days or more after the date of receipt by Agent
from Borrowers of Borrowers's election to exercise such option pursuant to this
paragraph, and (ii) the interest rate applicable to a particular portion of the
Principal Balance may be converted from a particular LIBOR Rate to the Floating
Rate, as of such Re-Set Date, only if such Re-Set Date constitutes the Roll Over
Date pertaining to such LIBOR Rate and such portion of the Principal Balance. If
Borrowers exercises the aforesaid option, the interest rate on the portion of
the Principal Balance with respect to which Borrowers has exercised such option
will automatically convert to and be calculated at the Floating Rate from and
including the Re-Set Date occurring immediately prior to the specified date of
prepayment, as set forth in Borrowers's notice of prepayment, to, but not
including, the earlier to occur of (i) the date upon which such portion of the
Principal Balance is paid in full, or (ii) the first Re-Set Date occurring five
(5) Business Days or more after the designated date of prepayment whereupon the
interest rate on such portion of the Principal Balance (or so much thereof as
may still be outstanding) shall (subject to the provisions of this Exhibit)
thereafter be calculated at a LIBOR Rate determined in accordance with the
provisions of this Exhibit. Nothing contained in the preceding sentence shall be
deemed to qualify, modify or affect in any manner whatsoever the provisions of
paragraph 10 of this Exhibit which provide that the portion of the Principal
Balance specified in any notice of prepayment given by Borrowers to Payee
pursuant to paragraph 10 of this Exhibit shall be absolutely and unconditionally
due and payable on the date designated for such prepayment in such notice.

            12. All sums which may or shall become due and payable by Borrowers
in accordance with the provisions of paragraph 7, 8, 9 or 10 of this Exhibit
shall be evidenced by the Credit Facility Notes, shall be secured by the
Mortgages and shall constitute part of the Debt.


                                       B-9
<PAGE>   85
                                    Exhibit C





                                      NOTE
                           (Revolving Credit Facility)


$______________                                               New York, New York
                                                         As of November 25, 1996


               FOR VALUE RECEIVED, BRANDYWINE REALTY TRUST, a Maryland real
estate investment trust, BRANDYWINE OPERATING PARTNERSHIP, L.P., a Delaware
limited partnership, LC/N HORSHAM LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a Pennsylvania limited
partnership; NICHOLS LANSDALE LIMITED PARTNERSHIP III, a Pennsylvania limited
partnership; NEWTECH III LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania limited partnership;
C/N OAKLANDS LIMITED PARTNERSHIP I, a Pennsylvania limited partnership; FIFTEEN
HORSHAM, L.P., a Pennsylvania limited partnership; C/N LEEDOM LIMITED
PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN LIMITED
PARTNERSHIP III, a Pennsylvania limited partnership; each having an office at
Newtown Square Corporate Campus, 16 Campus Boulevard, Suite 150, Newtown Square,
Pennsylvania (hereinafter collectively referred to as "Maker"), promise to pay
__________________________________, a ____________________ having an office at
____________________, ________, ________ (hereinafter referred to as "Payee") or
order, at such place as may be designated from time to time in writing by Payee,
the principal sum of ________________________________ and 00/100 Dollars
($______________) in lawful money of the United States of America, or so much
thereof as may be advanced and readvanced by Payee to Maker and be outstanding
from time to time in accordance with the provisions of the Credit Agreement,
with interest thereon from and including the date of this Note to, but not
including, the date this Note is paid in full, calculated in the manner
hereinafter set forth, as follows:

               (i) interest on the Principal Balance calculated in the manner
         set forth in the Credit Agreement shall be due and payable in Federal
         funds or other immediately available funds on each Re-Set Date during
         the term of this Note and otherwise in accordance with the provisions
         of the Credit Agreement; and

               (ii) the entire Principal Balance, together with all interest
         accrued and unpaid thereon calculated in the manner set forth in the
         Credit Agreement and all other sums due under this Note, shall be due
         and payable on the Maturity Date and otherwise in accordance with the
         provisions of the Credit Agreement.

               1. The term "Credit Agreement" as used in this Note means a
certain Revolving Credit Agreement dated as of the date hereof entered into
among Smith Barney Mortgage Capital Group, Inc., NationsBank, N.A., in its
individual capacity, Maker and NationsBank, N.A., acting in its capacity as
administrative and documentation agent for the Credit Facility, and pursuant to
the provisions of which the Credit Facility is being extended by Co-Lenders to
Maker. This Note constitutes one of the Credit Facility Notes which have been
executed and delivered by Maker to Co-Lender in accordance with the Credit
Agreement and which together evidence the Credit Facility. All other capitalized
terms used in this Note shall, unless otherwise defined in this Note, have the
meaning given to such term in the Credit Agreement.
<PAGE>   86
               2. It is hereby expressly agreed that the entire Debt shall
become immediately due and payable at the option of Co-Lenders on the happening
of any Event of Default.

               3. All of the terms, covenants and provisions contained in the
Credit Agreement and the other Credit Facility Documents which are to be kept
and performed by Maker are hereby made part of this Note to the same extent and
with the same force and effect as if they were fully set forth herein. Maker
agrees to perform and comply with each of the terms, covenants and provisions
contained in this Note, the Credit Agreement and the other Credit Facility
Documents on the part of Maker to be observed and performed.

               4. If any installment of interest payable under this Note is not
paid when due, Maker shall pay to Administrative Agent upon demand an amount
equal to four percent (4%) of such unpaid installment as a late payment charge.

               5. In addition to any late payment charge which may be due under
this Note, if the Debt is declared immediately due and payable pursuant to the
provisions of the Credit Facility Documents, or if the Debt is not paid in full
on the Maturity Date, Maker shall thereafter pay interest on the then entire
outstanding Principal Balance from the date of such declaration or the Maturity
Date, as the case may be, until the date the Principal Balance is paid in full,
at the Default Rate. In addition, if an Event of Default shall occur, the
Principal Balance shall, from and including the date upon which such Event of
Default has occurred and for so long as such Event of Default continues and
without further act or instrument and without the necessity of any further or
prior notice by Payee or Agent to Maker, bear interest at the Default Rate
irrespective of whether the Debt shall have been declared to be immediately due
and payable as the result of the occurrence of such Event of Default.

               6. Maker hereby waives presentment and demand for payment, notice
of dishonor, protest and notice of protest of this Note. If any payment under
this Note is not made when due, Maker agrees to pay all costs of collection when
incurred, including reasonable attorneys' fees (which costs shall be added to
the amount due under this Note and shall be receivable therewith). No release of
any security for the payment of this Note or extension of time for payment of
this Note, or any installment hereof, and no alteration, amendment or waiver of
any provision of this Note or any of the other Credit Facility Documents made by
agreement between or among Co-Lenders, Agent and/or Payee and any other person
or party shall release, discharge, modify, change or affect the liability of
Maker under this Note or any of the other Credit Facility Documents.

               7. This Note is subject to the express condition that at no time
shall Maker be obligated or required to pay interest on the Principal Balance at
a rate which could subject Payee to either civil or criminal liability as a
result of being in excess of the maximum rate which Maker is permitted by law to
contract or agree to pay. If by the terms of this Note Maker is at any time
required or obligated to pay interest on the Principal Balance at a rate in
excess of such maximum rate, the rate of interest under this Note shall be
deemed to be immediately reduced to such maximum rate and interest payable
hereunder shall be computed at such maximum rate and the portion of all prior
interest payments in excess of such maximum rate shall be applied and shall be
deemed to have been payments in reduction of the Principal Balance.

               8. If Maker consists of more than one person or party, the
obligations and liabilities of each such person or party hereunder shall be
joint and several.


                                      -2-
<PAGE>   87
               9. Except as otherwise specifically provided to the contrary in
the Credit Facility Documents, this Note is secured on a pari passu basis with
the other Credit Facility Notes by the Mortgages and the other Credit Facility
Documents.

               10. The terms of this Note shall be governed by and construed
under the laws of the State of New York.

               11. This Note may only be modified, amended, changed or
terminated by an agreement in writing signed by Payee, Agent and Maker. No
waiver of any term, covenant or provision of this Note shall be effective unless
given in writing by Payee and Agent and if so given by Payee and Agent shall
only be effective in the specific instance in which given.

               12. Maker acknowledges that this Note and Maker's obligations
under this Note are and shall at all times continue to be absolute and
unconditional in all respects, and shall at all times be valid and enforceable
irrespective of any other agreements or circumstances of any nature whatsoever
which might otherwise constitute a defense (other than a defense of payment) to
this Note and the obligations of Maker under this Note or the obligations of any
other person or party relating to this Note or the obligations of Maker
hereunder or otherwise with respect to the Credit Facility. Maker absolutely,
unconditionally and irrevocably waives any and all right to assert any defense,
setoff, counterclaim (other than a compulsory counterclaim in a court of
competent jurisdiction) or crossclaim of any nature whatsoever with respect to
this Note or the obligations of Maker under this Note or the obligations of any
other person or party relating to this Note or the obligations of Maker
hereunder or otherwise with respect to the Credit Facility in any action, case
or proceeding brought by Payee or Agent to collect the Debt, or any portion
thereof, or to enforce, foreclose and realize upon the liens and security
interests created by the Mortgages and the other Credit Facility Documents
(provided, however, that the foregoing provisions of this sentence shall not be
deemed a waiver of the right of Maker to assert any compulsory counterclaim in
any such action, case or proceeding brought by Payee or Agent in any state court
if such counterclaim is compelled under local law or rule or procedure, or in
any such action, case or proceeding brought by Payee or Agent in a court of the
United States, nor shall the foregoing provisions of this sentence be deemed a
waiver of the right of Maker to assert any claim which would otherwise
constitute a defense, setoff, counterclaim or crossclaim of any nature
whatsoever against Payee or Agent in any separate action, case or proceeding
brought by Maker against Payee or Agent). MAKER ACKNOWLEDGES THAT NO ORAL OR
OTHER AGREEMENTS, UNDERSTANDINGS, REPRESENTATIONS OR WARRANTIES EXIST WITH
RESPECT TO THIS NOTE OR WITH RESPECT TO THE OBLIGATIONS OF MAKER UNDER THIS
NOTE, EXCEPT THOSE SPECIFICALLY SET FORTH IN THIS NOTE AND THE OTHER CREDIT
FACILITY DOCUMENTS, AND THAT THIS NOTE AND THE OTHER CREDIT FACILITY DOCUMENTS
SETS FORTH THE ENTIRE AGREEMENT AND UNDERSTANDING OF PAYEE, AGENT, CO-LENDERS
AND MAKER.

               13. No delay on the part of Payee, Agent or Co-Lenders in
exercising any right or remedy under this Note or the other Credit Facility
Documents or failure to exercise the same shall operate as a waiver in whole or
in part of any such right or remedy. No notice to or demand on Maker shall be
deemed to be a waiver of the obligation of Maker or of the right of Payee, Agent
or Co-Lender to take further action without further notice or demand as provided
in this Note and the other Credit Facility Documents.

               14. Maker agrees to submit to personal jurisdiction in the State
of New York in any action, case or proceeding arising out of this Note and, in
furtherance of such agreement, Maker hereby agrees and consents that without
limiting other methods of obtaining jurisdiction, personal jurisdiction over
Maker in any such action, case or proceeding may be obtained within or without
the jurisdiction of any court located in New York and that any process or


                                      -3-
<PAGE>   88
notice of motion or other application to any such court in connection with any
such action, case or proceeding may be served upon Maker by registered or
certified mail to or by personal service at the last known address of Maker,
whether such address be within or without the jurisdiction of any such court.
Maker also agrees that the venue of any litigation arising in connection with
the Debt or in respect of any of the obligations of Maker under this Note shall,
to the extent permitted by law, be in New York County.

               15. Maker (and the undersigned representative of Maker, if any)
represents that Maker has full power, authority and legal right to execute and
deliver this Note and that this Note constitutes a valid and binding obligation
of Maker.

               16. MAKER HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, AND
PAYEE BY ITS ACCEPTANCE OF THIS NOTE IRREVOCABLY AND UNCONDITIONALLY WAIVES, ANY
AND ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, CASE, PROCEEDING, SUIT OR
COUNTERCLAIM ARISING IN CONNECTION WITH, OUT OF OR OTHERWISE RELATING TO THE
CREDIT FACILITY, THIS NOTE, OR THE OTHER CREDIT FACILITY DOCUMENTS.

               17. Whenever used, the singular number shall include the plural,
the plural the singular, and the words "Payee", "Agent", "Co-Lenders", and
"Maker" shall include their respective successors and assigns, provided,
however, that Maker shall in no event or under any circumstance have the right
without obtaining the prior written consent of Co-Lenders to assign or transfer
its obligations under this Note or the other Credit Facility Documents, in whole
or in part, to any other person, party or entity.

               18. No recourse shall be had for any obligation of BRT under this
Note or any of the other Credit Facility Documents or for any claim based
thereon or otherwise in respect thereof, against any past, present or future
trustee, shareholder, officer or employee of BRT, whether by virtue of any
statute or rule of law, or by the enforcement of any assessment or penalty or
otherwise, all such liability being expressly waived and released by Payee and
each other party to this Note and the other Credit Facility Documents.

               IN WITNESS WHEREOF, Maker has duly executed this Note the day and
year first above written.


                                  BRANDYWINE REALTY TRUST

                                  By:    ______________________________
                                         Name:   Gerard H. Sweeney
                                         Title:  President and Chief
                                                 Executive Officer

                                  BRANDYWINE OPERATING PARTNERSHIP, L.P.

                                  By:    Brandywine Realty Trust, a Maryland
                                         real estate investment trust, its
                                         general partner

                                         By:___________________________
                                            Name:   Gerard H. Sweeney
                                            Title:  President and Chief
                                                    Executive Officer


                                      -4-
<PAGE>   89
                            LC/N HORSHAM LIMITED PARTNERSHIP, a
                            Pennsylvania limited partnership

                            By:    Witmer Operating Partnership I,
                                   L.P., a Delaware limited
                                   partnership, its general partner

                                   By:    Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                         By:___________________________
                                             Name:  Gerard H. Sweeney
                                             Title: President and Chief
                                                    Executive Officer

                            LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a
                            Pennsylvania limited partnership

                            By:    Witmer Operating Partnership I,
                                   L.P., a Delaware limited
                                   partnership, its general partner

                                   By:    Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                         By:___________________________
                                             Name:  Gerard H. Sweeney
                                             Title: President and Chief
                                                    Executive Officer

                            NICHOLS LANSDALE LIMITED PARTNERSHIP III,
                            a Pennsylvania limited partnership

                            By:    Witmer Operating Partnership I,
                                   L.P., a Delaware limited
                                   partnership, its general partner

                                   By:    Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                         By:___________________________
                                             Name:  Gerard H. Sweeney
                                             Title: President and Chief
                                                    Executive Officer


                                      -5-
<PAGE>   90
                                NEWTECH III LIMITED PARTNERSHIP, a
                                Pennsylvania limited partnership

                                By:    Witmer Operating Partnership I,
                                       L.P., a Delaware limited
                                       partnership, its general partner

                                       By:    Brandywine Holdings I, Inc., a
                                              Pennsylvania corporation, its
                                              general partner

                                             By:___________________________
                                                 Name:   Gerard H. Sweeney
                                                 Title:  President and Chief
                                                         Executive Officer

                                NEWTECH IV LIMITED PARTNERSHIP, a
                                Pennsylvania limited partnership

                                By:    Witmer Operating Partnership I,
                                       L.P., a Delaware limited
                                       partnership, its general partner

                                       By:    Brandywine Holdings I, Inc., a
                                              Pennsylvania corporation, its
                                              general partner

                                             By:___________________________
                                                 Name:   Gerard H. Sweeney
                                                 Title:  President and Chief
                                                         Executive Officer

                                C/N OAKLANDS LIMITED PARTNERSHIP I, a
                                Pennsylvania limited partnership

                                By:    Witmer Operating Partnership I,
                                       L.P., a Delaware limited
                                       partnership, its general partner

                                       By:    Brandywine Holdings I, Inc., a
                                              Pennsylvania corporation, its
                                              general partner

                                             By:___________________________
                                                 Name:   Gerard H. Sweeney
                                                 Title:  President and Chief
                                                         Executive Officer


                                      -6-
<PAGE>   91
                               FIFTEEN HORSHAM, L.P., a Pennsylvania
                               limited partnership

                               By:    Witmer Operating Partnership I,
                                      L.P., a Delaware limited
                                      partnership, its general partner

                                      By:    Brandywine Holdings I, Inc., a
                                             Pennsylvania corporation, its
                                             general partner

                                            By:___________________________
                                                Name:   Gerard H. Sweeney
                                                Title:  President and Chief
                                                        Executive Officer

                               C/N LEEDOM LIMITED PARTNERSHIP II, a
                               Pennsylvania limited partnership

                               By:    Brandywine Operating Partnership,
                                      L.P., a Delaware limited
                                      partnership, its general partner

                                      By:    Brandywine Realty Trust, a
                                             Maryland real estate
                                             investment trust, its general
                                             partner

                                             By:___________________________
                                                Name:   Gerard H. Sweeney
                                                Title:  President and Chief
                                                        Executive Officer

                               C/N IRON RUN LIMITED PARTNERSHIP III, a
                               Pennsylvania limited partnership

                               By:    Brandywine Operating Partnership,
                                      L.P., a Delaware limited
                                      partnership, its general partner

                                      By:    Brandywine Realty Trust, a
                                             Maryland real estate
                                             investment trust, its general
                                             partner

                                             By:___________________________
                                                Name:   Gerard H. Sweeney
                                                Title:  President and Chief
                                                        Executive Officer


                                        -7-
<PAGE>   92
                                    EXHIBIT D

              (Form of Request for Advance under Credit Facility)*


                                    (No. __)

                  Reference is hereby made to a certain Revolving Credit
Agreement (the "Credit Agreement") dated as of _________________, 1996, entered
into among SMITH BARNEY MORTGAGE CAPITAL GROUP, INC.; NATIONSBANK, N.A.; acting
in its individual capacity; BRANDYWINE REALTY TRUST; BRANDYWINE OPERATING
PARTNERSHIP, L.P.; LC/N HORSHAM LIMITED PARTNERSHIP; LC/N KEITH VALLEY LIMITED
PARTNERSHIP I; NICHOLS LANSDALE LIMITED PARTNERSHIP III; NEWTECH III LIMITED
PARTNERSHIP; NEWTECH IV LIMITED PARTNERSHIP; C/N OAKLANDS LIMITED PARTNERSHIP I;
FIFTEEN HORSHAM, L.P.; C/N LEEDOM LIMITED PARTNERSHIP II; C/N IRON RUN LIMITED
PARTNERSHIP III; LC/N HORSHAM LIMITED PARTNERSHIP; LC/N KEITH VALLEY LIMITED
PARTNERSHIP I; NICHOLS LANSDALE LIMITED PARTNERSHIP III; NEWTECH III LIMITED
PARTNERSHIP; NEWTECH IV LIMITED PARTNERSHIP; C/N OAKLANDS LIMITED PARTNERSHIP I;
FIFTEEN HORSHAM, L.P.; C/N LEEDOM LIMITED PARTNERSHIP II; C/N IRON RUN LIMITED
PARTNERSHIP III; and NATIONSBANK, N.A. acting in its capacity as administrative
and documentation agent.

                  Pursuant to the provisions of paragraphs 9 and 10 of the
Credit Agreement, BRT and BOP hereby certify to and request of Agent as follows:

1.             Borrowers are entitled to and hereby requests Agent to make an
               advance under the Credit Facility in the amount of $____________.

2.             The requested date of the advance is_________________________.

3.             The Interest Period applicable to the advance is______________.

4.             The proceeds of such advance are to be used for_______________,
               which is a permitted purpose under paragraph 8 of the Credit
               Agreement.

5.             This request for an advance is made pursuant to and in accordance
               with the provisions of the Credit Agreement.

6.             The principal amount outstanding under the Credit Facility on the
               date hereof, prior to any advance in response to this request, is
               $______________________.

