
<PAGE>

                                                                  Exhibit 10.12


                        AGREEMENT OF PURCHASE AND SALE

                                   BETWEEN

                       VIRGINIA DRIVE ASSOCIATES, L.P.
                                  AS SELLER

                                     AND

                    BRANDYWINE OPERATING PARTNERSHIP, L.P.
                                   AS BUYER

                              December 15, 1997


<PAGE>



                              TABLE OF CONTENTS
                                                                            Page
                                      
                                      
                                 ARTICLE I
                                DEFINITIONS
Section 1.1  Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Section 1.2  Terms Generally . . . . . . . . . . . . . . . . . . . . . . . . .6
                                      
                                      
                                 ARTICLE II
                       PURCHASE AND SALE OF PROPERTY
Section 2.1  Sale. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Section 2.2  Purchase Price. . . . . . . . . . . . . . . . . . . . . . . . . .7
Section 2.3  Due Diligence . . . . . . . . . . . . . . . . . . . . . . . . . .9
                                      
                                      
                                ARTICLE III
                           CONDITIONS PRECEDENT
Section 3.1  Conditions to Buyer's Obligation to Purchase. . . . . . . . . . .9
Section 3.2  Conditions to Seller's Obligations to Sell. . . . . . . . . . . 11
Section 3.3  Termination . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Section 3.4  Waiver by Buyer . . . . . . . . . . . . . . . . . . . . . . . . 11
Section 3.5  [Intentionally Omitted].  . . . . . . . . . . . . . . . . . . . 12
                                      
                                      
                                ARTICLE IV
     REPRESENTATIONS AND WARRANTIES;BUYER'S EXAMINATION OF THE PROPERTY
Section 4.1  Representations and Warranties of Seller. . . . . . . . . . . . 12
Section 4.2  Estoppels . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Section 4.3  Limitation on Claims; Survival of Representations and 
             Warranties. . . . . . . . . . . . . . . . . . . . . . . . . . . 14


                                     -i-
<PAGE>

Section 4.4  Representations and Warranties of Buyer . . . . . . . . . . . . 16
Section 4.5  Buyer's Independent Investigation . . . . . . . . . . . . . . . 17
Section 4.6  Entry and Indemnity; Limits on Government Contacts. . . . . . . 20
Section 4.7  Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
                                          
                                          
                                     ARTICLE V
                                       TITLE
Section 5.1  Conveyance of Title . . . . . . . . . . . . . . . . . . . . . . 22
Section 5.2  Evidence of Title . . . . . . . . . . . . . . . . . . . . . . . 23
                                      
                                      
                                 ARTICLE VI
                           BROKERS AND EXPENSES
Section 6.1  Brokers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Section 6.2  Expenses. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
                                      
                                      
                                ARTICLE VII
                    INTERIM OPERATION OF THE PROPERTY
Section 7.1  Interim Operation of the Property . . . . . . . . . . . . . . . 24
Section 7.2  Tenant Improvement Costs, Leasing Commissions and Free Rent . . 25
Section 7.3  Seller's Maintenance of the Property. . . . . . . . . . . . . . 26
Section 7.4  Lease Enforcement . . . . . . . . . . . . . . . . . . . . . . . 26
Section 7.5  Lease Termination Prior to Closing. . . . . . . . . . . . . . . 26
Section 7.6  Tenant Notices. . . . . . . . . . . . . . . . . . . . . . . . . 27
Section 7.7  Risk of Loss and Insurance Proceeds . . . . . . . . . . . . . . 27
Section 7.8  Notifications . . . . . . . . . . . . . . . . . . . . . . . . . 27
                                      
                                      
                                ARTICLE VIII
                             CLOSING AND ESCROW
Section 8.1  Escrow Instructions . . . . . . . . . . . . . . . . . . . . . . 28

                                     -ii-
<PAGE>

Section 8.2  Closing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Section 8.3  Deposit of Documents. . . . . . . . . . . . . . . . . . . . . . 28
Section 8.4  Estoppel Certificates . . . . . . . . . . . . . . . . . . . . . 31
Section 8.5  Prorations. . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Section 8.6  Tax Certiorari Proceedings. . . . . . . . . . . . . . . . . . . 34
Section 8.7  Tenant Obligations. . . . . . . . . . . . . . . . . . . . . . . 35
                                      
                                      
                                 ARTICLE IX
                                MISCELLANEOUS
Section 9.1  Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Section 9.2  Entire Agreement. . . . . . . . . . . . . . . . . . . . . . . . 36
Section 9.3  Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Section 9.4  Attorneys' Fees . . . . . . . . . . . . . . . . . . . . . . . . 37
Section 9.5  No Merger . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Section 9.6  Assignment. . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Section 9.7  Counterparts. . . . . . . . . . . . . . . . . . . . . . . . . . 37
Section 9.8  Governing Law; Jurisdiction and Venue . . . . . . . . . . . . . 37
Section 9.9  Waiver of Trial by Jury . . . . . . . . . . . . . . . . . . . . 38
Section 9.10  Confidentiality and Return of Documents. . . . . . . . . . . . 38
Section 9.11  Interpretation of Agreement. . . . . . . . . . . . . . . . . . 40
Section 9.12  Amendments . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Section 9.13  No Recording . . . . . . . . . . . . . . . . . . . . . . . . . 41
Section 9.14  No Third Party Beneficiary . . . . . . . . . . . . . . . . . . 41
Section 9.15  Severability . . . . . . . . . . . . . . . . . . . . . . . . . 41
Section 9.16  Drafts not an Offer to Enter into a Legally Binding Contract . 41
Section 9.17  Further Assurances . . . . . . . . . . . . . . . . . . . . . . 41
Section 9.18  Special Provisions Regarding Property Located in the
              Commonwealth of Pennsylvania. . . . . . . . . . . . . . . . . .41
Section 9.19  Exculpation. . . . . . . . . . . . . . . . . . . . . . . . . . 42
Section 9.20  Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . 42


EXHIBITS

EXHIBIT A     REAL PROPERTY DEED
EXHIBIT B     [INTENTIONALLY OMITTED ]


                                    -iii-
<PAGE>





EXHIBIT C     INTENTIONALLY OMITTED
EXHIBIT D     INTENTIONALLY OMITTED
EXHIBIT E     BILL OF SALE
EXHIBIT F     ASSIGNMENT OF LEASES
EXHIBIT G     ASSIGNMENT OF CONTRACTS, WARRANTIES AND
              GUARANTEES AND OTHER INTANGIBLE PROPERTY
EXHIBIT H     DESIGNATION AGREEMENT
EXHIBIT I     BUYER'S AS-IS CERTIFICATE
EXHIBIT J     TENANT ESTOPPEL CERTIFICATE
EXHIBIT K     INTENTIONALLY OMITTED
EXHIBIT L     SELLER'S AFFIDAVIT
EXHIBIT M     [INTENTIONALLY OMITTED]
EXHIBIT N     ESCROW AGREEMENT

SCHEDULES

SCHEDULE 1         SELLER
SCHEDULE 2.1.1     PROPERTY DESCRIPTIONS
]SCHEDULE 2.1.3    EXISTING LEASES
SCHEDULE 2.1.5     PURCHASE RIGHTS
]SCHEDULE 2.2.2    WIRING INSTRUCTIONS
SCHEDULE 4.1.1     REQUIRED CONSENTS
SCHEDULE 4.1.2     NON-TERMINABLE CONTRACTS
SCHEDULE 4.1.3     PENDING LITIGATION
SCHEDULE 4.1.4    MUNICIPAL VIOLATION NOTICES
SCHEDULE 7.2       LEASING COSTS
    
    
                                         -iv-

<PAGE>

 

                            AGREEMENT OF PURCHASE AND SALE


         AGREEMENT OF PURCHASE AND SALE, dated as of December 15, 1997 (this
"Agreement"), between Virginia Drive Associates, a Delaware limited partnership
("Seller"), and Brandywine Operating Partnership, L.P., a Delaware limited
partnership ("Buyer").


                                      ARTICLE I

                                     DEFINITIONS

         Section 1.1  Definitions.  As used in this Agreement, the following 
terms shall have the meanings set forth below, which meanings shall be 
applicable equally to the singular and plural of the terms defined:

         "Additional Rents" shall have the meaning set forth in Section 8.5(a).

         "Affiliate" shall mean with respect to any Person (i) any other Person
    that directly or indirectly through one or more intermediaries controls or
    is controlled by or is under common control with such Person, (ii) any
    other Person owning or controlling 10% or more of the outstanding voting
    securities of or other ownership interests in such Person, (iii) any
    officer, director or partner of such Person, or (iv) if such Person is an
    officer, director or partner, any other company for which such Person acts
    in any such capacity.

         "Agreement" shall have the meaning set forth in the first paragraph of
    this Agreement.

         "Assignment of Contracts" shall have the meaning set forth in Section
    8.3(a).

         "Assignment of Leases" shall have the meaning set forth in Section
    8.3(a).

         "Bill of Sale" shall have meaning set forth in Section 8.3(a).

         "Business Day" shall mean any day other than a Saturday, a Sunday, or
    a federal holiday recognized by the Federal Reserve Bank of New York.

         "Buyer" shall have the meaning set forth in the first paragraph of
    this Agreement and shall include any assignee of Buyer (including, without
    limitation, any Permitted Assignee).
    
                                           
<PAGE>
    


         "Buyer Party" or "Buyer Parties" shall have the meaning set forth in
    Section 4.6.

         "Claim Notice" shall mean a written notice delivered by Buyer or a
    Permitted Assignee to Seller setting forth (i) the identity of the Property
    with respect to which a breach or inaccuracy of a representation or
    warranty is alleged to have occurred, (ii) a reasonably detailed
    description of the claimed breach or inaccuracy, including reasonably
    detailed information as to the adverse effect on the value of the Property
    to which such claimed breach relates, (iii) the specific provision of this
    Agreement under which such breach is claimed and (iv) complete and detailed
    evidence of the satisfaction of the conditions to Buyer's or a Permitted
    Assignee's recovery set forth in Section 4.3.

         "Claims" shall have the meaning set forth in Section 4.3(a).

         "Closing" shall have the meaning set forth in Section 2.2(b).

         "Closing Date" shall have the meaning set forth in Section 8.2.

         "Closing Documents" shall have the meaning set forth in
    Section 4.3(a).

         "Code" shall mean the Internal Revenue Code of 1986, as amended, or
    any corresponding provision(s) of any succeeding law.

         "Confidential Information" shall have the meaning set forth in Section
    9.10(c).

         "Confidentiality Agreement" shall mean the Confidentiality Agreement,
    dated October 8, 1997, between Brandywine Realty Trust and Seller. 

         "Contracts" shall have the meaning set forth in Section 2.1(e).

         "Deed" shall have the meaning set forth in Section 5.1(a).

         "Deposit" shall have the meaning set forth in Section 2.2(a).

         "Designation Agreement" shall have the meaning set forth in Section
    8.3(a).

         "Document Delivery Date" shall have the meaning set forth in Section
    8.3.

         "Due Diligence Materials" shall mean all of the documents and other
    materials delivered to, or made available for inspection by, Buyer, its
    Permitted Assignees and their representatives including, without
    limitation, the materials delivered to Buyer and its 

                                         -2-
<PAGE>

    representatives entitled on or about November 21, 1997, and on-site
    materials made available to Buyer for inspection.

         "Effective Date" shall mean the date of this Agreement.

         "Evaluation Material" shall have the meaning set forth in
    Section 9.10(a).

         "Existing Leases" shall mean those leases, license agreements and
    occupancy agreements identified on Schedule 2.1.3, as the same may be
    amended or modified from time to time in accordance with the terms of this
    Agreement.

         "Fee Parcel" shall have the meaning set forth in Section 2.1(a). 

         "Governmental Authority" shall mean any federal, state, county or
    municipal government, or political subdivision thereof, any governmental
    agency, authority, board, bureau, commission, department, instrumentality,
    or public body, or any court or administrative tribunal.

         "Hazardous Materials" shall mean materials, wastes or substances that
    are (A) included within the definition of any one or more of the terms
    "hazardous substances," "hazardous materials," "toxic substances," "toxic
    pollutants" and "hazardous waste" in the Comprehensive Environmental
    Response, Compensation and Liability Act of 1980, as amended (42 U.S.C.
    Sections 9601, et seq.), the Resource Conservation and Recovery Act of 1976
    (42 U.S.C. Section 6901, et seq.), the Clean Water Act (33 U.S.C. Section
    1251, et seq.), the Safe Drinking Water Act (14 U.S.C. Section 1401, et
    seq.), the Hazardous Materials Transportation Act (49 U.S.C. Section 1801,
    et seq.), and the Toxic Substance Control Act (15 U.S.C. Section 2601, et
    seq.) and the regulations promulgated pursuant to such laws, (B) regulated,
    or classified as hazardous or toxic, under federal, state or local
    environmental laws or regulations, (C) petroleum, (D) asbestos or asbestos-
    containing materials, (E) polychlorinated biphenyls, (F) flammable
    explosives or (G) radioactive materials.

         "Improvements" shall have the meaning set forth in Section 2.1(a).

         "Indemnified Party" shall have the meaning set forth in Section 6.1.

         "Initial Deposit Date" shall mean the first Business Day after the
    Effective Date.

         "Intangible Property" shall have the meaning set forth in Section
    2.1(h).

         "Leases" shall mean all Existing Leases and New Leases, collectively.

