
<PAGE>
 
                                                                     Exhibit 1.1

================================================================================


                            BOSTON PROPERTIES, INC.
                           (a Delaware corporation)


                       25,120,000 Shares of Common Stock



                            U.S. PURCHASE AGREEMENT
                            -----------------------



Dated:  June __, 1997


================================================================================
<PAGE>
 
                               Table of Contents

<TABLE> 
<CAPTION> 

                                                                                                 Page
                                                                                                 ----
<S>                                                                                               <C> 
U.S. PURCHASE AGREEMENT.........................................................................   1
      SECTION 1. Representations and Warranties.................................................   4
                 ------------------------------
          (a)  Representations and Warranties by the Company....................................   4
                 (i)       Compliance with Registration Requirements............................   4
                           -----------------------------------------
                 (ii)      Independent Accountants..............................................   5
                           -----------------------
                 (iii)     Financial Statements.................................................   5
                           --------------------
                 (iv)      No Material Adverse Change in Business...............................   6
                           --------------------------------------
                 (v)       Good Standing of the Company.........................................   6
                           ----------------------------
                 (vi)      Good Standing of Subsidiaries........................................   6
                           -----------------------------
                 (vii)     Good Standing of Property Partnerships...............................   7
                           --------------------------------------
                 (ix)      Authorization of Agreement...........................................   7
                           --------------------------
                 (x)       Authorization and Description of Securities..........................   8
                           -------------------------------------------
                 (xi)      Authorization of the Operating Partnership Agreement.................   8
                           ----------------------------------------------------
                 (xiii)    Absence of Defaults and Conflicts....................................   8
                           ---------------------------------
                 (xiv)     Authorization of the Formation Transaction Documents.................  10
                           ----------------------------------------------------
                 (xvi)     Absence of Proceedings...............................................  10
                           ----------------------
                 (xvii)    Qualification as a REIT..............................................  10
                           -----------------------
                 (xviii)   Accuracy of Exhibits.................................................  10
                           --------------------
                 (xix)     New York Stock Exchange Listing......................................  11
                           -------------------------------
                 (xx)      Absence of Further Requirements......................................  11
                           -------------------------------
                 (xxi)     Possession of Licenses and Permits...................................  11
                           ----------------------------------
                 (xxii)    The Properties.......................................................  11
                           --------------
                 (xxiii)   Insurance............................................................  12
                           ---------
                 (xxiv)    Taxes................................................................  12
                           -----
                 (xxv)     Mortgages and Deeds of Trust.........................................  12
                           ----------------------------
                 (xxvii)   Investment Company Act...............................................  13
                           ----------------------
                 (xxviii)  Environmental Laws...................................................  13
                           ------------------
                 (xxix)    Registration Rights..................................................  14
                           -------------------
          (b)    Officer's Certificates.........................................................  14
      SECTION 2. Sale and Delivery to U.S. Underwriters; Closing................................  14
                 -----------------------------------------------
          (a)    Initial Securities.............................................................  14
          (b)    Option Securities..............................................................  14
          (c)    Payment........................................................................  15
          (d)    Denominations; Registration....................................................  16
      SECTION 3.  Covenants of the Company......................................................  16
                 ------------------------
          (a)    Compliance with Securities Regulations and Commission Requests.................  16
          (b)    Filing of Amendments...........................................................  16
          (c)    Delivery of Registration Statements............................................  17
 
</TABLE>

                                       i
<PAGE>
 
<TABLE>
      <S>                                                                                         <C> 
          (d)    Delivery of Prospectuses.......................................................  17
          (e)    Continued Compliance with Securities Laws......................................  17
          (f)    Blue Sky Qualifications........................................................  18
          (g)    Rule 158.......................................................................  18
          (h)    Use of Proceeds................................................................  18
          (i)    Listing........................................................................  18
          (j)    Restriction on Sale of Securities..............................................  18
          (k)    Lock-up Agreements.............................................................  19
          (l)    Qualification as a REIT........................................................  19
          (m)    Compliance with NASD Rules.....................................................  19
          (n)    Compliance with Rule 463.......................................................  19
      SECTION 4. Payment of Expenses............................................................  19
                 -------------------
          (a)    Expenses.......................................................................  19
          (b)    Termination of Agreement.......................................................  20
      SECTION 5. Conditions of U.S. Underwriters' Obligations...................................  20
                 --------------------------------------------
          (a)    Effectiveness of Registration Statement........................................  20
          (b)    Opinion of Counsel for Company.................................................  20
          (c)    Opinion of General Counsel of Company..........................................  21
          (d)    Opinion of Counsel for U.S. Underwriters.......................................  21
          (e)    Officers' Certificate..........................................................  21
          (f)    Accountant's Comfort Letter....................................................  22
          (g)    Bring-down Comfort Letter......................................................  22
          (h)    Approval of Listing............................................................  22
          (i)    No Objection...................................................................  22
          (k)    Purchase of Initial International Securities...................................  22
          (l)    Conditions to Purchase of U.S. Option Securities...............................  22
          (m)    Additional Documents...........................................................  23
          (n)    Termination of Agreement.......................................................  23
      SECTION 6. Indemnification................................................................  24
                 ---------------
      (a) Indemnification of U.S. Underwriters..................................................  24
          (b)    Indemnification of Company, Directors and Officers.............................  25
          (c)    Actions against Parties; Notification..........................................  25
          (d)    Settlement without Consent if Failure to Reimburse.............................  26
          (e)    Indemnification for Reserved Securities........................................  26
      SECTION 7. Contribution...................................................................  26
                 ------------
      SECTION 8. Representations, Warranties and Agreements to Survive Delivery.................  28
                 --------------------------------------------------------------
      SECTION 9. Termination of Agreement.......................................................  28
                 ------------------------
          (a)    Termination; General...........................................................  28
          (b)    Liabilities....................................................................  28
      SECTION 10. Default by One or More of the U.S. Underwriters...............................  28
                  -----------------------------------------------
      SECTION 11. Notices.......................................................................  29
                  -------
      SECTION 12. Parties.......................................................................  29
                  -------
      SECTION 13. GOVERNING LAW AND TIME........................................................  30
                  ----------------------

</TABLE> 

                                      ii
 
<PAGE>
 
<TABLE>
     <S>                                                                                     <C> 
     SECTION 14.  Effect of Headings............................................................. 30
                  ------------------
     SCHEDULE A............................................................................. Sch A-1
     SCHEDULE B............................................................................. Sch B-1

</TABLE>

                                      iii
<PAGE>
 
                            BOSTON PROPERTIES, INC.