7.             All of the affirmative and negative covenants and all of the
               representations and warranties contained in the Credit Agreement
               and the other Credit Facility Documents, and all of the other
               terms, covenants and conditions contained in the Credit Facility
               Documents (including, without limitation, those set forth in
               paragraphs 22 and 23 of the Credit Agreement) continue to be true
               and correct and continue to be complied with on the date hereof,
               and will continue to be true and correct and will continue to be
               complied with as of the date of, and subsequent to, the requested
               advance.

8.             No default or Event of Default has occurred or is continuing 
               under the Credit Facility Documents.

--------
*       All terms used in this Request for Advance shall have the meanings given
        to such terms in the Credit Agreement.


                                       D-1
<PAGE>   93
9.             There has been no material adverse change in the financial
               condition of any Borrower or Guarantor since the date of the last
               financial statements delivered to Co-Lenders pursuant to the
               Credit Agreement.

10.            All of the other terms and conditions set forth in the Credit
               Agreement and the other Credit Facility Documents pertaining to
               advances of the Credit Facility have been satisfied.

11.            All items which Borrowers is required to furnish to Agent and
               Agent pursuant to the Credit Agreement accompany this request.

12.            The undersigned is an authorized signatory of BRT, individually
               and acting in its capacity as the sole general partner of BOP.

13.            No recourse shall be had for any obligation of BRT under this
               Request for Advance or under any of the other Credit Facility
               Documents or for any claim based thereon or otherwise in respect
               thereof, against any past, present or future trustee, 
               shareholder, officer or employee of BRT whether by virtue of any 
               statute or rule of law, or by the enforcement of any assessment 
               or penalty or otherwise, all such liability being expressly  
               waived and released by each party to this Request for Advance and
               to the other Credit Facility Documents.


Dated:___________________, 199_

                                BRANDYWINE REALTY TRUST, a Maryland real
                                estate trust

                                By:__________________________
                                   Name:   Gerard H. Sweeney
                                   Title:  President and Chief
                                           Executive Officer

                                BRANDYWINE OPERATING PARTNERSHIP, L.P.

                                By:    Brandywine Realty Trust, a Maryland
                                       real estate trust, its general
                                       partner

                                       By:______________________
                                          Name:   Gerard H. Sweeney
                                          Title:  President and Chief
                                                  Executive Officer

                                LC/N HORSHAM LIMITED PARTNERSHIP, a
                                Pennsylvania limited partnership

                                By:    Witmer Operating Partnership I,
                                       L.P., a Delaware limited
                                       partnership, its general partner

                                       By:  Brandywine Holdings I, Inc., a
                                            Pennsylvania corporation, its
                                            general partner

                                             By:___________________________
                                                 Name:   Gerard H. Sweeney
                                                 Title:  President and Chief
                                                         Executive Officer


                                       D-2
<PAGE>   94
                                 LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a
                                 Pennsylvania limited partnership

                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer

                                 NICHOLS LANSDALE LIMITED PARTNERSHIP III,
                                 a Pennsylvania limited partnership

                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer

                                 NEWTECH III LIMITED PARTNERSHIP, a
                                 Pennsylvania limited partnership

                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer


                                       D-3
<PAGE>   95
                                 NEWTECH IV LIMITED PARTNERSHIP, a
                                 Pennsylvania limited partnership

                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer

                                 C/N OAKLANDS LIMITED PARTNERSHIP I, a
                                 Pennsylvania limited partnership

                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer

                                 FIFTEEN HORSHAM, L.P., a Pennsylvania
                                 limited partnership
 
                                 By:    Witmer Operating Partnership I,
                                        L.P., a Delaware limited
                                        partnership, its general partner

                                        By:    Brandywine Holdings I, Inc., a
                                               Pennsylvania corporation, its
                                               general partner

                                               By:___________________________
                                                  Name:   Gerard H. Sweeney
                                                  Title:  President and Chief
                                                          Executive Officer


                                       D-4
<PAGE>   96
                                  C/N LEEDOM LIMITED PARTNERSHIP II, a
                                  Pennsylvania limited partnership

                                  By:    Brandywine Operating Partnership,
                                         L.P., a Delaware limited
                                         partnership, its general partner

                                         By:    Brandywine Realty Trust, a
                                                Maryland real estate
                                                investment trust, its general
                                                partner

                                                By:___________________________
                                                   Name:   Gerard H. Sweeney
                                                   Title:  President and Chief
                                                           Executive Officer

                                  C/N IRON RUN LIMITED PARTNERSHIP III, a
                                  Pennsylvania limited partnership

                                  By:    Brandywine Operating Partnership,
                                         L.P., a Delaware limited
                                         partnership, its general partner

                                         By:    Brandywine Realty Trust, a
                                                Maryland real estate
                                                investment trust, its general
                                                partner

                                                By:___________________________
                                                   Name:   Gerard H. Sweeney
                                                   Title:  President and Chief
                                                           Executive Officer


                                       D-5
<PAGE>   97
                                    EXHIBIT E


                  1. Prior to the requested date of inclusion of an Additional
Property in the collateral pool for the Credit Facility, Co-Lenders shall have
received the following due diligence materials with respect to such Additional
Property, each of which shall be in form and substance satisfactory in all
respects to Co-Lenders and their counsel:

                           (a) A detailed description of the Additional Property
                  and pertinent market data pertaining to this Additional
                  Property.

                           (b) An up-to-date survey (i.e., sufficiently current
                  to cause the standard survey exception to be deleted from the
                  mortgage title insurance policies described below), which
                  survey shall be prepared by a surveyor acceptable to
                  Co-Lenders and the Title Company and shall be certified to the
                  Title Company and to Co-Lenders.

                           (c) A written commitment of the Title Company to
                  issue a mortgage title insurance policy insuring the lien of
                  the Mortgage as a first lien on the Additional Property for
                  the full amount outstanding from time to time under the Credit
                  Facility, subject only to those exceptions to title as are
                  approved by Co-Lenders and their counsel, and with affirmative
                  insurance on such matters as Co-Lenders or their counsel may
                  require.

                           (d) Executed copies (certified by Borrowers to be
                  true, correct and complete) of the Ground Lease, if any, the
                  REA, if any, and all other agreements of any nature whatsoever
                  affecting or relating to the use, operation or development of
                  the Additional Property. Notwithstanding the foregoing, if
                  final executed copies of any of the foregoing Material
                  Agreements are not available, the most current version of such
                  Agreements shall be furnished to Co-Lenders and all
                  subsequent drafts thereof (blacklined to show all changes made
                  to the draft previously distributed to Co-Lenders) shall be
                  furnished to Co-Lenders as they are available.

                           (e) Copies of all Leases affecting the Additional
                  Properties and a certified rent roll for the Additional
                  Properties.

                           (f) Evidence of compliance with all zoning,
                  environmental and other laws, ordinances, rules, regulations
                  and restrictions affecting the Additional Property and the
                  operation and use of the Additional Property. Co-Lenders
                  acknowledge that, in some jurisdictions, public officials will
                  not issue comfort letters with respect to zoning laws and,
                  with respect to such jurisdictions, Co-Lenders will accept a
                  certification of a qualified engineer or other evidence of
                  compliance in form and substance satisfactory to Co-Lenders.

                           (g) Permanent certificate(s) of occupancy (or, if
                  unavailable in the applicable jurisdiction, other evidence
                  satisfactory to Co-Lenders confirming such Additional
                  Property's compliance with applicable building code
                  requirements) and all other licenses, permits and approvals
                  required for the use and operation of the Additional Property,
                  including enclosed parking structures and pools.

                           (h) A detailed structural and physical inspection
                  report prepared by an inspecting engineer designated by
                  Borrowers and


                                       E-1
<PAGE>   98
                  approved by Co-Lenders, which report shall be dated no earlier
                  than six (6) months prior to the date of inclusion of the 
                  Additional Property in the collateral pool for the Credit 
                  Facility (it being agreed that there shall have been no
                  significant capital expenditures or repair at the Additional
                  Property subsequent to the date of such report), shall give a
                  detailed description of the physical condition of such
                  Additional Property shall indicate that such Additional
                  Property is generally in good condition and repair and shall
                  otherwise be in form and substance acceptable to Co-Lenders.
                  Notwithstanding Co-Lenders' approval of the inspecting
                  engineer, Co-Lenders shall not incur any liability as a result
                  of such inspecting engineer's failure to deliver the required
                  satisfactory structural and physical inspection report within
                  the time period required hereby, it being expressly understood
                  that Borrowers acknowledge and assume all risks in connection
                  therewith.

                           (i) Copies of real estate tax bills (or other
                  evidence of the real estate taxes allocable to the Additional
                  Property) for the preceding two (2) years; and copies of
                  utility bills for the preceding two (2) years, provided,
                  however, if Borrowers is unable to obtain copies of such
                  utility bills for the second preceding year from the seller of
                  the Additional Property, copies of utility bills for the
                  immediately preceding year shall be sufficient.

                           (j) In the case of unimproved land, evidence from the
                  utility companies and municipalities servicing the local in
                  which such unimproved land is located that water, sewer,
                  electric, telephone and gas services are and will continue to
                  be available to the improvements to be constructed as part of
                  the Development thereof. The requirement set forth in this
                  subparagraph shall be satisfied as a condition precedent to
                  acquisition of any unimproved land (irrespective of whether
                  constituting part of the collateral pool for the Credit
                  Facility).

                           (k) Evidence of insurance satisfying the requirements
                  of paragraph 30 of the main body of this Agreement.

                           (l) A current (i.e. dated not earlier than six months
                  prior to delivery) phase one level environmental audit report
                  (and such additional reports as may be required by Co-Lenders
                  if any environmental problems are disclosed by the phase one
                  level reports) prepared by qualified environmental
                  consultant(s) or firm(s) designated and retained by Borrowers
                  and approved by Co-Lenders, which reports shall indicate that
                  such Additional Property is free and clear of all Hazardous
                  Materials, and complies in all respects with all Environmental
                  Requirements, and shall otherwise be in form and substance
                  satisfactory in all respects to Co-Lenders. Notwithstanding
                  that the environmental consultant is approved by Co-Lenders,
                  Co-Lenders shall not incur any liability as a result of such
                  environmental consultant's failure to deliver the required
                  satisfactory environmental reports within the time period
                  required hereby, it being expressly understood that Borrowers
                  acknowledge and assume all risks in connection therewith.

                           (m) A comprehensive current written "as is" appraisal
                  report prepared by an MAI appraiser designated by Agent and
                  complying with FIRREA standards. The basis of the appraisal
                  calculation shown in the appraisal report and all other
                  aspects of the appraisal report shall be satisfactory in all
                  respects to Co-Lenders. Notwithstanding Co-Lenders'
                  designation of the MAI


                                       E-2
<PAGE>   99
                  appraiser, Co-Lenders shall not incur any liability as a 
                  result of such appraiser's failure to deliver the required 
                  satisfactory appraisal reports within the time period
                  required hereby, it being expressly understood that Borrowers
                  acknowledge and assume all risks in connection therewith.

                           (n) Copies of unaudited financial reports required by
                  paragraph 28 of this Agreement with respect to the Additional
                  Property for the immediately preceding three (3) years;
                  provided, however, if Borrowers is unable to obtain all such
                  reports from the seller of the Additional Property, copies of
                  such unaudited financial reports for the immediately preceding
                  year shall be sufficient.

                           (o) Detailed operating projections with respect to
                  the Additional Property for not less than three (3) years
                  (including all projected capital expenditures) and two (2)
                  years of historicals, if available.

                           (p) Such other documents, instruments, certificates,
                  opinions, assurances, consents, or approvals as Agent or its
                  counsel may reasonably request or require.

                           (q) If applicable, all Required Due Diligence
                  Materials shall cover any undeveloped land adjacent to the
                  Additional Property being acquired by Borrowers.

                  2. Borrowers shall have executed and delivered, or caused to
be executed and delivered, each of the following documents and/or instruments
with respect to the Additional Property, each of which shall be in form and
substance satisfactory in all respects to Agent and its counsel:

                           (a) Estoppel letters from all parties other than
                  Borrowers to the agreements listed in paragraph 1(d) of this
                  Exhibit E, it being understood that to the extent any such
                  other party is not obligated to provide such estoppel letter
                  pursuant to the terms and provisions of the agreement in
                  question, Borrowers shall use commercially reasonable efforts
                  to obtain such an estoppel letter. Estoppels from such tenants
                  under the Leases as may be required by Co-Lenders.

                           (b) Mortgage given by Borrowers to Co-Lenders
                  (alternatively, if the Additional Property is located in a
                  jurisdiction where there is an outstanding Mortgage of record,
                  and if feasible in the opinion of Co-Lenders, and acceptable
                  to Borrowers, such Mortgage will be modified by an Amendment
                  of Mortgage pursuant to which the lien of such Mortgage will
                  be spread to cover the Additional Property).

                           (c) Assignment of Leases and Rents given by Borrowers
                  to Agent (alternatively, if the Additional Property is located
                  in a jurisdiction where there is an outstanding Assignment of
                  Leases of record, and if feasible in the opinion of
                  Co-Lenders, and acceptable to Borrowers, such Assignment of
                  Leases will be modified by an Amendment of Assignment of
                  Leases pursuant to which the lien of such Assignment of Leases
                  will be spread to cover the Additional Property).

                           (d) UCC Financing Statements.


                                       E-3
<PAGE>   100
                           (e) Such other documents, instruments, certificates,
                  opinions, assurances, consents, or approvals as Agent or its
                  counsel may reasonably request or require.

                  3. Borrowers shall be required to pay all fees, commissions,
costs, charges, taxes and other expenses incurred by Co-Lenders in connection
with the inclusion of an Additional Property in the collateral pool for the
Credit Facility, including but not limited to reasonable fees of Co-Lenders'
counsel, appraisal fees, fees and expenses incurred in accounting review, fees
and charges for surveys, examination of title to the Additional Property and
mortgage title insurance thereon, hazard insurance, mortgage taxes, transfer
taxes and all recording fees and charges.

                  4. Co-Lenders shall not be required to pay any brokerage fees
or commissions or other remuneration of any nature whatsoever arising from the
inclusion of an Additional Property in the collateral pool for the Credit
Facility, and Borrowers agrees, to defend, indemnify, and hold Co-Lenders
harmless from and against any and all such claims in connection therewith and
brought by any party claiming a fee, commission or other compensation from, by,
through or under Borrowers or otherwise as the result of dealings or alleged
dealings with Borrowers.


                                       E-4
<PAGE>   101
                                    EXHIBIT F

                              (Initial Properties)

<TABLE>
<CAPTION>
              Name                   Address                       Owner
<S>                            <C>                              <C>                                                    
        Keith Valley 1         One Progress Avenue,             LC/N Horsham
                               Montgomery County, PA            Limited Partnership

        Keith Valley 7         500 Enterprise Road,             LC/N Keith Valley
                               Montgomery County, PA            Limited Partnership I

        Lansdale 150           1510 Gehman Road, Montgomery     Nichols Lansdale
                               County, PA                       Limited Partnership III

        Newtown 12             16 Campus Boulevard, Delaware    Newtech III
                               County, PA                       Limited Partnership

        Newtown 11             18 Campus Boulevard, Delaware    Newtech IV
                               County, PA                       Limited Partnership

        Oaklands 5             456 Creamery Way, Chester        C/N Oaklands
                               County, PA                       Limited Partnership I

        Horsham 15             1155 Business Center Drive,      Fifteen Horsham, L.P.
                               Montgomery County, PA

        Meeting House 1        2240/50 Butler Pike,             BOP
                               Montgomery County, PA

        Meeting House 2        120 West Germantown Pike,        C/N Leedom
                               Montgomery County, PA            Limited Partnership II

        Meeting House 3        140 West Germantown Pike,        BOP
                               Montgomery County, PA

        Meeting House 4        2260 Butler Pike, Montgomery     BOP
                               County, PA

        Iron Run 3             7248 Tilghman, Lehigh County,    C/N Iron Run
                               PA                               Limited Partnership III

        700 & 800 Horsham      700 & 800 Horsham Business       BOP
        Business Center (2     Center, Montgomery County, PA
        buildings)

        Delaware Corp. Center  Delaware Corp. Center 1, New     BOP
        1                      Castle County, DE

        8000 Lincoln Drive     8000 Lincoln Drive, Burlington   BOP
                               County, NJ

        BCBP 2250              2250 Cabot Boulevard, Bucks      BOP
                               County, PA

        BCBP 2200              2200 Cabot Boulevard, Bucks      BOP
                               County, PA

        BCBP 2260/2270 (2      2260/2270 Cabot Boulevard,       BOP
        buildings)             Bucks County, PA

        BCBP 3000              3000 Cabot Boulevard, Bucks      BOP
                               County, PA

        One/Two/Three          33 Street Road, Bucks County,    BOP
        Greenwood Square (3    PA
        buildings)

        500 N. Gulph Road      500 N. Gulph Road, Montgomery    BOP
                               County, PA
</TABLE>
<PAGE>   102
                                    Exhibit G








--------------------------------------------------------------------------------


                     BRANDYWINE OPERATING PARTNERSHIP, L.P.,
                  a Delaware limited partnership, as Mortgagor

                                       to

                       NATIONSBANK, N.A., not individually
                  but acting in its capacity as administrative
                    and documentation agent for the equal and
                        ratable benefit of the co-lenders
                         described herein, as Mortgagee



                           --------------------------

                                    MORTGAGE

                           --------------------------



                        Dated: As of ______________, 199_

                        Location: ____________________
                                  ____________________
                                  ____________________
                                           



                              RECORD AND RETURN TO:

                              Battle Fowler LLP
                              Park Avenue Tower
                              75 East 55th Street
                              New York, New York 10022

                              Attention: Dean A. Stiffle, Esq.










--------------------------------------------------------------------------------
<PAGE>   103
                                TABLE OF CONTENTS
                                                                           PAGE
                                                                           ----

        1.  Payment of Debt.................................................  3

        2.  Warranty of Title...............................................  3

        3.  Leases and Rents................................................  3

        4.  Notice..........................................................  4

        5.  Sale of Mortgaged Property......................................  5

        6.  Changes in Laws Regarding Taxation..............................  5

        7.  No Credits on Account of the Debt...............................  5

        8.  Documentary Stamps..............................................  5

        ***[9.  The Ground Lease............................................  5

        ***[10.  No Merger of Fee and Leasehold Estates.....................  6

        11.  Events of Default..............................................  7

        12.  Appointment of Receiver........................................  7

        13.  Non-Waiver.....................................................  7

        14.  Construction...................................................  8

        15.  Security Agreement.............................................  8

        16.  Further Acts, etc..............................................  8

        17.  Headings, etc..................................................  9

        18.  Filing of Mortgage, etc........................................  9

        19.  Recovery of Sums Required To Be Paid...........................  9

        20.  Actions, Cases and Proceedings.................................  9

        21.  Inapplicable Provisions........................................  9

        22.  Duplicate Originals............................................  9

        23.  Certain Usage..................................................  9

        24.  Waiver of Notice...............................................  9

        25.  No Oral Change................................................. 10

        26.  Waiver of Statutory Rights..................................... 10

        27.  Credit Agreement............................................... 10

        28.  Revolving Credit Facility...................................... 10

        29.  Binding Effect................................................. 11
<PAGE>   104
                                                                           PAGE
                                                                           ----

        30.  Exculpation.................................................... 11

               ACKNOWLEDGEMENT
               EXHIBIT A            (Definitions)
               EXHIBIT B            (Description of Premises)
               ***[EXHIBIT B-1      (Description of Ground Lease)]***


                                      -ii-
<PAGE>   105
                                    MORTGAGE



                      This Mortgage entered into as of the ___ day of ________,
        199_, between BRANDYWINE OPERATING PARTNERSHIP, L.P., a Delaware limited
        partnership having an office c/o Brandywine Realty Trust, Newtown Square
        Corporate Campus, 16 Campus Boulevard, Suite 150, Newtown Square,
        Pennsylvania (hereinafter referred to as "Mortgagor"); and NATIONSBANK,
        N.A., a national banking association having an office at 8300 Greensboro
        Drive, McLean, Virginia, not individually, but acting in its capacity as
        administrative and documentation agent for the equal and ratable benefit
        of Co-Lenders, pursuant to and in accordance with the terms and
        provisions of the Credit Agreement (NationsBank, N.A., acting in such
        capacity as administrative and documentation agent being hereinafter
        referred to as "Mortgagee").