                                         -3-
<PAGE>


         "Leasing Costs" shall have the meaning set forth in Section 7.2.

         "Licenses and Permits" shall have the meaning set forth in Section
    2.1(h).

         "New Leases" shall mean those leases, license agreements and occupancy
    agreements encumbering the Real Property which are entered into after the
    Effective Date in accordance with the terms of this Agreement, as the same
    may be amended or modified from time to time in accordance with the terms
    of this Agreement.

         "Non-Terminable Contracts" shall have the meaning set forth in Section
    4.1(h).

         "Order" shall mean an order or decree of any Governmental Authority.

         "Permitted Assignee" shall have the meaning set forth in Section 9.6.

         "Permitted Exceptions" shall have the meaning set forth in Section
    5.1.

         "Person" shall mean any individual, partnership, corporation, limited
    liability company, trust or other legal entity.

         "Personal Property" shall have the meaning set forth in Section
    2.1(c).

         "Prescribed Form" shall have the meaning set forth in Section 8.4.

         "Prime Rate" shall mean the prime (or base) rate of interest publicly
    announced by Citibank, N.A. or its successors from time to time.

         "Property" shall have the meaning set forth in Section 2.1.

         "Purchase Price" shall have the meaning set forth in Section 2.2(a).

         "Real Estate Taxes" shall have the meaning set forth in Section
    4.5(b).

         "Real Property" shall have the meaning set forth in Section 2.1.

         "Records and Plans" shall have the meaning set forth in Section
    2.1(g).

         "Rent Rolls" shall have the meaning set forth in Section 4.1(g).

         "Representatives" shall have the meaning set forth in Section 9.10(a).

                                         -4-
<PAGE>


         "Required Deletion Items" shall have the meaning set forth in
    Section 3.1(c).

         "Required Percentage" shall have the meaning set forth in Section
    8.4(a).

         "Schedule of Contracts" shall have the meaning set forth in Section
    4.1(h).

         "Seller" shall have the meaning set forth in the first paragraph of
    this Agreement. 

         "Seller Party" shall have the meaning set forth in Section 4.7(a).

         "Seller's Affidavit" shall have the meaning set forth in
    Section 8.3(a)(ix).

         "Significant Tenant" shall mean any Tenant occupying space equal to
    twenty percent (20%) or more of the rentable square footage of the
    Property.

         "Survey" shall have the meaning set forth in Section 4.5(a).

         "Tenant" shall mean the tenant, occupier or licensee under any lease,
    license agreement or occupancy agreement encumbering the Real Property.

         "Threshold Amount" shall have the meaning set forth in Section 4.3.

         "Title Commitment" shall have the meaning set forth in Section 3.1(c).

         "Title Company" shall have the meaning set forth in Section 2.2(b).

         "Title Policy" shall have the meaning set forth in Section 5.2.

         "Warranties" shall have the meaning set forth in Section 2.1(f).

         Section 1.2  Terms Generally.  For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

         (a)  the words "herein," "hereof" and "hereunder" and other words of
similar import refer to this Agreement as a whole and not to any particular
Article, Section or other subdivision;

         (b)  the words "including" and "include" and other words of similar
import shall be deemed to be followed by the phrase "without limitation"; and


                                         -5-
<PAGE>

         (c)   any consent, determination, election or approval required to be
obtained, or permitted to be given, by or of any party hereunder, shall be
granted, withheld or made (as the case may be) by such party in the exercise of
such party's sole and absolute discretion.


                                      ARTICLE II

                            PURCHASE AND SALE OF PROPERTY

         Section 2.1  Sale.  Seller agrees to sell to Buyer, and Buyer agrees
to purchase from Seller, subject only to the Permitted Exceptions and to all
other terms, covenants and conditions set forth herein, all of Seller's right,
title and interest in and to the following:  (a) each parcel of land described
in Schedule 2.1.1 attached hereto (each, a "Fee Parcel") identified as being
owned by Seller on Schedule 2.1.1, together with any and all rights, privileges
and easements appurtenant thereto owned by Seller (including any rights of
Seller as declarant), together with all buildings, improvements and fixtures
(other than fixtures owned or removable by any Tenant or third party) located
thereon (collectively, the "Improvements"; each Fee Parcel, together with the
Improvements thereon, the "Real Property"); (b) [intentionally omitted]; (c) all
tangible personal property not owned or removable by any Tenant or third party,
if any, located on the Real Property and owned by Seller and used in the
operation or maintenance of any one or more of the Real Property (the "Personal
Property"); (d) (i) Seller's interest, as landlord, owner or licensor, in each
of the Existing Leases, (ii) Seller's interest, as landlord, owner or licensor,
in any New Leases and (iii) to the extent assignable, any guarantees, letters of
credit or other instruments that secure or guarantee the performance of the
obligations of each Tenant; (e) to the extent assignable, all service contracts,
maintenance contracts, operating contracts, warranties, guarantees, listing
agreements, parking contracts and like contracts and agreements relating to the
Real Property, and commission agreements, equipment leases, contracts,
subcontracts and agreements relating to the construction of any unfinished
tenant improvements (collectively, the "Contracts"); (f) to the extent
assignable, all warranties and guaranties made by or received from any third
party with respect to any building, building component, structure, fixture,
machinery, equipment or material situated on the Real Property, or contained in
any or comprising a part of any Improvement or Leasehold Improvement
(collectively, the "Warranties"); (g) to the extent Seller currently has such
items in its possession and to the extent assignable, all (i) preliminary, final
and proposed building plans and specifications (including "as-built" floor plans
and drawings) and tenant improvement plans and specifications for the
Improvements and (ii) surveys, grading plans, topographical maps, architectural
and structural drawings and engineering, soils, seismic, geologic and
architectural reports, studies and tests relating to the Real Property ((g)(i)
and (g)(ii) collectively, the "Records and Plans"); and (h) to the extent trans-
ferable, any intangible personal property now or hereafter owned by Seller and
used in the ownership, use or operation of any one or more of the Real Property
and/or the Personal Property, excluding materials or information which in
Seller's judgment is privileged or 

                                         -6-
<PAGE>

confidential information, the name of the Seller and related names and
proprietary computer equipment, software and systems, but including all
(i) licenses, permits, building inspection approvals, certificates of occupancy,
approvals, subdivision maps and entitlements issued, approved or granted by
Governmental Authorities in connection with the Real Property, (ii) unrecorded
covenants, conditions and restrictions, reciprocal easement agreements, area
easement agreements and other common or planned development agreements or
documents affecting the Real Property and (iii) licenses, consents, easements,
rights of way and approvals obtained from private parties to make use of
utilities and to ensure vehicular and pedestrian ingress and egress for the Real
Property ((h)(i), (h)(ii) and (h)(iii) collectively, the "Licenses and Permits")
or other rights relating to the ownership, use or operation of any of the Real
Property or the Personal Property (collectively, the "Intangible Property"). 
The Real Property, together with the Personal Property, the Leases, the
Contracts, the Warranties, the Records and Plans and the Intangible Property
relating thereto are referred to herein as the "Property".

         Section 2.2  Purchase Price.

         (a)  The purchase price of the Property is Four Million Dollars
($4,000,000) (the "Purchase Price"), subject to prorations, credits and
adjustments as set forth herein. 

         (b)  The Purchase Price shall be paid by Buyer as follows:

            (i)    By 3:00 P.M. (Eastern Standard Time) on the Initial Deposit
Date, Buyer shall deposit by wire transfer (made in accordance with the wiring
instructions set forth on Schedule 2.2.2 attached hereto) of immediately
available funds, in escrow with Commonwealth Land Title Insurance Company, 1700
Market Street, Philadelphia, Pennsylvania 19103, Attention: Mr. Gordon Daniels
(the "Title Company"), a cash payment in the amount of $200,000.  The Deposit
and shall be held by the Title Company pursuant to an escrow agreement among
Buyer, Seller and the Title Company in the form of Exhibit N attached hereto.

           (ii)    The Deposit shall be held in an interest bearing account
reasonably designated by Buyer and all interest thereon shall be deemed a part
of the Deposit.  If the sale of the Property as contemplated hereunder is
consummated, then the Deposit (including the interest accrued on the Deposit)
shall be paid to Seller at the consummation of the purchase and sale of the
Property contemplated hereunder (the "Closing") and credited against the
Purchase Price.

          (iii)    The balance of the Purchase Price over and above the
Deposit, as adjusted pursuant to Section 8.5, shall be deposited by Buyer, by
wire transfer (made in accordance with the wiring instructions set forth on
Schedule 2.2.1 attached hereto) of immediately available funds, with the Title
Company and paid to Seller at the Closing.

                                         -7-
<PAGE>


         (c)     (i) IF THE SALE OF THE PROPERTY IS NOT CONSUMMATED DUE TO THE
FAILURE OF ANY CONDITION TO BUYER'S OBLIGATION TO PURCHASE OR SELLER'S INABILITY
TO PERFORM OR SELLER'S DEFAULT HEREUNDER, THEN THE DEPOSIT SHALL BE RETURNED TO
BUYER, AND BUYER'S SOLE REMEDY, AT LAW OR IN EQUITY, SHALL BE THE RETURN OF THE
DEPOSIT, PROVIDED, THAT IF THE SALE OF THE PROPERTY IS NOT CONSUMMATED BECAUSE
OF SELLER'S FAILURE TO CLOSE WHEN OBLIGATED TO DO SO UNDER THIS AGREEMENT, BUYER
MAY EITHER (A) TERMINATE THIS AGREEMENT BY WRITTEN NOTICE OF TERMINATION TO
SELLER ON THE CLOSING DATE, WHEREUPON THE DEPOSIT SHALL BE IMMEDIATELY RETURNED
TO BUYER AND SELLER SHALL BE OBLIGATED TO REIMBURSE BUYER FOR ITS OUT OF POCKET
EXPENSES (NOT TO EXCEED $25,000) OR (B) CONTINUE THIS AGREEMENT PENDING BUYER'S
ACTION FOR SPECIFIC PERFORMANCE, IN WHICH LATTER EVENT BUYER, AS A CONDITION TO
SUCH ACTION, SHALL NOT ACCEPT RETURN OF THE DEPOSIT AND SHALL PLACE THE FULL
AMOUNT OF THE PURCHASE PRICE ABOVE THE DEPOSIT INTO ESCROW.  (ii) IF THE SALE OF
THE PROPERTY IS NOT CONSUMMATED AS A RESULT OF A DEFAULT BY BUYER HEREUNDER,
THEN, AS ITS SOLE AND EXCLUSIVE REMEDY, SELLER SHALL RETAIN THE DEPOSIT AS
LIQUIDATED DAMAGES.  THE PARTIES HAVE AGREED THAT SELLER'S ACTUAL DAMAGES, IN
THE EVENT OF A FAILURE TO CONSUMMATE THIS SALE DUE TO BUYER'S DEFAULT, WOULD BE
EXTREMELY DIFFICULT OR IMPRACTICABLE TO DETERMINE.  AFTER NEGOTIATION, THE
PARTIES HAVE AGREED THAT, CONSIDERING ALL THE CIRCUMSTANCES EXISTING ON THE DATE
OF THIS AGREEMENT, THE AMOUNT OF THE DEPOSIT IS A REASONABLE ESTIMATE OF THE
DAMAGES THAT SELLER WOULD INCUR IN SUCH EVENT.  BY PLACING THEIR INITIALS BELOW,
EACH PARTY SPECIFICALLY CONFIRMS THE ACCURACY OF THE STATEMENTS MADE ABOVE AND
THE FACT THAT EACH PARTY WAS REPRESENTED BY COUNSEL WHO EXPLAINED, AT THE TIME
THIS AGREEMENT WAS MADE, THE CONSEQUENCES OF THIS LIQUIDATED DAMAGES PROVISION. 
THE FOREGOING IS NOT INTENDED TO LIMIT BUYER'S INDEMNITY OBLIGATIONS UNDER
SECTIONS 4.6(a), 6.1, 9.4 AND 9.10(a) OR SELLER'S OBLIGATIONS UNDER SECTIONS 6.1
0R 9.4. 

         INITIALS:  Seller ___________ BUYER ___________

         (d)  In the event that Buyer fails to fund within one Business Day
after the Initial Deposit Date or the Additional Deposit Date (with time being
of the essence) the full amount of the Initial Deposit or the Additional
Deposit, as the case may be, for any or no reason whatsoever in accordance with
the terms of Section 2.2(b)(i), this Agreement shall immediately and
automatically terminate.  Upon any termination of this Agreement pursuant to
this Section 2.2(d) 

                                         -8-
<PAGE>

or Section 2.3, no party shall have any further rights or obligations hereunder,
except as provided in Sections 4.6(a), 6.1, 9.4 and 9.10(a).

         Section 2.3  Due Diligence.  Buyer has reviewed, accepted and approved
(and all representations and warranties of Seller made herein shall be subject
to and qualified by) all of the Due Diligence Materials.  Notwithstanding
anything to the contrary herein, Seller shall have no liability whatsoever to
Buyer with respect to any matter disclosed to or actually known by Buyer or its
agents prior to the Closing Date.


                                     ARTICLE III

                                 CONDITIONS PRECEDENT

         Section 3.1  Conditions to Buyer's Obligation to Purchase.  Buyer's
obligation to purchase the Property is conditioned upon the satisfaction (or
Buyer's written waiver) on or prior to the Closing Date of the following
conditions:

         (a)  There shall exist on the Closing Date no pending Order
prohibiting, enjoining or restraining Seller from consummating the transactions
contemplated hereby with respect to the Property.