                            (a Delaware corporation)

                       25,120,000 Shares of Common Stock

                          (Par Value $ .01 Per Share)

                            U.S. PURCHASE AGREEMENT
                            -----------------------

                                                                   June __, 1997

MERRILL LYNCH & CO.
Merrill Lynch, Pierce, Fenner & Smith
  Incorporated
GOLDMAN, SACHS & CO.
BEAR, STEARNS & CO. INC.
MORGAN STANLEY & CO. INCORPORATED
PAINEWEBBER INCORPORATED
PRUDENTIAL SECURITIES INCORPORATED
SMITH BARNEY INC.
 as U.S. Representatives of the several U.S. Underwriters
c/o  Merrill Lynch & Co.
     Merrill Lynch, Pierce, Fenner & Smith
       Incorporated
North Tower
World Financial Center
New York, New York  10281-1209

Ladies and Gentlemen:
 
     Boston Properties, Inc., a Delaware corporation (the "Company") and Boston
Properties Limited Partnership, a Delaware limited partnership (the "Operating
Partnership"), each confirms its agreement with Merrill Lynch & Co., Merrill
Lynch, Pierce, Fenner & Smith Incorporated ("Merrill Lynch"), Goldman, Sachs &
Co. ("Goldman, Sachs") and each of the other U.S. Underwriters named in Schedule
A hereto (collectively, the "U.S. Underwriters", which term shall also include
any underwriter substituted as hereinafter provided in Section 10 hereof), for
whom Merrill Lynch and Goldman, Sachs, Bear, Stearns & Co. Inc., PaineWebber
Incorporated, Prudential Securities Incorporated, Smith Barney Inc. are acting
as representatives (in such capacity, the "U.S. Representatives"), with respect
to the issue and sale by the Company and the purchase by the U.S. Underwriters,
acting severally and not jointly, of the respective numbers of shares of Common
Stock, par value $.01 per share, of the Company
<PAGE>
 
("Common Stock") set forth in said Schedule A, and with respect to the grant by
the Company to the U.S. Underwriters, acting severally and not jointly, of the
option described in Section 2(b) hereof to purchase all or any part of 3,768,000
additional shares of Common Stock to cover over-allotments, if any.  The
aforesaid 25,120,000 shares of Common Stock (the "Initial U.S. Securities") to
be purchased by the U.S. Underwriters and all or any part of the 3,768,000
shares of Common Stock subject to the option described in Section 2(b) hereof
(the "U.S. Option Securities") are hereinafter called, collectively, the "U.S.
Securities".

     It is understood that the Company and the Operating Partnership are
concurrently entering into an agreement dated the date hereof (the
"International Purchase Agreement") providing for the offering by the Company of
an aggregate of 6,280,000 shares of Common Stock (the "Initial International
Securities") through arrangements with certain underwriters outside the United
States and Canada (the "International Managers") for which Merrill Lynch
International, Goldman Sachs International, Bear, Stearns International Limited,
PaineWebber International (UK) Ltd., Prudential-Bache Securities (U.K.) Inc.,
and Smith Barney Inc. are acting as lead managers (the "Lead Managers") and the
grant by the Company to the International Managers, acting severally and not
jointly, of an option to purchase all or any part of the International Managers'
pro rata portion of up to 942,000 additional shares of Common Stock solely to
cover overallotments, if any (the "International Option Securities" and,
together with the U.S. Option Securities, the "Option Securities").  The Initial
International Securities and the International Option Securities are hereinafter
called the "International Securities".  It is understood that the Company is not
obligated to sell and the U.S. Underwriters are not obligated to purchase, any
Initial U.S. Securities unless all of the Initial International Securities are
contemporaneously purchased by the International Managers.

     The U.S. Underwriters and the International Managers are hereinafter
collectively called the "Underwriters", the Initial U.S. Securities and the
Initial International Securities are hereinafter collectively called the
"Initial Securities", and the U.S. Securities and the International Securities
are hereinafter collectively called the "Securities".

     The Underwriters will concurrently enter into an Intersyndicate Agreement
of even date herewith (the "Intersyndicate Agreement") providing for the
coordination of certain transactions among the Underwriters under the direction
of Merrill Lynch & Co., Merrill Lynch, Pierce, Fenner & Smith Incorporated and
Goldman, Sachs & Co. (in such capacity, the "Global Coordinators").

     The Company and the Operating Partnership each understand that the U.S.
Underwriters propose to make a public offering of the U.S. Securities as soon as
the U.S. Representatives deem advisable after this Agreement has been executed
and delivered.

     The Company and the U.S. Underwriters agree that up to [750,000] shares of
the Initial U.S. Securities to be purchased by the U.S. Underwriters and that up
to [       ] shares of the Initial International Securities to be purchased by
the International Managers (collectively, the "Reserved Securities") shall be
reserved for sale by the Underwriters to certain eligible

                                       2
<PAGE>
 
employees and persons having business relationships with the Company, as part of
the distribution of the Securities by the Underwriters, subject to the terms of
this Agreement, the applicable rules, regulations and interpretations of the
National Association of Securities Dealers, Inc. and all other applicable laws,
rules and regulations.  To the extent that such Reserved Securities are not
orally confirmed for purchase by such eligible employees and persons having
business relationships with the Company by the end of the first business day
after the date of this Agreement, such Reserved Securities may be offered to the
public as part of the public offering contemplated hereby.

     The Company has filed with the Securities and Exchange Commission (the
"Commission") a registration statement on Form S-11 (No. 333-25279) covering the
registration of the Securities under the Securities Act of 1933, as amended (the
"1933 Act"), including the related preliminary prospectus or prospectuses.
Promptly after execution and delivery of this Agreement, the Company will either
(i) prepare and file a prospectus in accordance with the provisions of Rule 430A
("Rule 430A") of the rules and regulations of the Commission under the 1933 Act
(the "1933 Act Regulations") and paragraph (b) of Rule 424 ("Rule 424(b)") of
the 1933 Act Regulations or (ii) if the Company has elected to rely upon Rule
434 ("Rule 434") of the 1933 Act Regulations, prepare and file a term sheet (a
"Term Sheet") in accordance with the provisions of Rule 434 and Rule 424(b).
Two forms of prospectus are to be used in connection with the offering and sale
of the Securities:  one relating to the U.S. Securities (the "Form of U.S.
Prospectus") and one relating to the International Securities (the "Form of
International Prospectus").  The Form of International Prospectus is identical
to the Form of U.S. Prospectus, except for the front cover and back cover pages
and the information under the caption "Underwriting."  The information included
in any such prospectus or in any such Term Sheet, as the case may be, that was
omitted from such registration statement at the time it became effective but
that is deemed to be part of such registration statement at the time it became
effective (a) pursuant to paragraph (b) of Rule 430A is referred to as "Rule
430A Information" or (b) pursuant to paragraph (d) of Rule 434 is referred to as
"Rule 434 Information."  Each Form of U.S. Prospectus and Form  of International
Prospectus used before such registration statement became effective, and any
prospectus that omitted, as applicable, the Rule 430A Information or the Rule
434 Information, that was used after such effectiveness and prior to the
execution and delivery of this Agreement, is herein called a "preliminary
prospectus."  Such registration statement, including the exhibits thereto and
schedules thereto at the time it became effective and including the Rule 430A
Information and the Rule 434 Information, as applicable, is herein called the
"Registration Statement."  Any registration statement filed pursuant to Rule
462(b) of the 1933 Act Regulations to register additional shares of Common Stock
to be sold in the public offering of the Securities is herein referred to as the
"Rule 462(b) Registration Statement," and after such filing the term
"Registration Statement" shall include the Rule 462(b) Registration Statement.
The final Form of U.S. Prospectus and the final Form of International Prospectus
in the forms first furnished to the Underwriters for use in connection with the
offering of the Securities are herein called the "U.S. Prospectus" and the
"International Prospectus," respectively, and collectively, the "Prospectuses."
If Rule 434 is relied on, the terms "U.S. Prospectus" and "International
Prospectus" shall refer to the preliminary U.S. Prospectus dated June 10, 1997
and preliminary International Prospectus dated June 10, 1997,

                                       3
<PAGE>
 
respectively, each together with the applicable Term Sheet, and all references
in this Agreement to the date of such Prospectuses shall mean the date of the
applicable Term Sheet.  For purposes of this Agreement, all references to the
Registration Statement, any preliminary prospectus, the U.S. Prospectus, the
International Prospectus or any Term Sheet or any amendment or supplement to any
of the foregoing shall be deemed to include the copy filed with the Commission
pursuant to its Electronic Data Gathering, Analysis and Retrieval system
("EDGAR").