                              PRELIMINARY STATEMENT

               A. All capitalized terms as used in this Mortgage shall, unless
otherwise defined in this Mortgage, have the meanings given to such terms in
Exhibit A attached hereto.

               ***[B. Mortgagor is the owner of a fee estate in the premises
described in Exhibit B attached hereto (hereinafter referred to as the
"Premises").]***

               ***[B. Mortgagor is the owner of a leasehold estate in the
premises described in Exhibit B attached hereto (the "Premises") under and
pursuant to the provisions of the lease described in Exhibit B-1 attached hereto
(hereinafter referred to as the "Ground Lease").]***

               C. Co-Lenders have on the terms, covenants and provisions set
forth in the Credit Agreement extended to Mortgagor a revolving credit facility
in the principal sum of up to, but not in excess of, $80,000,000 (hereinafter
referred to as the "Credit Facility"), which Credit Facility is evidenced by,
and payable together with interest thereon in accordance with the provisions of,
the Credit Facility Notes.

               ***[D. Co-Lenders were willing to extend the Credit Facility to
Mortgagor only if Mortgagor executed and delivered this Mortgage to Mortgagee,
as administrative and documentation agent for the equal and ratable benefit of
Co-Lenders, as security for the payment of the Debt]***.

               ***[D. Co-Lenders have approved the inclusion of the Premises and
the Improvements as part of the collateral pool for the Credit Facility in
accordance with the provisions of the Credit Agreement, and in connection
therewith, and as consideration therefor, Mortgagor has agreed to execute and
deliver this Mortgage to Mortgagee, as administrative and documentation agent
for the equal and ratable benefit of Co-Lenders, as security for the payment of
the Debt.]***

               E. NOW, THEREFORE, to secure the payment of an indebtedness in
the principal sum of up to, but not in excess of, Eighty Million and 00/100
Dollars ($80,000,000.00), lawful money of the United States of America, or so
much thereof as may be advanced and readvanced and be outstanding from time to
time in accordance with the provisions of the Credit Agreement, to be paid with
interest in accordance with the provisions of the Credit Facility Notes
<PAGE>   106
and the Credit Agreement (said indebtedness, interest and any and all sums which
may or shall become due in accordance with the provisions of the Credit Facility
Documents being hereinafter collectively referred to as the "Debt"), Mortgagor
has mortgaged, given, granted, bargained, sold, aliened, enfeoffed, conveyed,
confirmed and assigned, and by these presents does mortgage, give, grant,
bargain, sell, alien, enfeoff, convey, confirm and assign unto Mortgagee forever
all right, title and interest of Mortgagor now owned, or hereafter acquired, in
and to the following property, rights and interests (such property, rights and
interests being hereinafter collectively referred to as the "Mortgaged
Property"):

               (a) the Premises;

               (b) all buildings and improvements now or hereafter located on 
         the Premises (hereinafter referred collectively to as the
         "Improvements");

               ***[(b)(1) the Ground Lease and the leasehold estate created
         thereunder;]***

               ***[(b)(2) all modifications, extensions and renewals of the 
         Ground Lease and all credits, deposits, options, purchase options,
         privileges and rights of Mortgagor under and in accordance with the
         provisions of the Ground Lease, including, but not limited to, the
         right, if any, to renew or extend the Ground Lease for a succeeding
         term or terms or to acquire fee title to or other interest in all or
         any portion of the Premises or the Improvements;]***

               (c) all of the estate, right, title, claim or demand of any 
         nature whatsoever of Mortgagor, either in law or in equity, in
         possession or expectancy, in and to the Mortgaged Property or any part
         thereof;

               (d) all easements, rights-of-way, gores of land, streets, ways,
         alleys, passages, sewer rights, waters, water courses, water rights and
         powers, and all estates, rights, titles, interests, privileges,
         liberties, tenements, hereditaments, and appurtenances of any nature
         whatsoever, in any way belonging, relating or pertaining to the
         Mortgaged Property (including, without limitation, any and all
         development rights, air rights or similar or comparable rights of any
         nature whatsoever now or hereafter appurtenant to the Premises or now
         or hereafter transferred to the Premises) and all land lying in the bed
         of any street, road or avenue, opened or proposed, in front of or
         adjoining the Premises to the center line thereof;

               (e) all FF&E and the right, title and interest of Mortgagor in
         and to any of the FF&E which may be subject to any security agreements
         (as defined in the Uniform Commercial Code) superior in lien to the
         lien of this Mortgage;

               (f) all awards or payments, including interest thereon, if any, 
         and the right to receive the same, which may be made with respect to
         the Mortgaged Property, whether from the exercise of the right of
         eminent domain (including any transfer made in lieu of the exercise of
         said right), or for any other injury to or decrease in the value of the
         Mortgaged Property;


                                       -2-
<PAGE>   107
               (g) all leases, licenses and other agreements ***[(other than the
         Ground Lease)]*** affecting or relating to the use or occupancy of the
         Mortgaged Property now or hereafter entered into (such leases, licenses
         and other agreements are hereinafter collectively referred to as the
         "Leases") and the right to receive and apply the rents, income,
         revenues, receipts, accounts, accounts receivable, issues and profits
         of or derived from or relating to the Mortgaged Property (hereinafter
         collectively referred to as the "Rents") to the payment of the Debt;

               (h) all proceeds of and any unearned premiums on any insurance
         policies covering the Mortgaged Property, including, without
         limitation, the right (subject to the provisions of the Credit
         Agreement) to receive and apply the proceeds of any insurance,
         judgments, or settlements made in lieu thereof, for damage to the
         Mortgaged Property; and

               (i) the right to appear in and defend any action, case or 
         proceeding brought with respect to the Mortgaged Property and to
         commence any action, case or proceeding to protect the interest of
         Mortgagee in the Mortgaged Property;

               TO HAVE AND TO HOLD the above granted and described Mortgaged
Property unto and to the proper use and benefit of Mortgagee, and the successors
and assigns of Mortgagee, forever;

               AND Mortgagor covenants and agrees with and represents and
warrants to Mortgagee as follows:

               1. PAYMENT OF DEBT. Mortgagor will pay the Debt at the time and
in the manner provided for its payment in the Credit Facility Documents.

               2. WARRANTY OF TITLE. Subject only to those exceptions to title
specifically set forth in the title policy issued or to be issued by the Title
Company to Mortgagee and insuring the lien of this Mortgage, Mortgagor warrants
the title to the Premises, the Improvements, the FF&E ***[, the Ground Lease]***
and the balance of the Mortgaged Property. ***[In addition, Mortgagor represents
and warrants that (i) the Ground Lease is in full force and effect and has not
been modified or amended in any manner whatsoever, (ii) there are no defaults
under the Ground Lease and no event has occurred, which but for the passage of
time, or notice, or both, would constitute a default under the Ground Lease,
(iii) all rents, additional rents and other sums due and payable under the
Ground Lease have been paid in full, and (iv) no action, case or proceeding has
commenced and no notice has been given or received for the purpose of
terminating the Ground Lease.]***

               3. LEASES AND RENTS. Subject to the terms of this paragraph,
Mortgagee waives the right to enter the Mortgaged Property for the purpose of
collecting the Rents, and grants Mortgagor the right to collect the Rents.
Mortgagor shall collect and hold the Rents, or an amount sufficient to discharge
all current sums due on the Debt, in trust for use in payment of the Debt. The
right of Mortgagor to collect the Rents may be revoked by Mortgagee upon the
occurrence of any Event of Default by giving notice of such revocation to
Mortgagor. Following such notice and as long as such Event of Default is
continuing (it being understood that the decision whether or not to accept the
cure of an Event of Default shall be in the sole and absolute discretion of
Mortgagee), Mortgagee may retain and apply the Rents toward payment of the Debt
in such order, priority and proportions as Mortgagee, in its discretion, shall
deem proper, or to the operation, maintenance and repair of the Mortgaged
Property, and irrespective of whether Mortgagee shall have


                                       -3-
<PAGE>   108
commenced a foreclosure of this Mortgage or shall have applied or arranged for
the appointment of a receiver. In addition, Mortgagee shall have the absolute
and unconditional right following the occurrence and during the continuance of
an Event of Default to notify the tenants under the Leases that all Rents should
be paid directly to Mortgagee. In addition to the rights which Mortgagee may
have herein, if an Event of Default shall occur and shall be continuing
Mortgagee, at its option, may require Mortgagor to pay monthly in advance to
Mortgagee, or any receiver appointed to collect the Rents, the fair and
reasonable rental value for the use and occupation of such part of the Mortgaged
Property as may be in possession of Mortgagor. Upon default in any such payment,
Mortgagor will vacate and surrender possession of the Mortgaged Property to
Mortgagee, or to such receiver and, in default thereof, Mortgagor may be evicted
by summary proceedings or otherwise. Nothing contained in this paragraph shall
be construed as imposing on Mortgagee any of the obligations of the landlord
under the Leases.

               4. NOTICE. Any notice, request, demand, statement, authorization,
approval or consent made hereunder shall be in writing and shall be sent by
Federal Express, or other reputable national courier service, or by postage
pre-paid registered or certified mail, return receipt requested, and shall be
deemed given (i) when received at the following addresses if sent by Federal
Express, or other reputable national courier service, and (ii) three (3)
business days after being postmarked and addressed as follows if sent by
registered or certified mail, return receipt requested:

               If to Mortgagor:

                      c/o Brandywine Realty Trust
                      Newtown Square Corporate Campus
                      16 Campus Boulevard, Suite 150
                      Newtown Square, Pennsylvania 19073
                      Attention:  Gerard H. Sweeney
                                  President and Chief Executive Officer

               With a copy to:

                      Pepper, Hamilton & Scheetz
                      3000 Two Logan Square
                      Eighteenth and Arch Streets
                      Philadelphia, Pennsylvania 19103-2799
                      Attention:  Michael H. Friedman, Esq.

               If to Mortgagee:

                      NationsBank, N.A.
                      Real Estate Banking
                      8300 Greensboro Drive
                      McLean, Virginia 22102-3604
                      Attention:  Gary P.F. Carr
                                  Vice President

               With copies to:

                      Cadwalader, Wickersham & Taft
                      201 South College Street - Suite 1510
                      Charlotte, North Carolina 28244
                      Attention:  James P. Carroll, Esq.


                                       -4-
<PAGE>   109
                                    and

                      Battle Fowler LLP
                      Park Avenue Tower
                      75 East 55th Street
                      New York, New York 10022
                      Attention:  Dean A. Stiffle, Esq.

Each party may designate a change of address by notice to the other party, given
at least fifteen (15) days before such change of address is to become effective.

               5. SALE OF MORTGAGED PROPERTY. If this Mortgage is foreclosed,
the Mortgaged Property, or any interest therein, may, at the discretion of
Mortgagee, be sold in one or more parcels or in several interests or portions
and in any order or manner.

               6. CHANGES IN LAWS REGARDING TAXATION. In the event of the
passage after the date of this Mortgage of any law of the State in which the
Premises are located deducting from the value of real property for the purpose
of taxation any lien or encumbrance thereon or changing in any way the laws for
the taxation of mortgages or debts secured by mortgages for state or local
purposes or the manner of the collection of any such taxes, and imposing a tax,
either directly or indirectly, on this Mortgage, the Credit Facility Notes or
the Debt, Mortgagor shall, if permitted by law, pay any tax imposed as a result
of any such law within the statutory period or within thirty (30) days after
demand by Mortgagee, whichever is less, provided, however, that if, in the
opinion of the attorneys for Mortgagee, Mortgagor is not permitted by law to pay
such taxes, Mortgagee shall have the right, at its option, to declare the Debt
due and payable on a date specified in a prior notice to Mortgagor of not less
than sixty (60) days.

               7. NO CREDITS ON ACCOUNT OF THE DEBT. Mortgagor will not claim or
demand or be entitled to any credit or credits on account of the Debt for any
part of the Taxes assessed against the Mortgaged Property or any part thereof
and no deduction shall otherwise be made or claimed from the taxable value of
the Mortgaged Property, or any part thereof, by reason of this Mortgage or the
Debt.

               8. DOCUMENTARY STAMPS. If at any time the United States of
America, any state thereof, or any governmental subdivision of any such state,
shall require revenue or other stamps to be affixed to the Credit Facility Notes
(or any of them), this Mortgage or any of the other Credit Facility Documents,
Mortgagor will, to the extent permitted by law, pay for the same, with interest
and penalties thereon, if any.

               ***[9. THE GROUND LEASE. Mortgagor shall (i) pay all rents,
additional rents and other sums required to be paid by Mortgagor as ground
lessee under and pursuant to the provisions of the Ground Lease, (ii) diligently
perform and observe all of the terms, covenants and conditions of the Ground
Lease on the part of Mortgagor, as ground lessee thereunder, to be performed and
observed, unless such performance or observance shall be waived or not required
in writing by the ground lessor under the Ground Lease, to the end that all
things shall be done which are necessary to keep unimpaired the rights of
Mortgagor, as ground lessee, under the Ground Lease, and (iii) promptly (but in
no event later than five (5) business days after notice thereof) notify
Mortgagee of the giving of any notice by the ground lessor under the Ground
Lease to Mortgagor of any default by Mortgagor in the


                                       -5-
<PAGE>   110
performance or observance of any of the terms, covenants or conditions of the
Ground Lease on the part of Mortgagor, as ground lessee thereunder, to be
performed or observed, and deliver to Mortgagee a true copy of each such notice.
Mortgagor shall not, without the prior consent of Mortgagee, surrender the
leasehold estate created by the Ground Lease or terminate or cancel the Ground
Lease or modify, change, supplement, alter or amend the Ground Lease, in any
respect, either orally or in writing, and Mortgagor hereby assigns to Mortgagee,
as further security for the payment of the Debt and for the performance and
observance of the terms, covenants and conditions of this Mortgage, all of the
rights, privileges and prerogatives of Mortgagor, as ground lessee under the
Ground Lease, to surrender the leasehold estate created by the Ground Lease or
to terminate, cancel, modify, change, supplement, alter or amend the Ground
Lease, and any such surrender of the leasehold estate created by the Ground
Lease or termination, cancellation, modification, change, supplement, alteration
or amendment of the Ground Lease without the prior consent of Mortgagee shall be
void and of no force and effect. If Mortgagor shall default in the performance
or observance of any term, covenant or condition of the Ground Lease on the part
of Mortgagor, as ground lessee thereunder, to be performed or observed, then,
without limiting the generality of the other provisions of this Mortgage, and
without waiving or releasing Mortgagor from any of its obligations hereunder,
Mortgagee shall have the right, but shall be under no obligation, to pay any
sums and to perform any act or take any action as may be appropriate to cause
all of the terms, covenants and conditions of the Ground Lease on the part of
Mortgagor, as ground lessee thereunder, to be performed or observed to be
promptly performed or observed on behalf of Mortgagor, to the end that the
rights of Mortgagor in, to and under the Ground Lease shall be kept unimpaired
and free from default, and Mortgagor shall upon demand of Mortgagee reimburse
Mortgagee for all sums so paid by Mortgagee and for all expenses (including,
reasonable attorneys fees) actually incurred by Mortgagee in taking any such
action, together with interest thereon at the Default Rate. If Mortgagee shall
make any payment or perform any act or take any action in accordance with the
preceding sentence, Mortgagee will notify Mortgagor of the making of any such
payment, the performance of any such act, or the taking of any such action. In
any such event, Mortgagee its agents and employees shall have, and are hereby
granted, the right to enter upon the Mortgaged Property at any time and from
time to time for the purpose of taking any such action. If the ground lessor
under the Ground Lease shall deliver to Mortgagee a copy of any notice of
default sent by said ground lessor to Mortgagor, as ground lessee under the
Ground Lease, such notice shall constitute full protection to Mortgagee for any
action taken or omitted to be taken by Mortgagee, in good faith, in reliance
thereon. Mortgagor shall, from time to time, use commercially reasonable best
efforts to obtain from the ground lessor under the Ground Lease such
certificates of estoppel with respect to compliance by Mortgagor with the terms
of the Ground Lease as may be requested by Mortgagee, to the extent the ground
lessor is obligated to provide such certificates of estoppel pursuant to the
terms and provisions of the Ground Lease. Mortgagor shall exercise each
individual option, if any, to extend or renew the term of the Ground Lease upon
demand by Mortgagee made at any time within one (1) year of the last day upon
which any such option may be exercised, and Mortgagor hereby expressly
authorizes and appoints Mortgagee its attorney-in-fact to exercise, either
jointly or individually, any such option in the name of and upon behalf of
Mortgagor, which power of attorney shall be irrevocable and shall be deemed to
be coupled with an interest.]***

               ***[10. NO MERGER OF FEE AND LEASEHOLD ESTATES. So long as any
portion of the Debt shall remain unpaid, unless Mortgagee shall otherwise
consent, the fee title to the Premises and the leasehold estate therein


                                       -6-
<PAGE>   111
created pursuant to the provisions of the Ground Lease shall not merge, but
shall always be kept separate and distinct, notwithstanding the union of such
estates in Mortgagor or in any other person, by purchase, operation of law or
otherwise. If Mortgagee shall acquire the fee title to the Premises and the
leasehold estate therein created pursuant to the provisions of the Ground Lease,
by foreclosure of this Mortgage or otherwise, such estates shall not merge as a
result of such acquisition and shall remain separate and distinct for all
purposes after such acquisition unless and until Mortgagee shall elect to merge
such estates.]***

               11. EVENTS OF DEFAULT. The Debt shall become due at the option of
Mortgagee upon the occurrence of any one or more of the Events of Default.

               12. APPOINTMENT OF RECEIVER. Mortgagee, in any action to
foreclose this Mortgage or upon the actual or threatened waste to any part of
the Mortgaged Property or upon the occurrence of any Event of Default, shall be
at liberty, without notice, to apply for the appointment of a receiver of the
Rents, and shall be entitled to the appointment of such receiver as a matter of
right, without regard to the value of the Mortgaged Property as security for the
Debt, or the solvency or insolvency of any person then liable for the payment of
the Debt.

               13. NON-WAIVER. The failure of Mortgagee to insist upon strict
performance of any term of this Mortgage shall not be deemed to be a waiver of
any term of this Mortgage. Mortgagor shall not be relieved of Mortgagor's
obligation to pay the Debt at the time and in the manner provided for its
payment in the Credit Facility Documents by reason of (i) failure of Mortgagee
to comply with any request of Mortgagor to take any action to foreclose this
Mortgage or any other mortgage or deed of trust securing the Debt or any portion
thereof or otherwise enforce any of the provisions of this Mortgage or any of
the other Credit Facility Documents, (ii) the release, regardless of
consideration, of the whole or any part of the Mortgaged Property or any other
security for the Debt, or (iii) any agreement or stipulation between Mortgagee
and any subsequent owner or owners of the Mortgaged Property or other person
extending the time of payment or otherwise modifying or supplementing the terms
of the Credit Facility Documents without first having obtained the consent of
Mortgagor, and in the latter event, Mortgagor shall continue to be obligated to
pay the Debt at the times and in the manner provided in the Credit Facility
Documents, as so extended, modified and supplemented, unless expressly released
and discharged from such obligation by Mortgagee in writing. Regardless of
consideration, and without the necessity for any notice to or consent by the
holder of any subordinate lien, encumbrance, right, title or interest in or to
the Mortgaged Property, Mortgagee may release any person at any time liable for
the payment of the Debt or any portion thereof or any part of the security held
for the Debt and may extend the time of payment of the Debt or otherwise modify
the terms of the Credit Facility Documents, including, without limitation, a
modification of the interest rate payable on the Principal Balance of the Credit
Facility Notes, without in any manner impairing or affecting this Mortgage or
the lien thereof or the priority of this Mortgage, as so extended and modified,
as security for the Debt over any such subordinate lien, encumbrance, right,
title or interest. Mortgagee may resort for the payment of the Debt to any other
security held by Mortgagee in such order and manner as Mortgagee, in its
discretion, may elect. Mortgagee may take action to recover the Debt, or any
portion thereof, or to enforce any covenant hereof without prejudice to the
right of Mortgagee thereafter to foreclose this Mortgage. Mortgagee shall not be
limited exclusively to the rights and remedies herein stated but shall be
entitled to every additional right and remedy set forth in the Credit Facility


                                       -7-
<PAGE>   112
Documents or now or hereafter afforded by law. The rights of Mortgagee under
this Mortgage and the other Credit Facility Documents shall be separate,
distinct and cumulative and none shall be given effect to the exclusion of the
others. No act of Mortgagee shall be construed as an election to proceed under
any one provision of this Mortgage or of the other Credit Facility Documents to
the exclusion of any other provision set forth in this Mortgage or the other
Credit Facility Documents.

