
<PAGE>
 
                                                                    EXHIBIT 99.5

                                   THREE ECW
                        PROPERTY CONTRIBUTION AGREEMENT


          THIS THREE ECW PROPERTY CONTRIBUTION AGREEMENT (this "AGREEMENT") is
made and entered into as of this 12th day of November, 1998, by and among THREE
EMBARCADERO CENTER WEST, a California limited partnership (the "PARTNERSHIP"),
THE PRUDENTIAL INSURANCE COMPANY OF AMERICA, a New Jersey corporation
("PRUDENTIAL"), PIC REALTY CORPORATION, a Delaware corporation ("PIC"),
PRUDENTIAL REALTY SECURITIES II, INC., a Delaware corporation ("PRS"), BOSTON
PROPERTIES LIMITED PARTNERSHIP, a Delaware limited partnership ("INVESTOR"),
BOSTON PROPERTIES, INC., a Delaware corporation ("PUBLIC COMPANY"), and BP EC
WEST LLC, a Delaware limited liability company ("BPECW LLC").


                                R E C I T A L S
                                - - - - - - - -

          A.   Pursuant to that certain Master Transaction Agreement dated as of
September 28, 1998, by and among Investor, Public Company, Prudential, PIC,
Fedmark Corporation ("FEDMARK"), Embarcadero Center Investors Partnership,
Pacific Property Services, L.P. and those Persons listed on Exhibit A-1 attached
thereto (the "MASTER TRANSACTION AGREEMENT"), the parties hereto have entered
into a series of transactions whereby BPECW LLC has received an undivided
37.9167% tenancy-in-common interest in and to the Property (defined below) in
liquidation of its interest in and to the Partnership.  All initially
capitalized terms used herein without definition shall have the respective
meanings given such terms in the Master Transaction Agreement.

          B.   The Partnership is currently governed by those certain Second
Amended and Restated Articles of Limited Partnership of Three Embarcadero Center
West dated as of January 9, 1989 (as amended, modified or supplemented, the
"PARTNERSHIP AGREEMENT").

          C.   The parties hereto desire to enter into this Agreement whereby
the Partnership will transfer its entire undivided 62.0833% tenancy-in-common
interest in and to the Property to BPECW LLC as a contribution to Investor, and
Investor shall issue to the Partnership in consideration of such contribution
Investor's Preferred Units (as defined below), all upon the terms and conditions
of this Agreement below.

          NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                       1
<PAGE>
 
                                   ARTICLE 1

                              CERTAIN DEFINITIONS
                              -------------------

      1.1  Definitions.  In addition to the terms defined in the Master
           -----------                                                 
Transaction Agreement and in this Agreement below, the following terms shall
have the meanings set forth below for the purposes of the transactions described
in this Agreement:

           "ASSIGNED CONTRACTS" shall have the meaning given such term in
Section 10.1.2(d) hereof.
-----------------        

           "ASSIGNMENT OF CONTRACTS" shall have the meaning given such term in
Section 10.1.2(d) hereof.
-----------------        

           "ASSIGNMENT OF LEASES" shall have the meaning given such term in
Section 10.1.2(c) hereof.
-----------------        

           "CLOSING" shall have the meaning given such term in Section 10.1.1
                                                               --------------
hereof.

           "COMMISSION" shall have the meaning given such term in Section 6.3.3
                                                                  -------------
hereof.

           "CONFIDENTIAL MATERIAL" shall have the meaning given such term in
Section 9.1.1 hereof.
-------------        

           "CONTRACTS" shall have the meaning given such term in Section 5.3.6
                                                                 -------------
hereof.

           "CONTRIBUTION UNITS" shall have the meaning given such term in
Section 2.2 hereof.
-----------        

           "CONTRIBUTION VALUE" shall have the meaning given such term in
Section 2.2 hereof.
-----------        

           "DEED" shall have the meaning given such term in Section 10.1.2(a)
                                                            -----------------
hereof.

           "DOCUMENTS" shall have the meaning given such term in Section 4.1.1
                                                                 -------------
hereof.

           "ENCUMBRANCE DOCUMENTS" shall have the meaning given such term in
Section 5.3.9 hereof.
-------------        

           "EXCLUDED LIABILITIES" shall have the meaning given such term in
Section 4.2.2(b) hereof.
----------------        

                                       2
<PAGE>
 
           "HAZARDOUS MATERIAL" shall have the meaning given such term in
Section 4.2.3 hereof.
-------------        

           "INVESTOR" shall have the meaning given such term in the Introductory
Paragraph.

           "INVESTOR AGREEMENT" shall have the meaning given such term in
Section 10.1.2(m) hereof.
-----------------        

          "INVESTOR COMMON UNITS" shall mean the Common Units as set forth in
the Investor Agreement.

           "INVESTOR PREFERRED UNITS" shall mean the Series Three Preferred
Units as set forth in the Investor Agreement.

           "INVESTOR-COVERED CLAIMS" shall have the meaning given such term in
Section 4.2.2(a) hereof.
----------------        

           "INVESTOR/BPECW LLC KNOWLEDGE PARTIES" shall have the meaning given
such term in Section 7.2 hereof.
             -----------        

           "LEASES" shall have the meaning given such term in Section 10.1.2(c)
                                                              -----------------
hereof.

           "LIMITATION DATE" shall have the meaning given such term in Article 8
                                                                       ---------
hereof.

           "MASTER TRANSACTION AGREEMENT" shall have the meaning given such term
in Recital A hereof.
   ---------        

           "OTHER PROPERTY RIGHTS" shall have the meaning given such term in
Section 2.1(c) hereof.
--------------        

           "PARTNER" shall mean any partner of the Partnership as of the
effective time of this Agreement.

           "PARTNERSHIP" shall have the meaning given such term in the
Introductory Paragraph.

           "PARTNERSHIP AGREEMENT" shall have the meaning given such term in
Recital B hereof.
---------        

           "PARTNERSHIP KNOWLEDGE PARTIES" shall have the meaning given such
term in Section 5.2 hereof.
        -----------        

                                       3
<PAGE>
 
           "PARTNERSHIP PARTIES" shall have the meaning given such term in
Section 4.2.1 hereof.
-------------        

           "PARTNERSHIP WARRANTIES" shall have the meaning given such term in
Section 4.2.1 hereof.
-------------        

           "PERSONAL PROPERTY" shall have the meaning given such term in Section
                                                                         -------
2.1(b) hereof.
------        

           "PROPERTY" shall have the meaning given such term in Section 2.1
                                                                -----------
hereof.

           "PROPERTY DOCUMENTS" shall have the meaning given such term in
Section 10.1.2(h) hereof.
-----------------        

           "PROVIDING PARTY" shall have the meaning given such term in Section
                                                                       -------
9.1.1 hereof.
-----        

           "PRUDENTIAL" shall have the meaning given such term in the
Introductory Paragraph.

           "PUBLIC COMPANY" shall have the meaning given such term in the
Introductory Paragraph.

           "PUBLIC COMPANY KNOWLEDGE PARTIES" shall have the meaning given such
term in Section 6.2 hereof.
        -----------        

           "REAL PROPERTY" shall have the meaning given such term in Section
                                                                     -------
2.1(a) hereof.
------        

           "RECEIVING PARTY" shall have the meaning given such term in Section
                                                                       -------
9.1.1 hereof.
-----        

           "REGISTRATION RIGHTS AGREEMENT" shall have the meaning given such
term in Section 10.1.2(n) hereof.
        -----------------        

           "REPRESENTATIVES" shall have the meaning given such term in Section
                                                                       -------
9.1.1 hereof.
-----        

           "SEC DOCUMENTS" shall have the meaning given such term in Section
                                                                     -------
6.3.3 hereof.
-----        

          "SECURITIES" shall mean, as applicable, the Shares, the Investor
Common Units and the Investor Preferred Units that may be issued pursuant to the
Investor Agreement.

           "SECURITIES ACT" shall mean the Securities Act of 1933, as amended.

           "SHARES" shall mean the shares of the Public Company's common stock,
$0.01 par value per share.

                                       4
<PAGE>
 
          "TAX REPORTING AGREEMENT" shall have the meaning given such term in
Section 10(p) attached hereto.
-------------                 

          "TAX RETURN" shall mean any return, report or other document or
information required to be supplied to a taxing authority in connection with
Taxes.

          "TAXES" shall mean all taxes, charges, fees, levies or other
assessments, including, without limitation, income, gross receipts, excise,
property, sales, withholding, social security, occupation, use, service,
license, payroll, franchise, transfer, recording taxes, fees and charges,
imposed by the United States, or any state, local or foreign government or
subdivision or agency thereof, whether computed on a separate, consolidated,
unitary, combined or any other basis; and such terms shall include any interest,
fines, penalties or additional amounts attributable to or imposed on or with
respect to any such taxes, charges, fees, levies or other assessments.

          "THREE ECW BUILDING MAXIMUM LIABILITY AMOUNT" shall mean an amount
equal to (i) 62.0833%, multiplied by (ii) the product of (x) five percent (5%),
                       ---------- --                                           
multiplied by (y) the NMV of the Property.

           "TRANSFEREE PARTIES" shall have the meaning given such term in
Section 4.2.2(a) hereof.
----------------        

                                   ARTICLE 2

                                 CONTRIBUTION
                                 ------------

      2.1  Contribution.  Subject to the terms and conditions set forth in this
           ------------                                                        
Agreement, the Partnership is hereby concurrently transferring to BPECW LLC (an
entity which is wholly owned by Investor), as a contribution to Investor, and
BPECW LLC is accepting, in exchange for the Contribution Units (defined below),
the Partnership's entire undivided 62.0833% tenancy-in-common right, title and
interest in and to the following (collectively, the "PROPERTY"):

           (a) Real Property.  That certain real estate located at 275 Battery
               -------------                                                  
     Street, City of San Francisco, County of San Francisco, State of
     California, legally described on Exhibit A attached hereto and incorporated
                                      ---------                                 
     herein by this reference, together with all buildings, improvements and
     fixtures located thereon and all rights, privileges and appurtenances
     pertaining thereto, including all of the Partnership's right, title and
     interest in and to all rights-of-way, open or proposed streets, alleys,
     easements, strips or gores of land adjacent thereto (herein collectively
     called the "REAL PROPERTY"); and

           (b) Personal Property.  All tangible and intangible personal property
               -----------------                                                
     of the Partnership (excluding any computer or computer equipment and
     software owned by the Partnership or PPS), located on the Real Property,
     and used in the ownership, operation and maintenance of the Real Property,
     and all books, records and files (excluding 

                                       5
<PAGE>
 
     appraisals, budgets, the Partnership's strategic plans for the Property,
     marketing information, submissions relating to the Partnership's obtaining
     of corporate authorization, or other information in the possession or
     control of the Partnership or PPS which is privileged (provided that
     inadvertent disclosure shall not constitute a waiver of any privilege),
     relating to the Real Property, and all accounts receivable, accounts
     payable, cash, deposit accounts and money held by the Partnership as of the
     Closing Date (herein collectively called the "PERSONAL PROPERTY"); and

          (c) Other Property Rights.  (i) The Partnership's interest as
              ---------------------                                    
     "landlord" in all Leases; and (ii) if and to the extent assignable by the
     Partnership, (A) all service, supply, maintenance and utility agreements,
     all equipment leases and all other agreements relating to the Property that
     are described on Exhibit B attached hereto and incorporated herein by this
                      ---------                                                
     reference, (B) all licenses, permits and other written authorizations
     necessary for the use, operation or ownership of the Real Property or
     Personal Property and in the Partnership's possession or control, (C) the
     Partnership's interest, if any, in and to the name "Embarcadero Center
     West" or any similar name of the Building, and (D) all other assets and
     liabilities of the Partnership (other than any liabilities that are
     Excluded Liabilities as defined in Section 4.2.2(b)) immediately prior to
                                        ----------------                      
     the Closing, it being acknowledged and agreed that the sole assets and
     liabilities of the Partnership immediately after the Closing shall be the
     name of the Partnership, "Three Embarcadero Center West", the Contribution
     Units received pursuant to this Agreement, and those liabilities of the
     Partnership expressly provided for in this Agreement (the rights of the
     Partnership described in clauses (i) and (ii) hereinabove being herein
                              -----------     ----                         
     collectively called the "OTHER PROPERTY RIGHTS"); provided, however, that
     the Partnership covenants to, at the request of BPECW LLC, change its name
     promptly after the Closing Date to eliminate the word "Embarcadero" from
     its name.