         (b)  All consents required to be obtained from, or filing required to
be made with, any Governmental Authority or third party in connection with the
execution and delivery of this Agreement by Seller or the consummation by Seller
of the transactions contemplated hereby shall have been obtained or made. 

         (c)  The Title Company has committed to issue,  upon payment of the
applicable premium therefor, a 1992 ALTA Owner's Policy of Title Insurance
(provided, that in jurisdictions where local regulations require a form of
policy other than a 1992 ALTA Owner's Policy, such other required form shall be
used) with respect to the Real Property in the form of the title insurance
commitment (each, a "Title Commitment") obtained by Buyer from the Title Company
and delivered to Seller prior to the Effective Date, showing title to the Real
Property vested in Buyer, subject only to the Permitted Exceptions.  It shall
not be a condition to Closing that Buyer obtain any endorsements or coverages
not set forth in the applicable Title Commitment.  Seller shall be entitled, by
notice to Buyer, to adjourn the Closing one or more times for an aggregate
period not to exceed thirty (30) days in order to remove any exceptions to title
that are not Permitted Exceptions.  Nothing contained herein shall require
Seller to bring any action or proceeding or otherwise to incur any expense to
correct, discharge or otherwise remove title exceptions or defects with respect
to the Property or to remove, remedy or comply with any other grounds for
Buyer's refusing to approve title, provided that Seller shall be obligated to

                                         -9-
<PAGE>

remove or discharge, or otherwise cause the Title Company to omit as an
exception to title or to insure against collection thereof from or against the
Property any mortgages or monetary liens created by Seller, any mechanics' liens
or judgment liens that are the obligation of Seller (as opposed to any Tenant or
other third party) and any liens and encumbrances voluntarily created by Seller
in violation of Section 7.1 (collectively, the "Required Deletion Items").  If
on the Closing Date there are any Required Deletion Items, Seller may use any
portion of the Purchase Price payable pursuant to Section 2.2(b) to satisfy
same, provided the Title Company shall omit such lien or encumbrance as an
exception to title.

         (d)  Buyer shall have received estoppel certificates for the Real
Property to the extent required by Section 8.4. 

         (e)  Each of the documents required to be delivered by Seller pursuant
to Section 8.3 shall have been delivered as provided therein and Seller shall
not otherwise be in material default of its material obligations hereunder, and
all of Seller's representations and warranties contained herein shall be true
and correct in all material respects as of the Closing Date (except that any
representations and warranties which are made as of a specified date shall be
true and correct as of such specified date).

         (f)  Buyer shall not have previously terminated this Agreement
pursuant to and in accordance with Section 7.7.

         Section 3.2  Conditions to Seller's Obligations to Sell.  Seller's
obligation to sell the Property is conditioned upon the satisfaction (or
Seller's written waiver) on or prior to the Closing Date of the following
conditions:

         (a)  There shall exist on the Closing Date no pending Order
prohibiting, enjoining or restraining Buyer from consummating the transactions
contemplated hereby with respect to the Property.

         (b)  as set forth in Section 3.5, all] All consents required to be
obtained from, or filings required to be made with, any Governmental Authority
or third party in connection with the execution and delivery of this Agreement
by Buyer or the consummation by Buyer of the transactions contemplated hereby
shall have been obtained or made. 

         (c)  Seller shall have actually received the Purchase Price in cash.

         (d)  Buyer shall not otherwise be in material default of its material
obligations hereunder.

                                         -10-
<PAGE>


         (e)  Each of the documents required to be delivered by Buyer pursuant
to Section 8.3 shall have been delivered as provided therein, and all of Buyer's
representations and warranties contained herein shall be true and correct in all
material respects as of the Closing Date.

         Section 3.3  Termination.  In the event that any condition set forth
in Section 3.1 or Section 3.2 is not satisfied on or prior to the Closing Date,
then the party to this Agreement whose obligations are conditioned upon the
satisfaction of such condition may in its sole and absolute discretion terminate
this Agreement, subject to Section 2.2(c), by written notice delivered to the
other party at or prior to the occurrence of the Closing.  Upon any termination
of this Agreement pursuant to this Section 3.3, no party shall have any further
rights or obligations hereunder, except as provided in Sections 2.2(c), 4.6(a),
6.1, 9.4 and 9.10(a).

         Section 3.4  Waiver by Buyer.  If Buyer and/or its Permitted
Assignees, with knowledge of (i) a default in any of the covenants, agreements
or obligations to be performed by Seller under this Agreement and/or (ii) any
breach of or inaccuracy in any representation or warranty of Seller made in this
Agreement, nonetheless elects to proceed to Closing, then, upon the consummation
of the Closing, Buyer and/or its Permitted Assignees shall be deemed to have
waived any such default and/or breach or inaccuracy and shall have no claim
against Seller with respect thereto.

         Section 3.5  [Intentionally Omitted]. 





                                      ARTICLE IV

                           REPRESENTATIONS AND WARRANTIES;
                         BUYER'S EXAMINATION OF THE PROPERTY

         Section 4.1  Representations and Warranties of Seller.  Subject to
(i) the provisions of Sections 2.3, 4.2 and 4.3 and (ii)  the information
disclosed in the Due Diligence Materials (except that the representations and
warranties in clauses (a), (b), (c) and (d) of this Section 4.1 shall not be
subject to the information disclosed in the Due Diligence Materials), Seller
hereby makes the following representations and warranties: 

         (a)  Seller has not (i) made a general assignment for the benefit of
creditors, (ii) filed any voluntary petition in bankruptcy or suffered the
filing of any involuntary petition by Seller's creditors, (iii) suffered the
appointment of a receiver to take possession of the Property or 

                                         -11-
<PAGE>

all, or substantially all, of Seller's other assets, (iv) suffered the
attachment or other judicial seizure of the Property or all, or substantially
all, of Seller's other assets, (v) admitted in writing its inability to pay its
debts as they come due, or (vi) made an offer of settlement, extension or
composition to its creditors generally.

         (b)  Seller is not a "foreign person" as defined in Section 1445 of
the Code and any related regulations.

         (c)  Seller is duly organized and validly existing and in good
standing under the laws of its state of formation.  Seller further represents
and warrants that this Agreement and all documents executed by Seller that are
to be delivered to Buyer at Closing (i) are, or at the time of Closing will be,
duly authorized, executed and delivered by Seller, (ii) do not, and at the time
of Closing will not, violate any provision of any agreement or judicial order to
which Seller is a party or to which Seller or the Property owned by Seller is
subject and (iii) constitute (or in the case of Closing Documents will
constitute) a valid and legally binding obligation of Seller, enforceable in
accordance with its terms.

         (d)  Seller has full and complete power and authority to enter into
this Agreement and, subject to obtaining any consents or waivers required to be
obtained prior to Closing, to perform its obligations hereunder.

         (e)  Seller is not aware of any consents required for the performance
of  Seller's obligations hereunder except as set forth on Schedule 4.1.1.

         (f)  The Due Diligence Materials contain (i) true, correct and
complete copies of all Existing Leases and all material Contracts in the
possession of Seller and (ii) all environmental and structural reports in the
possession of Seller.  This representation shall not be deemed breached by
virtue of any Leases or Contracts entered into after the Effective Date in
accordance with Section 7.1.

         (g)  Except as included in the Due Diligence Materials (including the
rent rolls, dated October 9, 1997, delivered to Buyer (the "Rent Rolls")),
(i) there are to Seller's knowledge no leases, license agreements or occupying
agreements (or any amendments or supplements thereto) encumbering, or in force
with respect to, the Property (except for any New Leases entered into after the
Effective Date in accordance with Section 7.1) and (ii) as of the Effective
Date, Seller has not received written notice from any Significant Tenant that
Seller has not performed its material obligations under such Significant
Tenant's Lease.

         (h)  To Seller's knowledge, the only Contracts and amendments thereto
that will be in effect on the Closing Date that are not terminable without cause
or penalty on sixty 


                                         -12-

<PAGE>

(60) days notice with respect to the Property (the "Non-Terminable Contracts")
are as set forth in Schedule 4.1.2 (the "Schedule of Contracts") or as entered
into in accordance with Section 7.1.

         (i)  As of the Effective Date, Seller has not received any written
notice of any pending or threatened condemnation of all or any portion of the
Property.

         (j)  Seller has not received written notice of any litigation that is
pending or threatened with respect to the Property, except (i) litigation fully
covered by insurance policies (subject to customary deductibles) or (ii)
litigation set forth in Schedule 4.1.3.

         (k)  As of the Effective Date, except as set forth in Schedule 4.1.4,
Seller has not received any written notice from any Governmental Authority that
all or any portion of the Property is in material violation of any applicable
building codes or any applicable environmental law (relating to clean-up or
abatement), zoning law or land use law, or any other applicable local, state or
federal law or regulation relating to the Property, which material violation has
not been cured or remedied prior to the Effective Date.

         (l)  Except as set forth in Schedule 2.1.5 or Schedule 4.1.1 attached
to this Agreement, Seller has not granted any option or right of first refusal
or first opportunity to any party to acquire any fee or ground leasehold
interest in any portion of the Property.

         (m)  Seller will have no employees at Closing, and any employees of
Seller existing on the date hereof shall have been terminated by Seller prior to
Closing in accordance with all applicable law, non-compliance with which could
result in a claim against Buyer.  Buyer will not be responsible for, nor assume
any liabilities of Seller regarding, any such employees.

         Each of the representations and warranties of Seller contained in this
Section 4.1:  (1) is made as of the Effective Date (subject to the information
disclosed in the Due Diligence Materials); (2) other than clauses (i) and (k)
above (which, in the case of clause (i) above, the parties acknowledge shall be
governed by Section 7.7 with respect to events occurring after the Effective
Date) shall be deemed remade by Seller, and shall be true in all material
respects, as of the Closing Date (except that any representations and warranties
which are made as of a specified date, shall have been true and correct as of
such specified date) subject to (A) the information disclosed in the Due
Diligence Materials, (B) litigation that is not reasonably likely to have a
material adverse effect on the Property, and (C) other matters expressly
permitted in this Agreement or otherwise specifically approved in writing by
Buyer; and (3) shall survive the Closing only as and to the extent expressly
provided in Section 4.2 and Section 4.3. 

         Section 4.2  Estoppels.  The representations and warranties of Seller
regarding Leases in Section 4.1(f) or 4.1(g) or in any estoppel delivered by
Seller pursuant to Section 8.4 

                                         -13-

<PAGE>


shall terminate to the extent specifically confirmed by a tenant estoppel
certificate delivered by a Tenant.

         Section 4.3  Limitation on Claims; Survival of Representations and
Warranties.  

         (a)  Notwithstanding any provision to the contrary herein or in any
document or instrument (including, without limitation, any deeds or assignments)
executed by Seller and delivered to Buyer or any Permitted Assignee at or in
connection with the Closing (collectively, "Closing Documents"), Seller shall
have no liability whatsoever with respect to any suits, actions, proceedings,
investigations, demands, claims, liabilities, fines, penalties, liens,
judgments, losses, injuries, damages, expenses or costs, including, without
limitation, attorneys' and experts' fees and costs and investigation, and
remediation costs (collectively "Claims") under, and Buyer shall be barred from
bringing any Claims with respect to, any of the representations and warranties
contained in this Agreement or in any Closing Document, except to the extent
(and only to the extent) that (i) with respect to Claims for breach of
representations and warranties relating to the Property, the amount of such
Claims exceeds Fifty Thousand Dollars ($50,000) ("Threshold Amount") and, in
such case, such Claims shall only be valid (and the Seller shall only be liable)
for the portion that exceeds the Threshold Amount; provided, however,
notwithstanding any provision to the contrary herein or in any Closing Document,
the (i) total liability of Seller for any or all Claims (inclusive of Claims
with respect to any estoppel certificates delivered by Seller pursuant to
Section 8.4(a)) with respect the Property shall not exceed two and three
quarters percent (2.75%) of the Purchase Price.  Further notwithstanding any
provision to the contrary herein or in any Closing Document, Seller shall have
no liability with respect to any Claim under any of the representations and
warranties contained in this Agreement or in any Closing Document, which Claim
relates to or arises in connection with (1) any Hazardous Materials (except
solely to the extent that Seller has breached its representation in
Section 4.1(k)), (2) the physical condition of the Property (except solely to
the extent that Seller has breached its representation in Section 4.1(k)) or
(3) any other matter not expressly set forth in the Seller's representations and
warranties set forth in Section 4.1.  Buyer shall not make any Claim or deliver
any Claim Notice unless it in good faith believes the Claims would exceed the
Threshold Amount provided in this Section 4.3(a).