               14. CONSTRUCTION. The terms of this Mortgage shall be construed
in accordance with the laws of the State in which the Premises are located.

               15. SECURITY AGREEMENT. This Mortgage constitutes both a real
property mortgage and a "security agreement", within the meaning of the Uniform
Commercial Code, and the Mortgaged Property includes both real and personal
property and all other rights and interest, whether tangible or intangible in
nature, of Mortgagor in the Mortgaged Property. Mortgagor by executing and
delivering this Mortgage has granted to Mortgagee, as security for the Debt, a
security interest in the Mortgaged Property, including, without limitation,
FF&E. If an Event of Default shall occur, Mortgagee, in addition to any other
rights and remedies which it may have, shall have and may exercise immediately
and without demand any and all rights and remedies granted to a secured party
upon default under the Uniform Commercial Code, including, without limiting the
generality of the foregoing, the right to take possession of the FF&E or any
part thereof, and to take such other measures as Mortgagee may deem necessary
for the care, protection and preservation of the FF&E. Mortgagor shall pay to
Mortgagee on demand any and all expenses (including reasonable attorneys' fees)
actually incurred or paid by Mortgagee in protecting its interest in the FF&E
and in enforcing its rights hereunder with respect to the FF&E. Any notice of
sale, disposition or other intended action by Mortgagee with respect to the FF&E
sent to Mortgagor in accordance with the provisions of this Mortgage at least
seven (7) business days prior to the date of any such sale, disposition or other
action, shall constitute reasonable notice to Mortgagor (except in the case of
FF&E which is perishable or is of a type customarily sold on a recognized
market, in which case such seven (7) business days' notice shall not be
required), and the method of sale or disposition or other intended action set
forth or specified in such notice shall conclusively be deemed to be
commercially reasonable within the meaning of the Uniform Commercial Code unless
objected to in writing by Mortgagor within five (5) days after receipt by
Mortgagor of such notice. The proceeds of any sale or disposition of the FF&E,
or any part thereof, may be applied by Mortgagee to the payment of the Debt in
such order, priority and proportions as Mortgagee in its discretion shall deem
proper.

               16. FURTHER ACTS, ETC. Mortgagor will, at the cost of Mortgagor,
and without expense to Mortgagee, do, execute, acknowledge and deliver all and
every such further acts, deeds, conveyances, mortgages, assignments, notices of
assignments, transfers and assurances as Mortgagee shall, from time to time,
require for the better assuring, conveying, assigning, transferring and
confirming unto Mortgagee the property and rights hereby mortgaged or intended
now or hereafter so to be, or which Mortgagor may be or may hereafter become
bound to convey or assign to Mortgagee, or for carrying out the intention or
facilitating the performance of the terms of this Mortgage or for filing,
registering or recording this Mortgage and, on demand, will execute and deliver
and hereby authorizes Mortgagee to execute in the name of Mortgagor to the
extent Mortgagee may lawfully do so, one or more financing statements, chattel
mortgages or comparable security instruments, to evidence more effectively the
lien hereof upon the Mortgaged Property.


                                       -8-
<PAGE>   113
               17. HEADINGS, ETC. The headings, titles and captions of various
paragraphs of this Mortgage are for convenience of reference only and are not to
be construed as defining or limiting, in any way, the scope or intent of the
provisions hereof.

               18. FILING OF MORTGAGE, ETC. Mortgagor forthwith upon the
execution and delivery of this Mortgage and thereafter, from time to time, will
cause this Mortgage, and any security instrument creating a lien or evidencing
the lien hereof upon the Mortgaged Property and each instrument of further
assurance to be filed, registered or recorded in such manner and in such places
as may be required by any present or future law in order to publish notice of
and fully to protect, preserve and perfect the lien hereof upon, and the
interest of Mortgagee in, the Mortgaged Property. Mortgagor will pay all filing,
registration and recording fees, and all expenses incident to the preparation,
execution and acknowledgement of this Mortgage, any mortgage supplemental
hereto, any security instrument with respect to the Mortgaged Property, and any
instrument of further assurance, and all Federal, state, county and municipal
taxes, duties, imposts, assessments and charges arising out of or in connection
with the execution and delivery of this Mortgage, any mortgage supplemental
hereto, any security instrument with respect to the Mortgaged Property or any
instrument of further assurance. Mortgagor shall hold harmless and indemnify
Mortgagee, its successors and assigns, against any liability incurred by reason
of the imposition of any tax on the making and recording of this Mortgage.

               19. RECOVERY OF SUMS REQUIRED TO BE PAID. Mortgagee shall have
the right from time to time to take action to recover any sum or sums which
constitute a part of the Debt as the same become due, without regard to whether
or not the balance of the Debt shall be due, and without prejudice to the right
of Mortgagee thereafter to bring an action of foreclosure, or any other action,
for a default or defaults by Mortgagor existing at the time such earlier action
was commenced.

               20. ACTIONS, CASES AND PROCEEDINGS. Mortgagee shall have the
right to appear in and defend any action, case or proceeding brought with
respect to the Mortgaged Property and to bring any action, case or proceeding,
which Mortgagee, in its discretion, feels should be brought to protect its
interest in the Mortgaged Property.

               21. INAPPLICABLE PROVISIONS. If any term, covenant or condition
of this Mortgage shall be held to be invalid, illegal or unenforceable in any
respect, this Mortgage shall be construed without such provision.

               22. DUPLICATE ORIGINALS. This Mortgage may be executed in any
number of duplicate originals and each such duplicate original shall be deemed
to constitute but one and the same instrument.

               23. CERTAIN USAGE. Unless the context clearly indicates a
contrary intent or unless otherwise specifically provided herein, words used in
this Mortgage shall be used interchangeably in singular or plural form. Whenever
the context may require, any pronouns used herein shall include the
corresponding masculine, feminine or neuter forms, and the singular forms of
nouns and pronouns shall include the plural and vice versa.

               24. WAIVER OF NOTICE. Mortgagor shall not be entitled to any
notices of any nature whatsoever from Mortgagee except with respect to matters
for which this Mortgage specifically and expressly provides for the giving of
notice by Mortgagee to Mortgagor, and Mortgagor (to the full extent it may


                                       -9-
<PAGE>   114
lawfully do so) hereby expressly waives the right to receive any notice from
Mortgagee with respect to any matter for which this Mortgage does not
specifically and expressly provide for the giving of notice by Mortgagee to
Mortgagor.

               25. NO ORAL CHANGE. This Mortgage may only be modified, amended
or changed by an agreement in writing signed by Mortgagor and Mortgagee, and may
only be released, discharged or satisfied of record by an agreement in writing
signed by Mortgagee. No waiver of any term, covenant or provision of this
Mortgage shall be effective unless given in writing by Mortgagee and if so given
by Mortgagee shall only be effective in the specific instance in which given.

               26. WAIVER OF STATUTORY RIGHTS. Mortgagor shall not and will not
apply for or avail itself of any appraisement, valuation, stay, extension or
exemption laws, or any so-called "Moratorium Laws", now existing or hereafter
enacted, in order to prevent or hinder the enforcement or foreclosure of this
Mortgage, but hereby waives the benefit of such laws to the full extent that
Mortgagor may do so under applicable law. Mortgagor for itself and all who may
claim through or under it waives any and all right to have the property and
estates comprising the Mortgaged Property marshalled upon any foreclosure of the
lien of this Mortgage and agrees that any court having jurisdiction to foreclose
such lien may order the Mortgaged Property sold as an entirety. Mortgagor hereby
waives for itself and all who may claim through or under it, and to the full
extent Mortgagor may do so under applicable law, any and all rights of
redemption from sale under any order or decree of foreclosure of this Mortgage
or granted under any statute now existing or hereafter enacted.

               27. CREDIT AGREEMENT. This Mortgage is subject to all of the
terms, covenants and conditions of the Credit Agreement, which Credit Agreement
and all of the terms, covenants and conditions thereof are by this reference
incorporated herein with the same force and effect as if fully set forth herein.
The proceeds of the Credit Facility secured hereby are to be advanced and
readvanced by Mortgagee to Mortgagor in accordance with the provisions of the
Credit Agreement. Mortgagor shall observe and perform all of the terms,
covenants and conditions of the Credit Agreement on Mortgagor's part to be
observed or performed. All advances made and all indebtedness arising and
accruing under the Credit Agreement from time to time shall constitute part of
the Debt and shall be secured hereby.

               28. REVOLVING CREDIT FACILITY. The Credit Facility is intended to
be a revolving credit facility. Mortgagor shall have the right upon compliance
with the conditions of the Credit Agreement and the other Credit Facility
Documents which pertain to the making of advances under the Credit Facility
(including, without limitation, the requirement that all advances be evidenced
and secured by the Credit Facility Documents and insured under acceptable title
insurance policies) to obtain readvances of amounts from time to time applied
(whether on a mandatory or voluntary basis) in reduction of the outstanding
Principal Balance of the Credit Facility pursuant to the provisions of the
Credit Agreement, or otherwise permitted to be made in accordance with the
provisions of the Credit Agreement or the other Credit Facility Documents
(including, without limitation, any portion of the outstanding Principal Balance
of the Credit Facility which is prepaid in accordance with the provisions of the
Credit Facility Notes and the Credit Agreement).


                                      -10-
<PAGE>   115
               29. BINDING EFFECT. The terms, covenants and provisions of this
Mortgage shall be binding on and shall inure to the benefit of Mortgagor,
Mortgagee, and their respective successors and assigns.

               30. EXCULPATION. No recourse shall be had for any obligation of
BRT under this Mortgage or any of the other Credit Facility Documents or for any
claim based thereon or otherwise in respect thereof, against any past, present
or future trustee, shareholder, officer or employee of BRT, whether by virtue of
any statute or rule of law, or by the enforcement of any assessment or penalty
or otherwise, all such liability being expressly waived and released by each
other party to this Mortgage and the other Credit Facility Documents.

               IN WITNESS WHEREOF, Mortgagor has duly executed and delivered
this Mortgage as of the day and year first above written.


                                  BRANDYWINE OPERATING PARTNERSHIP, L.P., a
                                  Delaware limited partnership

                                  By:    Brandywine Realty Trust, a Maryland
                                         real estate investment trust

                                         By:_________________________________
                                            Name:   Gerard H. Sweeney
                                            Title:  President and Chief
                                                    Executive Officer


                                      -11-
<PAGE>   116
                                    EXHIBIT A

                                  (Definitions)

BOP: The term "BOP" as used in this Mortgage shall mean Brandywine Operating
Partnership, L.P., a Delaware limited partnership.

BRT: The term "BRT" as used in this Mortgage shall mean Brandywine Realty Trust,
a Maryland real estate investment trust.

BRT/BOP Limited Partnerships: The term "BRT/BOP Limited Partnerships" as used in
this Mortgage shall collectively mean LC/N HORSHAM LIMITED PARTNERSHIP, a
Pennsylvania limited partnership; LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a
Pennsylvania limited partnership; NICHOLS LANSDALE LIMITED PARTNERSHIP III, a
Pennsylvania limited partnership; NEWTECH III LIMITED PARTNERSHIP, a
Pennsylvania limited partnership; NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania
limited partnership; C/N OAKLANDS LIMITED PARTNERSHIP I, a Pennsylvania limited
partnership; FIFTEEN HORSHAM, L.P., a Pennsylvania limited partnership; C/N
LEEDOM LIMITED PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN
LIMITED PARTNERSHIP III, a Pennsylvania limited partnership.

Co-Lenders: The term "Co-Lenders" as used in this Mortgage shall mean,
collectively, Smith Barney, NB and all other parties from time to time to whom
direct interests in the Credit Facility are sold, transferred and assigned, and
who are as a result thereof designated as Co-Lenders, under and pursuant to the
provisions of the Credit Agreement and the Co-Lenders Agreement.

Co-Lenders Agreement: The term "Co-Lenders Agreement" as used in this Mortgage
shall mean that certain Co-Lender and Servicing Agreement dated as of the date
hereof between Smith Barney and NB, in its individual capacity and in its
capacity as administrative and documentation agent for the Credit Facility, as
the same may be amended from time to time.

Credit Agreement: The term "Credit Agreement" as used in this Mortgage shall
mean that certain Revolving Credit Agreement dated as of November 25, 1996 among
Smith Barney, NationsBank, N.A., in its individual capacity, BOP, BRT, and the
BRT/BOP Limited Partnership, and NB, acting in its capacity as administrative
and documentation agent for the Credit Facility, as the same may be amended from
time to time, and pursuant to the provisions of which the Credit Facility is
being extended by Co-Lenders to Mortgagor.

Credit Facility: The term "Credit Facility" as used in this Mortgage shall have
the meaning given to such term in paragraph C of the Preliminary Statement of
this Mortgage.

Credit Facility Documents: The term "Credit Facility Documents" as used in this
Mortgage shall have the meaning given to such term in the Credit Agreement.

Credit Facility Notes: The term "Credit Facility Notes" as used in this Mortgage
shall have the meaning given to such term in the Credit Agreement.

Debt: The term "Debt" as used in this Mortgage shall have the meaning given to
such term in paragraph E of the Preliminary Statement of this Mortgage.

Default Rate: The term "Default Rate" as used in this Mortgage shall have the
meaning given to such term in the Credit Agreement.

Events of Default: The term "Events of Default" as used in this Mortgage shall
have the meaning given to such term in the Credit Agreement.
<PAGE>   117
FF&E: The term "FF&E" as used in this Mortgage shall mean, collectively, all
goods (as such term is defined in the Uniform Commercial Code), now owned or
hereafter acquired by Mortgagor, located at or used in connection with the
Improvements and the operation of the Improvements, including, without
limitation, (i) all furniture and furnishings and all other items of personal
property (including inventory now owned or hereafter acquired by Mortgagor) now
and hereafter located on, or used in connection with the operation of the
Improvements, together with all replacements, modifications, alterations and
additions thereto; and (ii) all equipment, fixtures, machinery and other items
of property required or incidental to the use of the Improvements, including all
components thereof, now and hereafter permanently affixed to or incorporated
into the Improvements, including, without limitation, all furnaces, boilers,
heaters, electrical equipment, heating, plumbing, lighting, ventilating,
refrigerating, incineration, air and water pollution control, waste, disposal,
air-cooling and air conditioning systems and apparatus, sprinkler systems and
fire and theft protection equipment, together with all replacements,
modifications, alterations and additions thereto.

***[Ground Lease:  The term "Ground Lease" as used in this Mortgage shall mean
______________.]***

Improvements: The term "Improvements" as used in this Mortgage shall have the
meaning given to such term in the granting clause of this Mortgage.

Leases: The terms "Leases" as used in this Mortgage shall have the meaning given
to such term in the granting clause of this Mortgage.

Principal Balance: The term "Principal Balance" as used in this Mortgage shall
have the meaning given to such term in the Credit Agreement.

Mortgaged Property: The term "Mortgaged Property" as used in this Mortgage shall
have the meaning given to such term in the granting clause of this Mortgage.

Mortgagee: The term "Mortgagee" as used in this Mortgage shall have the meaning
given to such term in the preamble to this Mortgage.

Mortgagor: The term "Mortgagor" as used in this Mortgage shall have the meaning
given to such term in the preamble to this Mortgage.

NB: The term "NB" as used in this Mortgage shall mean NationsBank, N.A., a
national banking association.

Premises: The term "Premises" as used in this Mortgage shall have the meaning
given to such term in paragraph B of the Preliminary Statement of this Mortgage.

Rents: The term "Rents" as used in this Mortgage shall have the meaning given to
such term in the granting clause of this Mortgage.

Smith Barney: The term "Smith Barney" as used in this Mortgage shall mean Smith
Barney Mortgage Capital Group, Inc., a Delaware corporation.

Taxes: The term "Taxes" as used in this Mortgage shall have the meaning given to
such term in the Credit Agreement.

Title Company: The term "Title Company" as used in this Mortgage shall have the
meaning given to such term in the Credit Agreement.

Uniform Commercial Code: The term "Uniform Commercial Code" as used in this
Mortgage shall mean the Uniform Commercial Code of the State in which the
Premises are located.


                                       A-2
<PAGE>   118
                                    Exhibit I










                     BRANDYWINE OPERATING PARTNERSHIP, L.P.,
                   a Delaware limited partnership, as Assignor

                                       and

             NATIONSBANK, N.A., not individually, but acting in its
         capacity as collateral agent for the equal and ratable benefit
                 of the co-lenders described herein, as Assignee






                         -------------------------------

                         ASSIGNMENT OF LEASES AND RENTS

                         -------------------------------



                        Dated: November 25, 1996

                        Location:   __________________
                                    __________________
                                    __________________

                        RECORD AND RETURN TO:


                                Battle Fowler LLP
                                Park Avenue Tower
                                75 East 55th Street
                                New York, New York 10022

                                Attention:  Dean A. Stiffle, Esq.









                                                     MASTER ASSIGNMENT OF LEASES
<PAGE>   119


                         ASSIGNMENT OF LEASES AND RENTS


                        This Assignment of Leases and Rents entered into as of
            the 25th day of November, 1996, by BRANDYWINE OPERATING PARTNERSHIP,
            L.P., a Delaware limited partnership having an office at c/o
            Brandywine Realty Trust, Newtown Square Corporate Campus, 16 Campus
            Boulevard, Suite 150, Newtown Square, Pennsylvania (hereinafter
            referred to as "Assignor"); and NATIONSBANK, N.A., a national
            banking association having an office at 8300 Greensboro Drive,
            McLean, Virginia, not individually, but acting in its capacity as
            administrative and documentation agent for the equal and ratable
            benefit of Co-Lenders pursuant to and in accordance with the terms
            and provisions of the Credit Agreement (NationsBank, N.A. acting in
            such capacity as administrative and documentation agent being
            hereinafter referred to as "Assignee").

                              PRELIMINARY STATEMENT

            A. All capitalized terms as used in this Assignment shall, unless
otherwise defined in this Assignment, have the meanings given to such terms in
EXHIBIT A attached hereto.

            ***[B.  Assignor is the owner of a fee estate in the premises
described in EXHIBIT B attached hereto (hereinafter referred to as the
"Premises");]***

            ***[B. Assignor is the owner of a leasehold estate in the premises
described in EXHIBIT B attached hereto (the "Premises") under and pursuant to
the provisions of the ground lease described in EXHIBIT B-1 attached hereto
(hereinafter referred to as the "Ground Lease");]***

            C. Co-Lenders have on the terms, covenants and provisions set forth
in the Credit Agreement extended to Borrowers a revolving credit facility in the
principal sum of up to, but not in excess of, $80,000,000 (hereinafter referred
to as the "Credit Facility"), which Credit Facility is evidenced by, and payable
together with interest thereon in accordance with the provisions of, the Credit
Facility Notes.