     2.2 Payment of Units.  In consideration of the contribution of the
         ----------------                                              
Property to BPECW LLC, Investor is hereby concurrently delivering to the
Partnership an aggregate number of Investor Preferred Units (the "CONTRIBUTION
UNITS") equal to (x) the Contribution Value (defined immediately below), divided
                                                                         -------
by (y) $50.  As used herein, the term "CONTRIBUTION VALUE" shall mean an amount
--                                                                             
equal to $9,600,037 (which amount equals (A) the Partnership's undivided
tenancy-in-common percentage interest in the Property immediately prior to the
Closing, multiplied by (B) the NEV of the Property, and which amount may be
         ---------- --                                                     
adjusted after the date hereof and after the Closing Date to an amount equal
such undivided tenancy-in-common percentage interest of the Partnership in the
Property immediately prior to the Closing Date multiplied by the Adjusted NEV of
the Property pursuant to and in accordance with the terms and provisions of
Section 10.1.7 hereof and Exhibit V of the Master Transaction Agreement).
--------------                                                           

                                       6
<PAGE>
 
                                   ARTICLE 3

                                 TITLE MATTERS
                                 -------------

     3.1 Title to Real Property.  The Partnership shall contribute, and BPECW
         ----------------------                                              
LLC shall accept, title to the Real Property, subject only to: (a) such matters
as are visible or apparent on that certain Preliminary ALTA/ACSM Survey of Three
Embarcadero Center West - Portion of Assessors Block 238, San Francisco,
California, prepared by KCA Engineers, Inc., 318 Brannan Street, San Francisco,
California 94107, dated August, 1998 (2 pages), (b) those exceptions to title
for the Property as are listed on Exhibit C attached hereto, (c) any and all
                                  ---------                                 
matters created by or on behalf of BPECW LLC, Investor or any of their
Affiliates (including, without limitation, any mechanics' liens or other claims
relating to any of its due diligence inspections or investigations of the
Property performed by or on behalf of BPECW LLC, Investor or any of their
Affiliates in connection with the transactions described herein and in the
Master Transaction Agreement), and (d) all matters disclosed to or discovered by
BPECW LLC, Investor or any of their Affiliates (whether in connection with their
respective due diligence investigations and inspections or otherwise) prior to
the date hereof.

                                   ARTICLE 4

                    DUE DILIGENCE/CONDITION OF THE PROPERTY
                    ---------------------------------------

     4.1 Inspections and Due Diligence.
         ----------------------------- 

         4.1.1 Due Diligence Approval.  BPECW LLC, Investor and Public Company
               ----------------------                                         
(Investor's sole general partner) each hereby acknowledges and agrees that, as
of the date of the execution of this Agreement, it has been given the full
opportunity to review, inspect and investigate all of the files known or made
available to such Person maintained by PPS on behalf of the Partnership relating
to the Property that it deems necessary to review (the "DOCUMENTS"), and has had
an opportunity to conduct a thorough review, investigation, and inspection of
the physical (including, without limitation, the seismic load bearing
capabilities), environmental, economic, and legal conditions of the Property,
the laws, regulations, covenants, conditions, and restrictions affecting or
governing the use or operation of the Property, the rentable square footage of
the Property, and all other matters which a prudent transferee of commercial
real property should review, inspect or investigate in the course of a due
diligence review, and BPECW LLC, Investor and Public Company has each approved
the condition of the Property and the results of such review, inspection and
investigation.

         4.1.2 Indemnity.  BPECW LLC, Investor and Public Company shall each
               ---------                                                    
indemnify, protect, defend, and hold harmless the Partnership and the Prudential
Partners from and against any and all claims, demands, causes of action, losses,
damages and liabilities, including, without limitation, personal injuries and
property damage, and shall immediately discharge any liens and encumbrances,
arising out of acts or omissions of BPECW LLC, Investor, 

                                       7
<PAGE>
 
Public Company or any of their agents, contractors, or representatives,
committed on or about the Property in the course of any such Person's due
diligence reviews, inspections and investigations, including, without
limitation, claims, demands, causes of action, losses, damages and liabilities
on the part of the tenants and lessees alleging breach of a Lease as a result of
any such Person's acts or omissions.

          4.1.3  Survivability.  The terms and provisions of this Section 4.1
                 -------------                                    -----------
shall survive the Closing.

     4.2  Property Contributed "As Is".
          ---------------------------- 

          4.2.1  "As Is, Where Is, With All Faults".  BPECW LLC, INVESTOR AND
                 ----------------------------------                          
PUBLIC COMPANY EACH ACKNOWLEDGES AND AGREES THAT : (i) EXCEPT FOR THE EXCLUDED
LIABILITIES, THE PROPERTY SHALL BE TRANSFERRED TO BPECW LLC, AND BPECW LLC SHALL
ACCEPT THE PROPERTY ON THE DATE HEREOF, "AS IS, WHERE IS, WITH ALL FAULTS"; (ii)
EXCEPT FOR THE REPRESENTATIONS AND WARRANTIES OF THE PARTNERSHIP SET FORTH IN
ARTICLES 5 AND 6, RESPECTIVELY TOGETHER WITH THE REPRESENTATIONS OF THE
----------     -                                                       
PARTNERSHIP IN ANY CLOSING DOCUMENT IT DELIVERS PURSUANT TO SECTION 10.1.2
                                                            --------------
(HEREIN COLLECTIVELY CALLED THE "PARTNERSHIP WARRANTIES"), NONE OF THE
PARTNERSHIP, ITS PARTNERS, THEIR RESPECTIVE SALES AGENTS, NOR ANY PARTNER,
OFFICER, DIRECTOR, EMPLOYEE, AGENT OR ATTORNEY OF THE PARTNERSHIP OR ITS
PARTNERS, THEIR COUNSEL, BROKERS, OR SALES AGENTS, NOR ANY OTHER PERSON RELATED
IN ANY WAY TO ANY OF THE FOREGOING (ALL OF WHICH PERSONS ARE HEREIN COLLECTIVELY
CALLED THE "PARTNERSHIP PARTIES") HAVE OR SHALL BE DEEMED TO HAVE MADE ANY
VERBAL OR WRITTEN REPRESENTATIONS, WARRANTIES, PROMISES OR GUARANTEES (WHETHER
EXPRESS, IMPLIED, STATUTORY OR OTHERWISE) TO BPECW LLC, INVESTOR OR PUBLIC
COMPANY WITH RESPECT TO THE PROPERTY, ANY MATTER SET FORTH, CONTAINED OR
ADDRESSED IN ANY DOCUMENTS REVIEWED BY BPECW LLC, INVESTOR OR PUBLIC COMPANY
(INCLUDING, BUT NOT LIMITED TO, THE ACCURACY AND COMPLETENESS THEREOF) OR THE
RESULTS OF BPECW LLC'S, INVESTOR'S AND PUBLIC COMPANY'S DUE DILIGENCE
INVESTIGATIONS; AND (iii) BPECW LLC, INVESTOR AND PUBLIC COMPANY EACH HAS
CONFIRMED INDEPENDENTLY ALL INFORMATION THAT IT CONSIDERS MATERIAL TO ITS
ACQUISITION OF THE PROPERTY AND THE TRANSACTIONS CONTEMPLATED HEREBY.  BPECW
LLC, INVESTOR AND PUBLIC COMPANY EACH HEREBY SPECIFICALLY ACKNOWLEDGES THAT,
EXCEPT FOR THE PARTNERSHIP WARRANTIES, IT IS NOT RELYING AND SHALL NOT RELY ON
                                             ---                   ---        
(AND EACH OF THE PARTNERSHIP PARTIES DOES HEREBY DISCLAIM AND RENOUNCE) ANY
REPRESENTATIONS OR WARRANTIES OF ANY KIND OR NATURE WHATSOEVER, WHETHER ORAL OR
WRITTEN, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, FROM ANY OF THE PARTNERSHIP
PARTIES, AS TO:  (1) THE OPERATION OF THE 

                                       8
<PAGE>
 
PROPERTY OR THE INCOME POTENTIAL, USES, OR MERCHANTABILITY OR FITNESS OF ANY
PORTION OF THE PROPERTY FOR A PARTICULAR PURPOSE; (2) THE PHYSICAL CONDITION OR
SAFETY OF THE PROPERTY OR ANY IMPROVEMENTS THEREON; (3) THE PRESENCE OR ABSENCE,
LOCATION OR SCOPE OF ANY HAZARDOUS MATERIALS IN, AT, OR UNDER THE PROPERTY; (4)
THE ACCURACY OF ANY STATEMENTS, CALCULATIONS OR CONDITIONS STATED OR SET FORTH
IN THE PARTNERSHIP'S OR PPS's BOOKS AND RECORDS CONCERNING THE PROPERTY OR SET
FORTH IN ANY OF THE PARTNERSHIP PARTIES' OFFERING MATERIALS WITH RESPECT TO THE
PROPERTY PRIOR TO THE DATE HEREOF; (5) THE DIMENSIONS OF THE PROPERTY OR THE
ACCURACY OF ANY FLOOR PLANS, SQUARE FOOTAGE, LEASE ABSTRACTS, SKETCHES, REVENUE
OR EXPENSE PROJECTIONS RELATED TO THE PROPERTY; (6) THE OPERATING PERFORMANCE,
THE INCOME AND EXPENSES OF THE PROPERTY OR THE ECONOMIC STATUS OF THE PROPERTY;
(7) THE ABILITY OF BPECW LLC, INVESTOR AND PUBLIC COMPANY TO OBTAIN ANY AND ALL
NECESSARY GOVERNMENTAL APPROVALS OR PERMITS FOR THE INTENDED USE AND DEVELOPMENT
OF THE PROPERTY; AND (8) THE LEASING STATUS OF THE PROPERTY OR THE INTENTIONS OF
ANY PERSONS WITH RESPECT TO THE NEGOTIATION AND/OR EXECUTION OF ANY LEASE FOR
ANY PORTION OF THE PROPERTY. BPECW LLC, INVESTOR AND PUBLIC COMPANY EACH FURTHER
ACKNOWLEDGES AND AGREES THAT, EXCEPT FOR THE PARTNERSHIP WARRANTIES, THE
PARTNERSHIP PARTIES ARE UNDER NO DUTY TO MAKE ANY AFFIRMATIVE DISCLOSURES OR
INQUIRY REGARDING ANY MATTER WHICH MAY BE KNOWN TO ANY OF THE PARTNERSHIP
PARTIES.