         (b)  Except as otherwise specifically set forth in this Agreement, the
representations and warranties of Seller contained herein or in any Closing
Document shall survive only until July 6, 1998.  Any Claim that Buyer may have
at any time against Seller for a breach of any such representation or warranty,
whether known or unknown, with respect to which a Claim Notice has not been
delivered to Seller on or prior to July 6, 1998 shall not be valid or effective.
For the avoidance of doubt, on July 6, 1998, Seller shall be fully discharged
and released (without the need for separate releases or other documentation) 
from any liability or obligation to Buyer, any Permitted Assignee and/or their
successors and assigns with respect to any Claims or any other matter relating
to this Agreement, any Closing Document or the 

                                         -14-
<PAGE>

Property, except solely for those matters that are then the subject of a pending
Claim Notice delivered by Buyer to Seller.  Any Claim that Buyer may have at any
time against Seller for a breach of any such representation or warranty, whether
known or unknown, with respect to which a Claim Notice has been delivered to
Seller on or prior to July 6, 1998 may be the subject of subsequent litigation
brought by Buyer against Seller, provided that such litigation is commenced
against Seller on or prior to October 6, 1998.  For the avoidance of doubt, on
October 6, 1998, Seller shall be fully discharged and released (without the need
for separate releases or other documentation) from any liability or obligation
to Buyer and/or its successors and assigns with respect to any Claims or any
other matter relating to this Agreement, any Closing Document or the Property,
except solely for those matters that are the subject of a litigation by Buyer
against Seller that is pending on October 6, 1998.

         (c)   This Section 4.3 shall survive the Closing.

         Section 4.4  Representations and Warranties of Buyer.  Buyer hereby
makes the following representations and warranties:

         (a)  Buyer is a limited partnership duly organized and validly
existing and in good standing under the laws of the State of Delaware.  Buyer
further represents and warrants to Seller that this Agreement and all documents
executed by Buyer that are to be delivered to Seller at Closing (i) are, or at
the time of Closing will be, duly authorized, executed and delivered by Buyer,
(ii) do not, and at the time of Closing will not, violate any provision of any
agreement or judicial order to which Buyer is a party or to which Buyer or any
property owned by Buyer is subject and (iii) constitutes (or in the case of
Closing documents will constitute) a valid and legally binding obligation of
Buyer, enforceable in accordance with its terms.

         (b)  Buyer has not (i) made a general assignment for the benefit of
creditors, (ii) filed any voluntary petition in bankruptcy or suffered the
filing, of any involuntary petition by Buyer's creditors, (iii) suffered the
appointment of a receiver to take possession of all, or substantially all, of
Buyer's assets, (iv) suffered the attachment or other judicial seizure of all,
or substantially all, of Buyer's assets, (v) admitted in writing its inability
to pay its debts as they come due, or (vi) made an offer of settlement,
extension or composition to its creditors generally.  As of the Closing Date,
Buyer will have sufficient funds to pay the Purchase Price and consummate the
transactions contemplated by this Agreement.

         (c)  Buyer has full and complete power and authority to enter into
this Agreement and to perform its obligations hereunder.

         (d)  Buyer (i) is a sophisticated investor, (ii) is represented by
competent counsel and (iii) understands the assumptions of risk and liability
set forth in this Agreement.

                                         -15-

<PAGE>


         (e)  No consents are required to be obtained from, and no filings are
required to be made with, any Governmental Authority or third party in
connection with the execution and delivery of this Agreement by Buyer or the
consummation by Buyer of the transactions contemplated hereby.

         Each of the representations and warranties of Buyer contained in this
Section (i) is made on the Effective Date; (ii) shall be deemed remade by Buyer
and/or its assignee(s), as applicable and appropriate, and shall be true in all
material respects, as of the Closing Date; and (iii) shall survive the Closing
until July 6, 1998.

         Section 4.5  Buyer's Independent Investigation.

         (a)  Buyer, for itself and any successors or assigns (including any
Permitted Assignees), acknowledges and agrees that it has been given the full
opportunity to inspect and investigate each and every aspect of the Property,
either independently or through agents, representatives or experts of Buyer's
choosing, as Buyer considers necessary or appropriate, and that Buyer is
completely satisfied (but the foregoing will not constitute a waiver of any
breach of representation or warranty set forth in Section 4.1 unless such breach
is disclosed in the Due Diligence Materials or is otherwise known by Buyer
and/or any Permitted Assignee before the Closing Date and Buyer and/or such
Permitted Assignee(s) elect to proceed with the Closing).  Such independent
investigation by Buyer may include, without limitation:

              (i)  all matters relating to title to such Property;

              (ii)  all matters relating to governmental and other legal
requirements with respect to such Property, such as taxes, assessments, zoning,
use permit requirements and building codes;

              (iii)  all zoning, land use, building, environmental and other
statutes, rules, or regulations applicable to the Real Property;

              (iv)  the physical condition of the Real Property, including,
without limitation, the interior, the exterior, the square footage of the
Improvements and of each tenant space therein, the structure, the roof, the
paving, the utilities, and all other physical and functional aspects of the Real
Property, including the presence or absence of Hazardous Materials;

              (v)  any easements and/or access rights affecting the Real
Property;


                                         -16-

<PAGE>


              (vi)  the Leases with respect to the Real Property and all
matters in connection therewith, including, without limitation, the ability of
the Tenants thereto to pay the rent;

              (vii)  the Contracts and any other documents or agreements of
significance affecting such Property;

              (viii)  all matters that would be revealed by an ALTA as-built
survey (a "Survey"), a physical inspection or an environmental site assessment
of the Real Property;

              (ix) all matters relating to the income and operating or capital
expenses of the Property and all other financial matters; and

              (x)  all other matters of significance affecting, or otherwise
deemed relevant by Buyer with respect to, such Property.

         (b)  The Due Diligence Materials heretofore delivered or made
available to Buyer for its review and approval include:

              (i) to the extent in the possession of Seller, a copy of a Survey
of the Real Property;

              (ii)  a Rent Roll for the Real Property, listing for any Tenant
the name, rent, amount of deposit and prepaid rent, if any, and lease term and
copies of the Existing Leases;

              (iii)  the Schedule of Contracts;

              (iv)  operating, income and expense statements for the Real
Property for the period in 1997 ending September 30, 1997;

              (v)  copies of all Licenses and Permits in the possession of
Seller;

              (vi)  Phase I Environmental Site Assessment prepared by EMG,
dated January 17, 1997; and

              (vii)  to the extent in the possession of Seller or Seller's
property managers, copies of (i) the bills issued for the most recent year for
the Real Property for all real estate taxes and assessments, water rates, water
meter charges, sewer rates, sewer charges, and similar matters, imposed by any
Governmental Authority ("Real Estate Taxes") and personal property taxes and
(ii) all notices or documents for any assessments or bonds relating to the Real
Property.

                                         -17-
<PAGE>


         (c)  Buyer acknowledges and agrees that (i) it has completed its
independent investigation of the Property and the Due Diligence Materials and
has obtained, reviewed and approved a Title Commitment for each Property, (ii)
it is acquiring the Property based on such independent investigation and subject
to all information disclosed in the Due Diligence Materials (and also in
reliance on Seller's representations and warranties contained herein) and (iii)
Buyer shall have no right to terminate this Agreement based on any further
investigations of the Property or the Due Diligence Materials.  Buyer has
approved each and every aspect of such Property.  The preceding sentence is not
intended to relieve, and shall not relieve, Seller from any of its obligations
under Section 4.1.  

         (d)  BUYER SPECIFICALLY ACKNOWLEDGES AND AGREES THAT (i) SELLER SHALL
SELL AND BUYER SHALL PURCHASE EACH PROPERTY "AS IS, WHERE IS AND WITH ALL
FAULTS," (ii) EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, BUYER IS NOT
RELYING ON ANY REPRESENTATIONS OR WARRANTIES OF ANY KIND WHATSOEVER, WHETHER
ORAL OR WRITTEN, EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE, FROM SELLER, NOR
ANY PARTNER, OFFICER, EMPLOYEE, ATTORNEY, AGENT OR BROKER OF SELLER, AS TO ANY
MATTER, CONCERNING ANY PROPERTY, OR SET FORTH, CONTAINED OR ADDRESSED IN THE DUE
DILIGENCE MATERIALS (INCLUDING WITHOUT LIMITATIONS, THE COMPLETENESS THEREOF),
INCLUDING WITHOUT LIMITATION: (i) the quality, nature, habitability,
merchantability, use, operation, value, marketability, adequacy or physical
condition of the Property or any aspect or portion thereof, including, without
limitation, structural elements, foundation, roof, appurtenances, access,
landscaping, parking facilities, electrical, mechanical, HVAC, plumbing, sewage,
and utility systems, facilities and appliances, soils, geology and groundwater,
(ii) the dimensions or lot size of the Real Property or the square footage of
the Improvements thereon or of any tenant space therein, (iii) the development
or income potential, or rights of or relating to, the Real Property, or the Real
Property's use, habitability, merchantability, or fitness, or the suitability,
value or adequacy of the Real Property for any particular purpose, (iv) the
zoning or other legal status of the Real Property or any other public or private
restrictions on the use of the Real Property, (v) the compliance of the Real
Property or its operation with any applicable codes, laws, regulations,
statutes, ordinances, covenants, conditions and restrictions of any Governmental
Authority or of any other person or entity (including, without limitation, the
Americans with Disabilities Act), (vi) the ability of Buyer to obtain any
necessary governmental approvals, licenses or permits for Buyer's intended use
or development of the Real Property, (vii) the presence or absence of Hazardous
Materials on, in, under, above or about the Real Property or any adjoining or
neighboring property, (viii) the quality of any labor and materials used in any
Improvements, (ix) the condition of title to the Real Property, (x) the Leases,
Contracts or any other agreements affecting the Real Property or the intentions
of any party with respect to the negotiation and/or execution of any lease or
contract with respect to the Real Property, (xi) Seller's ownership of the
Property or any portion thereof or (xii) the economics of, or the income and
expenses, revenue or 

                                         -18-
<PAGE>

expense projections or other financial matters, relating to, the operation of
the Real Property.  Without limiting the generality of the foregoing, except as
otherwise set forth herein, Buyer expressly acknowledges and agrees that Buyer
is not relying on any representation or warranty of Seller, nor any partner,
officer, employee, attorney, agent or broker of Seller, whether implied,
presumed or expressly provided at law or otherwise, arising by virtue of any
statute, common law or other legally binding right or remedy in favor of Buyer. 
Buyer further acknowledges and agrees that Seller is under no duty to make any
inquiry regarding any matter that may or may not be known to Seller or any
partner, officer, employee, attorney, agent or broker of Seller.  This Section
4.5(d) shall survive the Closing, or, if the Closing does not occur, beyond the
termination of this Agreement.

         (e)  ANY REPORTS, REPAIRS OR WORK REQUIRED BY BUYER ARE THE SOLE
RESPONSIBILITY OF BUYER, AND BUYER AGREES THAT THERE IS NO OBLIGATION ON THE
PART OF SELLER TO MAKE ANY CHANGES, ALTERATIONS OR REPAIRS TO THE PROPERTY OR TO
CURE ANY VIOLATIONS OF LAW OR TO COMPLY WITH THE REQUIREMENTS OF ANY INSURER. 
BUYER IS SOLELY RESPONSIBLE FOR OBTAINING ANY CERTIFICATE OF OCCUPANCY OR ANY
OTHER APPROVAL OR PERMIT NECESSARY FOR TRANSFER OR OCCUPANCY OF THE PROPERTY AND
FOR ANY REPAIRS OR ALTERATIONS NECESSARY TO OBTAIN THE SAME, ALL AT BUYER'S SOLE
COST AND EXPENSE.

         Section 4.6  Entry and Indemnity; Limits on Government Contacts.  

         (a)  In connection with any entry by Buyer, its Permitted Assignee(s)
or any of their agents, employees or contractors (collectively, the "Buyer
Parties" and each a "Buyer Party") onto the Real Property, Buyer shall give
Seller reasonable advance notice of such entry and shall conduct such entry and
any inspections in connection therewith so as to minimize, to the greatest
extent possible, interference with Seller's business and the business of the
Tenants and otherwise in a manner reasonably acceptable to Seller.  Without
limiting the foregoing, prior to any entry to perform any necessary on-site
testing, Buyer shall give Seller written notice thereof, including the identity
of the company or persons who will perform such testing and the proposed scope
of the testing and the party performing the testing.  Seller shall approve or
disapprove any proposed testing and the party performing the same within three
(3) Business Days after receipt of such notice.  If a Buyer Party takes any
sample from the Real Property in connection with any such approved testing,
Buyer shall provide to Seller a portion of such sample being tested to allow
Seller, if it so chooses, to perform its own testing.  Seller or its
representative may be present to observe any testing, or other inspection
performed on the Real Property.  Buyer shall promptly deliver to Seller copies
of any reports relating to any testing or other inspection of the Real Property
performed by or on behalf of any Buyer Party.  Buyer shall maintain, and shall
ensure that its contractors maintain, public liability and property damage
insurance insuring the Buyer Parties against any liability arising out of any
entry or inspections of 

                                         -19-
<PAGE>

the Real Property pursuant to the provisions hereof.  Such insurance maintained
by Buyer shall be in the amount of Ten Million Dollars ($10,000,000) combined
single limit for injury to or death of one or more persons in an occurrence, and
for damage to tangible property (including loss of use) in an occurrence.  The
policy maintained by Buyer shall insure the contractual liability of Buyer
covering the indemnities herein and shall (i) name Seller (and their successors,
assigns and Affiliates) as additional insureds, (ii) contain a cross-liability
provision, and (iii) contain a provision that "the insurance provided by Buyer
hereunder shall be primary and noncontributing with any other insurance
available to Seller."  Buyer shall provide Seller with evidence of such
insurance coverage prior to any entry or inspection of the Real Property.  Buyer
shall indemnify and hold the Seller Parties harmless from and against any Claims
arising out of or relating to any entry on the Real Property by any Buyer Party,
in the course of performing any inspections, testings or inquiries.  The
foregoing indemnity shall survive the Closing, or, if the Closing does not
occur, beyond the termination of this Agreement.