     At or prior to Closing Time (as hereinafter defined), the Company will
complete a series of transactions (the "Formation Transactions") described in
the Prospectuses under the caption "Structure and Formation of the Company--
Formation Transactions."  As part of the Formation Transactions (i) certain
Property Partnerships (as defined in the Registration Statement) will contribute
properties to the Operating Partnership, or will merge into the Operating
Partnership, in exchange for units of limited partnership of the Operating
Partnership ("OP Units"), (ii) certain persons will contribute their direct and
indirect interests in certain Property Partnerships to the Operating Partnership
or its designee in exchange for OP Units, (iii) the Company will contribute a
portion of its third-party management business to Boston Properties Management,
Inc. (the "Development and Management Company"), a subsidiary of the Operating
Partnership, in exchange for OP Units, and (iv) the Company will contribute the
net proceeds from the public offering of the Securities to the Operating
Partnership in exchange for OP Units.

     SECTION 1.  Representations and Warranties.
                 -------------------------------

     (a)  Representations and Warranties by the Company.  The Company and the
Operating Partnership each severally represents and warrants to each U.S.
Underwriter as of the date hereof, as of the Closing Time referred to in Section
2(c) hereof, and as of each Date of Delivery (if any) referred to in Section
2(b), hereof and agrees with each U.S. Underwriter, as follows:

                 (i) Compliance with Registration Requirements.  Each of the
                     -----------------------------------------              
     Registration Statement and any Rule 462(b) Registration Statement has
     become effective under the 1933 Act and no stop order suspending the
     effectiveness of the Registration Statement or any Rule 462(b) Registration
     Statement has been issued under the 1933 Act and no proceedings for that
     purpose have been instituted or are pending or, to the knowledge of the
     Company, are contemplated by the Commission, and any request on the part of
     the Commission for additional information has been complied with.

                     At the respective times the Registration Statement, any
     Rule 462(b) Registration Statement and any post-effective amendments
     thereto became effective and at the Closing Time (and, if any U.S. Option
     Securities are purchased, at the Date of Delivery), the Registration
     Statement, the Rule 462(b) Registration Statement and any amendments and
     supplements thereto complied and will comply in all material respects with
     the requirements of the 1933 Act and the 1933 Act Regulations and did not
     and will not contain an untrue statement of a material fact or omit to
     state a material fact required

                                       4
<PAGE>
 
     to be stated therein or necessary to make the statements therein not
     misleading, and the Prospectuses, any preliminary prospectuses and any
     supplement thereto or prospectus wrapper prepared in connection therewith,
     at their respective times of issuance and at the Closing Time, complied and
     will comply in all material respects with any applicable laws or
     regulations of foreign jurisdictions in which the Prospectuses and such
     preliminary prospectuses, as amended or supplemented, if applicable, are
     distributed in connection with the offer and sale of Reserved Securities.
     Neither of the Prospectuses nor any amendments or supplements thereto
     (including any prospectus wrapper), at the time the Prospectuses or any
     amendments or supplements thereto were issued and at the Closing Time (and,
     if any U.S. Option Securities are purchased, at the Date of Delivery),
     included or will include an untrue statement of a material fact or omitted
     or will omit to state a material fact necessary in order to make the
     statements therein, in the light of the circumstances under which they were
     made, not misleading.  If Rule 434 is used, the Company will comply with
     the requirements of Rule 434 and the Prospectuses shall not be "materially
     different", as such term is used in Rule 434, from the prospectuses
     included in the Registration Statement at the time it became effective.
     The representations and warranties in this subsection shall not apply to
     statements in or omissions from the Registration Statement or the U.S.
     Prospectus made in reliance upon and in conformity with information
     furnished to the Company in writing by any U.S. Underwriter through the
     U.S. Representatives expressly for use in the Registration Statement or the
     U.S. Prospectus.

               Each preliminary prospectus and the prospectuses filed as part of
     the Registration Statement as originally filed or as part of any amendment
     thereto, or filed pursuant to Rule 424 under the 1933 Act, complied when so
     filed in all material respects with the 1933 Act Regulations and each
     preliminary prospectus and the Prospectuses delivered to the Underwriters
     for use in connection with this offering was identical to the
     electronically transmitted copies thereof filed with the Commission
     pursuant to EDGAR, except to the extent permitted by Regulation S-T.

                (ii) Independent Accountants.  The accountants who certified the
                     -----------------------                                    
     financial statements and supporting schedules included in the Registration
     Statement are independent public accountants as required by the 1933 Act
     and the 1933 Act Regulations.

               (iii) Financial Statements.  The combined financial statements
                     --------------------                                    
     included in the Registration Statement and the Prospectuses, together with
     the related schedules and notes, present fairly the financial position of
     the Boston Properties Predecessor Group (as defined in the Registration
     Statement) at the dates indicated, and the combined statements of
     operations, owners' equity and cash flows of the Boston Properties
     Predecessor Group for the periods specified; said financial statements have
     been prepared in conformity with generally accepted accounting principles
     ("GAAP") applied on a consistent basis throughout the periods involved.
     The supporting schedules included in the Registration Statement present
     fairly in accordance with GAAP the information

                                       5
<PAGE>
 
     required to be stated therein.  The unaudited pro forma condensed
     consolidated financial statements and the related notes thereto included in
     the Registration Statement and the Prospectuses present fairly the
     information shown therein, have been prepared in accordance with the
     Commission's rules and guidelines with respect to pro forma financial
     statements and have been properly compiled on the bases described therein,
     and the assumptions used in the preparation thereof are reasonable and the
     adjustments used therein are appropriate to give effect to the transactions
     and circumstances referred to therein.  The selected financial data and the
     summary financial information included in the Prospectuses present fairly
     the information shown therein and have been compiled on a basis consistent
     with that of the audited financial statements included in the Registration
     Statement.  Other than the historical and pro forma financial statements
     (and schedules) included in the Registration Statement and Prospectuses, no
     other historical or pro forma financial statements (or schedules) are
     required by the 1933 Act or the 1933 Act Regulations to be included
     therein.