            ***[D. Co-Lenders were willing to extend the Credit Facility to
Assignor only if Assignor assigned to Assignee, for the equal and ratable
benefit of Co-Lenders, in the manner hereinafter provided, as additional
security for the payment of the Debt and the observance and performance by
Borrowers of all of the terms, covenants and provisions of the Credit Facility
Documents on Borrowers' part to be observed and performed, all right, title and
interest of Assignor now owned, or hereafter acquired, in and to (i) all leases,
licenses and other agreements *[(other than the Ground Lease)]* (hereinafter
collectively referred to as the "Leases") now as hereafter entered into and
affecting or relating to the use or occupancy of the Premises or of the
improvements now or hereafter erected thereon (the "Improvements"), and (ii) the
rents, income, revenues, receipts, accounts, accounts receivable, issues and
profits of or derived from or relating to the Premises or the Improvements or
any portion thereof (hereinafter collectively referred to as the "Rents").]***

            ***[D.  Co-Lenders have approved the inclusion of the Premises as
part of the collateral pool for the Credit Facility in accordance with the
provisions of the Credit Agreement, and in connection therewith, and as
<PAGE>   120
consideration therefor, Assignor has agreed to assign to Assignee, for the equal
and ratable benefit of Co-Lenders, in the manner hereinafter provided, as
additional security for the payment of the Debt and the observance and
performance by Borrowers of all of the terms, covenants and provisions of the
Credit Facility Documents on Borrowers' part to be observed and performed, all
right, title and interest of Assignor now owned, or hereafter acquired, in and
to (i) all leases, licenses and other agreements *[(other than the Ground
Lease)]* (hereinafter collectively referred to as the "Leases") now or hereafter
entered into and affecting or relating to the use or occupancy of the Premises
or of the improvements now or hereafter erected thereon (the "Improvements"),
and (ii) the rents, income, revenues, receipts, accounts, accounts receivable,
issues and profits of or derived from or relating to the Premises or the
Improvements or any portion thereof (hereinafter collectively referred to as the
"Rents").]***

            E. NOW, THEREFORE, in consideration of the extension of the Credit
Facility and other good and valuable consideration, the receipt of which is
hereby acknowledged, Assignor hereby assigns to Assignee, as additional security
for the payment of the Debt and the observance and performance by Borrowers of
all of the terms, covenants and provisions of the Credit Facility Documents on
Borrowers' part to be observed or performed, all of Assignor's right, title and
interest now owned, or hereafter acquired, in and to the Leases and the Rents,
and Assignor hereby represents and warrants to and covenants and agrees with
Assignee as follows:

            1. Except as expressly set forth to the contrary in the certified
rent roll for the Property being delivered by Assignor to Assignee in connection
with the execution and delivery of this Assignment, Assignor represents and
warrants that as of the date hereof (i) Assignor is the owner and holder of the
landlord's interest under the Leases, (ii) there are no prior or subordinate
assignments of the Leases or of any portion of the Rents due and payable or to
become due and payable thereunder which are presently outstanding, (iii) all of
the Leases are in full force and effect and the respective terms thereof have
commenced pursuant to the provisions thereof, (iv) the premises demised under
each of the Leases have been completed and the tenants under the Leases have
taken possession of the premises demised thereunder on a rent-paying basis, (v)
neither Assignor nor any tenant under the Leases is in default under any of the
terms, covenants or provisions of the Leases and Assignor knows of no event
which, but for the passage of time or the giving of notice or both, would
constitute an event of default under any of the Leases, (vi) neither Assignor
nor any tenant under the Leases has commenced any action or given or served any
notice for the purpose of terminating any of the Leases, (vii) all Rents due and
payable under the Leases have been paid in full and no such Rents have been paid
more than one (l) month in advance of the due dates thereof, and (viii) there
are no offsets or defenses to the payment of any portion of the Rents.

            2. Assignor shall, at its sole cost and expense, (i) fulfill and
perform, or cause to be fulfilled and performed, each and every term, covenant
and provision of the Leases on the part of the Assignor thereunder to be
observed and performed, (ii) promptly send copies of all notices of default
which Assignor shall send or receive under the Leases to Assignee, (iii) enforce
the observance and performance of the terms and provisions of the Leases by the
tenants thereunder, (iv) enforce the observance and performance of each and
every term, covenant and provision of the Leases on the part of the tenants
thereunder to be observed and performed and (v) appear in and defend any action
or proceeding arising under or in any manner connected with the Leases or with
the obligations and undertakings of the landlord or the tenants thereunder.

            3. Assignor shall not, without the prior consent of Co-Lenders, (i)
further transfer, sell, assign, pledge, encumber or grant a security


                                       -2-
<PAGE>   121
interest in all or any portion of the Rents or the Leases, (ii) accept
prepayments of installments of the Rents for a period of more than one (1) month
in advance, (iii) make or suffer to be made any Lease, including any renewal of
an existing Lease (other than renewals at rents and/on other terms expressly
reserved in such Lease) other than in accordance and in a manner consistent with
the provisions of the Credit Agreement, (iv) consent to or permit the assignment
or subletting of any leasehold estate created under any Lease (other than in
accordance with the express provisions of such Lease), (v) terminate, modify or
amend, or consent to the termination, modification or amendment of, any Lease or
any term thereof other than in accordance and in a manner consistent with the
provisions of the Credit Agreement, (vi) commence or continue proceedings to
evict, remove or dispossess the tenant under any Lease, provided, however, that
Assignor may commence and continue such a proceeding without obtaining the prior
consent of Assignor if the Lease in question does not cover in excess of 20,000
square feet of space in the Improvements and the commencement of such proceeding
is otherwise consistent with customary business practices for the operation of
improvements which are comparable to the Improvements, or (vii) waive, cancel,
release, modify, excuse, condone, set-off, compromise or in any manner release
or discharge the tenant under any Lease other than in a manner which is
consistent with customary business practices for the operation of improvements
comparable to the Improvements.

            4. This Assignment shall not be deemed or construed to obligate
Assignee or any Co-Lender to take any action or incur any expense or perform or
discharge any obligation, duty or liability under the Leases, and Assignor
hereby agrees to indemnify and hold Assignee and Co-Lenders harmless from and
against all liability, loss or damage, including, but not limited to, reasonable
attorneys' fees, which Assignee or any Co-Lender may or might incur under the
Leases or under or by reason of this Assignment and from and against any and all
claims whatsoever which may be asserted against Assignee or any Co-Lender by
reason of any alleged obligation or undertaking on the part of Assignee or any
Co-Lender to perform or discharge any of the terms, covenants or provisions
contained in the Leases.

            5. This Assignment has been made as additional security for the
payment of the Debt and the observance and performance by Borrowers of the
terms, covenants and provisions of the Credit Facility Documents on Borrowers'
part to be observed and performed. Subject to the provisions of this Assignment
hereinafter set forth, Assignee waives the right to enter the Premises for the
purpose of collecting the Rents, and grants Assignor the right to collect the
Rents. Assignor shall collect and hold the Rents, or an amount sufficient to
discharge all current sums due on the Debt, in trust for use in the payment of
the Debt. The right of Assignor to collect the Rents may be revoked by Assignee
upon the occurrence of any Event of Default, by giving notice of such revocation
to Assignor. Following such notice and as long as such Event of Default is
continuing (it being understood that the decision whether or not to accept the
cure of an Event of Default shall be in the sole and absolute discretion of
Assignee), Assignee may retain and apply the Rents toward payment of the Debt in
such order, priority and proportions as Assignee in its discretion, shall deem
proper, or to the operation, maintenance and repair of the Property, and
irrespective of whether Assignee shall have declared the Debt to be immediately
due and payable, or shall have commenced a foreclosure of the Mortgage or shall
have applied or arranged for the appointment of a receiver. In addition,
Assignee shall have the absolute and unconditional right following the
occurrence and during the continuance of an Event of Default, to notify the
tenants under the Leases that all Rents should be paid directly to Assignee.
Upon the occurrence and during the continuance of an Event of Default, the
tenants under the Leases shall, upon notice from Assignee of the occurrence of
such Event of Default, thereafter pay to Assignee or to any appointed receiver
the Rents due or to become due under the Leases without any obligation to
determine whether or not such Event


                                       -3-
<PAGE>   122
of Default does in fact exist, and Assignor shall facilitate in all reasonable
ways the collection of the Rents by Assignee, and without implying the necessity
therefor will, upon demand of Assignee, execute written notices to the tenants
under the Leases directing the tenants under the Leases to pay the Rents to
Assignee, which Rents may, during the continuance of such Event of Default, be
retained and applied by Assignee toward the payment of the Debt in such order,
priority and proportions as Assignee in its discretion, shall deem proper, or to
the operation, maintenance and repair of the Property.

            6. Upon the occurrence of an Event of Default and for so long as
such Event of Default continues Assignee shall have the right, at its option, to
enter upon and take over and assume the management, operation and maintenance of
the Property and to perform all necessary and proper acts and to expend such
sums out of the income of the Property as may be necessary in connection
therewith, in the same manner and to the same extent as Assignor theretofore
might do, including the right to effect new Leases, cancel or surrender the
Leases, alter, modify or amend the provisions thereof, or make concessions to
the tenants thereunder and Assignor hereby releases and waives all claims
against Assignee arising out of such management, operation and maintenance.
Assignor shall, from time to time, at its expense, execute, deliver, file and
record any statement, assignment, instrument, document, agreement or other paper
and take any other action (including any filings of financing or continuation
statements under the Uniform Commercial Code) that from time to time may be
necessary or desirable, or that Assignee may reasonable request, in order to
create, preserve, perfect, confirm or validate the assignment of the Leases and
Rents made pursuant to the provisions of this Assignment or to enable Assignee
to obtain the full benefits of this Assignment, or to enable Assignee to
exercise and enforce any of its rights, powers and remedies hereunder. To the
extent permitted by applicable law, Assignor hereby authorizes Assignee, and
appoints Assignee as its true and lawful attorney (with full power of
substitution, in the name of Assignor), to execute and file financing statements
or continuation statements without Assignor's signature appearing thereon.

            7. Nothing contained in this Assignment, and no entry by Assignee
upon the Property as hereinabove provided, shall be construed as to constitute
Assignee as a mortgagee in possession.

            8. Nothing contained in this Assignment is intended or shall be
construed to prevent Assignee in the exercise of its discretion from foreclosing
the Mortgage or otherwise enforcing the provisions thereof or of any of the
other Credit Facility Documents, in whole or in part, in accordance with their
terms.

            9. No alteration, extension, renewal, change, modification, release,
amendment, compromise or cancellation, in whole or in part, of any term,
covenant or provision of any of the other Credit Facility Documents shall affect
this Assignment in any manner or diminish or release any of the rights of
Assignee hereunder.

            10. Assignor hereby waives any and all legal requirements that
Assignee institute any action or proceeding in law or in equity against any
other party, or exhaust its remedies under any of the other Credit Facility
Documents as a condition precedent to exercising its rights and remedies under
this Assignment. All remedies afforded to Assignee by reason of this Assignment
are separate and cumulative remedies and it is agreed that no one of such
remedies whether exercised by Assignee or not, shall be deemed to be in
exclusion of any of the other remedies available to Assignee and shall not in
any manner limit or prejudice any other legal or equitable remedies which
Assignee may have, including, but not limited to, all rights and remedies of
Assignee under any of the other Credit Facility Documents.


                                       -4-
<PAGE>   123
            11. It is the intention of the parties hereto that any and all other
Leases affecting the Property or any portion thereof presently in effect or
hereafter entered into by Assignor or in which Assignor shall otherwise have an
interest shall be covered by the provisions of this Assignment and all such
Leases and all of Assignor's right, title and interest in all such Leases, and
the rents, additional rents, charges, issues, profits and other sums payable
thereunder, are hereby assigned to Assignee until the end of the respective
terms thereof and any renewals or extensions thereof, subject to all of the
terms, covenants and provisions of this Assignment. Assignor shall deliver a
true and correct copy of each such Lease to Assignee promptly after the
execution and delivery of the same. Assignor shall, upon the request of
Assignee, execute and deliver in recordable form all instruments which Assignee
may reasonably request to further evidence and confirm such assignment of each
such Lease.

            12. This Assignment shall be binding upon Assignor, and its
successors and assigns and shall inure to the benefit of Assignee, and its
successors and assigns.

            13. This Assignment may only be modified, altered, amended, or
terminated by an agreement in writing executed by the parties hereto.

            14. Any notice, request, demand, statement or consent made hereunder
or in connection herewith shall be in writing and shall be sent in the manner
specified in the Credit Agreement.

            15. If any term, covenant or condition of this Assignment shall be
held to be invalid, illegal or unenforceable in any respect, this Assignment
shall be construed without such provision.

            16. This Assignment shall be governed by and construed under the
laws of the State in which the Property is located.

            18. No recourse shall be had for any obligation of BRT under this
Assignment or any of the other Credit Facility Documents or for any claim based
thereon or otherwise in respect thereof, against any past, present or future
trustee, shareholder, officer or employee of BRT, whether by virtue of any
statute or rule of law, or by the enforcement of any assessment or penalty or
otherwise, all such liability being expressly waived and released by each other
party to this Assignment and the other Credit Facility Documents.


                                       -5-
<PAGE>   124
            IN WITNESS WHEREOF, Assignor has duly executed this Assignment as of
the day and year first above written.


                                    BRANDYWINE OPERATING PARTNERSHIP, L.P., a
                                    Delaware limited partnership

                                    By:   Brandywine Realty Trust, a Maryland
                                          real estate investment trust

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                       -6-
<PAGE>   125
                                    EXHIBIT A
                                  (Definitions)


Assignee: The term "Assignee" as used in this Assignment shall have the meaning
given to such term in the preamble to this Agreement.


Assignor: The term "Assignor" as used in this Assignment shall have the meaning
given to such term in the preamble to this Agreement.


Approved Leasing Parameters: The term "Approved Leasing Parameters" as used in
this Assignment shall have the meaning given to such term in the Credit
Agreement.


BOP: The term "BOP" as used in this Agreement shall mean Brandywine Operating
Partnership, L.P., a Delaware limited partnership.


Borrowers: The term "Borrowers" as used in this Assignment shall collectively
mean BRT, BOP and the BRT/BOP Limited Partnerships.

BRT: The term "BRT" as used in this Assignment shall mean Brandywine Realty
Trust, a Maryland real estate investment trust.

BRT/BOP Limited Partnerships: The term "BRT/BOP Limited Partnerships" as used in
this Assignment shall mean LC/N HORSHAM LIMITED PARTNERSHIP, a Pennsylvania
limited partnership; LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a Pennsylvania
limited partnership; NICHOLS LANSDALE LIMITED PARTNERSHIP III, a Pennsylvania
limited partnership; NEWTECH III LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania limited partnership;
C/N OAKLANDS LIMITED PARTNERSHIP I, a Pennsylvania limited partnership; FIFTEEN
HORSHAM, L.P., a Pennsylvania limited partnership; C/N LEEDOM LIMITED
PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN LIMITED
PARTNERSHIP III, a Pennsylvania limited partnership.

Co-Lenders: The term "Co-Lenders" as used in this Assignment shall collectively
mean, Smith Barney Mortgage Capital Group, Inc., and NationsBank, N.A., acting
in its individual capacity, and all other parties from time to time to whom
direct interests in the Credit Facility are sold, transferred and assigned, and
who are as a result thereof are designated as Co-Lenders under and pursuant to
the provisions of the Credit Agreement and the Co-Lenders Agreement

Co-Lenders Agreement: The term "Co-Lenders Agreement" as used in this Assignment
shall mean that certain Co-Lender and Servicing Agreement dated as of November
25, 1996 among Smith Barney Mortgage Capital Group, Inc., NationsBank, N.A.,
acting in its individual capacity, and NationsBank, N.A., acting in its capacity
as administrative and documentation agent for the equal and ratable benefit of
Co-Lenders in accordance with the provisions of the Credit Agreement, as the
same may be further amended from time to time.

Credit Agreement: The term "Credit Agreement" as used in this Assignment shall
mean that certain Revolving Credit Agreement dated as of November 25, 1996 among
Smith Barney Mortgage Capital Group, Inc., NationsBank, N.A., acting in its
individual capacity, Borrowers and NationsBank, N.A., acting in its capacity as
administrative and documentation agent for the equal and ratable benefit of
Co-Lenders, as the same may be amended from time to time, and pursuant to the
provisions of which the Credit Facility is being extended by Co-Lenders to
Borrowers.
<PAGE>   126
Credit Facility: The term "Credit Facility" as used in this Assignment shall
have the meaning given to such term in paragraph C of the Preliminary Statement
of this Assignment.

Credit Facility Note: The term "Credit Facility Note" as used in this Assignment
shall have the meaning given to such term in the Credit Agreement.

Credit Facility Documents: The term "Credit Facility Documents" as used in this
Assignment shall have the meaning given to such term in the Credit Agreement.

Debt:  The term "Debt" as used in this Assignment shall have the meaning given
to such term in the Credit Agreement.

Event of Default: The term "Event of Default" as used in this Assignment shall
have the meaning given to such term in the Credit Agreement.

***[Ground Lease.  The term "Ground Lease" as used in this Assignment shall
mean _______________________________.]***

Improvements: The term "Improvements" as used in this Assignment shall have the
meaning given to such term in paragraph D of the Preliminary Statement of this
Assignment.

Leases: The term "Leases" as used in this Assignment shall have the meaning
given to such term in paragraph D of the Preliminary Statement of this
Assignment.

Mortgage: The term "Mortgage" as used in this Assignment shall mean ***[that
certain Mortgage dated as of the date hereof given by Assignor to Assignee OR
ALTERNATIVELY that certain Deed of Trust dated as of the date hereof given by
Assignor to _________, as trustee, for this use and benefit of Assignee]***, as
security for the payment of the Debt and the observance and performance by
Borrowers of the terms, covenants and provisions of the Credit Facility Document
on Borrowers' part to be observed and performed, and encumbering Assignor's
right, title and interest in and to the Property and intended to be duly
recorded in the office of the _______ of ______ County, __________.

Property: The term "Property" as used in this Assignment shall collectively mean
the Premises and the Improvements.

Premises: The term "Premises" as used in this Assignment shall have the meaning
given to such term in paragraph B of the Preliminary Statement of this
Assignment.

Rents: The term "Rents" as used in this Assignment shall have the meaning given
to such term in paragraph D of the Preliminary Statement of this Assignment.


                                       A-2
<PAGE>   127
                                    EXHIBIT J

                               GUARANTY OF PAYMENT


                  This Guaranty entered into as of the 25th day of November,
      1996, among WITMER OPERATING PARTNERSHIP, L.P. ("WOP"), a Delaware general
      partnership; BRANDYWINE REALTY PARTNERS, a Pennsylvania general
      partnership ("BRP"); BRANDYWINE REALTY SERVICES CORPORATION ("BRSC"), a
      Pennsylvania corporation (WOP, BRP and BRSC are hereinafter collectively
      referred to as "Guarantors"); and NATIONSBANK, N.A., a national banking
      association having an office at 8300 Greensboro Drive, McLean, Virginia,
      in its capacity as administrative and documentation agent for the equal
      and ratable benefit of Co-Lenders pursuant to and in accordance with the
      terms and provisions of the Credit Agreement (NationsBank, N.A., acting in
      such capacity as administrative and documentation agent being hereinafter
      referred to as "Agent").

                              PRELIMINARY STATEMENT

            A. All capitalized terms as used in this Guaranty shall, unless
otherwise defined in this Guaranty, have the meanings given to such terms in
Exhibit A attached hereto.

            B. The Initial Co-Lenders have agreed on the terms, covenants and
provisions of the Credit Agreement to extend to Borrowers a revolving credit
facility in the principal sum of up to, but not in excess of, $80,000,000 (the
"Credit Facility"), which Credit Facility shall be evidenced by the Credit
Facility Notes and secured inter alia by the Mortgages.

            C. The Initial Co-Lenders were willing to extend the Credit Facility
to Borrowers only if Guarantors execute and deliver this Guaranty and guarantee
payment in full of the Debt to Agent, for the equal and ratable benefit of
Co-Lenders.

            NOW, THEREFORE, in consideration of Ten Dollars ($10.00) and other
good and valuable consideration, the receipt of which is hereby acknowledged,
and to induce Initial Co-Lenders to extend the Credit Facility, Guarantors
hereby represent and warrant to and covenant and agree with Agent, for the equal
and ratable benefit of Co-Lenders, as follows:

            1. Guarantors hereby guarantee, absolutely and unconditionally, to
Agent, for the equal and ratable benefit of Co-Lenders, the payment in full of
the Debt.

            2. Guarantors agree that, with or without notice or demand,
Guarantors will reimburse Agent, to the extent that such reimbursement is not
made by Borrowers, for all costs and expenses (including, without limitation,
reasonable attorney's fees) incurred by Agent or any Co-Lender in connection
with the collection of the Debt or any portion thereof or in any action, case or
proceeding brought by Agent to enforce the obligations of Guarantors under this
Guaranty.