         (b)  Notwithstanding any provision in this Agreement to the contrary,
neither Buyer nor any other Buyer Party shall contact any Governmental Authority
regarding any Hazardous Materials on or the environmental condition of the Real
Property without Seller's prior written consent thereto; provided that if Buyer
or Buyer's consultant is unconditionally obligated by applicable law to notify a
Governmental Authority regarding any Hazardous Materials on, or the
environmental condition of, the Real Property discovered by Buyer's
environmental testing, Buyer shall first provide prior written notice to Seller
and shall not contact any Governmental Authority except in conjunction with
Seller.  In addition, if Seller's consent is obtained by Buyer, Seller shall be
entitled to receive at least five (5) Business Days prior written notice of the
intended contact and to have a representative present when Buyer has any such
contact with any governmental official or representative.


         Section 4.7  Release.  

         (a)  Without limiting the provisions of Section 4.5, Buyer, for itself
and any successors and assigns of Buyer (including, without limitation, any
Permitted Assignee), waives its right to recover from, and forever releases and
discharges, and covenants not to sue, Seller, Seller's Affiliates, Seller's
asset manager, any lender to Seller, the partners, trustees, shareholders,
controlling persons, LLC members, directors, officers, attorneys, employees and
agents of each of them, and their respective heirs, successors, personal
representatives and assigns (each a "Seller Party", and collectively, the
"Seller Parties") with respect to any and all Claims, whether direct or
indirect, known or unknown, foreseen or unforeseen, that may arise on account of
or in any way be connected with any Property including, without limitation, the
physical, environmental and structural condition of the Real Property or any law
or regulation applicable thereto, including, without limitation, any Claim or
matter relating to the use, presence, discharge or release of Hazardous
Materials on, under, in, above or about the Real Property; provided, however,
Buyer does not waive its rights, if any, to recover from, and does 

                                         -20-
<PAGE>

not release or discharge or covenant not to sue Seller for (i) any act that is
found by a court of competent jurisdiction to constitute fraud, (ii) any breach
of Seller's representations or warranties set forth in Section 4.1 or in
Seller's estoppel certificate delivered pursuant to Section 8.4, subject to the
limitations and conditions provided in this Agreement, or (iii) any breach of
Seller's obligations set forth in this Agreement that expressly survive Closing.

         (b)   This Section 4.7 shall survive the Closing indefinitely.


                                      ARTICLE V

                                        TITLE

         Section 5.1  Conveyance of Title.  Buyer has obtained a Title
Commitment for the Property.  A copy of each Title Commitment delivered to Buyer
has been delivered to Seller and its counsel.  At the Closing, as a condition
precedent to Buyer's obligation to close, Seller shall have delivered to Buyer a
deed for the Real Property in the form of Exhibit A (each, a "Deed"), each
subject to no exceptions other than the following (the "Permitted Exceptions"):

              (i)  Interests and rights of Tenants in possession under Existing
Leases and New Leases, including, without limitation, those Tenant purchase
rights listed on Schedule 2.1.5;

              (ii)  Liens for Real Estate Taxes that are apportioned as
provided in Section 8.5 (including special assessments and special improvement
district or local improvement district bonds);

              (iii)  Any exceptions, exclusions and other matters set forth in
or disclosed by the Title Commitment for the Real Property or other documents
made available to Buyer and any other exceptions to title that would be
disclosed by an inspection and/or survey of the Real Property, including those
disclosed on a Survey;

              (iv)  Any and all present and future laws, ordinances,
restrictions, requirements, resolutions, orders, rules and regulations of any
Governmental Authority, as now or hereafter existing or enforced (including,
without limitation, those related to zoning and land use), and all notes or
notices of violation of any such laws, ordinances, rules or regulations set
forth in the Due Diligence Materials or in any title reports, commitments or
updates delivered to Buyer prior to the Effective Date;

              (v)  Any lien or encumbrance encumbering such Property as to
which Seller shall deliver to Buyer, or the Title Company, at or prior to the
Closing, proper instruments, 

                                         -21-
<PAGE>

in recordable form, canceling such lien or encumbrance, together with funds to
pay the cost of recording and canceling the same;

              (vi)  Such other exceptions as the Title Company shall commit to
insure over in a manner reasonably satisfactory to Buyer, without any additional
cost to Buyer, whether such insurance is made available in consideration of
payment, bonding or indemnity by Seller or otherwise;

              (vii)   Uniform Commercial Code filings that have expired or
terminated by operation of law on or prior to the Closing Date;

              (viii)  Any exceptions caused by Buyer, its agents,
representatives or employees; and

              (ix)    Any other matters affecting title to such Property that
have been approved or waived by Buyer pursuant to the terms hereof.

The acceptance by Buyer of the Deeds shall be deemed to be a full performance
and discharge of every obligation on the part of Seller to be performed under
this Agreement with respect to the applicable Property, other than those that
are specifically stated herein to survive the Closing.

         Section 5.2  Evidence of Title.  Delivery of title in accordance with
the foregoing shall be evidenced by the Title Company issuing, or to committing
to issue, at Closing, upon payment of the applicable premium therefor, a 1992
ALTA Owner's Policy of Title Insurance in the amount of the Purchase Price
showing title to the Property vested in Buyer or its Permitted Assignee or
designee, subject only to the Permitted Exceptions (the "Title Policy").


                                      ARTICLE VI

                                 BROKERS AND EXPENSES

         Section 6.1  Brokers.  Seller and Buyer represent and warrant to each
other that no broker or finder, other GMH Realty, Inc. ("GMH"), whose fees will
be the responsibility of Seller pursuant to a separate agreement among between
GMH and Seller, was instrumental in arranging or bringing about this transaction
and that there are no claims or rights for brokerage commissions or finders'
fees in connection with the transactions contemplated hereby by any person or
entity other than GMH.  If any person brings a claim for a commission or
finder's fee based upon any contact, dealings or communication with Buyer or
Seller, then the party through whom such person makes its claim shall defend the
other party (the "Indemnified Party") from such claim, and shall indemnify the
Indemnified Party and hold the Indemnified Party harmless 

                                         -22-
<PAGE>

from any and all costs, damages, claims, liabilities or expenses (including
without limitation, reasonable attorneys' fees and disbursements) incurred by
the Indemnified Party in defending against the claim.  The provisions of this
Section 6.1 shall survive the Closing or, if the Closing does not occur, any
termination of this Agreement.

         Section 6.2  Expenses.  Except as provided in Section 8.5(e), each
party hereto shall pay its own expenses incurred in connection with this
Agreement and the transactions contemplated hereby.


                                     ARTICLE VII

                          INTERIM OPERATION OF THE PROPERTY

         Section 7.1  Interim Operation of the Property.  

         (a)  Except as otherwise contemplated or permitted by this Agreement
or approved by Buyer in writing, from the Effective Date to the Closing Date,
Seller agrees that it will operate, maintain, repair and lease the Real Property
in the ordinary course, on an arm's-length basis and consistent with Seller's
past practices and will not dispose of or encumber the Property, except for
dispositions of personal property in the ordinary course of business or as
otherwise permitted by Section 7.1 or Section 7.3.  Without limiting the
foregoing, Seller shall, in the ordinary course, negotiate with prospective
Tenants and enter into New Leases (on terms that Seller believes, in its good
faith business judgment, to be market terms), enforce Leases in all material
respects, perform in all material respects all of landlord's obligations under
the Leases (other than Leases that are or that are in the process of being
terminated due to Tenant's default thereunder, provided that this provision
shall not be deemed breached by virtue of Seller's failure to perform under
Leases expiring on or before December 30, 1997) and pay all costs and expenses
of the Property, including without limitation debt service and Real Estate
Taxes.

         (b)  Seller shall not, without Buyer's consent, enter into any New
Leases or materially modify any Existing Lease.  Any consent to be given by
Buyer pursuant to this Section 7.1(b) shall not be unreasonably withheld or
delayed and shall be deemed granted if Buyer does not respond in writing to
Seller's request for consent within three (3) Business Days. 

         (c)  Seller shall not enter into or terminate any operating agreement
or any contract, agreement or other commitment of any sort (including any
contract for capital items or expenditures, but excluding any liens or other
encumbrances on title other than Permitted Exceptions), with respect to the
Property that (A) requires payments to or by Seller in excess of $50,000 per
annum, or the performance of services by Seller the value of which is in excess
of 

                                         -23-
<PAGE>

$50,000 per annum and (B) is not terminable without cause and without penalty on
thirty (30) days' notice or less; provided that Seller, in its good faith but
sole discretion, believes such contract is on market terms and will benefit the
Property. At least three (3) Business Days prior to becoming legally bound with
respect to any such matter, Seller shall consult with and seek the consent of
Buyer, and shall provide reasonable detail to Buyer (including, at Buyer's
request, copies of the relevant documentation), with respect thereto.  Any
consent to be given by Buyer pursuant to this Section 7.1(c) shall not be
unreasonably withheld or delayed and shall be deemed granted if Buyer does not
respond in writing to Seller's request for consent within three (3) Business
Days. 

         (d)  Except for New Leases or other agreements entered into in
accordance with this Section 7.1, Seller shall not enter into any agreement to
create a lien or encumbrance on the Property without Buyer's prior written
consent (which consent shall not be unreasonably withheld or delayed with
respect to any utility or similar easement necessary for the operation of a
Property, and which shall be deemed granted if Buyer does not respond in writing
to Seller's request for consent within three (3) Business Days).

         (e)  Prior to the Closing Date or the earlier termination of this
Agreement, Seller shall not sell the Property or portion thereof without Buyer's
prior written consent, except for dispositions of personal property in the
ordinary course of business or as otherwise permitted by Section 7.1 or Section
7.3.

         (f)  Within three (3) days after the execution thereof, Seller shall
provide Buyer with copies of all Contracts entered into by Seller after the
Effective Date affecting the Property (other than Contracts terminable on
30 days' notice or less), and all operating statements, rent rolls, receivable
aging reports, leasing reports and other periodic reports prepared by or
delivered to Seller.

         Section 7.2  Tenant Improvement Costs, Leasing Commissions and Free
                      Rent.  
If the Closing occurs, Buyer shall be responsible and shall pay for the costs of
tenant improvement work or allowances, third-party leasing commissions and other
leasing costs (collectively, "Leasing Costs") relating to or arising from
(i) those Leases or modifications of Leases entered into on or after October 9,
1997  (ii) the exercise by a Tenant of a renewal, expansion or extension option
contained in any Lease, which renewal or extension period commences, or which
expansion space such Tenant first has the right to occupy, on or after October
9, 1997 (notwithstanding that such Tenant may have exercised such option prior
to October 9, 1997 and (iii) any items set forth on Schedule 7.2.1, and any
amounts paid by Seller in respect of such Leasing Costs shall result in an
upward adjustment to the Purchase Price at Closing equal to the amounts so paid.
Free rent periods provided for in Leases entered into by Seller prior to October
9, 1997 that occur, in whole or in part, after the Closing Date shall be for 

                                         -24-
<PAGE>

the account of, and borne by, Buyer without adjustment to the Purchase Price at
closing.  The provisions of this Section 7.2 shall survive the Closing.

         Section 7.3  Seller's Maintenance of the Property.  Between the
Effective Date and the Closing Date, Seller shall (a) maintain the Real Property
in substantially the same manner as prior hereto pursuant to Seller's normal
course of business, subject to reasonable wear and tear and further subject to
the occurrence of any damage or destruction to the Real Property by casualty or
other causes or events beyond the control of Seller; provided, however, that
Seller's maintenance obligations under this Section 7.3 shall not include any
obligation to make capital expenditures not incurred in Seller's normal course
of business or any other expenditures not incurred in Seller's normal course of
business; (b) continue to maintain its existing insurance coverage; and (c) not
grant any voluntary liens or encumbrances affecting such Property other than
Permitted Exceptions of the type described in clauses (i) and (ix) of
Section 5.1.

         Section 7.4  Lease Enforcement.  Subject to the provisions of Section
7.1, prior to the Closing Date, Seller shall have the right, but not the
obligation, to enforce the rights and remedies of the landlord under any Lease
or New Lease, by summary proceedings or otherwise, and to apply all or any
portion of any security deposits then held by Seller toward any loss or damage
incurred by Seller by reason of any defaults by any Tenant, provided, that
(i) with respect to delinquent rents, Seller may (to the extent permitted under
the Lease) apply Tenant security deposits held by Seller only to rents that are
thirty (30) days or more past due and (ii) with respect to any application by
Seller of Tenant security deposits held by Seller, Seller will deliver, in
connection with any such application, written notice to the affected Tenant(s)
indicating that their security deposits have been or are being so applied).

         Section 7.5  Lease Termination Prior to Closing.  The bankruptcy or
default of any Tenant or the termination of any Lease or New Lease or the
removal of any Tenant by reason of a default by such Tenant (by summary
proceedings or otherwise) or by operation of the terms of such Lease or New
Lease shall not affect the obligations of Buyer under this Agreement in any
manner or entitle Buyer to a reduction in, or credit or allowance against, the
Purchase Price or give rise to any other claim on the part of Buyer.