               (iv) No Material Adverse Change in Business.  Since the
                    --------------------------------------            
     respective dates as of which information is given in the Registration
     Statement and the Prospectuses, except as otherwise stated therein, (A)
     there has been no material adverse change in the condition, financial or
     otherwise, or in the earnings, business affairs or business prospects of
     the Company, the Operating Partnership and the Subsidiaries (as hereinafter
     defined) considered as one enterprise, whether or not arising in the
     ordinary course of business (a "Material Adverse Effect"), (B) no material
     casualty loss or material condemnation or other material adverse event with
     respect to any of the properties set forth in Schedule C hereto has
     occurred, (C) there have been no transactions entered into by the Company,
     the Operating Partnership or any of the Subsidiaries, other than those in
     the ordinary course of business, which are material with respect to the
     Company, the Operating Partnership and the Subsidiaries considered as one
     enterprise, and (D) there has been no dividend or distribution of any kind
     declared, paid or made by the Company on any class of its capital stock or
     by the Operating Partnership or any of its Subsidiaries with respect to its
     partnership interests or any class of its capital stock.

               (v)  Good Standing of the Company.  The Company has been duly
                    ----------------------------                            
     organized and is validly existing as a corporation in good standing under
     the laws of the State of Delaware and has corporate power and authority to
     own, lease and operate its properties and to conduct its business as
     described in the Prospectuses and to enter into and perform its obligations
     under this Agreement; and the Company is duly qualified as a foreign
     corporation to transact business and is in good standing in each other
     jurisdiction in which such qualification is required, whether by reason of
     the ownership or leasing of property or the conduct of business, except
     where the failure so to qualify or to be in good standing would not result
     in a Material Adverse Effect.

               (vi) Good Standing of Subsidiaries.  Each of the subsidiaries of
                    -----------------------------                              
     the Company, including without limitation the Operating Partnership and the
     Development and Management Company, (each a "Subsidiary" and, collectively,
     the "Subsidiaries")

                                       6
<PAGE>
 
     has been duly organized and is validly existing as a general or limited
     partnership or corporation, as the case may be, in good standing (in the
     case of corporations and limited partnerships) under the laws of the
     jurisdiction of its organization, has partnership or corporate power and
     authority, as the case may be, to own, lease and operate its properties and
     to conduct its business as described in the Prospectuses and is duly
     qualified as a foreign partnership or corporation to transact business and
     is in good standing in each jurisdiction in which such qualification is
     required, whether by reason of the ownership or leasing of property or the
     conduct of business, except where the failure so to qualify or to be in
     good standing would not result in a Material Adverse Effect; all of the
     issued and outstanding capital stock of each of the Subsidiaries that is a
     corporation has been duly authorized and validly issued, is fully paid and
     non-assessable, and all of the partnership interests in each Subsidiary
     that is a partnership are validly issued and fully paid; except as
     otherwise disclosed in the Registration Statement, all such shares and
     interests, as the case may be, are owned by the Company, directly or
     through Subsidiaries, free and clear of any security interest, mortgage,
     pledge, lien, encumbrance, claim or equity; none of the outstanding shares
     of capital stock or partnership interests of any Subsidiary was issued in
     violation of the preemptive or similar rights of any securityholder of such
     Subsidiary.

               (vii)  Good Standing of Property Partnerships.  Each of the
                      --------------------------------------              
     Property Partnerships (as defined in the Registration Statement) has been
     duly organized and is validly existing as a general or limited partnership,
     in good standing (in the case of limited partnerships) under the laws of
     the jurisdiction of its organization, has partnership power and authority,
     to own, lease and operate its properties, to conduct its business as
     described in the Prospectuses and to enter into and perform its respective
     obligations under the Formation Transaction Documents and is duly qualified
     as a foreign partnership to transact business and is in good standing in
     each jurisdiction in which such qualification is required, whether by
     reason of the ownership or leasing of property or the conduct of business,
     except where the failure so to qualify or to be in good standing would not
     result in a Material Adverse Effect; all of the partnership interests in
     each Property Partnership are validly issued and fully paid; none of the
     outstanding partnership interests of any Property Partnership was issued in
     violation of the preemptive or similar rights of any securityholder of such
     Property Partnership.

               (viii) Capitalization.  The authorized capital stock of the
                      --------------                                      
     Company is as set forth in the Prospectuses under the caption "Description
     of Capital Stock" and the issued and outstanding capital stock of the
     Company, as of the Closing Time, will be  as set forth in the Prospectuses
     under the caption "Capitalization." The shares of issued and outstanding
     capital stock of the Company have been duly authorized and validly issued
     and are fully paid and non-assessable; none of the outstanding shares of
     capital stock of the Company was issued in violation of the preemptive or
     other similar rights of any securityholder of the Company.

                                       7
<PAGE>
 
               (ix)     Authorization of Agreement.  This Agreement and the
                        --------------------------                         
     International Purchase Agreement have been duly authorized, executed and
     delivered by the Company and the Operating Partnership.

               (x)      Authorization and Description of Securities. The
                        -------------------------------------------
     Securities to be purchased by the U.S. Underwriters and the International
     Managers from the Company have been duly authorized for issuance and sale
     to the U.S. Underwriters pursuant to this Agreement and the International
     Managers pursuant to the International Purchase Agreement, respectively,
     and, when issued and delivered by the Company pursuant to this Agreement
     and the International Purchase Agreement, respectively, against payment of
     the consideration set forth herein and the International Purchase
     Agreement, respectively, will be, as of the Closing Time, validly issued,
     fully paid and non-assessable; the Common Stock conforms, in all material
     respects, to all statements relating thereto contained in the Prospectuses
     and such description conforms, in all material respects, to the rights set
     forth in the instruments defining the same; no holder of the Securities
     will be subject to personal liability by reason of being such a holder; and
     the issuance of the Securities is not subject to the preemptive or other
     similar rights of any securityholder of the Company; the Company has duly
     reserved a sufficient number of shares of Common Stock for issuance upon
     exchange of outstanding OP Units in accordance with the Operating
     Partnership Agreement (as defined below).

               (xi)     Authorization of the Operating Partnership Agreement.
                        ----------------------------------------------------
     The Amended and Restated Limited Partnership Agreement of the Operating
     Partnership (the "Operating Partnership Agreement") has been duly and
     validly authorized, executed and delivered by the parties thereto.

               (xii)    Authorization and Description of OP Units.  The OP Units
                        -----------------------------------------               
     to be issued in connection with the Formation Transactions, including,
     without limitation, the OP Units to be issued to the Company, have been
     duly authorized for issuance by the Operating Partnership to the holders or
     prospective holders thereof, and at Closing Time will be validly issued,
     and fully paid and owned in the percentage amounts set forth in the
     Prospectuses by the Company and by the entities or persons described in the
     Prospectuses.  The OP Units have been and will be offered, issued and sold
     at or prior to Closing Time in compliance with all applicable laws
     (including, without limitation, federal and state securities laws).