           4.2.2  Releases and Indemnities.  BPECW LLC'S, INVESTOR'S AND PUBLIC
                  ------------------------                                     
COMPANY'S RELEASE AND INDEMNITY:

                 (a) FROM AND AFTER THE DATE HEREOF, BPECW LLC SHALL ASSUME ALL
          RISKS WITH RESPECT TO THE PROPERTY, KNOWN AND UNKNOWN, SUSPECTED AND
          UNSUSPECTED, EXCEPTING ONLY THE EXCLUDED LIABILITIES (AS DEFINED IN
          SECTION 4.2.2(b) BELOW). EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN
          ----------------                                                  
          SECTION 4.2.2(b) BELOW WITH RESPECT TO EXCLUDED LIABILITIES AND
          ----------------                                               
          SECTION 4.2.2(c) BELOW WITH RESPECT TO THE PARTNERSHIP WARRANTIES,
          ----------------                                                  
          UPON THE CLOSING, BPECW LLC, INVESTOR, PUBLIC COMPANY AND THEIR
          AGENTS, EMPLOYEES, AFFILIATES, SUCCESSORS AND ASSIGNS (COLLECTIVELY,
          "TRANSFEREE PARTIES"), SHALL BE SOLELY LIABLE FOR, AND SHALL
          INDEMNIFY, DEFEND, PROTECT AND HOLD HARMLESS THE PARTNERSHIP PARTIES
          FROM ANY AND ALL CLAIMS, DEMANDS, CAUSES OF ACTION, LOSSES,
          LIABILITIES, COSTS AND EXPENSES (INCLUDING REASONABLE ATTORNEYS' FEES)
          AT LAW OR IN EQUITY, KNOWN OR UNKNOWN, SUSPECTED OR UNSUSPECTED,
          RELATING TO BODILY 

                                       9
<PAGE>
 
          INJURY, DEATH, PROPERTY DAMAGE, ECONOMIC LOSS, OR OTHER DAMAGES
          SUFFERED BY ANY OF THE PARTNERSHIP PARTIES ARISING OUT OF OR RELATING
          TO THE PROPERTY, INCLUDING, WITHOUT LIMITATION, THE PHYSICAL,
          ENVIRONMENTAL, ECONOMIC, LEGAL OR OTHER CONDITION OF THE PROPERTY,
          INCLUDING, WITHOUT LIMITATION, ANY SUCH CLAIMS OR LIABILITIES RELATING
          TO THE PRESENCE, DISCOVERY OR REMOVAL OF ANY HAZARDOUS MATERIALS IN,
          AT, ABOUT OR UNDER THE PROPERTY, OR FOR, CONNECTED WITH OR ARISING OUT
          OF ANY AND ALL CLAIMS OR CAUSES OF ACTION BASED UPON CERCLA
          (COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT
          OF 1980, 42 U.S.C. (S)(S)9601 ET SEQ., AS AMENDED BY SARA [SUPERFUND
          AMENDMENT AND REAUTHORIZATION ACT OF 1986] AND AS MAY BE FURTHER
          AMENDED FROM TIME TO TIME), THE RESOURCE CONSERVATION AND RECOVERY ACT
          OF 1976, 42 U.S.C. (S)(S)6901 ET SEQ., OR ANY RELATED CLAIMS OR CAUSES
          OF ACTION OR ANY OTHER FEDERAL OR STATE BASED STATUTORY OR REGULATORY
          CAUSES OF ACTION FOR ENVIRONMENTAL CONTAMINATION AT, IN OR UNDER THE
          PROPERTY (HEREINAFTER "INVESTOR-COVERED CLAIMS").

               (b) NOTWITHSTANDING THE FOREGOING, THE TERM "INVESTOR-COVERED
          CLAIMS" SHALL EXCLUDE, AND NONE OF BPECW LLC, INVESTOR OR THE PUBLIC
          COMPANY SHALL ASSUME, THE FOLLOWING (COLLECTIVELY, "EXCLUDED
          LIABILITIES"): (x) ANY AND ALL LIABILITIES AND OBLIGATIONS OF THE
          PARTNERSHIP TO THE EXTENT THAT SUCH LIABILITIES AND OBLIGATIONS DO NOT
          ARISE FROM OR RELATE TO THE USE, OWNERSHIP OR OPERATION OF THE
          PROPERTY, AND (y) ANY AND ALL OBLIGATIONS AND LIABILITIES ARISING FROM
          OR IN CONNECTION WITH THE USE, OWNERSHIP OR OPERATION OF THE PROPERTY
          ACCRUING PRIOR TO THE DATE HEREOF OTHER THAN (i) OBLIGATIONS AND
          LIABILITIES ASSUMED IN WRITING BY BPECW LLC IN CONNECTION WITH THE
          LEASES AND/OR CONTRACTS AND ALL OTHER OBLIGATIONS AND LIABILITIES THAT
          BPECW LLC EXPRESSLY ASSUMES IN WRITING AT OR PRIOR TO THE CLOSING,
          (ii) OBLIGATIONS AND LIABILITIES FOR WHICH BPECW LLC OR INVESTOR HAS
          RECEIVED A PRORATION CREDIT PURSUANT TO EXHIBIT V OF THE MASTER
          TRANSACTION AGREEMENT, AND (iii) OBLIGATIONS AND LIABILITIES RELATING
          IN ANY WAY TO THE PHYSICAL OR ENVIRONMENTAL CONDITION OF THE PROPERTY
          OTHER THAN ANY CLAIMS MADE BY, OR CAUSES OF ACTION BROUGHT BY, ANY
          THIRD PARTY UNRELATED TO BPECW LLC, INVESTOR OR ANY OF THEIR
          AFFILIATES WHERE THE INJURY OR 

                                       10
<PAGE>
 
          DAMAGE GIVING RISE TO SUCH CLAIM OR CAUSE OF ACTION AROSE OR OCCURRED
          DURING THE PERIOD PRIOR TO THE DATE HEREOF.

               (c) TRANSFEREE PARTIES EACH HEREBY GENERALLY AND FULLY RELEASE
          THE PARTNERSHIP PARTIES FROM ANY AND ALL STATEMENTS OR OPINIONS
          HERETOFORE MADE, OR INFORMATION FURNISHED IN CONNECTION WITH THE
          TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT, BY THE PARTNERSHIP
          PARTIES TO ANY OF THE TRANSFEREE PARTIES, EXCEPT FOR THE PARTNERSHIP
          WARRANTIES; AND FROM ANY AND ALL INVESTOR-COVERED CLAIMS, KNOWN OR
          UNKNOWN, SUSPECTED OR UNSUSPECTED.

               WITH RESPECT TO THE RELEASES AND WAIVERS CONTAINED IN THIS
          SUBSECTION 4.2.2(c), THE TRANSFEREE PARTIES EXPRESSLY WAIVE THE
          -------------------                                            
          BENEFITS OF SECTION 1542 OF THE CALIFORNIA CIVIL CODE, WHICH PROVIDES
          AS FOLLOWS:

               "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR
               DOES NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME OF
               EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY
               AFFECTED HIS SETTLEMENT WITH THE DEBTOR."

               BPECW LLC, INVESTOR AND PUBLIC COMPANY HAS EACH BEEN ADVISED BY
          ITS LEGAL COUNSEL AND UNDERSTANDS THE SIGNIFICANCE OF THIS WAIVER OF
          SECTION 1542 RELATING TO UNKNOWN, UNSUSPECTED AND CONCEALED CLAIMS.
          BY ITS INITIALS BELOW, EACH OF BPECW LLC, INVESTOR AND PUBLIC COMPANY
          ACKNOWLEDGES THAT IT FULLY UNDERSTANDS, APPRECIATES, AND ACCEPTS ALL
          OF THE TERMS OF THIS SUBSECTION 4.2.2(c).
                               ------------------- 

                                         _________________________
                                         BPECW LLC's Initials

                                         _________________________
                                         Investor's Initials

                                         _________________________
                                         Public Company's Initials

                                       11
<PAGE>
 
                 (d) NOTWITHSTANDING THE FOREGOING, THE PARTNERSHIP SHALL BE
          SOLELY LIABLE FOR, AND SHALL INDEMNIFY, DEFEND (AND CONTROL THE
          RESOLUTION OF), PROTECT AND HOLD HARMLESS TRANSFEREE PARTIES FROM ANY
          AND ALL CLAIMS, DEMANDS, CAUSES OF ACTION, LOSSES, LIABILITIES, COSTS
          AND EXPENSES (INCLUDING REASONABLE ATTORNEYS' FEES) AT LAW OR IN
          EQUITY, KNOWN OR UNKNOWN, SUSPECTED OR UNSUSPECTED, RELATING TO BODILY
          INJURY, DEATH, PROPERTY DAMAGE, ECONOMIC LOSS, OR OTHER DAMAGES
          SUFFERED BY ANY TRANSFEREE PARTIES ARISING OUT OF OR RELATING TO THE
          EXCLUDED LIABILITIES.

          4.2.3  Definition of Hazardous Materials.  For purposes of this
                 ---------------------------------                       
Agreement, the term "HAZARDOUS MATERIAL" shall mean any substance, chemical,
waste or material that is or becomes regulated by any federal, state or local
governmental authority because of its toxicity, infectiousness, radioactivity,
explosiveness, ignitability, corrosiveness or reactivity, including, without
limitation, asbestos or any substance containing more than 0.1 percent asbestos,
the group of compounds known as polychlorinated biphenyls, flammable explosives,
oil, petroleum or any refined petroleum product.

          4.2.4  Provisions Material. BPECW LLC, Investor and Public Company
                 -------------------         
each acknowledges and agrees that the provisions of this Article 4 were a
                                                         ---------       
material factor in the transfer of the Property to BPECW LLC as a contribution
to Investor and the acceptance of the Contribution Value by the Partnership and,
while the Partnership has made the Documents available to BPECW LLC, Investor
and Public Company and cooperated with BPECW LLC, Investor and Public Company in
their due diligence investigations and inspections, the Partnership is unwilling
to contribute the Property to BPECW LLC unless the Partnership Parties are
expressly released as set forth in Subsection 4.2.2(b).
                                   ------------------- 

          4.2.5  Survivability. Notwithstanding anything to the contrary herein,
                 -------------        
the provisions of this Section 4.2 shall survive the Closing and shall not be
                       -----------                                           
merged in the transfer of the Property as a contribution to Investor.

                                   ARTICLE 5

               REPRESENTATIONS AND WARRANTIES AS TO THE PROPERTY
               -------------------------------------------------

     5.1  General Statement.  The Partnership and its Partners make the
          -----------------                                            
representations and warranties with respect to the Partnership and the Property
to BPECW LLC, Investor and Public Company which are set forth in this Article 5.
                                                                      ---------
All representations and warranties set forth in Section 5.3 below shall, subject
                                                -----------                     
 to the limitations of Section 11.1, survive the Closing (and none shall merge
                       ------------                                           
into any instrument of conveyance) for the period of time set forth in Article 8
                                                                       ---------
and all representations and warranties set forth in Sections 5.5 and 5.6 hereof
                                                    ------------     ---       
shall, subject to the 

                                       12
<PAGE>
 
limitations of Section 11.1, survive the Closing (and none shall merge into any
               ------------                               
instrument of conveyance) for the period of any relevant statute of limitations
therefor. All representations and warranties of the Partnership are made as of
the date of this Agreement.

     5.2  Attribution.  For purposes of this Agreement, the words "knowledge of
          -----------                                                          
the Partnership" or "Partnership's knowledge" shall mean the actual and not
constructive knowledge of John Triece, Richard E. Salomon, Thomas Hendrian and
John Syage (collectively, the "PARTNERSHIP KNOWLEDGE PARTIES"). The Partnership
Knowledge Parties shall have no liability hereunder of any kind. Any fact,
matter or other statement shall not be deemed to be within the knowledge of the
Partnership or Partnership's knowledge unless the Partnership Knowledge Parties
have actual knowledge of such fact, matter or other statement. Notwithstanding
the foregoing, the representations and warranties made by the Partnership under
Sections 5.5 and 5.6 below are intended to be absolute in nature and are not
------------     ---                                                        
limited by the knowledge or attribution limitations of this Section 5.2.
                                                            ----------- 

     5.3  Representations and Warranties Re: Property.  The Partnership and its
          -------------------------------------------                          
Partners hereby represent and warrant to BPECW LLC, Investor and Public Company,
except as set forth on any Exhibit attached hereto and referred to below, that:
                           -------                                             

          5.3.1  The execution and delivery of this Agreement and the other
     documents to be executed by the Partnership or any Partner in connection
     herewith, and the consummation of the transactions described in this
     Agreement and such documents do not require, to the knowledge of the
     Partnership, the consent or approval of any governmental authority, nor to
     the Partnership's knowledge does the execution and delivery of this
     Agreement and the other documents to be executed by the Partnership or any
     Partner in connection herewith violate, in any way material to the
     transactions described herein, any contract or agreement to which the
     Partnership or any Partner is a party or (to the knowledge of the
     Partnership) any governmental or judicial order, judgment, decree, statute,
     law, rule or regulation applicable to the Partnership, any Partner or the
     Property, and this Agreement and all documents to be executed by the
     Partnership or any Partner in connection with the transactions described
     herein constitute the legal, valid and binding obligations of the
     Partnership and each such Partner.

          To the Partnership's knowledge, the Partnership and the Partners are
     not a party to, or bound by, any unexpired, undischarged or unsatisfied
     contract, agreement, indenture, mortgage (other than with respect to the
     Existing Mortgage Loans, ECW Swap Notes made by Three ECW and Three ECW I/P
     Loans), debenture, note or other instrument under the terms of which
     performance by the Partnership or any such Partner in accordance with the
     terms and provisions of this Agreement will be a default or an event of
     acceleration, or grounds for termination, and whereby such default,
     acceleration or termination would reasonably be expected to have a material
     adverse effect on the timely performance by the Partnership or any such
     Partner of its obligations under this Agreement and the other documents to
     be executed by the Partnership or such Partner in connection 

                                       13
<PAGE>
 
     herewith, nor does the execution of this Agreement or the other documents
     to be executed by the Partnership or any such Partner in connection
     herewith, or the consummation of the transactions contemplated hereby and
     thereby, violate the partnership agreement of the Partnership or constitute
     a breach thereunder.