         Section 7.6  Tenant Notices.  At the Closing, Seller shall furnish
Buyer with a signed notice to be given to each Tenant.  Such notice shall
disclose that the Property has been sold to Buyer and that, after the Closing,
all rents should be paid to Buyer.

         Section 7.7  Risk of Loss and Insurance Proceeds.  Buyer shall be
bound to purchase the Property for the full Purchase Price as required by the
terms hereof, without regard to the occurrence or effect of any damage to the
Real Property or destruction of any improvements thereon or condemnation of any
portion of  the Property, provided that upon the Closing, there shall be a
credit against the Purchase Price due hereunder equal to the amount of 

                                         -25-
<PAGE>

any insurance proceeds or condemnation awards collected by Seller as a result of
any such damage or destruction or condemnation, plus the amount of any insurance
deductible or any uninsured amount or retention, less any sums reasonably
expended by Seller prior to the Closing for the restoration or repair of  the
Property.  Seller has provided Buyer with a certificate of insurance for
Seller's casualty insurance policy so that Buyer can confirm its satisfaction
with such policy.  Seller agrees that it will maintain such policy in full force
and effect until the Closing.  If the proceeds or awards have not been collected
as of the Closing, then such proceeds or awards shall be assigned to Buyer,
except to the extent needed to reimburse Seller for sums it reasonably expended
prior to the Closing for the restoration or repair of such Property. 
Notwithstanding the foregoing, (i) Seller shall not settle, compromise or
otherwise stipulate any award or recovery in connection with any damage,
destruction or condemnation, in each case if such damage, destruction or
condemnation impairs the value of the Property by at least $250,000, without the
prior written approval of Buyer, which approval shall not be unreasonably
withheld, (ii) Buyer shall have the right to participate in any such settlement
or other proceedings, and (iii) if the amount of the damage or destruction as
described in this Section 7.7 exceeds ten percent (10%) of the Purchase Price,
then Buyer may, at its option to be exercised within five (5) Business Days of
Seller's written notice of the occurrence of the damage or destruction, either
terminate this Agreement or consummate the purchase for the full Purchase Price
as required by the terms hereof.  If Buyer elects to terminate this Agreement,
then the Deposit shall be immediately returned to Buyer and neither party shall
have any further rights or obligations hereunder except to the extent set forth
in Sections 4.6(a), 6.1, 9.4 and 9.10(a).  If Buyer elects to proceed with the
purchase, then upon the Closing, Buyer shall be entitled to a credit against the
Purchase Price and shall receive an assignment of any uncollected proceeds or
awards, all as set forth in this Section 7.7 above.  The provisions of this
Section 7.7 shall survive the Closing.

         Section 7.8  Notifications.  Between the Effective Date and the
Closing, Seller shall promptly notify Buyer of any condemnation, environmental,
zoning or other land-use regulation proceedings relating to any of the Property
of which Seller obtains actual knowledge by written notice, any notices of
violations of any legal requirements relating to any of the Property received by
Seller, any litigation of which Seller obtains actual knowledge by written
notice that arises out of the ownership of the Property unless fully covered by
insurance (subject to customary deductibles), and any other matters that would
materially affect Seller's representations and warranties hereunder.

                                         -26-
<PAGE>

                                     ARTICLE VIII

                                  CLOSING AND ESCROW

         Section 8.1  Escrow Instructions.  Upon execution of this Agreement,
the parties hereto shall deposit an executed counterpart of this Agreement with
the Title Company, and this instrument shall serve as the instructions to the
Title Company as the escrow holder for consummation of the purchase and sale
contemplated hereby.  Seller and Buyer agree to execute such reasonable
additional and supplementary escrow instructions as may be appropriate to enable
the Title Company to comply with the terms of this Agreement; provided, however,
that in the event of any conflict between the provisions of this Agreement and
any supplementary escrow instructions, the terms of this Agreement shall
control, unless a contrary intent is expressly indicated in such supplementary
instructions.

         Section 8.2  Closing. The Closing hereunder shall be held and delivery
of all items to be made at the Closing under the terms of this Agreement shall
be made at the offices of Seller's counsel (or such other location as the
parties may agree) at 10:00 A.M. (Eastern Standard Time) on January 5, 1998 or
such earlier or later date and time as Buyer and Seller may mutually agree upon
in writing (the "Closing Date"), in either case, with time being of the essence.
Except as otherwise permitted under this Agreement, such date and time may not
be extended without the prior written approval of both Seller and Buyer.

         Section 8.3  Deposit of Documents.

         (a)  At or before the December 16, 1997 (the "Document Delivery
Date"), at the offices of Seller's counsel (or such other time and location as
the parties may agree) Seller shall deposit into escrow with the Title Company
the following items (pursuant to escrow instructions reasonably acceptable to
Seller and Buyer):

              (i)  a duly executed and acknowledged Deed for the Real Property;

              (ii)  [intentionally omitted];

              (iii)  [intentionally omitted]

              (iv)  a duly executed counterpart of a Bill of Sale for the
Property in the form attached hereto as Exhibit E (each, a "Bill of Sale");

              (v)  a duly executed counterpart of an Assignment and Assumption
of Leases for the Property in the form attached hereto as Exhibit F (each, an
"Assignment of Leases");

                                         -27-
<PAGE>


              (vi)  a duly executed counterpart of an Assignment and Assumption
of Contracts, Warranties and Guaranties and Other Intangible Property for the
Property in the form attached hereto as Exhibit G (each, an "Assignment of
Contracts");

              (vii) a duly executed counterpart of an agreement designating the
Title Company as the "Reporting Person" for the transaction contemplated hereby
pursuant to Section 6045(e) of the Federal Code and the regulations promulgated
thereunder, substantially in the form of Exhibit H attached hereto (the
"Designation Agreement"); 

              (viii)  a duly executed counterpart of such disclosures and
reports (including withholding certificates) as are required by applicable state
and local law in connection with the conveyance of the Property;

              (ix)  the Seller's affidavit to the Title Company, in the form of
Exhibit L attached hereto (the "Seller's Affidavit"); and

              (x)  an affidavit pursuant to Section 1445(b)(2) of the Code, and
on which Buyer is entitled to rely, that Seller is not a "foreign person" within
the meaning of Section 1445(f)(3) of the Code.

         (b)  At or before the Document Delivery Date, at the offices of
Seller's counsel (or such other time and location as the parties may agree),
Buyer shall deposit into escrow with the Title Company the following items
(pursuant to escrow instructions reasonably acceptable to Seller and Buyer):

              (i)  [intentionally omitted];

              (ii)  a duly executed counterpart of each Bill of Sale;

              (iii)  a duly executed counterparts of each Assignment of Leases;

              (iv)  a duly executed counterpart of each Assignment of
Contracts;

              (v)  a duly executed counterpart of the Designation Agreement

              (vi) a duly executed counterpart of Buyer's As-Is Certificate and
Agreement, substantially in the form of Exhibit I attached hereto; and

              (vii)  a duly executed counterpart of such disclosures and
reports as are required by applicable state and local law in connection with the
conveyance of the Property.

                                         -28-
<PAGE>


         (c)  On the morning of the Closing Date, Buyer shall effect a wire
transfer of federal funds to the Title Company's escrow account (in accordance
with the wiring instructions set forth on Schedule 2.2.1) in an amount equal to
the sum of (i) the Purchase Price and (ii) the amount (if any) of the costs,
expenses and adjustments payable by Buyer under this Agreement.  The amount of
the funds to be wired to the Title Company's escrow account shall be reduced by
the Deposit (including all interest thereon).  After Seller's  confirmation of
receipt of the Purchase Price (as reduced by the costs, expenses, prorations and
adjustments payable by Seller under this Agreement) by wire transfer of federal
funds by the Title Company to one or more accounts designated by Seller: (i) the
Title Company shall be authorized to record the Deed for the Real Property, (ii)
the Title Company shall deliver to Buyer all other documents and instruments
received by it which, in accordance with the terms of this Agreement, are to be
delivered by Seller to Buyer on the Closing Date, and (iii) the Title Company
shall deliver to Buyer all other documents and instruments received by it which,
in accordance with the terms of this Agreement are to be delivered by Buyer to
Seller on the Closing Date.  Buyer and Seller shall each deposit such other
instruments as are reasonably required by the Title Company or otherwise
required to close the escrow and consummate the purchase and sale of the
Property in accordance with the terms hereof; provided, that Seller shall not be
required to provide any indemnities or affidavits or to escrow any funds other
than the Seller's Affidavit.

         (d)  Seller shall deliver to Buyer originals of the Leases (or, if
originals are not available, copies), copies of the tenant correspondence files
of the Real Property in Seller's possession, a set of keys to the Real Property
and originals (or copies, if originals are not available) of any other items in
Seller's possession relating to the use, ownership, operation, maintenance,
leasing, repair, alteration, management or development of the Real Property, on
the Closing Date (at such location as Buyer and Seller shall mutually agree). 
Following the Closing, Buyer shall make all Leases, Contracts, other documents,
books, records and any other materials in its possession, to the extent the same
relate to the period of Seller's ownership of the Property, available to Seller
or its representatives for inspection and/or copying at Buyer's offices (at
Seller's sole cost and expense) at reasonable times and upon reasonable notice.

         Section 8.4  Estoppel Certificates.  Seller shall use its reasonable
efforts (without incurring any additional expense) to obtain prior to the
Closing Date tenant estoppel certificates from each Tenant substantially in the
form attached hereto as Exhibit J; provided, however, that if a form of estoppel
certificate is attached to or otherwise prescribed in a particular lease
document, that form (the "Prescribed Form") shall be deemed to be acceptable to
Buyer in the event that any Tenant is unwilling to sign the form attached hereto
as Exhibit J.  It shall be a condition to Buyer's obligation to close the sale
and purchase of a Property that on or before the Closing Seller delivers to
Buyer tenant estoppel certificates substantially in the form attached hereto as
Exhibit J (or in the Prescribed Form, if applicable) from (i) Tenants occupying
seventy five percent (75%) of the total leased square footage of the Property;
and (ii) Significant Tenants occupying seventy five percent (75%) of the total
leased square footage covered by such 

                                         -29-
<PAGE>

Significant Tenants' Leases (with respect to each of preceding clauses (i)-(ii),
the "Required Percentage"); provided, however, if Seller is unable to obtain the
aforesaid tenant estoppel certificates from Tenants or Significant Tenants (as
the case may be) occupying the Required Percentage, Seller may, but shall not be
obligated to, provide a certificate to Buyer, with respect to such missing
estoppel certificates, as chosen by Seller, to the effect that (except as
disclosed in the Due Diligence Materials or in the Leases to which such
estoppels relate): (i) to Seller's knowledge the Leases for those Tenants or
Significant Tenants (as the case may be) are in full force and effect; (ii) the
amount of the Tenants' or Significant Tenants' security deposits; (iii) the
dates through which rent has been paid; (iv) neither Seller nor, to Seller's
knowledge, any of those Tenants or Significant Tenants (as the case may be) is
in default thereunder;  (v) a true, correct and complete copy of the Leases are
attached; (vi) the Leases expire on the dates specified and are not subject to
any renewal or extension options, except as specified, and (viii) there are no
options to purchase or rights of first refusal except as specified.  Buyer shall
be obligated to accept Seller's certification in lieu of any missing estoppel
certificates.  Seller's representations and warranties in the certificate shall
survive the Closing, provided that (i)  Buyer must give Seller a Claim Notice
with respect to any claim it may have against Seller for a breach of any such
representation and warranty by July 6, 1998, and must commence litigation (if
any) relating to such Claim Notice not later than October 6, 1998 (and any claim
that Buyer may have that is not so asserted, or litigation by Buyer that is not
so commenced, shall be barred and not be valid or effective and Seller shall
have no liability whatsoever with respect thereto) and (ii) any certificate
delivered by Seller pursuant to this Section 8.4 shall cease to survive the
Closing to the extent specifically confirmed by a tenant estoppel certificate
delivered by a Tenant or a Significant Tenant.  In no event shall the minimum
thresholds to Buyer's recovery set forth in Section 4.3(a) apply to any
certificates delivered by Seller (but Buyer's recovery under any such
certificates shall be limited by the maximum limitations set forth in
Section 4.3(a)).

         Section 8.5  Prorations.