               (xiii)   Absence of Defaults and Conflicts.  Neither the Company
                        ---------------------------------                      
     nor any of its Subsidiaries is in violation of its charter or by-laws or in
     default in the performance or observance of any obligation, agreement,
     covenant or condition contained in any contract, indenture, mortgage, deed
     of trust, loan or credit agreement, note, lease or other agreement or
     instrument to which the Company or any of its Subsidiaries is a party or by
     which it or any of them may be bound, or to which any of the property or
     assets of the Company or any Subsidiary is subject (collectively,
     "Agreements and Instruments") except for such defaults that would not
     result in a Material Adverse Effect;

                                       8
<PAGE>
 
     and the execution, delivery and performance of this Agreement and the
     International Purchase Agreement and the consummation of the transactions
     contemplated in this Agreement, the International Purchase Agreement and
     the Registration Statement (including the completion of the Formation
     Transactions, the issuance and sale of the Securities and the use of the
     proceeds from the sale of the Securities as described in the Prospectuses
     under the caption "Use of Proceeds") and compliance by the Company and the
     Operating Partnership with their obligations under this Agreement and the
     International Purchase Agreement have been duly authorized by all necessary
     corporate or partnership action, as the case may be, and (except as
     contemplated by the Prospectuses) do not and will not, whether with or
     without the giving of notice or passage of time or both, conflict with or
     constitute a breach of, or default or Repayment Event (as defined below)
     under, or result in the creation or imposition of any lien, charge or
     encumbrance upon any property or assets of the Company or any Subsidiary
     pursuant to, the Agreements and Instruments or violations of any applicable
     law, statute, rule, regulation, judgment, order, writ or decree of any
     government, government instrumentality or court, domestic or foreign,
     having jurisdiction over the Company or any Subsidiary or any of their
     assets, properties or operations (except for such conflicts, breaches or
     defaults or liens, charges, encumbrances or violations that would not
     result in a Material Adverse Effect), nor will such action result in any
     violation of the provisions of the charter or by-laws of the Company or any
     Subsidiary.   As used herein, a "Repayment Event" means any event or
     condition which gives the holder of any note, debenture or other evidence
     of indebtedness (or any person acting on such holder's behalf) the right to
     require the repurchase, redemption or repayment of all or a portion of such
     indebtedness by the Company or any Subsidiary.

               Consummation of the Formation Transactions and compliance by the
     Company, its Subsidiaries and the Property Partnerships with their
     respective obligations under each of the documents relating thereto
     (collectively, the "Formation Transaction Documents") have been duly
     authorized by all necessary corporate or partnership action of such
     entities, as the case may be, and (except as contemplated by the
     Prospectuses) did not and will not violate or conflict with or constitute a
     breach of, or default under, or result in the creation or imposition of any
     lien, charge or encumbrance upon any of the Properties (as defined in the
     Registration Statement) or any other properties or assets of the Company or
     any of the Subsidiaries pursuant to any contract, indenture, mortgage, deed
     of trust, loan or credit agreement, note, lease or other agreement or
     instrument, including without limitation, any partnership agreement, to
     which the Company, any of the Subsidiaries or any Property Partnership is
     or was a party or by which it or any of them may be bound or affected, or
     to which any of the Properties or any other properties or assets of the
     Company or any of its Subsidiaries is subject (except for such violations,
     conflicts, breaches, defaults, liens, charges or encumbrances that would
     not result in a Material Adverse Effect); none of the Formation
     Transactions resulted or will result in the violation of any provisions of
     the charter, by-laws, partnership agreements or other governing document of
     the Company, any of the Subsidiaries or any Property Partnership (except in
     each case as may have been waived

                                       9
<PAGE>
 
     by all applicable parties), or any applicable law, administrative
     regulation or administrative or court decree (except for such violations of
     any applicable law, administrative regulation or administrative or court
     decree that would not result in a Material Adverse Effect); all
     authorizations, consents and approvals necessary to consummate the
     Formation Transactions were timely obtained; and the offer, issuance and
     exchange of the OP Units and general partnership interests in the Operating
     Partnership, the issuance and sale by the Company of Common Stock prior to
     the date hereof will be exempt from the registration requirements of the
     1933 Act and applicable state securities laws.  At or prior to Closing
     Time, each of the Formation Transactions will have occurred, in all
     material respects, in the manner described in the Prospectuses.

                   (xiv)  Authorization of the Formation Transaction Documents.
                          ----------------------------------------------------  
     Each of the Formation Transaction Documents to which the Company, any of
     the Subsidiaries, any of the Property Partnerships or any affiliate of any
     such entity is a party has been duly authorized, executed and delivered by
     such party.

                   (xv)   Absence of Labor Dispute.  No material labor dispute
                          ------------------------
     with the employees of the Company or any Subsidiary exists or, to the
     knowledge of the Company, is imminent.

                   (xvi)  Absence of Proceedings.  There is no action, suit,
                          ----------------------                            
     proceeding, inquiry or investigation before or brought by any court or
     governmental agency or body, domestic or foreign, now pending, or, to the
     knowledge of the Company, threatened, against or affecting the Company or
     any Subsidiary, which is required to be disclosed in the Registration
     Statement (other than as disclosed therein), or which might reasonably be
     expected to result in a Material Adverse Effect, or which might reasonably
     be expected to materially and adversely affect the Properties or assets
     thereof or the consummation of the transactions contemplated in this
     Agreement, the International Purchase Agreement and the Formation
     Transaction Documents or the performance by the parties of their
     obligations hereunder or thereunder; the aggregate of all pending legal or
     governmental proceedings to which the Company or any Subsidiary is a party
     or of which any of their respective property or assets, including without
     limitation the Properties, is the subject which are not described in the
     Registration Statement, including ordinary routine litigation incidental to
     the business, could not reasonably be expected to result in a Material
     Adverse Effect.

                   (xvii) Qualification as a REIT.  Commencing with the taxable
                          -----------------------                              
     year ending December 31, 1997, the Company will be organized in conformity
     with the requirements for qualification as a real estate investment trust
     (a "REIT") under the Internal Revenue Code 1986, as amended (the "Code"),
     and its proposed method of operation will enable it to meet the
     requirements for taxation as a REIT under the Code.

                                       10
<PAGE>
 
               (xviii)  Accuracy of Exhibits.  There are no contracts or
                        --------------------                            
     documents which are required to be described in the Registration Statement
     or the Prospectuses or to be filed as exhibits thereto which have not been
     so described and filed as required.

                 (xix)  New York Stock Exchange Listing.  The Common Stock has
                        -------------------------------                       
     been approved for listing on the New York Stock Exchange, subject to
     official notice of issuance.

                  (xx) Absence of Further Requirements.  No filing with, or
                       -------------------------------                     
     authorization, approval, consent, license, order, registration,
     qualification or decree of, any court or governmental authority or agency
     is necessary or required for the performance by the Company and the
     Operating Partnership of their obligations hereunder, in connection with
     the offering, issuance or sale of the Securities under this Agreement and
     the International Purchase Agreement or the consummation of the
     transactions contemplated by this Agreement, the International Purchase
     Agreement and the Formation Transaction Documents, except (i) such as have
     been already obtained or as may be required under the 1933 Act or the 1933
     Act Regulations and foreign or state securities or blue sky laws, (ii) such
     as have been obtained under the laws and regulations of jurisdictions
     outside the United States in which the Reserved Securities are offered and
     (iii) state filings in connection with the Formation Transactions (which
     state filings will be made prior to or at the Closing Time).