          5.3.2  The Partnership has no employees.

          5.3.3  To the Partnership's knowledge, except as listed on Exhibit D,
                                                                     --------- 
     the Partnership has not received any written notice of pending or
     threatened litigation, judgment, arbitration, investigation or proceeding
     against the Property that, if determined adversely, would reasonably be
     expected to have a material adverse effect on the operation, use or value
     of the Property or on BPECW LLC's or Investor's ability to obtain any
     financing necessary to close the transactions contemplated by this
     Agreement, nor has the Partnership received any explicit oral notice of any
     such threatened litigation, judgment, arbitration, investigation or
     proceeding.

          5.3.4  To the Partnership's knowledge, except as listed on Exhibit D,
                                                                     --------- 
     there are no Claims or liabilities affecting the Property that have not
     been previously disclosed in writing to BPECW LLC, Investor, Public Company
     or any of their Affiliates which would be binding upon BPECW LLC or
     Investor after Closing and have a material adverse effect on the operation,
     use or value of the Property or on BPECW LLC's or Investor's ability to
     obtain any financing necessary to close the transactions contemplated by
     this Agreement.

          5.3.5  To the Partnership's knowledge, except as listed on Exhibit D,
                                                                     --------- 
     the Partnership has not received any written notice from any governmental
     authority of any special assessment, pending condemnation, and to the
     Partnership's knowledge, the Property is not in violation and the
     Partnership has not received notice of violation of any zoning, building,
     fire, or health code, statute, ordinance, rule or regulation applicable to
     the Property that would reasonably be expected to have a material adverse
     effect on the operation, use or value of the Property or on BPECW LLC's or
     Investor's ability to obtain any financing necessary to close the
     transactions contemplated by this Agreement.

          5.3.6  To the Partnership's knowledge, the Partnership has not entered
     into any written equipment leases, service contracts or other such
     contracts or agreements affecting the Property which will remain in effect
     after the Closing Date and which will be binding upon BPECW LLC after the
     Closing Date and which are not terminable or cancelable upon thirty (30)
     days notice (collectively, "CONTRACTS") other than those listed on Exhibit
                                                                        -------
     B attached hereto.
     -                 

          5.3.7  To the Partnership's knowledge, the only Leases which will
     encumber the Property after the Closing are listed on Exhibit E attached
                                                           ---------         
     hereto.

                                       14
<PAGE>
 
          5.3.8  To the Partnership's knowledge, there are no agreements
     affecting the Property with third parties for the provision of leasing
     brokerage services or under which leasing commissions would become due from
     and after the Closing, except as set forth on Exhibit D attached hereto.
                                                   ---------                 

          5.3.9  To the Partnership's knowledge, the Partnership is not in
     default and has not received any written notice of any defaults under the
     terms of any of the Contracts, Leases or Encumbrance Documents that would
     have a material adverse effect on the use, operation or value of the
     Property after the Closing or on BPECW LLC's or Investor's ability to
     obtain any financing necessary to close the transactions contemplated by
     this Agreement, except as set forth on Exhibit D. As used herein, the term
                                            ---------                           
     "ENCUMBRANCE DOCUMENTS" shall mean, collectively, all mortgages, deeds of
     trust, easements and other material agreements appurtenant to or burdening
     the Property.

          5.3.10 To the Partnership's knowledge, no rent or other amounts (other
     than security deposits) have been prepaid under any of the Leases,
     Contracts or Encumbrance Documents more than thirty (30) days in advance of
     the due dates thereof, except as set forth on Exhibit D or, in the case of
                                                   ---------                   
     Contracts, the proration schedule attached to Exhibit V of the Master
     Transaction Agreement (which will be provided on the date required by said
     Exhibit V).

     5.4  Qualifications to Representations and Warranties.  To the extent that
          ------------------------------------------------                     
any of the representations or warranties of the Partnership and its Partners
under Section 5.3 are known to BPECW LLC, Investor, Public Company or any of
      -----------                                                           
their Affiliates to be inaccurate on the Closing Date and such Persons
nevertheless close the transactions contemplated by this Agreement, such
representation(s) and warranty(ies) shall be deemed modified to the extent of
such known inaccuracy and the Partnership shall not be deemed in breach of the
representation or warranty. Notwithstanding anything to the contrary stated or
implied herein and in furtherance of the foregoing provisions of this Section
                                                                      -------
5.4, the Partnership shall have no liability for or with respect to any
---                                                                    
representation or warranty (or breach thereof) from and after the Closing if,
prior to the Closing, BPECW LLC, Investor, Public Company or any of their
Affiliates discovers or learns of information (from whatever source, including,
without limitation, the Partnership, its partners or any of their employees), or
any reports, instruments or other documentation which were reviewed by or made
available for review by BPECW LLC, Investor, Public Company or any of their
Affiliates in connection with the transactions contemplated hereby and/or by the
Master Transaction Agreement (including, without limitation, any reports,
surveys, and other due diligence documentation procured independently by BPECW
LLC, Investor, Public Company or any of their Affiliates in connection with the
transactions contemplated hereby) contain information that contradicts such
representation and warranty, or renders such representation and warranty untrue
or incorrect.

     5.5  Due Formation, Etc.  The Partnership is a limited partnership duly
          -------------------                                               
formed and existing under the laws of the State of California and is not
insolvent, and has all necessary power 

                                       15
<PAGE>
 
and authority to execute and deliver this Agreement and all documents executed
by it in connection herewith and to perform all its obligations hereunder and
thereunder. This Agreement has been duly authorized by all requisite partnership
action on the part of the Partnership. The Partnership is not a Person other
than a United States Person within the meaning of the Code and the transactions
contemplated herein are not subject to the withholding provisions of section
3406 or subchapter A of Chapter 3 of the Code. The Partnership conducts business
in accordance with all statutes, laws, rules and regulations applicable to it,
and does not violate or fail to comply with, any statutes, laws, rules or
regulations applicable to it that would have a material adverse effect on the
business or operations of the Partnership or the Property or on the Investor's
ability to obtain any financing necessary to close the transactions contemplated
hereby or by the Master Transaction Agreement.

     5.6  Securities Laws.  Subject to the provisions of this Agreement, each of
          ---------------                                                       
the Partnership and each Partner hereby represents and warrants that it is
acquiring the Investor Preferred Units for its own account and not with a view
to or for sale in connection with any distribution thereof within the meaning of
the Securities Act.  The Partnership and each Partner understand that the
Investor Preferred Units and Investor Common Units that may be upon conversion
of Investor Preferred Units (and, subject to the Registration Rights Agreement,
the Shares that may be issued in lieu of redemption Investor Common Units) will
not be registered under the Securities Act or any state securities laws, will be
offered and sold pursuant to exemptions therefrom and cannot be resold without
registration thereunder or exemption therefrom.  Each of the Partnership and
each Partner represents that it has sufficient knowledge and experience in
financial and business matters to enable it to evaluate the merits and risks of
investment in the Investor Preferred Units and Investor Common Units that may be
issued upon conversion of Investor Preferred Units (and the Shares that may be
issued in lieu of redemption of Investor Common Units).  The Partnership and
each Partner have the ability to bear the economic risk of acquiring the
Investor Preferred Units and have been supplied with, or had access to,
information to which a reasonable investor would attach significance in making
investment decisions, including, but not limited to, all information as they
have requested, to answer all of their inquiries about Public Company, and to
enable them to make their decision to acquire the Investor Preferred Units and
the Investor Common Units that may be issued upon conversion of Investor
Preferred Units (and the Shares that may be issued in lieu of redemption of
Investor Common Units).  The Securities shall, if represented by certificates,
contain a prominent legend with respect to the foregoing restrictions.  Each of
the Partnership and each Partner further represents and warrants that it is an
"accredited investor" as such term is defined in Rule 501 under the Securities
Act.

                                       16
<PAGE>
 
                                   ARTICLE 6

               REPRESENTATIONS AND WARRANTIES OF PUBLIC COMPANY
               ------------------------------------------------

      6.1 General Statement.  Public Company hereby makes the representations
          -----------------                                                  
and warranties to the Partnership and Prudential Partners which are set forth in
this Article 6.  All representations and warranties set forth in Section 6.4
     ---------                                                   -----------
shall survive the Closing (and none shall merge into any instrument of
conveyance) for the period of any relevant statute of limitations therefor.
Representations and warranties of Public Company are made as of the date of this
Agreement.

      6.2 Attribution.  For purposes of the representations and warranties of
          -----------                                                        
Public Company set forth in this Article 6 only, the words "knowledge of Public
                                 ---------                                     
Company" or "Public Company's knowledge" shall mean the actual and not
constructive knowledge of Mortimer Zuckerman, Edward Linde and Thomas O'Connor
(collectively, the "PUBLIC COMPANY KNOWLEDGE PARTIES"). The Public Company
Knowledge Parties shall have no liability hereunder of any kind.  Any fact,
matter or other statement shall not be deemed to be within the knowledge of
Public Company or Public Company's knowledge unless the Public Company Knowledge
Parties, or any of them, have actual knowledge of such fact, matter or other
statement.  Notwithstanding the foregoing, the representations and warranties
made by Public Company under Section 6.4 below are intended to be absolute in
                             -----------                                     
nature and are not limited by the knowledge or attribution limitations of this
Section 6.2.
----------- 

      6.3 Representations and Warranties Re: Public Company Business and
          --------------------------------------------------------------
Operations. Public Company hereby represents and warrants as follows:
----------                                                           

          6.3.1  Public Company is organized and, to Public Company's knowledge,
     has conducted its business in accordance with applicable laws, to the
     extent applicable, the failure or the violation of which would reasonably
     be expected to have a material adverse effect on the results of operations
     of the Public Company.

          6.3.2  There are no actions, suits or proceedings pending and, to
     Public Company's knowledge, no such proceedings are threatened or
     contemplated by governmental authorities or others, which would reasonably
     be expected to either (i) question the validity of this Agreement or the
     consummation of the transactions contemplated hereby, the issuance of the
     Shares that may be issued in lieu of redemption of Investor Common Units
     that may be issued upon conversion of Investor Preferred Units, any other
     agreements contemplated hereby or any actions taken pursuant to any of the
     foregoing or (ii) result in any material adverse change in the condition,
     financial or otherwise, or in the earnings, business affairs, management or
     business prospects of Public Company. As of the date hereof, there is no
     action or suit against Public Company pending or threatened by any Person
     which would reasonably be expected to have a material adverse effect on
     Public Company.

                                       17
<PAGE>
 
          6.3.3  The Public Company has filed with the Securities and Exchange
     Commission (the "COMMISSION") all reports required by the Exchange Act to
     be filed by the Company (collectively, and in each case including all
     exhibits and schedules thereto and documents incorporated by reference
     therein, the "SEC DOCUMENTS").  As of their respective filing dates (or if
     amended, revised or superseded by a subsequent filing with the Commission,
     then on the date of such subsequent filing), the SEC Documents complied in
     all material respects with the requirements of the Securities Act or the
     Exchange Act, as the case may be, and none of the SEC Documents (including
     any and all financial statements included therein) as of such dates
     contained any untrue statement of a material fact or omitted to state a
     material fact required to be stated therein or necessary in order to make
     the statements therein, in light of the circumstances under which they are
     made, not misleading.  The consolidated financial statements of Public
     Company included in all SEC Documents, including any amendments thereto,
     comply as to form in all material respects with applicable accounting
     requirements and the published rules and regulations of the Commission with
     respect thereto.  Since the most recently filed SEC Document, there has not
     occurred or arisen any change in or event affecting Public Company that has
     had or would reasonably be expected to have a material adverse effect on
     the results of operations of Public Company.

          6.3.4  No proceeding or other action has been commenced or undertaken
     relating to the dissolution or merger of Public Company and none is
     presently contemplated except that this representation shall not apply to
     any merger of another entity with and into Public Company that meets the
     criteria of Section 251(f) of the Delaware General Corporation Law for
     consummating a merger without a vote of stockholders.