         (a)  Rents, including, without limitation, percentage rents, 
escalation charges for Real Estate Taxes, parking charges, marketing fund 
charges, operating expenses, maintenance escalation rents or charges, 
cost-of-living increases or other charges of a similar nature ("Additional 
Rents"), and any additional charges and expenses payable under Leases; Real 
Estate Taxes and personal property taxes, including refunds with respect 
thereto, if any; the current installment (only) of any improvement bond or 
assessment that is a lien on  the Property or that is pending and may become 
a lien on any Property; water, sewer and utility charges; amounts payable 
under any existing Contract, Contract entered into after the Effective Date 
and in accordance with this Agreement; annual permits and/or inspection fees 
(calculated on the basis of the period covered); and any other income or 
expenses relating to the operation and maintenance of the Property (other 
than any Leasing Costs and free rent which shall be prorated as provided in 
Section 7.2), shall all be prorated as of 12:01 a.m. Eastern Standard Time on 
the Closing Date, on the basis of a 365-day year, with Buyer deemed the owner 
of the Property on the entire Closing 

                                         -30-
<PAGE>

Date.  Rent which is due but uncollected as of the Closing Date shall not be
adjusted.  On the Closing Date, Seller shall deliver to Buyer a schedule of all
such past due but uncollected rent owed by tenants.  Buyer agrees to cause the
amount of such rental arrears to be included in the first bills thereafter
submitted by Buyer to such tenants after the Closing Date.  Any rents collected
from a tenant after the Closing Date shall be applied first to the month in
which the Closing Date occurs, next to any rents payable by such tenant after
the Closing Date and thereafter to any arrearage owed by such tenant on the
Closing Date in the inverse order of maturity.  Additional rent payments (and
estimated additional rent payments) actually paid by tenants prior to Closing
attributable to real estate taxes and operating costs shall be adjusted as of
the Closing Date.  Additional rent payments (and estimated additional rent
payments) attributable to real estate taxes and operating costs to be paid by
tenants after the Closing shall be adjusted upon receipt by Buyer.  The
adjustments of additional rent payments shall be based upon the number of days
in the period for which such payment relates that are before or after the
Closing Date.  In no event will Buyer be entitled to receive any payments on or
under the promissory notes or other agreements referred to in Section 8.7. 
Buyer shall use reasonable efforts until October 6, 1998 to collect any
delinquent rents that accrued prior to the Closing Date (but Seller shall have
the right to commence and pursue litigation against any Tenant to collect
delinquent rents and/or expense reimbursements, provided that Seller may not
seek as a remedy in any such litigation the termination of any Leases or the
dispossession of any Tenant).  Seller agrees to forward any rents received by it
after the Closing Date to Buyer for application in accordance with the
provisions hereof.  The amount of any security deposits that are required to be
returned to Tenants under Leases shall be credited against the Purchase Price
(and Seller shall be entitled to retain such security deposits).  In the event 
the Property has been assessed for property taxes purposes at such rates as
would result in reassessment (i.e., "escape assessment" or "roll-back taxes")
based upon the change in land usage or ownership of such Property resulting from
or after the consummation of the transactions described in this Agreement, as
between Buyer and Seller, Buyer hereby agrees to pay all such taxes and to
indemnify and save Seller harmless from and against all claims and liability for
such taxes.  Such indemnity shall survive the Closing.

         (b)  Seller and Buyer hereby agree that if any of the aforesaid
prorations cannot be calculated accurately on the Closing Date, then the same
shall be calculated as soon as reasonably practicable after the Closing Date,
and that if any Tenant is required to pay Additional Rents and such Additional
Rents are not finally adjusted between the landlord and tenant under the
applicable Lease until after the end of the 1997 calendar year, then such
prorations shall be calculated as soon as reasonably practicable after such
Additional Rents have been finally adjusted.  Either party owing the other party
a sum of money based on proration(s) calculated after the Closing Date shall
promptly pay said sum to the other party, together with interest thereon at the
rate of two percent (2%) per annum over the Prime Rate from the Closing Date to
the date of payment, if payment is not made within ten (10) days after delivery
of a bill therefor.  If the real estate and/or personal property tax rate and
assessments have not been set for the calendar year in which the Closing occurs,
then the proration of such taxes shall be based upon 

                                         -31-
<PAGE>

the rate and assessments for the preceding calendar year, and such proration
shall be adjusted between Seller and Buyer as soon as reasonably practicable
after such tax rate or assessment has been set.

         (c)  Buyer shall calculate the prorations contemplated by Section
8.5(b).  Seller and its representatives and auditors shall be afforded the
opportunity to review all underlying financial records and work papers
pertaining to the preparation of Buyer's proration statements, and Buyer shall
permit Seller and its representatives and auditors during regular business hours
and upon reasonable prior written notice to have reasonable access to the books
and records in the possession of Buyer or any party to whom Buyer has given
custody of the same relating to the Property to permit Seller to review Buyer's
proration statements.  Seller shall have sixty (60) days after receipt of
Buyer's calculations to accept or contest such prorations.

         (d)  Buyer shall pay for all recording and escrow fees.  Buyer shall
also pay the costs of the Title Commitments, Title Policies and all endorsements
thereto, and Surveys and Survey updates, and all costs of any appraisal,
engineering and environmental reports not delivered by Seller.  Seller and Buyer
shall each pay one half of the realty transfer taxes payable with respect to the
deed.  Seller and Buyer shall each be responsible for paying their respective
attorneys' fees and costs.  Buyer and Seller agree that, given the de minimis
amount of Personal Property included within the Property, no portion of the
Purchase Price is allocable or attributable to such Personal Property.

         (e)  Buyer agrees that for purposes of any appeals relating to Real
Estate Taxes after the Closing Date, Buyer shall not value the Property in a
manner (or otherwise take a position) inconsistent with the Purchase Price set
forth herein.

         (f)  Notwithstanding anything to the contrary herein, to the extent
set forth in Section 8.6 Seller reserves the right to protest any Real Estate
Taxes relating to the period prior to the Closing Date and to receive and retain
any refunds on account of such Real Estate Taxes. 

         (h)  The obligations of Seller and Buyer under this Section 8.5 shall
survive the Closing until October 6, 1998 (except with respect to prorations of
taxes and municipal assessments).

         Section 8.6  Tax Certiorari Proceedings.  Seller is hereby authorized,
but not obligated, to (a) commence (prior to the Closing Date) or continue
(after the Effective Date and after the Closing Date) any proceeding for the
reduction of the assessed valuation of  the Property for any tax year which, in
accordance with the laws and regulations applicable to such Property, requires
that, to preserve the right to bring a tax certiorari proceeding with respect to
such tax year, such proceeding be commenced prior to the Closing Date and (b)
endeavor to settle any such proceeding in Seller's discretion.  After the
Closing, with respect to  the Property, (i) Seller 

                                         -32-
<PAGE>

shall retain all rights (subject to any rights of Tenants under their Leases)
with respect to any tax year ending prior to the tax year (and all refunds
relating thereto) in which the Closing Date occurs, and shall have the sole
right to participate in and settle any proceeding relating thereto (provided,
that such settlement does not affect the assessed tax value for any subsequent
tax year), and (ii) Buyer shall have all rights (subject to any rights of
Tenants under their Leases) with respect to any tax year (and all refunds
relating thereto) which ends after the Closing Date; provided, however, that if
the proceeding is for a tax year in which the Closing Date occurs, such
settlement shall not be made without Buyer's prior consent, which consent shall
not be unreasonably withheld or delayed.  With respect to any such proceeding
for a tax year in which the Closing Date occurs (whether commenced by Seller or
Buyer), any refund or credit of taxes for such tax year shall be applied first
to the unreimbursed out-of-pocket expenses, including reasonable counsel fees,
necessarily incurred in obtaining such refund or credit, and second, to any
Tenant entitled to same, and the balance shall be apportioned between Seller and
Buyer as of the Closing Date in accordance with the proportion of the applicable
tax year occurring before and after the Closing Date.  In each case, the party
which prosecuted the proceeding shall deliver to the other copies of receipted
tax bills and any decision or settlement agreement evidencing the reduction in
taxes.  If any refund shall be received by Seller which is for the account of
Buyer as provided in this Section 8.6, then Seller shall hold Buyer's share
thereof in trust for Buyer and, promptly upon receipt thereof, pay such share to
Buyer or any other party entitled to same as provided above.  If any refund
shall be received by Buyer which is for the account of Seller as provided in
this Section 8.6, then Buyer shall hold Seller's share thereof in trust for
Seller and, promptly upon receipt thereof, pay such share to Seller or any other
party entitled to same as provided above.  Each party shall execute any and all
consents or other documents as may be reasonably necessary to be executed by
such party so as to permit the other party to commence or continue any tax
certiorari proceeding which such other party is authorized to commence or
continue pursuant to the terms of this Section 8.6, or to collect any refund or
credit with respect to any such tax proceeding.  The provisions of this Section
8.6 shall survive the Closing.

         Section 8.7  Tenant Obligations.  Notwithstanding anything herein that
may be construed to the contrary (including, without limitation, Section 8.5),
promissory notes or other agreements (other than the Leases) delivered to Seller
that evidence, deal with or otherwise relate solely to a Tenant's rental or
expense reimbursement obligations under its Lease that, as of the Closing Date,
are or were past due, shall not be conveyed to Buyer and shall be retained by
Seller.  Seller agrees that in enforcing its rights against Tenants under any
such promissory notes or other agreements, Seller will not seek to exercise any
remedies that may be available to it under the affected Leases.

                                         -33-
<PAGE>


                                      ARTICLE IX

                                    MISCELLANEOUS

         Section 9.1  Notices.  Any notices required or permitted to be given
hereunder shall be given in writing and shall be delivered (a) in person, (b) by
certified mail, postage prepaid, return receipt requested, (c) by a commercial
overnight courier that guarantees next day delivery and provides a receipt, or
(d) by legible facsimile (followed by hard copy delivered in accordance with
preceding subsections (a)-(c)), and such notices shall be addressed as follows:

      To Buyer:    Brandywine Operating Partnership, L.P.
                   16 Campus Blvd., Suite 150
                   Newtown Square, Pennsylvania 19073
                   Attn: Gerard H. Sweeney, President
                   Facsimile No.(610) 325-5622

with a copy to:    Brad A. Molotsky, Esq., General Counsel
                   c/o Brandywine Realty Trust
                   16 Campus Blvd., Suite 150
                   Newtown Square, Pennsylvania 19073
                   Facsimile No.(610) 325-5622

     To Seller:    Virginia Drive Associates, L.P.
                   c/o GMH Associates, Inc.
                   353 West Lancaster Avenue, Suite 210
                   Wayne, Pennsylvania 19087
                   Attn: Mr. Bruce Robinson
                   Facsimile No. (610) 687-6567

with a copy to:    Crosstown Asset Corp. I
                   c/o Cargill Financial Services Corp.
                   6000 Clearwater Drive
                   Minnetonka, Minnesota 55343
                   Attention:  Mr. Thomas S. Huettner
                   Fax No.:  (612) 984-3905
                   
                   
                   
                                         -34-
<PAGE>
         

or to such other address as either party may from time to time specify in
writing to the other party.  Any notice shall be effective only upon receipt (or
refusal by the intended recipient to accept delivery).  Notices may be given by
attorneys for the notifying partner.

          Section 9.2  Entire Agreement.  This Agreement, together with the
Exhibits and Schedules hereto, and the Confidentiality Agreement, contains all
representations, warranties and covenants made by Buyer and Seller and
constitutes the entire understanding between the parties hereto with respect to
the subject matter hereof. Any correspondence, memoranda or agreements between
the parties, including, without limitation, or any oral or written statements
made by Seller, its Affiliates, employees or agents, are not binding on or
enforceable against any party, and are superseded and replaced in total by this
Agreement together with the Exhibits and Schedules hereto.

          Section 9.3  Time.  Time is of the essence in the performance of each
of the parties' respective obligations contained herein.

          Section 9.4  Attorneys' Fees.  If either party hereto fails to perform
any of its obligations under this Agreement or if any dispute arises between the
parties hereto concerning the meaning or interpretation of any provision of this
Agreement, then the defaulting party or the party not prevailing in such
dispute, as the case may be, shall pay any and all costs and expenses incurred
by the other party on account of such default and/or in enforcing or
establishing its rights hereunder, including, without limitation, court costs
(including costs of any trial or appeal therefrom) and reasonable attorneys'
fees and disbursements.

          Section 9.5  No Merger.  The obligations contained herein, the
performance of which is contemplated after the Closing, shall not merge with the
transfer of title to the Property but shall remain in effect until fulfilled.

          Section 9.6  Assignment.  Buyer's rights and obligations hereunder
shall not be assignable, directly or indirectly, without the prior written
consent of Seller.

          Section 9.7  Counterparts.  This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original, but all of which
taken together shall constitute one and the same instrument.

          Section 9.8  Governing Law; Jurisdiction and Venue.  

          (a)  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE COMMONWEALTH OF PENNSYLVANIA.  THE PARTIES RECOGNIZE THAT,
IT MAY BE NECESSARY FOR THE PARTIES TO COMPLY WITH CERTAIN ASPECTS OF THE LAWS
OF OTHER STATES IN ORDER TO 

                                         -35-
<PAGE>

CONSUMMATE THE PURCHASE AND SALE OF SUCH PROPERTY PURSUANT HERETO.  THE PARTIES
AGREE TO COMPLY WITH SUCH OTHER LAWS TO THE EXTENT NECESSARY TO CONSUMMATE THE
PURCHASE AND SALE OF PROPERTY.  IT IS THE PARTIES' INTENT THAT THE PROVISIONS OF
THIS AGREEMENT BE APPLIED TO EACH PROPERTY IN A MANNER THAT RESULTS IN THE
GREATEST CONSISTENCY POSSIBLE.

          (b)  For the purposes of any suit, action or proceeding involving this
Agreement, Buyer and Seller hereby expressly submit to the jurisdiction of all
federal and state courts sitting in the Commonwealth of Pennsylvania and consent
that any order, process, notice of motion or other application to or by any such
court or a judge thereof may be served within or without such court's
jurisdiction by registered mail or by personal service, provided that a
reasonable time for appearance is allowed, and Buyer and Seller agree that such
courts shall have the exclusive jurisdiction over any such suit, action or
proceeding commenced by any party.  In furtherance of such agreement, Buyer and
Seller agree upon the request of the other party to discontinue (or agree to the
discontinuance of) any such suit, action or proceeding pending in any other
jurisdiction.