                 (xxi) Possession of Licenses and Permits.  The Company and its
                       ----------------------------------                      
     Subsidiaries possess such permits, licenses, approvals, consents and other
     authorizations (collectively, "Governmental Licenses") issued by the
     appropriate federal, state, local or foreign regulatory agencies or bodies
     necessary to conduct the business now operated by them; the Company and its
     subsidiaries are in compliance with the terms and conditions of all such
     Governmental Licenses, except where the failure so to comply would not,
     singly or in the aggregate, have a Material Adverse Effect; all of the
     Governmental Licenses are valid and in full force and effect, except when
     the invalidity of such Governmental Licenses or the failure of such
     Governmental Licenses to be in full force and effect would not have a
     Material Adverse Effect; and neither the Company nor any of its
     Subsidiaries has received any notice of proceedings relating to the
     revocation or modification of any such Governmental Licenses which, singly
     or in the aggregate, if the subject of an unfavorable decision, ruling or
     finding, would result in a Material Adverse Effect.

                (xxii) The Properties.  (a) Upon consummation of the Formation
                       --------------                                         
     Transactions, the Operating Partnership and the Subsidiaries will have good
     and marketable title in fee simple to all of the Properties and good and
     marketable title to all other real properties owned by them, in each case,
     free and clear of all mortgages, pledges, liens, security interests,
     claims, restrictions or encumbrances of any kind except such as (i) are
     described in the Prospectuses or (ii) do not, singly or in the aggregate,
     materially affect the value of such property and do not interfere with the
     use made and

                                       11
<PAGE>
 
     proposed to be made of such property by the Company or any of its
     Subsidiaries; (b)  all mortgages, pledges, liens, security interests,
     claims, restrictions or encumbrances on or affecting the properties and
     assets (including without limitation the Properties) of the Company or any
     of the Subsidiaries that are required to be disclosed in the Prospectuses
     are disclosed therein; (c) neither the Company nor the Operating
     Partnership knows of any violation of any municipal, state or federal law,
     rule or regulation (including those pertaining to environmental matters)
     concerning the Properties or any part thereof which would, upon
     consummation of the Formation Transactions, have a Material Adverse Effect;
     (d)  each of the Properties complies with all applicable zoning laws,
     ordinances, regulations and deed restrictions or other covenants in all
     material respects and, if and to the extent there is a failure to comply,
     such failure does not result in a Material Adverse Effect and will not
     result in a forfeiture or reversion of title; (e) none of the Company, any
     Subsidiary nor any Property Partnership has received from any governmental
     authority any written notice of any condemnation of or zoning change
     affecting the Properties or any part thereof, and none of the Company, any
     Subsidiary nor any Property Partnership knows of any such condemnation or
     zoning change which is threatened and which if consummated would have a
     Material Adverse Effect; and (f) no lessee of any portion of any of the
     Properties is in default under any of the leases governing such Properties
     and there is no event which, but for the passage of time or the giving of
     notice or both, would constitute a default under any of such leases, except
     such defaults that would not have a Material Adverse Effect.

               (xxiii)  Insurance.  Upon consummation of the Formation
                        ---------                                     
     Transactions, the Company and each of the Subsidiaries will be insured by
     insurers of recognized financial responsibility against such losses and
     risks and in such amounts as are prudent and customary in the businesses in
     which they will be engaged; and neither the Company nor any of the
     Subsidiaries has any reason to believe that any of them will not be able to
     renew its existing insurance coverage as and when such coverage expires or
     to obtain similar coverage from similar insurers as may be necessary to
     continue its business.

                (xxiv)  Taxes.  The Company and each of the Subsidiaries has
                        -----                                               
     filed all material foreign, federal, state and local tax returns that are
     required to be filed or have requested extensions thereof (except in any
     case in which the failure so to file would not, upon consummation of the
     Formation Transactions, have a Material Adverse Effect) and has paid all
     taxes required to be paid by it and any other assessment, fine or penalty
     levied against it, to the extent that any of the foregoing is due and
     payable, except for any such assessment, fine or penalty that is currently
     being contested in good faith or as described in or contemplated by the
     Prospectuses.

                 (xxv)  Mortgages and Deeds of Trust.  Except as set forth in
                        ----------------------------
     the Registration Statement and the Prospectuses, the mortgages and deeds of
     trust encumbering the properties and assets described in the Prospectus are
     not convertible and neither the Company, any of its Subsidiaries, any
     Property Partnership, nor any person affiliated therewith holds a
     participating interest therein, and such mortgages and deeds

                                       12
<PAGE>
 
     of trust are not cross-defaulted or cross-collateralized to any property
     not owned directly or indirectly by the Company or any of its Subsidiaries.

               (xxvi)   Compliance with Cuba Act.  The Company has complied
                        ------------------------
     with, and is and will be in compliance with, the provisions of that certain
     Florida act relating to disclosure of doing business with Cuba, codified as
     Section 517.075 of the Florida statutes, and the rules and regulations
     thereunder (collectively, the "Cuba Act") or is exempt therefrom.

               (xxvii)  Investment Company Act.  The Company and the Operating
                        ----------------------                                
     Partnership are not, and upon the issuance and sale of the Securities as
     herein contemplated and the application of the net proceeds therefrom as
     described in the Prospectuses will not be, an "investment company" as such
     term is defined in the Investment Company Act of 1940, as amended (the
     "1940 Act").

               (xxviii) Environmental Laws.  Except as otherwise disclosed in
                        ------------------                                   
     the Prospectuses or in the Phase I Environmental Site Assessments and
     Asbestos Survey Reports previously delivered to the U.S. Representatives
     and International Managers or their counsel (the "Environmental Reports"),
     (i) the Company, its Subsidiaries and the Property Partnerships have been
     and are in compliance with applicable Environmental Statutes; (ii) neither
     the Company, any of the Subsidiaries, the Property Partnerships, nor, to
     the best knowledge of the Company, any other owners of the property at any
     time or any other party has at any time released (as such term is defined
     in Section 101(22) of CERCLA (as hereinafter defined)) or otherwise
     disposed of or dealt with, Hazardous Materials (as hereinafter defined) on,
     to or from the Properties, except for such releases as would not be
     reasonably likely to cause the Company to incur material liability that
     would require disclosure pursuant to federal or state laws regulating the
     issuance of securities; (iii) the Company does not intend to use the
     Properties or any subsequently acquired properties, other than in
     compliance with applicable Environmental Statutes (as hereinafter defined),
     (iv) neither the Company nor any of the Subsidiaries knows of any seepage,
     leak, discharge, release, emission, spill, or dumping of Hazardous
     Materials into waters (including, but not limited, to groundwater and
     surface water) on, beneath or adjacent to the Properties or onto lands from
     which Hazardous Materials might seep, flow or drain into such waters; (v)
     neither the Company nor any of the Subsidiaries has received any notice of,
     or has any knowledge of any occurrence or circumstance which, with notice
     or passage of time or both, would give rise to a claim under or pursuant to
     any Environmental Statute or common law with respect to the Properties or
     the assets described in the Prospectus or arising out of the conduct of the
     Company, its Subsidiaries, or the Property Partnerships, except for such
     claims that would not be reasonably likely to cause the Company to incur
     material liability that would require disclosure pursuant to federal or
     state laws regulating the issuance of securities; (vi) neither the
     Properties nor any other land owned by the Company or any of the
     Subsidiaries is included or, to the best of the Company's knowledge,
     proposed for inclusion on the National Priorities List issued pursuant to
     CERCLA by the United States

                                       13
<PAGE>
 
     Environmental Protection Agency (the "EPA") or to the best of the Company's
     knowledge, proposed for inclusion on any similar list or inventory issued
     pursuant to any other Environmental Statute or issued by any other
     Governmental Authority (as hereinafter defined).