          6.3.5  As of the date of this Agreement, the authorized capital
     securities of Public Company consists of Preferred Stock, $.01 par value,
     50,000,000 Shares authorized, none issued or outstanding, Excess Stock,
     $.01 par value, 150,000,000 shares authorized, none issued or outstanding,
     and 250,000,000 Shares of common stock, $0.01 par value per share, of which
     63,526,785 Shares are currently issued and outstanding.  Except as
     contemplated pursuant to this Agreement, and except for (i) any Shares that
     may be issued in lieu of redemption of outstanding units of limited
     partnership in Investor and (ii) any Shares or units of limited partnership
     in Investor which may be issued in accordance with agreements that have
     been described in or filed with the SEC Filings or otherwise disclosed on
     Exhibit F, there are no securities convertible or exchangeable for Shares
     ---------                                                                
     or any rights or options to subscribe for or purchase any Shares or
     securities convertible or exchangeable for Shares.  All of the outstanding
     Shares have been duly and validly authorized and issued and are fully paid
     and non-assessable.  All of the outstanding Shares have been issued in
     compliance with all applicable federal and state securities laws.

                                       18
<PAGE>
 
          6.3.6   The Shares that may be issued in lieu of redemption of
     Investor Common Units that may be issued upon conversion of Preferred Units
     issuable hereunder, when issued in accordance with the provisions of this
     Agreement and the Investor Agreement, will be duly and validly authorized
     and issued and will be fully paid and non-assessable. Neither Public
     Company, Investor nor any Person acting on their behalf has taken or will
     take any action which would subject the issuance of the Investor Preferred
     Units to the Partnership to the registration requirements of Section 5 of
     the Securities Act.

          6.3.7   Except as provided in Exhibit F, Public Company has no 
                                      ---------  
     obligation (contingent or other) to purchase, redeem or otherwise acquire
     any of its Shares or any interest therein or to pay any dividend or make
     any other distribution in respect thereof (except for any distribution that
     was declared prior to the date hereof and not paid on or before the date
     hereof). Public Company has authorized and reserved for issuance a
     sufficient number of Shares to satisfy its obligations under this Agreement
     and the Investor's Investor Agreement.

          6.3.8   Public Company has duly and timely filed with the appropriate
     governmental authorities all Tax Returns required to be filed by it for all
     periods ending on or prior to the Closing Date, except to the extent of any
     Tax Return for which an extension of time for filing has been properly
     filed.  Each such Tax Return is true and correct in all material respects.
     All Taxes owed by Public Company have been paid (whether or not shown on a
     Tax Return).  All Taxes which Public Company is required by law to withhold
     or collect, including, without limitation, Taxes required to have been
     withheld in connection with amounts paid or owing to any employee,
     independent contractor, creditor, partner, or other third party and sales,
     gross receipts and use taxes, have been duly withheld or collected and, to
     the extent required, have been paid over to the proper governmental
     authorities or are held in separate bank accounts for such purpose.  There
     are no liens for Taxes upon the assets of Public Company except for
     statutory liens for Taxes not yet due.

          6.3.9   Public Company has not filed for an extension of a statute of
     limitations with respect to any Taxes and no governmental authorities have
     requested an extension of the statute of limitations with respect to any
     Taxes.  Public Company is not a party to any pending action or any formal
     or informal proceeding by any taxing authority for a deficiency, assessment
     or collection of Taxes, and no claim of any deficiency, assessment or
     collection of Taxes has been asserted or, to the knowledge of Public
     Company, threatened against it, including claims by any taxing authority in
     a jurisdiction where Public Company does not file Tax Returns that it is or
     may be subject to taxation in that jurisdiction.

          6.3.10  Public Company is organized and has operated from its
     commencement through the date hereof in such a manner so as to qualify for
     taxation as a real estate investment trust under the Code, and Public
     Company intends to operate in such a manner so as to qualify and to
     continue to so qualify as a real estate investment trust.

                                       19
<PAGE>
 
          6.3.11  Public Company does not hold "plan assets" within the meaning
     of 29 C.F.R. Section 2510.3-101.

      6.4 Due Organization, Etc. of Public Company.
          ---------------------------------------- 

          6.4.1  Public Company is a corporation duly organized, validly
     existing and in good standing under the laws of the State of Delaware, is
     (or prior to the Closing will be) duly qualified and in good standing as a
     foreign corporation under the laws of the State of California, and has all
     necessary power, corporate and otherwise, to execute and deliver this
     Agreement and all other documents and instruments to be executed and
     delivered by Public Company in connection herewith and to perform all its
     obligations hereunder and thereunder. This Agreement has been duly
     authorized by all requisite corporate action on the part of Public Company.
     The execution and delivery of this Agreement and the other documents and
     instruments to be executed and delivered by Public Company in connection
     with the transactions described herein, and the consummation of the
     transactions contemplated hereby and thereby, do not require the consent or
     approval of the shareholders of Public Company or, to the knowledge of
     Public Company, the consent or approval of any governmental authority, nor,
     to the knowledge of Public Company, does the execution and delivery of this
     Agreement violate, in any way material to the transactions contemplated
     hereby, any contract or agreement to which Public Company is a party or any
     governmental or judicial order, judgment, decree, statute, law, rule or
     regulation applicable to Public Company, and this Agreement and all
     documents and other instruments to be executed and delivered by Public
     Company in connection herewith constitute the legal, valid and binding
     obligations of Public Company.

          6.4.2  Public Company is not a party to, or bound by, any unexpired,
     undischarged or unsatisfied contract, agreement, indenture, mortgage,
     debenture, note or other instrument under the terms of which performance by
     Public Company according to the terms of this Agreement will be a default
     or an event of acceleration, or grounds for termination, or whereby timely
     performance by Public Company, according to the terms of this Agreement,
     may be prohibited, prevented or delayed.

                                   ARTICLE 7

           REPRESENTATIONS AND WARRANTIES OF INVESTOR AND BPECW LLC
           --------------------------------------------------------

      7.1 General Statement.  Investor and BPECW LLC hereby make the
          -----------------                                         
representations and warranties to the Partnership and the Prudential Partners
which are set forth in this Article 7. All representations and warranties set
                            ---------                                        
forth in Sections 7.4 and 7.5 shall survive the Closing (and none shall merge
         ------------     ---                                                
into any instrument of conveyance) for the period of any relevant statute of
limitations therefor.  Representations and warranties of Investor and BPECW LLC
are made as of the date of this Agreement.

                                       20
<PAGE>
 
      7.2 Attribution.  For purposes of the representations and warranties of
          -----------                                                        
Investor and BPECW LLC set forth in this Article 7 only, the words "knowledge of
                                         ---------                              
Investor" or "knowledge of BPECW LLC" or "Investor's knowledge" or "BPECW LLC's
knowledge" shall mean the actual and not constructive knowledge of Mortimer
Zuckerman, Edward Linde and Thomas O'Connor (collectively, the "INVESTOR/BPECW
LLC KNOWLEDGE PARTIES").  The Investor/BPECW LLC Knowledge Parties shall have no
liability hereunder of any kind.  Any fact, matter or other statement shall not
be deemed to be within the knowledge of Investor or BPECW LLC or Investor's or
BPECW LLC's knowledge unless the Investor/BPECW LLC Knowledge Parties, or any of
them, have actual knowledge of such fact, matter or other statement.
Notwithstanding the foregoing, the representations and warranties made by
Investor under Section 7.4 below are intended to be absolute in nature and are
               -----------                                                    
not limited by the knowledge or attribution limitations of this Section 7.2.
                                                                ----------- 

      7.3 Representations and Warranties Re: Investor Business and Operations.
          -------------------------------------------------------------------  
Investor hereby represents and warrants as follows:

          7.3.1  Investor is organized and, to Investor's knowledge, has
     conducted its business in accordance with all applicable laws, to the
     extent applicable, the failure or the violation of which would reasonably
     be expected to have a material adverse effect on the results of operations
     of Investor.

          7.3.2  There are no actions, suits or proceedings pending and, to
     Investor's knowledge, no such proceedings are threatened or contemplated by
     governmental authorities or by others, which would reasonably be expected
     to either (i) question the validity of this Agreement or the consummation
     of the transactions contemplated hereby or the issuance of the Investor
     Preferred Units contemplated hereby, any other agreements contemplated
     hereby or any actions taken pursuant to any of the foregoing or (ii) result
     in any material adverse change in the condition, financial or otherwise, or
     in the earnings, business affairs, management or business prospects of
     Investor.  As of the date hereof, there is no material action or suit
     against Investor pending or threatened by any Person.

          7.3.3  No proceeding or other action has been commenced or undertaken
     relating to the dissolution or merger of Investor (except in connection
     with an acquisition of property for units in Investor in which Investor is
     the surviving party in the merger) and none is presently contemplated.

          7.3.4  Investor has duly and timely filed with the appropriate
     governmental authorities all Tax Returns required to be filed by it for all
     periods ending on or prior to the Closing Date, except to the extent of any
     Tax Return for which an extension of time for filing has been properly
     filed.  Each such Tax Return is true and correct in all material respects.
     All Taxes owed by Investor have been paid (whether or not shown on a Tax
     Return).  All Taxes which Investor is required by law to withhold or
     collect, including, without limitation, Taxes required to have been
     withheld in connection with amounts paid 

                                       21
<PAGE>
 
     or owing to any employee, independent contractor, creditor, partner, or
     other third party and sales, gross receipts and use taxes, have been duly
     withheld or collected and, to the extent required, have been paid over to
     the proper governmental authorities or are held in separate bank accounts
     for such purpose. There are no liens for Taxes upon the assets of Investor
     except for statutory liens for Taxes not yet due.

          7.3.5  Investor has not filed for an extension of a statute of
     limitations with respect to any Taxes and no governmental authorities have
     requested an extension of the statute of limitations with respect to any
     Taxes.  Investor is not a party to any pending action or any formal or
     informal proceeding by any taxing authority for a deficiency, assessment or
     collection of Taxes, and no claim of any deficiency, assessment or
     collection of Taxes has been asserted or, to the knowledge of Investor,
     threatened against it, including claims by any taxing authority in a
     jurisdiction where Investor does not file Tax Returns that it is or may be
     subject to taxation in that jurisdiction.

          7.3.6  Investor is not, and will not become, a "publicly traded
     partnership" within the meaning of Section 7704 of the Code.

          7.3.7  Investor does not hold "plan assets" within the meaning of 29
     C.F.R. Section 2510.3-101.

          7.3.8  Investor is the sole member of BPECW LLC and has directed the
     Partnership to transfer the Property to BPECW LLC as a contribution to
     Investor in exchange for the Investor Preferred Units.

      7.4 Due Formation, Etc. of Investor.  Investor is a limited partnership
          -------------------------------                                    
duly formed and in good standing under the laws of the State of Delaware, is (or
prior to Closing will be) duly qualified and in good standing as a foreign
limited partnership under the laws of the State of California, and has all
necessary power, partnership and otherwise, to execute and deliver this
Agreement and all other documents and instruments to be executed and delivered
by Investor in connection herewith and to perform all its obligations hereunder
and thereunder.  This Agreement has been duly authorized by all requisite
partnership action on the part of Investor.  The execution and delivery of this
Agreement and the other documents and instruments to be executed and delivered
by Investor in connection with the transactions described herein, and the
consummation of the transactions contemplated hereby and thereby, do not require
the consent or approval of the partners of Investor or, to the knowledge of
Investor, the consent or approval of any governmental authority, nor, to the
knowledge of Investor, does the execution and delivery of this Agreement
violate, in any way material to the transactions contemplated hereby, any
contract or agreement to which Investor is a party or any governmental or
judicial order, judgment, decree, statute, law, rule or regulation applicable to
Investor, and this Agreement and all documents and other instruments to be
executed and delivered by Investor in connection herewith constitute the legal,
valid and binding obligations of Investor.  Investor is not a party to, or bound
by, any unexpired, undischarged or unsatisfied contract, agreement, indenture,
mortgage, debenture, note or other

                                       22
<PAGE>
 
instrument under the terms of which performance by Investor according to the
terms of this Agreement will be a default or an event of acceleration, or
grounds for termination, or whereby timely performance by Investor, according to
the terms of this Agreement, may be prohibited, prevented or delayed.