            3. All moneys available to Agent for application in payment or
reduction of the Debt may be applied by Agent in such manner and in such amounts
and at such time or times and in such order, priority and proportions as Agent
may see fit to the payment or reduction of such portion of the Debt as Agent may
elect.

            4. Guarantors hereby consent that from time to time, before or after
any default by Borrowers, with or without further notice to or assent from
Guarantors, any security at any time held by or available to Agent or any
Co-Lender for any obligation of Borrowers, or any security at any time held by
or available to Agent or any Co-Lender for any obligation of any other person
<PAGE>   128
or party secondarily or otherwise liable for all or any portion of the Debt, may
be exchanged, surrendered or released and any obligation of Borrowers, or of any
such other person or party, may be changed, altered, renewed, extended,
continued, surrendered, compromised, waived or released in whole or in part, or
any default with respect thereto waived, and Agent or any Co-Lender may fail to
set off and may release, in whole or in part, any balance of any deposit account
or credit on its books in favor of Borrowers, or of any such other person or
party, and may extend further credit in any manner whatsoever to Borrowers, and
generally deal with Borrowers or any such security or other person or party as
Agent or such Co-Lender may see fit; and Guarantors shall remain bound under
this Guaranty notwithstanding any such exchange, surrender, release, change,
alteration, renewal, extension, continuance, compromise, waiver, inaction,
extension of further credit or other dealing.

            5. Guarantors hereby waive (a) notice of acceptance of this Guaranty
and of the extension of the Credit Facility and of the making of any advance
thereof pursuant to the Credit Facility Documents; (b) presentment and demand
for payment of the Debt or any portion thereof; (c) protest and notice of
dishonor or default to Guarantors or to any other person or party with respect
to the Debt or any portion thereof; (d) all other notices to which Guarantors
might otherwise be entitled except as otherwise specifically provided to the
contrary herein; and (e) any demand for payment under this Guaranty.

            6. This Guaranty is a guaranty of payment and not of collection and
Guarantors further waive any right to require that any action, case or
proceeding be brought against Borrowers or any other person or party or to
require that resort be had to any security or to any balance of any deposit
account or credit on the books of Agent or any Co-Lender in favor of Borrowers
or any other person or party.

            7. Each reference herein to Agent or Co-Lenders shall be deemed to
include their respective successors and assigns, in whose favor the provisions
of this Guaranty shall also inure. Each reference herein to Guarantors shall be
deemed to include the successors and assigns of Guarantors, all of whom shall be
bound by the provisions of this Guaranty, provided, however, that Guarantors
shall in no event or under any circumstance have the right without obtaining the
prior written consent of Agent to assign or transfer their respective
obligations and liabilities under this Guaranty, in whole or in part, to any
other person, party or entity.

            8. The term "Guarantors" as used herein shall mean the "Guarantors
and each of them" and each undertaking herein contained shall be their joint and
several undertaking, provided, however, that in the next succeeding paragraph
hereof the term "Guarantors" shall mean the "Guarantors or any of them".

            9. No delay on the part of Agent in exercising any right or remedy
under this Guaranty or failure to exercise the same shall operate as a waiver in
whole or in part of any such right or remedy. No notice to or demand on
Guarantors shall be deemed to be a waiver of the obligation of Guarantors or of
the right of Agent to take further action without notice or demand as provided
in this Guaranty.

            10. This Guaranty may only be modified, amended, changed or
terminated by an agreement in writing signed by Agent and Guarantors. No waiver
of any term, covenant or provision of this Guaranty shall be effective unless
given in writing by Agent and if so given by Agent shall only be effective in
the specific instance in which given.

            11. Guarantors acknowledge that this Guaranty and Guarantors'
obligations under this Guaranty are and shall at all times continue to be


                                       -2-
<PAGE>   129
absolute and unconditional in all respects, and shall at all times be valid and
enforceable irrespective of (a) any other agreements or circumstances of any
nature whatsoever which might otherwise constitute a defense (other than a
defense of payment) to this Guaranty and the obligations of Guarantors under
this Guaranty or the obligations of Borrowers or any other person or party
relating to this Guaranty or the obligations of Guarantors hereunder or
otherwise with respect to the Credit Facility, including, but not limited to,
the realization by Agent or any Co-Lender upon any collateral given, pledged or
assigned as security for all or any portion of the Debt, or the filing of a
petition or the commencement of a case with respect to any Borrower or any
Guarantor under Title 11 of the United States Code, as now constituted or
hereafter amended (the "Bankruptcy Code"), or under any other applicable Federal
or state bankruptcy, insolvency or similar law, or the obtaining by Agent or any
Co-Lender of title to any collateral given, pledged or assigned as security for
the Debt, by foreclosure or enforcement of Agent's or any Co-Lender's lien
thereon, acceptance of an assignment or deed in lieu of foreclosure or sale, or
otherwise, or (b) any modification, impairment, abatement, reduction, release,
limitation, restructure, reinstatement or cure, in whole or part, of interest,
principal or other sum payable by Borrowers under the Credit Agreement, the
Credit Facility Notes, the Mortgages or the other Credit Facility Documents or
of any other obligation of Borrowers under the Credit Facility Documents
pursuant to an order by a bankruptcy court or other court of competent
jurisdiction in any action, case or proceeding brought under the Bankruptcy Code
or under any other applicable Federal or state bankruptcy, insolvency or similar
law, it being expressly acknowledged and agreed by Guarantors that if any such
modification, impairment, abatement, reduction, release, limitation,
restructure, reinstatement or cure, in whole or part, is so ordered in any such
action, case or proceeding, Guarantors' obligations under this Guaranty will
nevertheless continue to be determined as if such order had not been issued
(i.e., as if Borrowers was still obligated to pay interest, principal and other
sums and to otherwise perform and observe its other obligations strictly in
accordance with the terms, covenants and provisions of the Credit Agreement, the
Credit Facility Notes, the Mortgages and the other Credit Facility Documents as
in existence prior to the issuance of any such order). Guarantors absolutely,
unconditionally and irrevocably waive any and all right to assert any defense,
setoff, counterclaim or crossclaim of any nature whatsoever with respect to this
Guaranty or the obligations of Guarantors under this Guaranty or the obligations
of Borrowers or any other person or party relating to this Guaranty or the
obligations of Guarantors hereunder or otherwise with respect to the Credit
Facility in any action, case or proceeding brought by Agent or Co-Lenders to
collect the Debt, or any portion thereof, or to enforce the obligations of
Guarantors under this Guaranty (provided, however, that the foregoing provisions
of this sentence shall not be deemed a waiver of the right of the Guarantors to
assert any compulsory counterclaim in any such action, case or proceeding
brought by Agent or Co-Lenders in any state court if such counterclaim is
compelled under local law or rule or procedure, or in any such action, case or
proceeding brought by Agent or Co-Lenders in a court of the United States, nor
shall the foregoing provisions of this sentence be deemed a waiver of the right
of the Guarantors to assert any claim which would otherwise constitute a
defense, setoff, counterclaim or crossclaim of any nature whatsoever against
Agent or Co-Lenders in any separate action, case or proceeding brought by the
Guarantors against Agent or Co-Lenders). Guarantors acknowledge that no oral or
other agreements, understandings, representations or warranties exist with
respect to this Guaranty or with respect to the obligations of Guarantors under
this Guaranty, except those specifically set forth in this Guaranty, and that
this Guaranty sets forth the entire agreement and understanding of Agent,
Co-Lenders and Guarantors.

            12. GUARANTORS HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVE, AND
AGENT AND CO-LENDERS BY THEIR ACCEPTANCE OF THIS GUARANTY IRREVOCABLY AND
UNCONDITIONALLY WAIVE, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, CASE,


                                       -3-
<PAGE>   130
PROCEEDING, SUIT OR COUNTERCLAIM ARISING IN CONNECTION WITH, OUT OF OR OTHERWISE
RELATING TO THIS GUARANTY.

            13. Notwithstanding any payments made by Guarantors pursuant to the
provisions of this Guaranty, Guarantors shall not seek to enforce or collect
upon any rights which Guarantors now have or may acquire against Borrowers
either by way of subrogation, indemnity, reimbursement or contribution for any
amount paid under this Guaranty, nor shall Guarantors file, assert or receive
payment on any claim, whether now existing or hereafter arising, against
Borrowers subsequent to the commencement of a case by or against Borrowers under
the Bankruptcy Code or under any other applicable Federal or state bankruptcy,
insolvency or similar law, in each case unless and until the Debt has been paid
in full and provided that no such action by Guarantors could, in the reasonable
opinion of Agent and its counsel, result in the "preference" period (as set
forth in Section 547(b)(4) of the Bankruptcy Code or any successor provision)
with respect to any payment or other transfer of assets to Agent or to any
Co-Lender from or on behalf of Borrowers being held to be longer than such
period would have been held to be if Guarantors had not taken such action. In
the event an action, case or proceeding is filed or commenced under the
Bankruptcy Code or under any other applicable Federal or state bankruptcy,
insolvency or similar law in regard to Borrowers or an action, case or
proceeding is otherwise commenced for the benefit of the creditors of Borrowers,
this Guaranty shall at all times thereafter remain effective in regard to any
payments or other transfers of assets to Agent or any Co-Lender received from or
on behalf of Borrowers which are held voidable on the grounds of preference,
fraudulent conveyance or otherwise, whether or not the Debt has been paid in
full.

            14. If at any time any payment, or portion thereof, made by, or for
the account of, Guarantors on account of the obligations under this Guaranty, is
set aside by any court or trustee having jurisdiction as a voidable preference,
fraudulent conveyance or otherwise as being subject to avoidance or recovery
under the provisions of the Bankruptcy Code or under any other applicable
Federal or state bankruptcy, insolvency or similar law, Guarantors hereby agree
that this Guaranty (a) shall continue and remain in full force and effect, or
(b) if previously terminated as a result of Guarantors having fulfilled
Guarantors' obligations hereunder in full or as a result of Agent having
released Guarantors from Guarantors' obligations and liabilities hereunder,
shall without further act or instrument be reinstated and shall thereafter
remain in full force and effect, in either case with the same force and effect
as though such payment or portion thereof had not been made, and if applicable,
as if such previous termination had not occurred.

            15. Any notice, request or demand given or made under this Guaranty
shall be in writing and shall be sent by Federal Express or other reputable
national courier service or by postage prepaid registered or certified mail,
return receipt requested, and shall be deemed given (i) when received at the
following addresses if sent by Federal Express or other reputable national
courier service, and (ii) three (3) business days after being postmarked and
addressed as follows if sent by registered or certified mail, return receipt
requested:

                  If to Agent:

                        NationsBank, N.A.
                        Real Estate Banking
                        8300 Greensboro Drive
                        McLean, Virginia 22102-3604
                        Attention:  Gary P.F. Carr
                                    Vice President


                                       -4-
<PAGE>   131
                  With copies to:

                        Cadwalader, Wickersham & Taft
                        201 South College Street - Suite 1510
                        Charlotte, South Carolina 28244
                        Attention: James P. Carroll, Esq.

                  and

                        Battle Fowler LLP
                        Park Avenue Tower
                        75 East 55th Street
                        New York, New York 10022
                        Attention: Dean A. Stiffle, Esq.

                  If to Guarantors:

                        c/o Brandywine Realty Trust
                        Newtown Square Corporate Campus
                        16 Campus Boulevard, Suite 150
                        Newtown Square, Pennsylvania 19073
                        Attention: Gerard H. Sweeney
                                   President and Chief Executive Officer

                  With a copy to:

                        Pepper, Hamilton & Scheetz
                        3000 Two Logan Square
                        Eighteenth and Arch Streets
                        Philadelphia, Pennsylvania 19103-2799
                        Attention: Michael H. Friedman, Esq.


Each party to this Guaranty may designate a change of address by notice given to
the other parties fifteen (15) days prior to the date such change of address is
to become effective.

            16. This Guaranty is, and shall be deemed to be, a contract entered
into under and pursuant to the laws of the State of New York and shall be in all
respects governed, construed, applied and enforced in accordance with the laws
of the State of New York. No defense given or allowed by the laws of any other
state or country shall be interposed in any action, case or proceeding hereon
unless such defense is also given or allowed by the laws of the State of New
York.

            17. No exculpatory provisions contained in the Credit Facility
Documents shall in any event or under any circumstance be deemed or construed to
modify, qualify, or affect in any manner whatsoever the personal recourse
obligations and liabilities of Guarantors under this Guaranty.

            18. Guarantors agree to submit to personal jurisdiction in the State
of New York in any action, case or proceeding arising out of this Guaranty and,
in furtherance of such agreement, Guarantors hereby agree and consent that
without limiting other methods of obtaining jurisdiction, personal jurisdiction
over Guarantors in any such action, case or proceeding may be obtained within or
without the jurisdiction of any court located in New York and that any process
or notice of motion or other application to any such court in connection with
any such action, case or proceeding may be served upon Guarantors by registered
or certified mail to or by personal service at the last known addresses of
Guarantors, whether such addresses be within or without the jurisdiction of any
such court. Guarantors also agree that the venue of any litigation arising in
connection with the Debt or in respect of


                                       -5-
<PAGE>   132
any of the obligations of Guarantors under this Guaranty shall, to the extent
permitted by law, be in New York County, New York.

            19. The obligations and liabilities of Guarantors under this
Guaranty are in addition to the obligations and liabilities of Guarantors under
the Other Guaranties (as hereinafter defined). The discharge of Guarantors'
obligations and liabilities under any one or more of the Other Guaranties by
Guarantors or by reason of operation of law or otherwise shall in no event or
under any circumstance constitute or be deemed to constitute a discharge, in
whole or in part, of Guarantors' obligations and liabilities under this
Guaranty. Conversely, the discharge of Guarantors' obligations and liabilities
under this Guaranty by Guarantors or by reason of operation of law or otherwise
shall in no event or under any circumstance constitute or be deemed to
constitute a discharge, in whole or in part, of Guarantors' obligations and
liabilities under any of the Other Guaranties. The term "Other Guaranties" as
used herein shall mean any other guaranty of payment, guaranty of performance,
completion guaranty, indemnification agreement or other guaranty or instrument
of personal recourse obligation or undertaking of any nature whatsoever (other
than this Guaranty) now or hereafter executed and delivered by Guarantors to
Agent or Co-Lenders or any of them in connection with the Credit Facility.

            20. This Guaranty may be executed in one or more counterparts by
some or all of the parties hereto, each of which counterparts shall be an
original and all of which together shall constitute a single agreement of
guaranty. The failure of any party listed below to execute this Guaranty, or any
counterpart hereof, shall not relieve the other signatories from their
obligations hereunder.

            21. No recourse shall be had for any obligation of BRT under this
Guaranty or for any claim based thereon or otherwise in respect thereof, against
any past, present or future trustee, shareholder, officer or employee of BRT,
whether by virtue of any statute or rule of law, or by the enforcement of any
assessment or penalty or otherwise, all such liability being expressly waived
and released by each other party to and beneficiary of this Guaranty.

            22. No personal recourse shall be had for any obligation of BRP
under this Guaranty or for any claim based thereon or otherwise in respect
thereof, against Brandywine Specified Property Investors Limited Partnership, a
Pennsylvania limited partnership and one of the general partners of BRP, whether
by virtue of any statute or rule of law, or by the enforcement of any assessment
or penalty or otherwise, all such liability being expressly waived and released
by each other party to and beneficiary of this Guaranty and by each of the other
general partners of BRP.


                                       -6-
<PAGE>   133
            IN WITNESS WHEREOF, Guarantors have duly executed and delivered this
Guaranty to Agent as of the day and year first above set forth.


                              WITMER OPERATING PARTNERSHIP, L.P., a Delaware
                              limited partner

                              By:   Brandywine Holdings I, Inc., a
                                    Pennsylvania corporation, its general
                                    partner

                                    By:   ______________________________
                                          Name:   Gerard H. Sweeney
                                          Title:  President and Chief
                                                  Executive Officer

                              BRANDYWINE REALTY PARTNERS, a Pennsylvania
                              general partnership

                              By:   Brandywine Realty Trust, a Maryland real
                                    estate investment trust, its general
                                    partner

                                    By:   ______________________________
                                          Name:   Gerard H. Sweeney
                                          Title:  President and Chief
                                                  Executive Officer

                              BRANDYWINE REALTY SERVICES CORPORATION, a
                              Pennsylvania corporation

                              By:   ______________________________
                                    Name:   Gerard H. Sweeney
                                    Title:  President and Chief
                                            Executive Officer


                                       -7-
<PAGE>   134
                                    EXHIBIT A
                                  (DEFINITIONS)



Agent: The term "Agent" as used in this Guaranty shall have the meaning given to
such term in the preamble to this Guaranty.

BOP: The term "BOP" as used in this Guaranty shall mean Brandywine Operating
Partnership, L.P., a Delaware Limited partnership.

Borrowers: The term "Borrowers" as used in this Guaranty shall mean collectively
BRT, BOP and the BRT/BOP Limited Partnership.

BRT: The term "BRT" as used in this Guaranty shall mean Brandywine Realty Trust,
a Maryland real estate investment trust.

BRT/BOP Limited Partnership: The term "BRT/BOP Limited Partnership" as used in
this Guaranty shall mean LC/N HORSHAM LIMITED PARTNERSHIP, a Pennsylvania
limited partnership; LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a Pennsylvania
limited partnership; NICHOLS LANSDALE LIMITED PARTNERSHIP III, a Pennsylvania
limited partnership; NEWTECH III LIMITED PARTNERSHIP, a Pennsylvania limited
partnership; NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania limited partnership;
C/N OAKLANDS LIMITED PARTNERSHIP I, a Pennsylvania limited partnership; FIFTEEN
HORSHAM, L.P., a Pennsylvania limited partnership; C/N LEEDOM LIMITED
PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN LIMITED
PARTNERSHIP III, a Pennsylvania limited partnership.

Co-Lenders: The term "Co-Lenders" as used in this Guaranty shall mean the
Initial Co-Lenders and all other parties from time to time to whom direct
interests in the Credit Facility are sold, transferred and assigned, and who are
as a result thereof designated as Co-Lenders, under and pursuant to the
provisions of the Credit Agreement and the Co-Lenders Agreement.

Co-Lenders Agreement: The term "Co-Lenders Agreement" as used in this Guaranty
shall mean that certain Co-Lender and Servicing Agreement dated as of the date
hereof among Smith Barney Mortgage Capital Group, Inc., NationsBank, N.A., in
its individual capacity, and NationsBank, N.A., in its capacity as Agent.

Credit Agreement: The term "Credit Agreement" as used in this Guaranty shall
mean that certain Revolving Credit Agreement dated as of the date hereof among
Smith Barney Mortgage Capital Group, Inc., NationsBank, N.A., in its individual
capacity, Borrowers and NationsBank, N.A., in its capacity as Agent and pursuant
to the provisions of which the Credit Facility is being extended by Co-Lenders
to Borrowers.

Credit Facility: The term "Credit Facility" as used in this Guaranty shall have
the meaning given to such term in paragraph B of the Preliminary Statement of
this Guaranty.

Credit Facility Documents: The term "Credit Facility Documents" as used in this
Guaranty shall have the meaning given to such term in the Credit Agreement.

Credit Facility Notes: The term "Credit Facility Notes" as used in this Guaranty
shall have the meaning given to such term in the Credit Agreement.

Debt: The term "Debt" as used in this Guaranty shall have the meaning given to
such term in the Credit Agreement.


                                       A-1
<PAGE>   135
Guarantors: The term "Guarantors" as used in this Guaranty shall have the
meaning given to such term in the preamble to this Guaranty.

Initial Co-Lenders: The term "Initial Co-Lenders" as used in this Guaranty shall
mean collectively Smith Barney Mortgage Capital Group, Inc., and NationsBank,
N.A.

Mortgages: The term "Mortgages" as used in this Guaranty shall have the meaning
given to such term in the Credit Agreement.

Other Guaranties: The term "Other Guaranties" as used in this Guaranty shall
have the meaning given to such term in paragraph 19 of this Guaranty.