                       As used herein, "Hazardous Material" shall include,
     without limitation any flammable explosives, radioactive materials,
     hazardous materials, hazardous wastes, toxic substances, or related
     materials, asbestos or any hazardous material as defined by any federal,
     state or local environmental law, ordinance, rule or regulation including,
     without limitation, the Comprehensive Environmental Response, Compensation,
     and Liability Act of 1980, as amended, 42 U.S.C. (S)(S) 9601-9675
     ("CERCLA"), the Hazardous Materials Transportation Act, as amended, 49
     U.S.C. (S)(S) 1801-1819, the Resource Conservation and Recovery Act, as
     amended, 42 U.S.C. (S)(S) 6901-K, the Emergency Planning and Community
     Right-to-Know Act of 1986, 42 U.S.C. (S)(S) 11001-11050, the Toxic
     Substances Control Act, 15 U.S.C. (S)(S) 2601-2671, the Federal
     Insecticide, Fungicide and Rodenticide Act, 7 U.S.C. (S)(S) 136-136y, the
     Clean Air Act, 42 U.S.C. (S)(S) 7401-7642, the Clean Water Act (Federal
     Water Pollution Control Act), 33 U.S.C. (S)(S) 1251-1387, the Safe Drinking
     Water Act, 42 U.S.C. (S)(S) 300f-300j-26, and the Occupational Safety and
     Health Act, 29 U.S.C. (S)(S) 651-678, as any of the above statutes may be
     amended from time to time, and in the regulations promulgated pursuant to
     each of the foregoing (including environmental statues not specifically
     defined herein) (individually, an "Environmental Statute" and collectively
     "Environmental Statutes") or by any federal, state or local governmental
     authority having or claiming jurisdiction over the properties and assets
     described in the Prospectus (a "Governmental Authority").

               (xxix)  Registration Rights.  Except as described in the
                       -------------------                             
     Registration Statement, there are no persons with registration rights or
     other similar rights to have any securities registered pursuant to the
     Registration Statement or otherwise registered by the Company under the
     1933 Act.

     (b) Officer's Certificates.  Any certificate signed by any officer of the
Company or any of its subsidiaries delivered to the Global Coordinators, the
U.S. Representatives or to counsel for the U.S. Underwriters shall be deemed a
representation and warranty solely by the Company to each U.S. Underwriter as to
the matters covered thereby.

     SECTION 2.  Sale and Delivery to U.S. Underwriters; Closing.
                 ----------------------------------------------- 

     (a) Initial Securities.  On the basis of the representations and warranties
herein contained and subject to the terms and conditions herein  set forth, the
Company agrees to sell to each U.S. Underwriter, severally and not jointly, and
each U.S. Underwriter, severally and not jointly, agrees to purchase from the
Company, at the price per share set forth in Schedule B, the number of Initial
U.S. Securities set forth in Schedule A opposite the name of such U.S.

                                       14
<PAGE>
 
Underwriter, plus any additional number of Initial U.S. Securities which such
Underwriter may become obligated to purchase pursuant to the provisions of
Section 10 hereof.

     (b) Option Securities.  In addition, on the basis of the representations
and warranties herein contained and subject to the terms and conditions herein
set forth, the Company hereby grants an option to the U.S. Underwriters,
severally and not jointly, to purchase up to an additional 3,540,000 shares of
Common Stock at the price per share set forth in Schedule B, less an amount per
share equal to any dividends or distributions declared by the Company and
payable on the Initial U.S. Securities but not payable on the U.S. Option
Securities.  The option hereby granted will expire 30 days after the date hereof
and may be exercised in whole or in part from time to time only for the purpose
of covering over-allotments which may be made in connection with the offering
and distribution of the Initial U.S. Securities upon notice by the Global
Coordinators to the Company setting forth the number of U.S. Option Securities
as to which the several U.S. Underwriters are then exercising the option and the
time and date of payment and delivery for such U.S. Option Securities.  Any such
time and date of delivery for the U.S. Option Securities (a "Date of Delivery")
shall be determined by the Global Coordinators, but shall not be earlier than
two nor later than seven full business days after the exercise of said option,
nor in any event prior to the Closing Time, as hereinafter defined.  If the
option is exercised as to all or any portion of the U.S. Option Securities, each
of the U.S. Underwriters, acting severally and not jointly, will purchase that
proportion of the total number of U.S. Option Securities then being purchased
which the number of Initial U.S. Securities set forth in Schedule A opposite the
name of such U.S. Underwriter bears to the total number of Initial U.S.
Securities, subject in each case to such adjustments as the Global Coordinators
in its discretion shall make to eliminate any sales or purchases of fractional
shares.

     (c) Payment.  Payment of the purchase price for, and delivery of
certificates for, the Initial Securities shall be made at the offices of
Goodwin, Procter & Hoar LLP, Exchange Place, Boston, Massachusetts, or at such
other place as shall be agreed upon by the Global Coordinators and the Company,
at 9:00 A.M. (Eastern time) on the third (fourth, if the pricing occurs after
4:30 P.M. (Eastern time) on any given day) business day after the date hereof
(unless postponed in accordance with the provisions of Section 10), or such
other time not later than ten business days after such date as shall be agreed
upon by the Global Coordinators and the Company (such time and date of payment
and delivery being herein called "Closing Time").

     In addition, in the event that any or all of the U.S. Option Securities are
purchased by the U.S. Underwriters, payment of the purchase price for, and
delivery of certificates for, such U.S. Option Securities shall be made at the
above-mentioned offices, or at such other place as shall be agreed upon by the
Global Coordinators and the Company, on each Date of Delivery as specified in
the notice from the Global Coordinators to the Company.

     Payment shall be made to the Company by wire transfer of immediately
available funds to a bank account designated by the Company, against delivery to
the U.S. Representatives for the respective accounts of the U.S. Underwriters of
certificates for the U.S. Securities to be purchased by them.  It is understood
that each U.S. Underwriter has authorized the U.S.