      7.5 Due Organization, Etc. of BPECW LLC.
          ----------------------------------- 

          7.5.1  BPECW LLC is a limited liability company duly organized,
     validly existing and in good standing under the laws of the State of
     Delaware, is (or prior to the Closing will be) duly qualified and in good
     standing as a foreign limited liability company under the laws of the State
     of California, and has all necessary power, corporate and otherwise, to
     execute and deliver this Agreement and all other documents and instruments
     to be executed and delivered by BPECW LLC in connection herewith and to
     perform all its obligations hereunder and thereunder. This Agreement has
     been duly authorized by all requisite action on the part of BPECW LLC's
     member. The execution and delivery of this Agreement and the other
     documents and instruments to be executed and delivered by BPECW LLC in
     connection with the transactions described herein, and the consummation of
     the transactions contemplated hereby and thereby, do not require the
     consent or approval of the member of BPECW LLC or, to the knowledge of
     BPECW LLC, the consent or approval of any governmental authority, nor, to
     the knowledge of BPECW LLC, does the execution and delivery of this
     Agreement violate, in any way material to the transactions contemplated
     hereby, any contract or agreement to which BPECW LLC is a party or any
     governmental or judicial order, judgment, decree, statute, law, rule or
     regulation applicable to BPECW LLC, and this Agreement and all documents
     and other instruments to be executed and delivered by BPECW LLC in
     connection herewith constitute the legal, valid and binding obligations of
     BPECW LLC.

          7.5.2  BPECW LLC is not a party to, or bound by, any unexpired,
     undischarged or unsatisfied contract, agreement, indenture, mortgage,
     debenture, note or other instrument under the terms of which performance by
     BPECW LLC according to the terms of this Agreement will be a default or an
     event of acceleration, or grounds for termination, or whereby timely
     performance by BPECW LLC, according to the terms of this Agreement, may be
     prohibited, prevented or delayed.

          7.5.3  Investor is the sole member of BPECW LLC.


                                   ARTICLE 8

                                  LIMITATIONS
                                  -----------

      8.1 Limitations.  Except for the representations and warranties set forth
          -----------                                                          
in Sections 5.3, 6.3 and 7.3 above (which shall survive the Closing until a date
   ------------  ---     ---                                                    
(the "LIMITATION DATE") which is

                                       23
<PAGE>
 
twelve (12) months after the Closing Date) all representations and warranties
shall survive the Closing without any time limit other than those limits imposed
by the applicable statute of limitations or other similar laws. The contractual
limitation on the Partnership's rights set forth in the preceding sentence shall
not constitute a waiver or release by the Partnership of its rights under
Federal Securities Laws. Notwithstanding the foregoing, the non-breaching
party(ies) shall have the right to commence or prosecute against the breaching
party(ies) any claim for the breach of a representation or warranty under 
Sections 5.3, 6.3 and 7.3 relating to events or occurrences which occurred 
------------  ---     ---
prior to the Limitation Date, provided such claim is actually filed no later
than forty-five (45) days after the Limitation Date, and otherwise no action
based thereon shall be commenced after the Closing Date. The representations and
warranties of the parties made in this Agreement are personal to the other
parties hereto and no Person other than a named party hereto shall be entitled
to bring any action based thereon. The representations and warranties set forth
above are further subject to the limitations of liability set forth in Section 
                                                                       -------
11.1 hereof and Article 12 of the Master Transaction Agreement, which 
----
limitations are in addition to (and not in lieu of) the limitations set forth in
this Agreement.


                                   ARTICLE 9

                                   COVENANTS
                                   ---------

      9.1 Confidentiality.
          --------------- 

          9.1.1  As used herein, "CONFIDENTIAL MATERIAL" means, with respect to
any party hereto (the "PROVIDING PARTY"), all information, whether oral, written
or otherwise, furnished to another party hereto (the "RECEIVING PARTY") or the
Receiving Party's directors, officers, partners, Affiliates, employees or
agents, or their respective representatives (collectively, "REPRESENTATIVES"),
by the Providing Party and all reports, analyses, compilations, studies and
other material prepared by the Receiving Party or its Representatives (in
whatever form maintained, whether documentary, computer storage or otherwise)
containing, reflecting or based upon, in whole or in part, any such information.
The term "CONFIDENTIAL MATERIAL" does not include information which (i) is or
becomes generally available to the public other than as a result of a disclosure
by the Receiving Party, its Representatives or anyone to whom the Receiving
Party or any of its Representatives transmit any Confidential Material in
violation of this Agreement or (ii) is or becomes known or available to the
Receiving Party on a nonconfidential basis from a source (other than the
Providing Party or one of its Representatives) who is not, to the knowledge of
the Receiving Party, prohibited from transmitting the information to the
Receiving Party or its Representatives by a contractual, legal, fiduciary or
other obligation.

          9.1.2  Subject to Section 9.1.3 below or except as required by
                            -------------                               
applicable laws, regulations or legal process as reasonably interpreted by
Public Company, the Confidential Material will be kept confidential and will
not, without the prior written consent of the Providing Party, be disclosed by
the Receiving Party or its Representatives, in whole or in part, and will not

                                       24
<PAGE>
 
be used by the Receiving Party or its Representatives, directly or indirectly,
for any purpose other than in connection with this Agreement, the other
Transaction Documents and the transactions contemplated hereby or thereby or
evaluating, negotiating or advising with respect to such matters.
Notwithstanding anything to the contrary herein, the Receiving Party has the
right to transmit Confidential Material to its Representatives only if and to
the extent that such Representatives need to know the Confidential Material for
purposes of such transactions and are informed by the Receiving Party of the
confidential nature of the Confidential Material and of the terms of this
Section 9.1.2. Notwithstanding the foregoing, each of  Public Company, Investor,
-------------
BPECW LLC, the Partnership and the Prudential Partners shall have the right to
disclose such Confidential Material to its actual or proposed financing and
capital sources and their respective representatives, provided that, prior to
disclosing such information to such Persons, as the case may be, it advises such
Persons of the confidential nature of such Confidential Information and causes
to be affixed to such Confidential Information and requires that such
Information be used only for the purposes specified by the parties hereto in
connection with the transactions contemplated by this Agreement and/or the
Master Transaction Agreement. In any event, the Receiving Party will be
responsible for any actions by its Representatives (and any other Person to whom
such Confidential Material is conveyed in accordance with the provisions hereof)
which are not in accordance with the provisions hereof.

          9.1.3  In the event that the Receiving Party, its Representatives or
anyone to whom the Receiving Party or its Representatives supply the
Confidential Material are requested (by oral questions, interrogatories,
requests for information or documents, subpoena, civil or criminal investigative
demand, any informal or formal investigation by any government or governmental
agency or authority or otherwise in connection with legal process) to disclose
any Confidential Material, the Receiving Party agrees (i) to immediately notify
the Providing Party of the existence, terms and circumstances surrounding such a
request, (ii) to consult with the Providing Party on the advisability of taking
legally available steps to resist or narrow such request, and (iii) if
disclosure of such information is required, to furnish only that portion of the
Confidential Material which, in the opinion of the Receiving Party's counsel,
the Receiving Party is legally compelled to disclose and to cooperate with any
action by the Providing Party to obtain an appropriate protective order or other
reliable assurance that confidential treatment will be accorded the Confidential
Material (it being agreed that the Providing Party shall reimburse the Receiving
Party for all reasonable out-of-pocket expenses incurred by the Receiving Party
in connection with such cooperation).

          9.1.4  In the event of the termination of this Agreement in accordance
with its terms, promptly upon request from the Providing Party, the Receiving
Party shall, except to the extent prohibited by applicable laws, regulations or
legal process, redeliver to the Providing Party or destroy all tangible
Confidential Material and will not retain any copies, extracts or other
reproductions thereof in whole or in part.  Any such destruction shall be
certified in writing to the Providing Party by an authorized officer of the
Receiving Party supervising the same.

                                       25
<PAGE>
 
      9.2 Public Statements.  The parties hereto shall consult with each other
          -----------------                                                   
prior to issuing any press release or any written public statement with respect
to this Agreement or the transactions contemplated hereby and, except as shall
be required by applicable law or the rules or regulations of any securities
exchange, shall not issue any such press release or written public statement
prior to review and approval by the other parties, it being understood that such
approval will not be unreasonably withheld or delayed.

      9.3 Survival.  The covenants in this Article 9 shall survive the Closing.
          --------                         ---------                           


                                  ARTICLE 10

                                    CLOSING
                                    -------

      10.1 Closing Deliveries.
           ------------------ 

          10.1.1  Closing.  As used herein, the term "CLOSING" shall mean the
                  -------
consummation of all transactions contemplated in this Agreement as provided in
Sections 10.1.2 and 10.1.3 below.
---------------     ------       

          10.1.2  Closing Deliveries of the Partnership.  On the date hereof, 
                  -------------------------------------     
the Partnership is hereby concurrently delivering to BPECW LLC, Investor and/or
the Public Company, or causing to be delivered to the Escrow Agent, the
following:

                  (a) Deed.  A grant deed in the form of Exhibit G attached 
                      ----                               ---------  
          hereto and incorporated herein by this reference, conveying to BPECW
          LLC all of the Partnership's undivided tenancy-in-common right, title
          and interest in and to the Real Property, subject only to the
          Permitted Exceptions ("DEED").

                  (b) Bill of Sale.  A bill of sale in the form of Exhibit H
                      ------------                                 ---------
          attached hereto and incorporated herein by this reference, conveying
          to BPECW LLC all of the Partnership's undivided tenancy-in-common
          right, title and interest in and to the Personal Property.

                  (c) Assignment of Tenant Leases.  An assignment and 
                      ---------------------------
          assumption of leases in the form of Exhibit I attached hereto and
                                              ---------
          incorporated herein by this reference ("ASSIGNMENT OF LEASES"),
          transferring to BPECW LLC all of the Partnership's undivided tenancy-
          in-common interest in the Leases encumbering the Property on the date
          hereof described on Exhibit E attached hereto and incorporated herein
                              ---------
          by this reference and any amendments, guarantees and other documents
          relating thereto (herein collectively called the "LEASES"), together
          with all assignable non-cash security deposits deposited by the
          tenants thereunder and not applied by the Partnership in accordance
          with the terms of such Leases.

                                       26
<PAGE>
 
               (d) Assignment of Equipment Leases and Service Contracts.  An
                   ----------------------------------------------------     
          assignment and assumption of equipment leases, service contracts,
          warranties and guaranties and the Other Property Rights (to the extent
          the same are not transferred by Deed, Bill of Sale or Assignment of
          Leases) in the form of Exhibit J attached hereto and incorporated
                                 ---------                                 
          herein by this reference ("ASSIGNMENT OF CONTRACTS"), transferring to
          BPECW LLC, to the extent assignable, without liability or expense to
          the Partnership, all of the Partnership's undivided tenancy-in-common
          interest in the equipment leases in effect at the Property on the date
          hereof, contracts described on Exhibit B, warranties and guaranties
                                         ---------                           
          which remain in effect on the date hereof and any Other Property
          Rights not otherwise transferred to BPECW LLC (all of the foregoing
          being herein collectively called the "ASSIGNED CONTRACTS").  The
          Partnership shall not assign any existing policies of insurance for
          the Property, and the Partnership shall terminate the management
          agreement for the Property on or before the date hereof.

               (e) Notices to Tenants.  A single form letter in the form of
                   ------------------                                      
          Exhibit K attached hereto and incorporated herein by this reference to
          ---------                                                             
          each tenant under the Leases, duplicate copies of which will be sent
          on or promptly after the date hereof notifying it of the transfer of
          the Property to BPECW LLC and advising it that all future payments of
          rent and other payments under the Leases are to be made to BPECW LLC
          at the address designated by BPECW LLC in such letter.

               (f) Non-Foreign Status Affidavit.  A non-foreign status affidavit
                   ----------------------------                                 
          in the form of Exhibit L attached hereto and incorporated herein by
                         ---------                                           
          this reference, as required by Section 1445 of the Internal Revenue
          Code.

               (g) Evidence of Authority.  (i) A certificate of each general
                   ---------------------                                    
          partner of the Partnership with respect to the authority to act on
          behalf of the Partnership to execute all documents contemplated by
          this Agreement and the authority of the individuals executing on
          behalf of the Partnership; and (ii) evidence of the organization,
          existence and authority of each Partner to enter into this Agreement
          and to consummate the transactions contemplated hereby, certified by
          an appropriate officer or partner of such Partner (together with an
          incumbency and signature certificate regarding the Person signing).