          (c)  Buyer and Seller each hereby irrevocably waive any objection that
it may now or hereafter have to the laying of venue of any suit, action or
proceeding arising out of or relating to this Agreement brought in any federal
or state court sitting in the Commonwealth of Pennsylvania and hereby further
irrevocably waive any claim that any such suit, action or proceeding brought in
any such court has been brought in an inconvenient forum.

          Section 9.9  Waiver of Trial by Jury.  EACH PARTY HEREBY WAIVES,
IRREVOCABLY AND UNCONDITIONALLY, TRIAL BY JURY IN ANY ACTION BROUGHT ON, UNDER
OR BY VIRTUE OF OR RELATING IN ANY WAY TO THIS AGREEMENT OR ANY OF THE DOCUMENTS
EXECUTED IN CONNECTION HEREWITH, THE PROPERTY, OR ANY CLAIMS, DEFENSES, RIGHTS
OF SET-OFF OR OTHER ACTIONS PERTAINING HERETO OR TO ANY OF THE FOREGOING.

          Section 9.10  Confidentiality and Return of Documents.  

          (a)  As a condition to Seller's agreement to furnish and/or disclose 
Evaluation Material (as defined below) to Buyer, any Permitted Assignee(s) and
their Affiliates and representatives for review and inspection, Buyer (on behalf
of itself, any Permitted Assignee(s), and their respective Affiliates and
representatives) hereby agrees to be bound by the terms set forth in this
Section 9.10(a).

            (i)     "Evaluation Material" shall include all documents, and other
     written or oral information, as well as diskettes and other forms of
     electronically transmitted data, 

                                         -36-
<PAGE>

     furnished to Buyer, a Permitted Assignee, or their respective officers,
     directors, employees, agents, advisors, Affiliates or representatives
     (collectively "Representatives") by Seller or its Affiliates relating to
     the Property, as well as written memoranda, notes, analyses, reports,
     compilations, or studies prepared by Buyer or its Representatives (in
     whatever form of medium) that contain, or are derived from, such
     information provided by Seller.  Notwithstanding the foregoing, information
     provided by Seller shall not constitute "Evaluation Material" if such
     information (i) is or becomes generally available to the public other than
     as a result of a disclosure by or through Buyer or its Representatives in
     contravention of this Section 9.10(a) or (ii) is or becomes available to
     Buyer from a source (other than Seller) not bound, to the knowledge of
     Buyer, by any legal or contractual obligation prohibiting the disclosure of
     Evaluation Material by such source to Buyer.

           (ii)     Buyer agrees that it and its Representatives will use the
     Evaluation Material exclusively for the purpose of evaluating the merits of
     a possible purchase of the Property as contemplated by this Agreement and
     not for any other purpose whatsoever.  Buyer (on behalf of itself and its
     Representatives) further agrees that it will not disclose any Evaluation
     Material or use it to the detriment of Seller or its Affiliates; provided,
     however, that  Buyer may without liability disclose Evaluation Material
     (x) to any Representative of Buyer who needs to know such Evaluation
     Material for the purpose of evaluating the transactions described in this
     Agreement involving Seller and the Property and Buyer or its Permitted
     Assignee(s) (it being understood and agreed that Buyer shall be fully
     responsible for any disclosures by any such Person) and (y) pursuant to
     administrative order or as otherwise required by law.

          (iii)     In the event that Buyer desires to disclose Evaluation
     Material under the circumstances contemplated by clause (y) of the
     preceding paragraph, Buyer will (x) provide Seller with prompt notice
     thereof, (y) consult with Seller on the advisability of taking steps to
     resist or narrow such disclosure, and (z) cooperate with Seller (at
     Seller's cost) in any attempt that Seller may make to obtain an order or
     other reliable assurance that confidential treatment will be accorded to
     designated portions of the Evaluation Material.

           (iv)     Buyer agrees that, in the event this Agreement is terminated
     prior to the consummation of the purchase and sale contemplated hereunder,
     all written Evaluation Material and all copies thereof will be returned to
     Seller promptly upon  Seller's request. All analyses, compilations, studies
     or other documents prepared by or for Buyer and reflecting Evaluation
     Material or otherwise based thereon will be (at Buyer's option) either
     (x) destroyed or (y) retained by Buyer in accordance with the
     confidentiality restrictions set forth in this Section 9.10(a).

                                         -37-
<PAGE>


            (v)     Buyer acknowledges that significant portions of the
     Evaluation Material are proprietary in nature and that Seller and its
     Affiliates would suffer significant and irreparable harm in the event of
     the misuse or disclosure of the Evaluation Material.  Without affecting any
     other rights or remedies that either party may have, Buyer acknowledges and
     agrees that  Seller shall be entitled to seek the remedies of injunction,
     specific performance and other equitable relief for any breach, threatened
     breach or anticipatory breach of the provisions of this agreement by Buyer
     or its Representatives.

           (vi)     Buyer agrees to indemnify and hold harmless Seller from and
     against all loss, liability, claim, damage and expense arising out of any
     breach of this Section 9.10(a) by Buyer or any of its Representatives
     (except that Buyer shall not be liable for consequential or punitive
     damages unless such breach was intentional).

          (vii)     This Section 9.10(a) shall survive, if the Closing does not
     occur, any termination of this Agreement, but shall terminate upon the
     Closing.

          (b)  Seller and Buyer hereby covenant that (i) prior to the Closing it
shall not issue any press release or public statement (a "Release") with respect
to the transactions contemplated by this Agreement without the prior consent of
all parties to this Agreement, except to the extent required by law or the
regulations of the Securities and Exchange Commission or the New York Stock
Exchange, and (ii) after the Closing, any Release issued by Seller or Buyer
shall be subject to the review and approval of all such parties (which approval
shall not be unreasonably withheld).  If Seller or Buyer is required by law to
issue a Release, such party shall, at least two (2) Business Days prior to the
issuance of the same, deliver a copy of the proposed Release to the other
parties for their review.  In response to inquiries concerning a Release, Buyer
cannot release any information concerning Seller without Seller's prior written
consent.

          (c)  Seller agrees for a period of one (1) year after the Closing Date
not to disclose capitalization rates and rates of return relating to the
Property (the  "Confidential Information"), provided that such disclosure may be
made (a) to any Person who is a member, partner, officer, director or employee
of Seller or counsel to or accountants of Seller solely for their use and on a
need-to-know basis, provided that such Persons are notified of Seller's
confidentiality obligations hereunder, (b) with the prior consent of Buyer, or
(c) subject to the next sentence, pursuant to legal, regulatory or
administrative process.  In the event that Seller shall receive a request to
disclose any Confidential Information under clause (c) of the preceding
sentence, Seller shall (i) promptly notify Buyer thereof, (ii) consult with
Buyer on the advisability of taking steps to resist or narrow such request and
(iii) if disclosure is required or deemed advisable, reasonably cooperate with
Buyer (at no cost to Seller) in any attempt it may make to obtain an order or
other assurance that confidential treatment will be accorded such Confidential
Information.

                                         -38-
<PAGE>


          Section 9.11  Interpretation of Agreement.  The article, section and
other headings of this Agreement are for convenience of reference only and shall
not be construed to affect the meaning of any provision contained herein.  Where
the context so requires, the use of the singular shall include the plural and
vice versa and the use of the masculine shall include the feminine and the
neuter.  The term "person" shall include any individual, partnership, joint
venture, corporation, trust, limited liability company, unincorporated
association, any other entity and any government or any department or agency
thereof, whether acting in an individual, fiduciary or other capacity.

          Section 9.12  Amendments.  This Agreement may be amended or modified
only by a written instrument signed by each of Buyer and Seller.

          Section 9.13  No Recording.  Neither this Agreement nor any memorandum
or short form thereof may be recorded by Buyer.

          Section 9.14  No Third Party Beneficiary.  The provisions of this
Agreement are not intended to benefit any third parties.

          Section 9.15  Severability.  If any provision of this Agreement, or
the application thereof to any person, place or circumstance, shall be held by a
court of competent jurisdiction to be invalid, unenforceable or void, the
remainder of this Agreement and such provisions as applied to other persons,
places and circumstances shall remain in full force and effect.

          Section 9.16  Drafts not an Offer to Enter into a Legally Binding
Contract.  The parties hereto agree that the submission of a draft of this
Agreement by one party to another is not intended by either party to be an offer
to enter into a legally binding contract with respect to the purchase and sale
of the Property.  The parties shall be legally bound with respect to the
purchase and sale of the Property pursuant to the terms of this Agreement only
if and when the parties have been able to negotiate all of the terms and
provisions of this Agreement in a manner acceptable to each of the parties in
their respective sole discretion, including, without limitation, all of the
Exhibits and Schedules hereto, and each of Seller and Buyer have fully executed
and delivered to each other a counterpart of this Agreement.

          Section 9.17  Further Assurances.  Each party shall, whenever and as
often as it shall be requested to do so by the other party, execute, acknowledge
and deliver, or cause to be executed, acknowledged and delivered, any and all
such other documents and do any and all other acts as may be necessary to carry
out the intent and purpose of this Agreement.

          Section 9.18  Special Provisions Regarding Property Located in the
Commonwealth of Pennsylvania.  Under the terms of the Pennsylvania Sewage
Facilities Act of January 24, 1966, No. 537, P.L. 12535 as amended, Seller has
received no written notice from a  

                                         -39-
<PAGE>

Governmental Authority that a tie-in or tap to a community sewage system
currently exists or is available or that such system or any other utility
systems or facilities are presently adequate for Buyer's use of the Property,
and Buyer agrees to assume full responsibility for contacting any agencies or
utility companies in order to obtain service to the Property and for any fee
incurred or payment required in connection therewith.

          Section 9.19  Exculpation.  No recourse shall be had for any
obligation under this Agreement , or any document executed and delivered by
Buyer in connection with the Closing, against any past, present or future
trustee, shareholder, officer or employee of Brandywine Realty Trust, 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
Seller and all parties claiming by, through or under Seller

          Section 9.20  Counterparts.  This Agreement may be executed in
counterparts, all of which taken together shall constitute one and the same
original, and the execution of counterparts by Buyer and Seller shall bind Buyer
and Seller as if they had executed the same counterpart.









                            [Signatures on following page]


                                         -40-
<PAGE>


          The parties hereto have executed this Agreement as of the date first
written above.


                    Buyer:    BRANDYWINE OPERATING PARTNERSHIP, L.P.

                              By:  Brandywine Realty Trust, General Partner

                              By:  ___________________________
                                   Gerard H. Sweeney
                                   President


                    Seller:   VIRGINIA DRIVE ASSOCIATES, L.P.

                              By:  GH Virginia Drive, Inc., its general partner


                              By:  _________________________
                                   Name:
                                   Title


                                         -41-
<PAGE>



                                      EXHIBIT N



                                   ESCROW AGREEMENT


     Commonwealth Land Title Insurance Company ("Escrowee") agrees to hold in
escrow pursuant to this Agreement the sum of $200,000 ("Deposit") to be
deposited by Brandywine Operating Partnership, L.P. ("Buyer") pursuant to a
certain Agreement of Purchase and Sale dated December 15, 1997 ("Agreement"),
between Buyer and Virginia Drive Associates, L.P. ("Seller"), the provisions of
which (including, without limitation, the defined terms) are hereby incorporated
herein by reference.  The Deposit shall be paid to Seller by Escrowee at the
time of Closing under the Agreement, or if Closing does not take place,
distributed in accordance with the terms of the Agreement.  Escrowee shall,
immediately upon receipt of the Deposit, deposit same in an interest bearing,
money market type escrow account with a federally insured bank or savings and
loan association located in Philadelphia, Pennsylvania.  All interest which
shall accrue on the Deposit shall be payable in accordance with the Agreement. 
Escrowee shall pay such interest to such party contemporaneously with Escrowee's
payment of the Deposit.  Seller and Buyer agree that Escrowee is an escrow
holder only and is merely responsible for the safekeeping of the Deposit and
interest and shall not be required to determine questions of fact or law.  If
Escrowee shall receive notice of a dispute as to the disposition of the Deposit
or the interest, then Escrowee shall not distribute the Deposit or interest
except in accordance with written instructions signed by both Buyer and Seller. 
Pending resolution of any such dispute,  Escrowee is authorized to pay the
Deposit and interest into court.  If Escrowee pays the Deposit and interest into
court, it shall be discharged from all further obligations hereunder.  This
Escrow Agreement shall be governed by the laws of the state of New York.

          Seller's Federal Tax ID Number is 23-2895748.

          Buyer's Federal Tax ID Number is 23-2862640.



<PAGE>

     IN WITNESS WHEREOF, Buyer, Seller and Escrowee, for valuable consideration,
each intending to be legally bound and to bind their respective successors and
assigns, have caused this Escrow Agreement to be executed and delivered as of
December 15, 1997.


                    Escrowee: COMMONWEALTH LAND TITLE INSURANCE COMPANY





                              By:  ___________________________
                                   Name:
                                   Title:


                    Buyer:    BRANDYWINE OPERATING PARTNERSHIP, L.P.

                              By:  Brandywine Realty Trust, General Partner

                              By:  ___________________________
                                   Gerard H. Sweeney
                                   President


                    Seller:   VIRGINIA DRIVE ASSOCIATES, L.P.

                              By:  GH Virginia Drive, its general partner


                              By:  _________________________
                                   Name:
                                   Title