                                       A-2
<PAGE>   136
                                    EXHIBIT K



                               HAZARDOUS MATERIAL
                                  GUARANTY AND
                            INDEMNIFICATION AGREEMENT


                  This Guaranty and Indemnification Agreement entered into as of
      the 25th day of November, 1996, among BRANDYWINE REALTY TRUST ("BRT"), a
      Maryland real estate investment trust; BRANDYWINE OPERATING PARTNERSHIP,
      L.P. ("BOP), a Delaware limited partnership, LC/N HORSHAM LIMITED
      PARTNERSHIP, a Pennsylvania limited partnership; LC/N KEITH VALLEY LIMITED
      PARTNERSHIP I, a Pennsylvania limited partnership; NICHOLS LANSDALE
      LIMITED PARTNERSHIP III, a Pennsylvania limited partnership; NEWTECH III
      LIMITED PARTNERSHIP, a Pennsylvania limited partnership; NEWTECH IV
      LIMITED PARTNERSHIP, a Pennsylvania limited partnership; C/N OAKLANDS
      LIMITED PARTNERSHIP I, a Pennsylvania limited partnership; FIFTEEN
      HORSHAM, L.P., a Pennsylvania limited partnership; C/N LEEDOM LIMITED
      PARTNERSHIP II, a Pennsylvania limited partnership; C/N IRON RUN LIMITED
      PARTNERSHIP III, a Pennsylvania limited partnership (collectively the
      "BRT/BOP Limited Partnerships") (BRT, BOP and the BRT/BOP Limited
      Partnerships are hereinafter collectively referred to as "Borrowers");
      WITMER OPERATING PARTNERSHIP, L.P. ("WOP"), a Delaware limited
      partnership; BRANDYWINE REALTY PARTNERS, a Pennsylvania general
      partnership ("BRP"); BRANDYWINE REALTY SERVICES CORPORATION ("BRSC"), a
      Pennsylvania corporation (BRT, BOP, the BRT/BOP Limited Partnerships, WOP,
      BRP and BRSC are hereinafter collectively referred to as "Guarantors");
      and NATIONSBANK, N.A., a national banking association having an office at
      8300 Greensboro Drive, McLean, Virginia in its capacity as administrative
      and documentation agent for the equal and ratable benefit of Co-Lenders
      pursuant to and in accordance with the terms and provisions of the Credit
      Agreement (NationsBank, N.A., acting in such capacity as administrative
      and documentation agent being hereinafter referred to as "Agent").

                              PRELIMINARY STATEMENT

            A. All capitalized terms as used in this Guaranty and
Indemnification Agreement shall, unless otherwise defined in this Guaranty and
Indemnification Agreement, have the meanings given to such terms in Exhibit A
attached hereto.

            B. The Initial Co-Lenders have agreed on the terms, covenants and
provisions of the Credit Agreement to extend to Borrowers a revolving credit
facility in the principal sum of up to, but not in excess of, $80,000,000 (the
"Credit Facility"), which Credit Facility shall be evidenced by the Credit
Facility Notes and secured inter alia by the Mortgages.

            C. The Initial Co-Lenders were willing to extend the Credit Facility
to Borrowers only if Guarantors execute and deliver this Guaranty and
Indemnification Agreement to Agent, individually, and as administrative and
documentation agent for the equal and ratable benefit of Co-Lenders.

            NOW, THEREFORE, in consideration of Ten Dollars ($10.00) and other
good and valuable consideration, the receipt of which is hereby acknowledged,
and to induce Initial Co-Lenders to extend the Credit Facility, Guarantors
hereby represent and warrant to and covenant and agree with Agent, individually
and for the equal and ratable benefit of Co-Lenders, as follows:
<PAGE>   137
            1. Guarantors hereby represents and warrants to Agent that to the
best of Guarantors' knowledge (i) no Hazardous Material is currently located at,
on, in, under or about any Property, except as specifically set forth in the
Environmental Reports, (ii) no Hazardous Material is currently located at, in,
on, under or about any Property in a manner which violates any Environmental
Requirement, or which requires cleanup or corrective action of any kind under
any Environmental Requirement, (iii) no releasing, emitting, discharging,
leaching, dumping or disposing of any Hazardous Material from any Property onto
or into any other property or from any other property onto or into any Property
has occurred or is occurring in violation of any Environmental Requirement, (iv)
no notice of violation, lien, complaint, suit, order or other notice with
respect to any Property is presently outstanding under any Environmental
Requirement, and (v) each Property and the operation thereof are in full
compliance with all Environmental Requirements.

            2. Guarantors absolutely and unconditionally guarantee to Agent that
Borrowers will fully comply with all of the Environmental Provisions of the
Credit Agreement. If Borrowers do not fully comply with all of the Environmental
Provisions of the Credit Agreement, Guarantors shall reimburse Agent upon demand
for all costs and expenses (including, but not limited to, reasonable legal
fees) incurred by Agent or any Co-Lender (to the extent not otherwise reimbursed
to Agent or any such Co-Lender by Borrowers) in connection with Agent or any of
Co-Lenders performing Borrowers' obligations under or in respect of the
Environmental Provisions of the Credit Agreement, together with interest thereon
at the Default Rate.

            3. Guarantors will defend, indemnify, and hold harmless Agent and
Co-Lenders, and their respective employees, agents, officers and directors, from
and against any and all claims, demands, penalties, causes of action, fines,
liabilities, settlements, damages, costs or expenses of whatever kind or nature,
known or unknown, foreseen or unforeseen, contingent or otherwise (including,
without limitation, consultant fees and expenses, investigation and laboratory
fees and expenses, court costs, litigation expenses and reasonable attorneys
fees) arising out of, or in any way related to (i) any breach by Borrowers of
any of the Environmental Provisions of the Credit Agreement, (ii) the presence,
disposal, spillage, discharge, emission, leakage, release, or threatened release
of any Hazardous Material which is at, in, on, under, about, from or affecting
any Property, including without limitation, any damage or injury resulting from
any such Hazardous Material to or affecting any Property or the soil, water,
air, vegetation, buildings, personal property, persons or animals located on any
Property or on any other property or otherwise, (iii) any personal injury
(including wrongful death) or property damage (real or personal) arising out of
or related to any such Hazardous Material, (iv) any lawsuit brought or
threatened, settlement reached, or order or directive of or by any Governmental
Authority relating to such Hazardous Material, or (v) any violation of any
Environmental Requirement.

            4. The indemnifications hereinabove set forth in this Guaranty and
Indemnification Agreement shall not be applicable to any claim, demand, penalty,
cause of action, fine, liability, settlement, damage, cost or other expense of
any type whatsoever pertaining to a particular Property (i) occasioned, arising
and caused solely and directly as the result of the negligence or willful
misconduct of Agent or any Co-Lender, or any nominee or any wholly owned
subsidiary of Agent or a Co-Lender or any of their respective employees or
agents and irrespective of whether occurring prior or subsequent to the date
upon which Agent or any Co-Lender or any nominees or any wholly owned
subsidiaries of Agent or any Co-Lender acquires possession of such Property by
foreclosure of a Mortgage, a sale of such Property pursuant to the provisions of
a Mortgage, acceptance of a deed or assignment in lieu of foreclosure or sale or
otherwise, or (ii) occasioned, arising and caused solely and directly as the
result of any act of any person or party (other


                                       -2-
<PAGE>   138
than (A) an act of Borrowers or Guarantors, their respective employees or agents
or persons or parties under the control of Borrowers or Guarantors, or (B) an
act of Agent or any Co-Lender, any nominee or any wholly owned subsidiary of
Agent or any Co-Lender or any of their respective employees or agents which does
not constitute negligence or willful misconduct, or (C) an act of any
Governmental Authority, including, without limitation, any change in any
Environmental Requirement) and occurring subsequent to the earlier to occur of
(x) the date of payment in cash of the entire Debt, and (y) the date upon which
Agent, Co-Lenders, any nominee(s) or any wholly owned subsidiary(ies) of Agent
or Co-Lenders acquire possession of such Property by foreclosure of a Mortgage,
a sale of such Property pursuant to the provisions of a Mortgage, acceptance of
a deed or assignment in lieu of foreclosure or sale or otherwise.

            5. Except as hereinabove specifically provided to the contrary in
paragraph 4 above, the obligations and liabilities of Guarantors under this
Guaranty and Indemnification Agreement shall survive and continue in full force
and effect and shall not be terminated, discharged or released, in whole or in
part, irrespective of whether the Debt has been paid in full and irrespective of
any foreclosure of the Mortgages, the sale of any one or more of the Properties
pursuant to the provisions of the Mortgages or acceptance by Agent, Co-Lenders,
their nominee(s) or wholly-owned subsidiary(ies), of one or more deeds or
assignments in lieu of foreclosure or sale and irrespective of any other fact or
circumstance whatsoever.

            6. Guarantors hereby consent that from time to time, before or after
any default by Borrowers, with or without further notice to or assent from
Guarantors, any security at any time held by or available to Agent or any
Co-Lender for any obligation of Borrowers, or any security at any time held by
or available to Agent or any Co-Lenders for any obligation of any other person
or party secondarily or otherwise liable for all or any portion of the Debt or
for the performance of all or any portion of the Environmental Provisions of the
Credit Agreement, may be exchanged, surrendered or released and any obligation
of Borrowers, or of any such other person or party, may be changed, altered,
renewed, extended, continued, surrendered, compromised, waived or released in
whole or in part, or any default with respect thereto waived, and Agent or any
Co-Lender may fail to set off and may release, in whole or in part, any balance
of any deposit account or credit on its books in favor of Borrowers, or of any
such other person or party, and may extend further credit in any manner
whatsoever to Borrowers, and generally deal with Borrowers or any such security
or other person or party as Agent or such Co-Lender may see fit; and Guarantors
shall remain bound under this Guaranty and Indemnification Agreement
notwithstanding any such exchange, surrender, release, change, alteration,
renewal, extension, continuance, compromise, waiver, inaction, extension of
further credit or other dealing.

            7. To the full extent that this Guaranty and Indemnification
Agreement relates to any monetary obligation of Borrowers in respect of the
Environmental Provisions of the Credit Agreement, this Guaranty and
Indemnification Agreement is a guaranty of payment and not of collection and
Guarantors further waive any right to require that any action, case or
proceeding be brought against Borrowers or any other person or party or to
require that resort be had to any security or to any balance of any deposit
account or credit on the books of Agent or any Co-Lender in favor of Borrowers
or any other person or party.

            8. Each reference herein to Co-Lenders and to Agent shall be deemed
to include their respective successors and assigns, in whose favor the
provisions of this Guaranty and Indemnification Agreement shall also inure. Each
reference herein to Guarantors shall be deemed to include the successors and
assigns of Guarantors, all of whom shall be bound by the provisions of this
Guaranty and Indemnification Agreement, provided, however, that


                                       -3-
<PAGE>   139
Guarantors shall in no event or under any circumstance have the right without
obtaining the prior written consent of Agent to assign or transfer their
respective obligations and liabilities under this Guaranty and Indemnification
Agreement, in whole or in part, to any other person, party or entity.

            9. The term "Guarantors" as used herein shall mean the "Guarantors
and each of them" and each undertaking herein contained shall be their joint and
several undertaking, provided, however, that in the next succeeding paragraph
hereof the term "Guarantors" shall mean the "Guarantors or any of them."

            10. No delay on the part of Agent in exercising any right or remedy
under this Guaranty and Indemnification Agreement or failure to exercise the
same shall operate as a waiver in whole or in part of any such right or remedy.
No notice to or demand on Guarantors shall be deemed to be a waiver of the
obligation of Guarantors or of the right of Agent to take further action without
notice or demand as provided in this Guaranty and Indemnification Agreement.

            11. This Guaranty and Indemnification Agreement may only be
modified, amended, changed or terminated by an agreement in writing signed by
Agent and Guarantors. No waiver of any term, covenant or provision of this
Guaranty and Indemnification Agreement shall be effective unless given in
writing by Agent and if so given by Agent shall only be effective in the
specific instance in which given.

            12. Guarantors acknowledge that this Guaranty and Indemnification
Agreement and Guarantors's obligations under this Guaranty and Indemnification
Agreement are and shall at all times continue to be absolute and unconditional
in all respects, and shall at all times be valid and enforceable irrespective of
(a) any other agreements or circumstances of any nature whatsoever which might
otherwise constitute a defense (other than a defense of payment) to this
Guaranty and Indemnification Agreement and the obligations of Guarantors under
this Guaranty and Indemnification Agreement or the obligations of Borrowers or
of any other person or party relating to this Guaranty and Indemnification
Agreement or the obligations of Guarantors hereunder or otherwise with respect
to the Credit Facility, including, but not limited to, the realization by Agent
or any Co-Lender upon any collateral given, pledged or assigned as security for
all or any portion of the Debt or for the performance of the Environmental
Provisions of the Credit Agreement, or the filing of a petition or the
commencement of a case with respect to any Borrower or any Guarantor under Title
11 of the United States Code, as now constituted or hereafter amended (the
"Bankruptcy Code"), or under any other applicable Federal or state bankruptcy,
insolvency or similar law, or the obtaining by Agent or any Co-Lender of title
to any collateral given, pledged or assigned as security for the Debt or for the
performance of the Environmental Provisions of the Credit Agreement, by
foreclosure or enforcement of Agent's or any Co-Lender's lien thereon,
acceptance of an assignment or deed in lieu of foreclosure or sale, or
otherwise, or (b) any modification, impairment, abatement, reduction, release,
limitation, restructure, reinstatement or cure, in whole or part, of the
Environmental Provisions of the Credit Agreement (including, without limitation,
any such modification, impairment, abatement, reduction, release, limitation,
restructure, reinstatement or cure, in whole or in part, of any interest or
other sums payable by Borrowers under or in respect of the Environmental
Provisions of the Credit Agreement) pursuant to an order by a bankruptcy court
or other court of competent jurisdiction in any action, case or proceeding
brought under the Bankruptcy Code or under any other applicable Federal or state
bankruptcy, insolvency or similar law, it being expressly acknowledged and
agreed by Guarantors that if any such modification, impairment, abatement,
reduction, release, limitation, restructure, reinstatement or cure, in whole or
part, is so ordered in any such action, case or proceeding, Guarantors'
obligations under this Guaranty and

                                       -4-
<PAGE>   140
Indemnification Agreement will nevertheless continue to be determined as if such
order had not been issued. Guarantors absolutely, unconditionally and
irrevocably waive any and all right to assert any defense, setoff, counterclaim
or crossclaim of any nature whatsoever with respect to this Guaranty and
Indemnification Agreement or the obligations of Guarantors under this Guaranty
and Indemnification Agreement or the obligations of Borrowers or any other
person or party relating to this Guaranty and Indemnification Agreement or the
obligations of Guarantors hereunder or otherwise with respect to the Credit
Facility, in any action, case or proceeding brought by Agent or Co-Lenders to
enforce the obligations of Guarantors under this Guaranty and Indemnification
Agreement (provided, however, that the foregoing provisions of this sentence
shall not be deemed a waiver of the right of the Guarantors to assert any
compulsory counterclaim in any such action, case or proceeding brought by Agent
or Co-Lenders in any state court if such counterclaim is compelled under local
law or rule or procedure, or in any such action, case or proceeding brought by
Agent or Co-Lenders in a court of the United States, nor shall the foregoing
provisions of this sentence be deemed a waiver of the right of the Guarantors to
assert any claim which would otherwise constitute a defense, setoff,
counterclaim or crossclaim of any nature whatsoever against Agent or Co-Lenders
in any separate action, case or proceeding brought by the Guarantors against
Agent of Co-Lenders). Guarantors acknowledge that no oral or other agreements,
understandings, representations or warranties exist with respect to this
Guaranty and Indemnification Agreement or with respect to the obligations of
Guarantors under this Guaranty and Indemnification Agreement, except those
specifically set forth in this Guaranty and Indemnification Agreement, and that
this Guaranty and Indemnification Agreement sets forth the entire agreement and
understanding of Agent, Co-Lenders and Guarantors.

            13. GUARANTORS HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVE, AND
AGENT AND CO-LENDERS BY THEIR ACCEPTANCE OF THIS GUARANTY AND INDEMNIFICATION
AGREEMENT IRREVOCABLY AND UNCONDITIONALLY WAIVE, ANY AND ALL RIGHT TO TRIAL BY
JURY IN ANY ACTION, CASE, PROCEEDING, SUIT OR COUNTERCLAIM ARISING IN CONNECTION
WITH, OUT OF OR OTHERWISE RELATING TO THIS GUARANTY AND INDEMNIFICATION
AGREEMENT.

            14. Notwithstanding any payments made by Guarantors pursuant to the
provisions of this Guaranty and Indemnification Agreement, Guarantors shall not
seek to enforce or collect upon any rights which Guarantors now have or may
acquire against Borrowers either by way of subrogation, indemnity, reimbursement
or contribution for any amount paid under this Guaranty and Indemnification
Agreement, nor shall Guarantors file, assert or receive payment on any claim,
whether now existing or hereafter arising, against Borrowers subsequent to the
commencement of a case by or against Borrowers under the Bankruptcy Code or
under any other applicable Federal or state bankruptcy, insolvency or similar
law, in each case unless and until the Debt has been paid in full and provided
that no such action by Guarantors could, in the reasonable opinion of Agent and
its counsel, result in the "preference" period (as set forth in Section
547(b)(4) of the Bankruptcy Code or any successor provision) with respect to any
payment or other transfer of assets to Agent or to any Co-Lender from or on
behalf of Borrowers being held to be longer than such period would have been
held to be if Guarantors had not taken such action. In the event an action, case
or proceeding is filed or commenced under the Bankruptcy Code or under any other
applicable Federal or state bankruptcy, insolvency or similar law in regard to
Borrowers or an action, case or proceeding is otherwise commenced for the
benefit of the creditors of Borrowers, this Guaranty and Indemnification
Agreement shall at all times thereafter remain effective in regard to any
payments to Agent or any Co-Lender or other transfers of assets to Agent or any
Co-Lender received from or on behalf of Borrowers under or in respect of the
Environmental Provisions of the Credit Facility Documents which are held
voidable on the grounds of preference, fraudulent conveyance or otherwise,
whether or not the Debt has been paid in full or whether or not the Mortgages or
any or all of the


                                       -5-
<PAGE>   141
Environmental Provisions of the Credit Agreement have been discharged or
released.

            15. If at any time any payment, or portion thereof, made by, or for
the account of, Guarantors on account of the obligations under this Guaranty and
Indemnification Agreement, is set aside by any court or trustee having
jurisdiction as a voidable preference, fraudulent conveyance or otherwise as
being subject to avoidance or recovery under the provisions of the Bankruptcy
Code or under any other applicable Federal or state bankruptcy, insolvency or
similar law, Guarantors hereby agree that this Guaranty and Indemnification
Agreement (a) shall continue and remain in full force and effect, or (b) if
previously terminated as a result of Guarantors having fulfilled Guarantors'
obligations hereunder in full or as a result of Agent having released Guarantors
from Guarantors' obligations and liabilities hereunder, shall without further
act or instrument be reinstated and shall thereafter remain in full force and
effect, in either case with the same force and effect as though such payment or
portion thereof had not been made, and if applicable, as if such previous
termination had not occurred.

            16. Any notice, request or demand given or made under this Guaranty
and Indemnification Agreement shall be in writing and shall be sent by Federal
Express or other reputable national courier service or by postage prepaid
registered or certified mail, return receipt requested, and shall be deemed
given (i) when received at the following addresses if sent by Federal Express or
other reputable national courier service, and (ii) three (3) business days after
being postmarked and addressed as follows if sent by registered or certified
mail, return receipt requested:

                  If to Agent:

                        NationsBank, N.A.
                        Real Estate Banking
                        8300 Greensboro Drive
                        McLean, Virginia 22102-3604
                        Attention: Gary P.F. Carr
                                   Vice President

                  With copies to:

                        Cadwalader, Wickersham & Taft
                        201 South College Street - Suite 1510
                        Charlotte, North Carolina 28244
                        Attention: James P. Carroll, Esq.

                  and

                        Battle Fowler LLP
                        Park Avenue Tower
                        75 East 55th Street
                        New York, New York 10022
                        Attention: Dean A. Stiffle, Esq.