               (h) Property Documents.  (i) To the extent in the possession of
                   ------------------                                         
          the Partnership or PPS, (x) the original (or, if unavailable, a copy)
          of the existing certificate or certificates of occupancy for the
          Property, and (y) all originals (or, if unavailable, copies of)
          certificates, licenses, permits, authorizations and approvals issued
          for or with respect to the Property by governmental and quasi-
          governmental authorities having jurisdiction; and (ii) all books and
          records (excluding appraisals, budgets, the Partnership's and its
          partners' strategic plans for the Property, marketing information,
          submissions relating to the Partnership's

                                       27
<PAGE>
 
          obtaining of corporate authorization, or other information in the
          possession or control of the Partnership, its partners or PPS prior to
          the date hereof and which is privileged, provided that inadvertent
          disclosure shall not constitute a waiver of any privilege) located at
          the Property or at the office of PPS relating to the Property and the
          ownership and operation thereof (the items described in clauses (i)
                                                                  -----------
          and (ii) being herein collectively called the "PROPERTY DOCUMENTS").
              ----      
           
               (i) Other Documents.  Such other documents as may be reasonably
                   ---------------                                            
          required by the Escrow Agent or as may be agreed upon by the
          Partnership and BPECW LLC to consummate the transactions contemplated
          by this Agreement.

               (j) Letters of Credit as Tenant Security Deposits.  With respect
                   ---------------------------------------------               
          to any security deposits which are letters of credit, the Partnership
          shall, if the same are assignable, (i) deliver to BPECW LLC on the
          date hereof such letters of credit, (ii) execute and deliver such
          other instruments as the issuers of such letters of credit shall
          reasonably require, and (iii) cooperate with BPECW LLC to change the
          named beneficiary under such letters of credit to BPECW LLC so long as
          the Partnership does not incur any additional liability or expense in
          connection therewith.

               (k) Keys and Original Documents.  Keys to all locks on the Real
                   ---------------------------                                
          Property (in the Partnership's or PPS's possession) and originals or,
          if originals are not available, copies, of the Leases and Assigned
          Contracts (unless canceled as set forth herein) encumbering the
          Property on the date hereof.

               (l) Transfer Taxes.  If applicable, duly completed and signed
                   --------------                                           
          real estate transfer tax forms (i.e., Preliminary Change of Ownership
                                          ----                                 
          Reports).

               (m) Investor Agreement.  The Investor Agreement in the form of
                   ------------------                                        
          Exhibit M attached hereto (the "INVESTOR AGREEMENT"), executed by the
          ---------                                                            
          Partnership.

               (n) Registration Rights Agreement.  The Registration Rights
                   -----------------------------                          
          Agreement in the form of Exhibit N attached hereto (the "REGISTRATION
                                   ---------                                   
          RIGHTS AGREEMENT"), executed by the Partnership.

               (o) Representation Letter.  A Representation Letter in the form
                   ---------------------                                      
          attached hereto as Exhibit O attached hereto executed by the
                             ---------                                
          Partnership indicating thereon that the Partnership is an "accredited
          investor".

               (p) Tax Reporting Agreement.  The Tax Reporting Agreement in the
                   -----------------------                                     
          form of Exhibit P attached hereto (the "TAX REPORTING AGREEMENT"),
                  ---------                                                 
          executed by the Partnership.

                                       28
<PAGE>
 
          10.1.3  Closing Deliveries of BPECW LLC, Investor and/or Public 
                  -------------------------------------------------------
Company. On the date hereof, BPECW LLC, Investor and/or Public Company are
-------
hereby concurrently delivering to the Partnership, or are causing to be
delivered to the Escrow Agent, the following:

                  (a) Assignment of Leases.  The Assignment of Leases executed 
                      --------------------    
          by BPECW LLC.

                  (b) Assignment of Equipment Leases and Service Contracts.  The
                      ----------------------------------------------------      
          Assignment of Contracts executed by BPECW LLC.

                  (c) Evidence of Authority.  Documentation to establish to the
                      ---------------------                                    
          Partnership's reasonable satisfaction the due authorization of BPECW
          LLC's acquisition of the Property and its signatories and Investor's
          delivery of the Contribution Units and documents required to be
          delivered by Investor pursuant to this Agreement.

                  (d) Other Documents.  Such other documents as may be 
                      ---------------      
          reasonably required by the Escrow Agent or may be agreed upon by the
          Partnership, BPECW LLC, Investor and Public Company to consummate the
          transactions contemplated by this Agreement.

                  (e) Transfer Taxes.  If applicable, duly completed and signed
                      --------------                                           
          real estate transfer tax forms (i.e., Preliminary Change of Ownership
                                          ----                                 
          Reports).

                  (f) Organization.  Evidence of the organization, existence and
                      ------------                                              
          authority of BPECW LLC, Public Company and Investor to enter into this
          Agreement and to consummate the transactions contemplated hereby,
          certified by an appropriate officer of BPECW LLC, Public Company or
          Investor, as appropriate (together with an incumbency and signature
          certificate regarding the officer(s) signing on their behalf).

                  (g) Investor Agreement.  The Investor Agreement executed by
                      ------------------                                     
          Public Company and any other partner whose execution is required by
          Investor's Investor Agreement, reflecting the issuance to the
          Partnership of the Investor Preferred Units in accordance with Section
                                                                         -------
          2.2 hereof.
          ---        

                  (h) Registration Rights Agreement.  The Registration Rights
                      -----------------------------                          
          Agreement, executed by Public Company.

                  (i) Tax Reporting Agreement.  The Tax Reporting Agreement,
                      -----------------------                               
          executed by the Partnership and Public Company.

                                       29
<PAGE>
 
          10.1.4  Delivery of Deed.  Effective upon delivery of the Deed, actual
                  ----------------                                              
and exclusive possession (subject only to the Permitted Exceptions) and risk of
loss to the Property shall pass from the Partnership to BPECW LLC.

          10.1.5  Waiver of Failure of Conditions Precedent.  By closing the
                  -----------------------------------------                 
transactions contemplated by this Agreement, each party hereto shall be
conclusively deemed to have waived the benefit of any remaining unfulfilled
conditions precedent set forth in this Agreement and/or the Master Transaction
Agreement.

          10.1.6  Apportionment Credit.  The Contribution Value (and the amount
                  -------------------- 
of Contribution Units delivered to the Partnership) shall be adjusted to reflect
the prorations and other adjustments pursuant to and as provided in Exhibit V of
the Master Transaction Agreement.

          10.1.7  Delayed Adjustment.  Investor and the Partnership shall
                  ------------------                                     
administer the provisions of Exhibit V of the Master Transaction Agreement
following the Closing based on the closing of the Property's books for the
Closing Month.  If, as a result of the Final Audit to be conducted pursuant to
Exhibit V, the amount of an item listed in Exhibit V of the Master Transaction
Agreement shall prove to be incorrect (whether as a result of an error in
calculation or a lack of complete and accurate information as of the date
hereof), Investor and the Partnership shall adjust the Contribution Units
initially issued (proportionately to the Contribution Units initially issued) by
Investor delivering an amended schedule to the Investor Agreement as reasonably
agreed to by the Partnership reflecting the corrected number of Investor
Preferred Units issued to the Partnership in order to correct such error upon
receipt of reasonable proof of such error, provided that such proof is delivered
to the party from whom payment is requested within 90 days of the date hereof.
The correction of any such error shall be made effective as of the date hereof
and shall include the further payment by Investor, or repayment by the
Partnership, of any distributions made by Investor in respect of the increase,
or decrease, of the number of Contribution Units initially held by the
Partnership prior to such adjustment.

          10.1.8  Survivability.  The provisions of this Article 10 shall 
                  -------------                          ----------  
survive the Closing and not be merged therein for a period of six months after
the Closing or such longer period as may be necessary to complete the Final
Audit and make the adjustment described in Section 10.1.7.
                                           -------------- 

          10.1.9  Closing Costs.  The parties shall bear certain closing costs 
                  -------------
of the transactions contemplated hereby as set forth in Exhibit V of the Master
Transaction Agreement. Any other Closing costs not covered by Exhibit V of the
Master Transaction Agreement shall be allocated between the parties in
accordance with the local practice and custom in San Francisco, California.

                                       30
<PAGE>
 
                                  ARTICLE 11

                       BREACH, DEFAULT, LIABILITY LIMITS
                       ---------------------------------

      11.1 Rights of Investor and Public Company.
           ------------------------------------- 

           11.1.1  In the event of any claim, suit or other action against the
Partnership or its Partners pertaining to (a) this Agreement, any of the
documents executed in connection herewith or any of the transactions
contemplated hereby or thereby (including, without limitation, any and all
indemnification obligations of the Partnership hereunder or thereunder) or (b) a
breach by the Partnership of any of the terms or provisions of this Agreement or
of any of the documents executed by the Partnership in connection with the
matters contemplated in this Agreement (including, without limitation, the
breach of any representation or warranty of the Partnership set forth herein or
therein), BPECW LLC's, Investor's and Public Company's sole remedy shall be an
action for monetary damages against the Partnership (or, only if the Partnership
has dissolved or does not hold sufficient Investor Preferred Units or other
Securities received in exchange therefor and/or cash to satisfy the judgment,
the Partners of the Partnership individually); provided that, except for the
                                               -------- ----                
breach of the representations and warranties set forth in Sections 5.3.1, 5.3.2,
                                                          --------------  ----- 
5.5 and 5.6 above (which will not be subject to any limitation on the amount of
---     ---                                                                    
such liability), and notwithstanding any provision to the contrary contained in
this Agreement, the Master Transaction Agreement or in any other documents
executed in connection herewith or therewith, the maximum aggregate liability of
the Partnership and its Partners, and the maximum aggregate amount which may be
awarded to and collected by BPECW LLC, Investor and Public Company or any other
Person, with respect to any claim, suit or other action relating to a breach of
a representation, covenant or indemnity of this Agreement, the Master
Transaction Agreement or any other documents executed in connection herewith or
therewith shall not exceed the Three ECW Building Maximum Liability Amount.
Each Partner's liability under this Agreement shall not exceed (x) an amount
equal to the Three ECW Building Maximum Liability Amount minus the sum of all
                                                         -----               
damages previously paid by, or concurrently being paid by, the Partnership,
multiplied by, (y) such partner's percentage interest in the Partnership
---------- --                                                           
immediately prior to the Closing. Notwithstanding the foregoing, the terms and
provisions of this Section 11.1.1 are further subject to the overall $43,000,000
                   --------------                                               
limitation of liability set forth in Section 12.1.2 of the Master Transaction
Agreement, it being acknowledged and agreed that the maximum liability caps
described hereinabove may be further reduced as a result of recoveries made by
BPECW LLC, Investor, Public Company or their Affiliates in connection with the
other transactions described in the Master Transaction Agreement in accordance
with said Section 12.1.2 of the Master Transaction Agreement.  Notwithstanding
the foregoing, the parties hereto hereby acknowledge and agree that the
foregoing limitations on the amount of liability (and any other cap on the
liability of the Partnership and/or its Partners set forth in any other
Transaction Document) does not apply to the breach of any of the representations
and warranties set forth in Sections 5.3.1, 5.3.2, 5.5 and 5.6 hereof.
                            --------------  -----  ---     ---        

                                       31
<PAGE>
 
           11.1.2  Except as provided in the last sentence of this Section 
                                                                   -------
11.1.2, BPECW LLC's, Investor's and Public Company's sole recourse against the
------ 
Partnership and its Partners, individually and/or as a group, for liability
assumed by, and for any indemnity of or breach of representation or warranty
made by the Partnership shall be limited to the recovery by BPECW LLC, Investor
and/or Public Company of Investor Preferred Units (and any Securities received
in exchange therefor or upon conversion thereof) issued to the Partnership and
then held by the Partnership or any Partner, and none of the Partnership or any
of its Partners shall have any personal liability to pay any damages or other
amounts in cash in respect thereof, except to the extent that the Partnership
and its Partners collectively hold an insufficient amount of Investor Preferred
Units and Securities to satisfy the claim or judgment, in which event such
Person shall be obligated to pay any damages or other amounts not satisfied by
the transfer of Investor Preferred Units or Securities in cash.  The number of
Investor Preferred Units or Shares recoverable from the Partnership or the
Partners, as the case may be, in respect of any claim (or damages) to be
satisfied by such Person as provided in this Agreement shall be determined on a
full diluted basis as if converted by reference to the closing trading price of
the Public Company's common shares on the date of payment of the damages or
other amounts.