                  If to Borrowers:

                        c/o Brandywine Realty Trust
                        Newtown Square Corporate Campus
                        16 Campus Boulevard, Suite 150
                        Newtown Square, Pennsylvania 19073
                        Attention: Gerard H. Sweeney
                                   President and Chief
                                   Executive Officer


                                       -6-
<PAGE>   142
                  With a copy to:

                        Pepper, Hamilton & Scheetz
                        3000 Two Logan Square
                        Eighteenth and Arch Streets
                        Philadelphia, Pennsylvania 19103-2799
                        Attention: Michael H. Friedman, Esq.

                  If to Guarantors:

                        c/o Brandywine Realty Trust
                        Newtown Square Corporate Campus
                        16 Campus Boulevard, Suite 150
                        Newtown Square, Pennsylvania 19073
                        Attention: Gerard H. Sweeney
                                   President and Chief
                                   Executive Officer

                  With a copy to:

                        Pepper, Hamilton & Scheetz
                        3000 Two Logan Square
                        Eighteenth and Arch Streets
                        Philadelphia, Pennsylvania 19103-2799
                        Attention: Michael H. Friedman, Esq.


Each party to this Guaranty and Indemnification Agreement may designate a change
of address by notice given to the other parties fifteen (15) days prior to the
date such change of address is to become effective.

            17. This Guaranty and Indemnification Agreement is, and shall be
deemed to be, a contract entered into under and pursuant to the laws of the
State of New York and shall be in all respects governed, construed, applied and
enforced in accordance with the laws of the State of New York. No defense given
or allowed by the laws of any other state or country shall be interposed in any
action, case or proceeding hereon unless such defense is also given or allowed
by the laws of the State of New York.

            18. Guarantors agree to submit to personal jurisdiction in the State
of New York in any action, case or proceeding arising out of this Guaranty and
Indemnification Agreement and, in furtherance of such agreement, Guarantors
hereby agree and consent that without limiting other methods of obtaining
jurisdiction, personal jurisdiction over Guarantors in any such action, case or
proceeding may be obtained within or without the jurisdiction of any court
located in New York and that any process or notice of motion or other
application to any such court in connection with any such action, case or
proceeding may be served upon Guarantors by registered or certified mail to or
by personal service at the last known addresses of Guarantors, whether such
addresses be within or without the jurisdiction of any such court. Guarantors
also agree that the venue of any litigation arising in connection with the
Environmental Provisions of the Credit Agreement, the Debt or in respect of any
of the obligations of Guarantors under this Guaranty and Indemnification
Agreement shall, to the extent permitted by law, be in New York County, New
York.

            19. No exculpatory provisions contained in any of the Credit
Facility Documents shall in any event or any circumstance be deemed or construed
to modify, qualify, or affect in any manner whatsoever the personal recourse
obligations and liabilities of Guarantors under this Guaranty and
Indemnification Agreement.


                                       -7-
<PAGE>   143
            20. The obligations and liabilities of Guarantors under this
Guaranty and Indemnification Agreement are in addition to the obligations and
liabilities of Guarantors under the Other Guaranties (as hereinafter defined).
The discharge of Guarantors' obligations and liabilities under any one or more
of the Other Guaranties by Guarantors or by reason of operations of law or
otherwise shall in no event or under any circumstance in and of itself
constitute or be deemed to constitute a discharge, in whole or in part, of
Guarantors' obligations and liabilities under this Guaranty and Indemnification
Agreement. Conversely, the discharge of Guarantors' obligations and liabilities
under this Guaranty and Indemnification Agreement by Guarantors or by reason of
operation of law or otherwise shall in no event or under any circumstance in and
of itself constitute or be deemed to constitute a discharge, in whole or in
part, of Guarantors' obligations and liabilities under any of the Other
Guaranties. The term "Other Guaranties" as used herein shall mean any other
guaranty of payment, guaranty of performance, completion guaranty,
indemnification agreement or other guaranty or instrument of personal recourse
obligation or undertaking of any nature whatsoever (other than this Guaranty and
Indemnification Agreement) now or hereafter executed and delivered by Guarantors
to Agent or Co-Lenders or any of them in connection with the Credit Facility.

            21. This Guaranty and Indemnification Agreement may be executed in
one or more counterparts by some or all of the parties hereto, each of which
counterparts shall be an original and all of which together shall constitute a
single agreement of guaranty. The failure of any party listed below to execute
this Guaranty and Indemnification Agreement, or any counterpart hereof, shall
not relieve the other signatories from their obligations hereunder.

            22. Guarantors agree that, with or without notice or demand,
Guarantors will reimburse Agent, (to the extent that such reimbursement is not
made by Borrowers), for all costs and expenses (including, without limitation,
reasonable attorneys' fees) incurred by Agent or any Co-Lender in connection
with any action, case or proceeding brought by Agent to enforce the obligations
of Guarantors under this Guaranty and Indemnification Agreement.

            23. No recourse shall be had for any obligation of BRT under this
Guaranty and Indemnification Agreement or for any claim based thereon or
otherwise in respect thereof, against any past, present or future trustee,
shareholder, officer or employee of BRT, whether by virtue of any statute or
rule of law, or by the enforcement of any assessment or penalty or otherwise,
all such liability being expressly waived and released by each other party to
and beneficiary of this Guaranty and Indemnification Agreement.

            24. No recourse shall be had for any obligation of BRP under this
Guaranty and Indemnification Agreement or any of the other Credit Facility
Documents or for any claim based thereon or otherwise in respect thereof,
against Brandywine Specified Property Investors Limited Partnership, a
Pennsylvania limited partnership and one of the general partners of BRP, whether
by virtue of any statute or rule of law, or by the enforcement of any assessment
or penalty or otherwise, all such liability being expressly waived and released
by each other party to and beneficiary of this Guaranty and Indemnification
Agreement and by the other general partners of BRP.


                                       -8-
<PAGE>   144
            IN WITNESS WHEREOF, Guarantors have duly executed and delivered this
Guaranty and Indemnification Agreement to Agent as of the day and year first
above set forth.

                              BRANDYWINE REALTY TRUST, a Maryland real estate
                              investment trust

                              By:_________________________________
                                    Name:   Gerard H. Sweeney
                                    Title:  President and Chief
                                            Executive Officer

                              BRANDYWINE OPERATING PARTNERSHIP, L.P., a
                              Delaware limited partnership

                              By:   Brandywine Realty Trust, a Maryland real
                                    estate investment trust, its general
                                     partner

                                    By:  _________________________
                                         Name:  Gerard H. Sweeney
                                         Title: President and Chief
                                                Executive Officer

                              LC/N HORSHAM LIMITED PARTNERSHIP, a Pennsylvania
                              limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              LC/N KEITH VALLEY LIMITED PARTNERSHIP I, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                       -9-
<PAGE>   145
                              NICHOLS LANSDALE LIMITED PARTNERSHIP III, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              NEWTECH III LIMITED PARTNERSHIP, a Pennsylvania
                              limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              NEWTECH IV LIMITED PARTNERSHIP, a Pennsylvania
                              limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                      -10-
<PAGE>   146
                              C/N OAKLANDS LIMITED PARTNERSHIP I, a
                              Pennsylvania limited partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              FIFTEEN HORSHAM, L.P., a Pennsylvania limited
                              partnership

                              By:   Witmer Operating Partnership I, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Holdings I, Inc., a
                                          Pennsylvania corporation, its
                                          general partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              C/N LEEDOM LIMITED PARTNERSHIP II, a
                              Pennsylvania limited partnership

                              By:   Brandywine Operating Partnership, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Realty Trust, a Maryland
                                          limited partnership, its general
                                          partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer


                                      -11-
<PAGE>   147
                              C/N IRON RUN LIMITED PARTNERSHIP III, a
                              Pennsylvania limited partnership

                              By:   Brandywine Operating Partnership, L.P., a
                                    Delaware limited partnership, its general
                                    partner

                                    By:   Brandywine Realty Trust, a Maryland
                                          limited partnership, its general
                                          partner

                                          By:___________________________
                                             Name:   Gerard H. Sweeney
                                             Title:  President and Chief
                                                     Executive Officer

                              WITMER OPERATING PARTNERSHIP, L.P.

                              By:   Brandywine Holdings I, Inc., a
                                    Pennsylvania corporation, its general
                                    partner

                                    By:___________________________
                                       Name:   Gerard H. Sweeney
                                       Title:  President and Chief
                                               Executive Officer

                              BRANDYWINE REALTY PARTNERS, a Pennsylvania
                              general partnership

                              By:   Brandywine Realty Trust, a Maryland
                                    limited partnership, its general partner

                                    By:___________________________
                                       Name:   Gerard H. Sweeney
                                       Title:  President and Chief
                                               Executive Officer

                              BRANDYWINE REALTY CORPORATION, a Pennsylvania
                              corporation

                                    By:___________________________
                                       Name:    Gerard H. Sweeney
                                       Title:   President and Chief
                                                Executive Officer


                                      -12-
<PAGE>   148
                                    EXHIBIT A

                                  (DEFINITIONS)




Agent: The term "Agent" as used in this Guaranty and Indemnification Agreement
shall have the meaning given to such term in the preamble to this Guaranty and
Indemnification Agreement.

BOP: The term "BOP" as used in this Guaranty and Indemnification Agreement shall
have the meaning given to such term in the preamble to this Guaranty and
Indemnification Agreement.

Borrowers: The term "Borrowers" as used in this Guaranty and Indemnification
Agreement shall have the meaning given to such term in the preamble to this
Guaranty and Indemnification Agreement.

BRT: The term "BRT" as used in this Guaranty and Indemnification Agreement shall
have the meaning given to such term in the preamble to this Guaranty and
Indemnification Agreement.

BRT/BOP Limited Partnership: The term "BRT/BOP Limited Partnership" as used in
this Guaranty and Indemnification Agreement shall have the meaning given to such
term in the preamble to this Guaranty and Indemnification Agreement.

Co-Lenders: The term "Co-Lenders" as used in this Guaranty and Indemnification
Agreement shall mean the Initial Co-Lenders and all other parties from time to
time to whom direct interests in the Credit Facility are sold, transferred and
assigned, and who are as a result thereof designated as Co-Lenders, under and
pursuant to the provisions of the Credit Agreement and the Co-Lenders Agreement.

Co-Lenders Agreement: The term "Co-Lenders Agreement" as used in this Guaranty
and Indemnification Agreement shall mean that certain Co-Lender and Servicing
Agreement dated as of the date hereof among Smith Barney Mortgage Capital Group,
Inc., NationsBank, N.A., in its individual capacity, and NationsBank, N.A., in
its capacity as Agent.

Credit Agreement: The term "Credit Agreement" as used in this Guaranty and
Indemnification Agreement shall mean that certain Revolving Credit Agreement
dated as of the date hereof among Smith Barney Mortgage Capital Group, Inc.,
NationsBank, N.A., in its individual capacity, Borrowers and NationsBank, N.A.,
in its capacity as Agent and pursuant to the provisions of which the Credit
Facility is being extended by Co-Lenders to Borrowers.

Credit Facility: The term "Credit Facility" as used in this Guaranty and
Indemnification Agreement shall have the meaning given to such term in paragraph
B of the Preliminary Statement of this Guaranty and Indemnification Agreement.

Credit Facility Documents: The term "Credit Facility Documents" as used in this
Guaranty and Indemnification Agreement shall have the meaning given to such term
in the Credit Agreement.

Credit Facility Notes: The term "Credit Facility Notes" as used in this Guaranty
and Indemnification Agreement shall have the meaning given to such term in the
Credit Agreement.

Debt:  The term "Debt" as used in this Guaranty and Indemnification Agreement
shall have the meaning given to such term in the Credit Agreement.

                                       A-1
<PAGE>   149
Default Rate: The term "Default Rate" as used in this Guaranty and
Indemnification Agreement shall to the extent necessary be determined on a daily
basis and shall be equal to four (4%) percent plus the Floating Rate.

Environmental Provisions: The term "Environmental Provisions" as used in this
Guaranty and Indemnification Agreement shall mean the terms, covenants and
provisions set forth in the paragraph of the Credit Agreement entitled
"Environmental Provisions" on the part of Borrowers to be observed and
performed.

Environmental Requirements: The term "Environmental Requirements" as used in
this Guaranty and Indemnification Agreement shall mean all present and future
laws, statutes, ordinances, rules, regulations, orders, codes, licenses,
permits, decrees, judgments, directives or the equivalent of or by any
Governmental Authority and relating to or addressing the protection of the
environment or human health.

Environmental Reports: The term "Environmental Reports" as used in this Guaranty
and Indemnification Agreement shall have the meaning given to such term in the
Credit Agreement.

Floating Rate: The term "Floating Rate" as used in this Guaranty and
Indemnification Agreement shall have the meaning given to such term in the
Credit Agreement.

Governmental Authority: The term "Governmental Authority" as used in this
Guaranty and Indemnification Agreement shall mean the Federal government, or any
state or other political subdivision thereof, or any agency, court or body of
the Federal government, any state or other political subdivision thereof,
exercising executive, legislative, judicial, regulatory or administrative
functions.

Guarantors: The term "Guarantors" as used in this Guaranty and Indemnification
Agreement shall have the meaning given to such term in the preamble to this
Guaranty and Indemnification Agreement.

Hazardous Material: The term "Hazardous Material" as used in this Guaranty and
Indemnification Agreement shall mean any material or substance that, whether by
its nature or use, is now or hereafter defined as a hazardous waste, hazardous
substance, pollutant or contaminant under any Environmental Requirement, or
which is toxic, explosive, corrosive, flammable, infectious, radioactive,
carcinogenic, mutagenic or otherwise hazardous and which is now or hereafter
regulated under any Environmental Requirement, or which is or contains
petroleum, gasoline, diesel fuel or another petroleum hydrocarbon product.

Initial Co-Lenders: The term "Initial Co-Lenders" as used in this Guaranty and
Indemnification Agreement shall mean collectively Smith Barney Mortgage Capital
Group, Inc., and NationsBank, N.A.

Mortgages: The term "Mortgages" as used in this Guaranty and Indemnification
Agreement shall have the meaning given to such term in the Credit Agreement.

Other Guaranties: The term "Other Guaranties" as used in this Guaranty and
Indemnification Agreement shall have the meaning given to such term in paragraph
20 of this Guaranty and Indemnification Agreement.

Properties: The term "Properties" as used in this Guaranty and Indemnification
Agreement shall have the meaning given to such term in the Credit Agreement.


                                       A-2
<PAGE>   150
                                    EXHIBIT L

                       (Form of Co-Lenders Certificate)**


                  NationsBank, N.A., not individually but in its capacity as
administrative agent and documentation agent ("Agent") for the equal and ratable
benefit of Co-Lenders, under a certain Revolving Credit Agreement (the "Credit
Agreement") dated November 25, 1996, entered into among SMITH BARNEY MORTGAGE
CAPITAL GROUP, INC.; NATIONSBANK, N.A., acting in its individual capacity;
BRANDYWINE REALTY TRUST; BRANDYWINE OPERATING PARTNERSHIP, L.P.; LC/N HORSHAM
LIMITED PARTNERSHIP; LC/N KEITH VALLEY LIMITED PARTNERSHIP I; NICHOLS LANSDALE
LIMITED PARTNERSHIP III; NEWTECH III LIMITED PARTNERSHIP; NEWTECH IV LIMITED
PARTNERSHIP; C/N OAKLANDS LIMITED PARTNERSHIP I; FIFTEEN HORSHAM, L.P.; C/N
LEEDOM LIMITED PARTNERSHIP II; C/N IRON RUN LIMITED PARTNERSHIP III; and
NATIONSBANK, N.A., as Agent, hereby certifies to Borrowers as follows:

                  The Credit Facility Percentage Interests held by each
Co-Lender in the Credit Facility (inclusive of any risk participations in any
Letter of Credit which is issued and outstanding under the Credit Facility) on
the date hereof are as follows:

                                    Amount         Percentage Interest


Smith Barney                     $__________             _____%

NationsBank                      $__________             _____%

____________                     $__________             _____%

____________                     $__________             _____%

____________                     $__________             _____%

____________                     $__________             _____%


Dated:  _______________, 199_               NATIONSBANK, N.A., as Agent



                                            By:      __________________________
                                                     Name:
                                                     Title:
________

**       All terms used in this Co-Lenders Certificate shall have the meanings
         given to such terms in the Credit Agreement.
<PAGE>   151
                                    EXHIBIT M

                         (Form of Operating Statements)


TO BE MUTUALLY AGREED UPON BY INITIAL LENDERS AND BORROWERS SUBSEQUENT TO THE
DATE OF THIS AGREEMENT.
<PAGE>   152
                                    EXHIBIT N

                         (Form of Financial Statements)

TO BE MUTUALLY AGREED UPON BY INITIAL LENDERS AND BORROWERS SUBSEQUENT TO THE
DATE OF THIS AGREEMENT.
<PAGE>   153
                                    EXHIBIT O

                           (Form of Operating Budgets)


TO BE MUTUALLY AGREED UPON BY INITIAL LENDERS AND BORROWERS SUBSEQUENT TO THE
DATE OF THIS AGREEMENT.
<PAGE>   154
                                    EXHIBIT P

                     (Form of Reconciled Quarterly Budgets)


TO BE MUTUALLY AGREED UPON BY INITIAL LENDERS AND BORROWERS SUBSEQUENT TO THE
DATE OF THIS AGREEMENT.
<PAGE>   155
                                    EXHIBIT Q

                            (Insurance Requirements)


                  Insurance Coverage. Borrowers will insure the Properties
against such perils and hazards, and in such amounts and with such limits, as
Co-Lender may from time to time require, and in any event will continuously
maintain, without cost or expense to Co-Lenders, each of the following described
Insurance Policies with respect to each Property and naming Co-Lenders, their
affiliates, subsidiaries, successors and assigns, as their interests may appear,
as additional insured:

                                    A. All risk property insurance against loss
                  and damage by all risks of physical loss or damage, including,
                  but not limited to, fire, sprinkler leakage, windstorm and
                  other risks covered by the so-called extended coverage
                  endorsement, covering the Property and the FF&E in amounts not
                  less than one hundred percent (100%) of the full replacement
                  cost value of the Property and the FF&E from time to time
                  constituting part of the Collateral, with a one hundred
                  percent (100%) co-insurance clause or an "agreed value" form
                  endorsement in lieu of a one hundred percent (100%)
                  co-insurance clause and an inflation adjustment endorsement;

                                    B. Business interruption insurance
                  (including rental interruption insurance) to cover loss of
                  income, including all Rents, in an amount not less than twelve
                  (12) months' projected gross income of the Properties, as
                  determined from time to time by Co-Lenders;

                                    C. Steam boiler, machinery and pressurized
                  vessel insurance, with a limit of not less than Ten Million
                  Dollars ($10,000,000);

                                    D. Commercial general liability insurance
                  (including coverage for elevators) against death, bodily
                  injury and property damage with a combined single limit in an
                  amount of not less than One Million Dollars ($1,000,000),
                  including a waiver of subrogation clause acceptable to
                  Co-Lenders;

                                    E. Excess liability insurance with a limit
                  of not less than Four Million Dollars ($4,000,000) over
                  primary insurance, which insurance shall include, but not be
                  limited to, general and automobile liability, and safeguarding
                  of personalty, with coverages, risks insured and waiver of
                  subrogation clauses acceptable to Co-Lenders;

                                    F. If a Property or any portion thereof lies
                  within a federally designated flood hazard area other than
                  Zone C or Zone X, as described in the document entitled
                  "Department of Housing and Urban Development, Federal
                  Insurance Administration Special Flood Hazard Area Maps",
                  flood insurance at the maximum limit available through the
                  Federal Flood Insurance Program and to the extent the same is
                  available at commercially reasonable rates, supplemental
                  commercial insurance for not less than one hundred percent
                  (100%) of the insurable value of the Property.

                                    G. The types and amounts of coverage as are
                  customarily (i) maintained by owners or operators of
                  properties which are comparable to the Properties, and/or (ii)
                  required by sophisticated institutional lenders on credit
                  facilities which are similar to the Credit Facility, which
                  types and amounts of coverage shall be determined by
                  Co-Lenders in the exercise of their sole and absolute
                  discretion.