           11.1.3  Investor shall promptly give the Partnership notice of any
claim made by any third party which would reasonably be expected to result in
liability of the Partnership or any Partner in respect of a breach of a
representation made by the Partnership in this Agreement or otherwise and shall
give the Partnership and its Partners the opportunity to cure any alleged claim
and to defend against and settle all such claims at their sole cost. The failure
to give such notice, however, shall not relieve the Partnership of any
liabilities hereunder to the extent that it is not materially prejudiced as a
result thereof.

           11.1.4  The terms and provisions of this Section 11.1 shall survive 
                                                    ------------ 
the Closing and shall not be merged therein.

      11.2 Rights of Partnership.
           --------------------- 

           11.2.1  In the event of a breach by BPECW LLC, Investor or Public
Company of any of the terms or provisions of this Agreement or any of the
documents executed in connection herewith, the Partnership and Prudential
Partners shall be entitled to pursue any and all rights and remedies at law or
in equity available to the Partnership and/or its Partners with respect to such
breach; provided that, except for breaches of the representations and 
        -------- ----     
warranties set forth in Articles 6 and 7 (which will not be subject to any 
                        ----------     -       
liability cap), and except as otherwise expressly provided in any other
Transaction Document, the maximum aggregate liability of BPECW LLC, Investor and
Public Company for any and all breaches of the representations and warranties of
BPECW LLC, Investor and/or Public Company contained in any Transaction Document
shall not exceed an amount equal to Forty-Three Million Dollars ($43,000,000) in
the aggregate.

           11.2.2  The terms and provisions of this Section 11.2 shall survive 
                                                    ------------
the Closing and shall not be merged therein.

                                       32
<PAGE>
 
                                  ARTICLE 12

                                 MISCELLANEOUS
                                 -------------

      12.1 Commissions.  The parties hereto each agree to indemnify, defend,
           -----------                                                      
protect and hold the others harmless from and against any and all commissions,
finder's and/or similar fees or compensation claimed by any broker or finder in
connection with the transactions described in this Agreement based on claimed
contacts with, or other acts or omissions of, such indemnifying party.  The
terms and provisions of this Section 12.1 shall survive the Closing or
                             ------------                             
termination of this Agreement.

      12.2 Expenses.  Except as otherwise expressly set forth herein or 
           --------  
expressly set forth in the Master Transaction Agreement, each party hereto shall
bear its own costs and expenses with respect to the transactions contemplated
hereby.

      12.3 Amendment.  This Agreement may be amended, modified or supplemented
           ---------                                                          
but only in writing signed by each of the parties hereto.

      12.4 Notices.  Any notice, request, instruction or other document to be
           -------                                                           
given hereunder by a party hereto shall be in writing and shall be deemed to
have been given, (a) when received if given in person or by courier or a courier
service, (b) on the date of transmission if sent by telex, facsimile or other
wire transmission or (c) three business days after being deposited in the U.S.
mail, certified or registered mail, postage prepaid:

           12.4.1  If to BPECW LLC, Public Company or Investor, addressed as
     follows:

           Boston Properties, Inc.
           8 Arlington Street
           Boston, Massachusetts 02116-3495
           Attention:  General Counsel
           Facsimile:  617-421-1555
           Telephone:  617-859-2600
         
           with a copy to:
         
           Goulston & Storrs, P.C.
           400 Atlantic Avenue
           Boston, Massachusetts 02110-3333
           Attention:  Eli Rubenstein, Esq.
           Facsimile:  617-574-4112
           Telephone:  617-482-1776
         

                                       33
<PAGE>
 
           12.4.2  If to the Partnership, addressed as follows:
         
           Prudential Realty Group
           8 Campus Drive
           4th Floor - Arbor Circle South
           Parsippany, New Jersey 07054
           Attention:  John R. Triece
           Facsimile:  (201) 683-1797
         
           with a copy to:
         
           The Prudential Insurance Company
           of America
           c/o Prudential Capital Group
           Four Embarcadero Center
           Suite 2700
           San Francisco, California 94111
           Attention:  Harry Mixon, Esq.
           Facsimile:  (415) 956-2197
         
           and a copy to:
         
           O'Melveny & Myers LLP
           Embarcadero Center West
           275 Battery Street
           San Francisco, California 94111
           Attention:  Stephen A. Cowan, Esq.
           Facsimile:  (415) 984-8701

or to such other individual or address as a party hereto may designate for
itself by notice given as herein provided.

      12.5 Waivers.  The failure of a party hereto at any time or times to
           -------                                                        
require performance of any provision hereof shall in no manner affect its right
at a later time to enforce the same.  No waiver by a party of any condition or
of any breach of any term, covenant, representation or warranty contained in
this Agreement shall be effective unless in writing, and no waiver in any one or
more instances shall be deemed to be a further or continuing waiver of any such
condition or breach in other instances or a waiver of any other condition or
breach of any other term, covenant, representation or warranty.

      12.6 Counterparts.  This Agreement may be executed in counterparts, each 
           ------------
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

                                       34
<PAGE>
 
      12.7  Interpretation.  The headings preceding the text of Articles and
            --------------                                                  
Sections included in this Agreement and the headings to Exhibits and Schedules
attached to this Agreement are for convenience only and shall not be deemed part
of this Agreement or be given any effect in interpreting this Agreement.  The
use of the masculine, feminine or neuter gender herein shall not limit any
provision of this Agreement.  The use of the term "including" or "include" shall
in all cases herein mean "including, without limitation" or "include, without
limitation," respectively.  Underscored references to Articles, Sections,
Subsections, Exhibits or Schedules shall refer to those portions of this
Agreement.

      12.8  Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
            -------------                                                       
ACCORDANCE WITH THE LAWS OF THE STATE OF CALIFORNIA.

      12.9  Assignment.  This Agreement shall be binding upon and inure to the
            ----------                                                        
benefit of the parties hereto and their respective successors and assigns.  No
assignment of any rights or obligations shall be made by any party without the
written consent of each other party.

      12.10 No Third Party Beneficiaries.  This Agreement is solely for the
            ----------------------------                                   
benefit of the parties hereto and, to the extent provided herein, their
respective Representatives, and no provision of this Agreement shall be deemed
to confer upon other third parties any remedy, claim, liability, reimbursement,
cause of action or other right.

      12.11 Further Assurances.  Upon reasonable request of any party, each 
            ------------------    
other party will execute and deliver such other documents, releases, assignments
and other instruments as may be required to effectuate completely the transfer
and assignment to Investor of the Property and to issue the Investor Preferred
Units, Investor Common Units and the Shares and to otherwise carry out the
purposes of this Agreement.

      12.12 Severability.  If any provision of this Agreement shall be held
            ------------                                                   
invalid, illegal or unenforceable, the validity, legality or enforceability of
the other provisions hereof shall not be affected thereby, and there shall be
deemed substituted for the provision at issue a valid, legal and enforceable
provision as similar as possible to the provision at issue.

      12.13 Remedies Cumulative.  The remedies provided in this Agreement shall
            -------------------  
be cumulative and shall not preclude the assertion or exercise of any other
rights or remedies available by law, in equity or otherwise.

      12.14 Entire Understanding.  This Agreement, together with the other
            --------------------                                          
Transaction Documents, sets forth the entire agreement and understanding of the
parties hereto with respect to the matters set forth herein and supersedes any
and all prior agreements, arrangements and understandings among the parties.

      12.15 Consent to Jurisdiction and Service of Process.  ALL JUDICIAL
            ----------------------------------------------               
PROCEEDINGS BROUGHT AGAINST ANY PERSON ARISING OUT OF OR RELATING 

                                       35
<PAGE>
 
TO THIS AGREEMENT MAY BE BROUGHT IN ANY STATE OR FEDERAL COURT OF COMPETENT
JURISDICTION IN THE STATE OF CALIFORNIA, AND BY EXECUTION AND DELIVERY OF THIS
AGREEMENT EACH PARTY HERETO ACCEPTS FOR ITSELF, GENERALLY AND UNCONDITIONALLY,
THE NONEXCLUSIVE JURISDICTION OF THE AFORESAID COURTS AND WAIVES ANY DEFENSE OF
FORUM NON CONVENIENS AND IRREVOCABLY AGREES TO BE BOUND BY ANY JUDGMENT RENDERED
THEREBY IN CONNECTION WITH THIS AGREEMENT. Each party hereby agrees that service
of all process in any such proceeding in any such court may be made by
registered or certified mail, return receipt requested, to any other party
hereto, at its address provided in this Agreement, such service being hereby
acknowledged by each party to be sufficient for personal jurisdiction in any
action against such party in any such court and to be otherwise effective and
binding service in every respect. Nothing herein shall affect the right to serve
process in any other manner permitted by law.

      12.16 Waiver of Jury Trial.  EACH OF THE PARTIES TO THIS AGREEMENT HEREBY
            --------------------                                               
AGREES TO WAIVE ITS RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF
ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT.  The scope of this waiver is
intended to be all-encompassing of any and all disputes that may be filed in any
court and that relate to the subject matter of this transaction, including,
without limitation, contract claims, tort claims, breach of duty claims and all
other common law and statutory claims.  Each party hereto acknowledges that this
waiver is a material inducement to enter into a business relationship, that each
has already relied on this waiver in entering into this Agreement, and that each
shall continue to rely on this waiver in their related future dealings.  Each
party hereto further warrants and represents that it has reviewed this waiver
with its legal counsel and that it knowingly and voluntarily waives its jury
trial rights following consultation with such legal counsel.  THIS WAIVER IS
IRREVOCABLE, MEANING THAT IT MAY NOT BE MODIFIED EITHER ORALLY OR IN WRITING,
AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS
OR MODIFICATIONS TO THIS AGREEMENT.  In the event of litigation, this Agreement
may be filed as a written consent to a trial by the court.

                                       36
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed and delivered as of the date first above written.


PARTNERSHIP:        THREE EMBARCADERO CENTER WEST,
                    a California limited partnership

                    By:  THE PRUDENTIAL INSURANCE COMPANY
                         OF AMERICA, a New Jersey corporation,
                         its General Partner



                         By: /s/ Gary L. Frazier
                            ----------------------------------
                         Name: _______________________________
                         Title: ______________________________


BPECW LLC:          BP EC WEST LLC,
                    a Delaware limited liability company

                    By:  BOSTON PROPERTIES LIMITED PARTNERSHIP,
                         a Delaware limited partnership,
                         its sole Member

                         By:  BOSTON PROPERTIES, INC.,
                              a Delaware corporation,
                              its General Partner



                              By: /s/ Thomas J. O'Connor
                                 -----------------------------
                              Name: Thomas J. O'Connor
                              Title: Vice President

                                       37
<PAGE>
 
INVESTOR:           BOSTON PROPERTIES LIMITED PARTNERSHIP,
                    a Delaware limited partnership

                    By:  BOSTON PROPERTIES, INC.,
                         a Delaware corporation,
                         its General Partner


                         By: /s/ Thomas J. O'Connor
                            ------------------------------------
                              Name: Thomas J. O'Connor
                              Title: Vice President


PUBLIC COMPANY:     BOSTON PROPERTIES, INC.,
                    a Delaware corporation


                    By: /s/ William J. Wedge
                       ----------------------------------
                    Name: William J. Wedge
                    Title: Senior Vice President

PRUDENTIAL:         THE PRUDENTIAL INSURANCE COMPANY OF AMERICA, a New Jersey
                    corporation


                    By: /s/ Gary L. Frazier
                       -----------------------------------------
                    Name: ______________________________________
                    Title: _____________________________________

PIC:                PIC REALTY CORPORATION,
                    a Delaware corporation


                    By: /s/ Gary L. Frazier
                       -----------------------------------------
                    Name: ______________________________________
                    Title: _____________________________________

PRS:                PRUDENTIAL REALTY SECURITIES II, INC.,
                    a Delaware corporation

                    By: /s/ Duane H. Tucker, Jr.
                       -----------------------------------------
                    Name:  Duane H. Tucker, Jr.
                    Title:  President

                                      A-1