                                       15
<PAGE>
 
Representatives, for its account, to accept delivery of, receipt for, and make
payment of the purchase price for, the Initial U.S. Securities and the U.S.
Option Securities, if any, which it has agreed to purchase.  Merrill Lynch,
individually and not as representative of the U.S. Underwriters, may (but shall
not be obligated to) make payment of the purchase price for the Initial U.S.
Securities or the U.S. Option Securities, if any, to be purchased by any U.S.
Underwriter whose funds have not been received by the Closing Time or the
relevant Date of Delivery, as the case may be, but such payment shall not
relieve such U.S. Underwriter from its obligations hereunder.

     (d)   Denominations; Registration.  Certificates for the Initial U.S.
Securities and the U.S. Option Securities, if any, shall be in such
denominations and registered in such names as the U.S. Representatives may
request in writing at least two full business day before the Closing Time or the
relevant Date of Delivery, as the case may be.  The certificates for the Initial
U.S. Securities and the U.S. Option Securities, if any, will be made available
for examination and packaging by the U.S. Representative(s) in The City of New
York not later than 10:00 A.M. (Eastern time) on the business day prior to the
Closing Time or the relevant Date of Delivery, as the case may be.

     SECTION 3.  Covenants of the Company.  Each of the Company and the
                 ------------------------                              
Operating Partnership covenants with each U.S. Underwriter as follows:

                 (a)   Compliance with Securities Regulations and Commission
     Requests.  The Company, subject to Section 3(b), will comply with the
     requirements of Rule 430A or Rule 434, as applicable, and will notify the
     Global Coordinators promptly, and confirm the notice in writing, (i) when
     any post-effective amendment to the Registration Statement shall become
     effective, or any supplement to the Prospectuses or any amended
     Prospectuses shall have been filed, (ii) of the receipt of any comments
     from the Commission, (iii) of any request by the Commission for any
     amendment to the Registration Statement or any amendment or supplement to
     the Prospectuses or for additional information, and (iv) of the issuance by
     the Commission of any stop order suspending the effectiveness of the
     Registration Statement or of any order preventing or suspending the use of
     any preliminary prospectus, or of the suspension of the qualification of
     the Securities for offering or sale in any jurisdiction, or of the
     initiation or threatening of any proceedings for any of such purposes.  The
     Company will promptly effect the filings necessary pursuant to Rule 424(b)
     and will take such steps as it deems necessary to ascertain promptly
     whether the form of prospectus transmitted for filing under Rule 424(b) was
     received for filing by the Commission and, in the event that it was not, it
     will promptly file such prospectus.  The Company will make every reasonable
     effort to prevent the issuance of any stop order and, if any stop order is
     issued, to obtain the lifting thereof at the earliest possible moment.

                 (b)   Filing of Amendments.  The Company will give the Global
     Coordinators notice of its intention to file or prepare any amendment to
     the Registration Statement (including any filing under Rule 462(b)), any
     Term Sheet or any amendment,

                                       16
<PAGE>
 
     supplement or revision to either the prospectus included in the
     Registration Statement at the time it became effective or to the
     Prospectuses, will furnish the Global Coordinators with copies of any such
     documents a reasonable amount of time prior to such proposed filing or use,
     as the case may be, and will not file or use any such document to which the
     Global Coordinators or counsel for the U.S. Underwriters shall reasonably
     object.

                 (c)   Delivery of Registration Statements.  The Company has
     furnished or, upon request, will deliver to the U.S. Representatives and
     counsel for the U.S. Underwriters, without charge, signed copies of the
     Registration Statement as originally filed and of each amendment thereto
     (including exhibits filed therewith or incorporated by reference therein)
     and signed copies of all consents and certificates of experts, and will
     also deliver to the U.S. Representatives, without charge, a conformed copy
     of the Registration Statement as originally filed and of each amendment
     thereto (without exhibits) for each of the U.S. Underwriters.  The copies
     of the Registration Statement and each amendment thereto furnished to the
     U.S. Underwriters will be identical to the electronically transmitted
     copies thereof filed with the Commission pursuant to EDGAR, except to the
     extent permitted or required by Regulation S-T.

                 (d)   Delivery of Prospectuses. The Company has delivered to
     each U.S. Underwriter, without charge, as many copies of each preliminary
     prospectus as such U.S. Underwriter reasonably requested, and the Company
     hereby consents to the use of such copies for purposes permitted by the
     1933 Act in connection with the offering of the Securities. The Company
     will furnish to each U.S. Underwriter, without charge, during the period
     when the U.S. Prospectus is required to be delivered under the 1933 Act or
     the Securities Exchange Act of 1934 (the "1934 Act"), such number of copies
     of the U.S. Prospectus (as amended or supplemented) as such U.S.
     Underwriter may reasonably request. The U.S. Prospectus and any amendments
     or supplements thereto furnished to the U.S. Underwriters will be identical
     to the electronically transmitted copies thereof filed with the Commission
     pursuant to EDGAR, except to the extent permitted or required by Regulation
     S-T.

                 (e)   Continued Compliance with Securities Laws. The Company
     will comply with the 1933 Act and the 1933 Act Regulations so as to permit
     the completion of the distribution of the Securities as contemplated in
     this Agreement, the International Purchase Agreement and in the
     Prospectuses. If at any time when a prospectus is required by the 1933 Act
     to be delivered in connection with sales of the Securities, any event shall
     occur or condition shall exist as a result of which it is necessary, in the
     reasonable opinion of counsel for the U.S. Underwriters or for the Company,
     to amend the Registration Statement or amend or supplement any Prospectus
     in order that the Prospectuses will not include any untrue statements of a
     material fact or omit to state a material fact necessary in order to make
     the statements therein not misleading in the light of the circumstances
     existing at the time it is delivered to a purchaser, or if it shall be
     necessary, in the reasonable opinion of such counsel, at any such time to
     amend the Registration Statement or amend or supplement any Prospectus in
     order to comply with

                                       17
<PAGE>
 
     the requirements of the 1933 Act or the 1933 Act Regulations, the Company
     will promptly prepare and file with the Commission, subject to Section
     3(b), such amendment or supplement as may be necessary to correct such
     statement or omission or to make the Registration Statement or the
     Prospectuses comply with such requirements, and the Company will furnish to
     the U.S. Underwriters such number of copies of such amendment or supplement
     as the U.S. Underwriters may reasonably request.

                 (f)   Blue Sky Qualifications.  The Company will use its best
     efforts, in cooperation with the U.S. Underwriters, to qualify, if
     necessary, the Securities for offering and sale under the applicable
     securities laws of such states and other jurisdictions (domestic or
     foreign) as the Global Coordinators may designate and to maintain such
     qualifications in effect for a period of not more than one year from the
     later of the effective date of the Registration Statement and any Rule
     462(b) Registration Statement; provided, however, that the Company shall
     not be obligated to file any general consent to service of process or to
     qualify as a foreign corporation or as a dealer in securities in any
     jurisdiction in which it is not so qualified or to subject itself to
     taxation in respect of doing business in any jurisdiction in which it is
     not otherwise so subject.  In each jurisdiction in which the Securities
     have been so qualified, the Company will file such statements and reports
     as may be required by the laws of such jurisdiction to continue such
     qualification in effect for a period of not more than one year from the
     effective date of the Registration Statement and any Rule 462(b)
     Registration Statement.

                 (g)   Rule 158. The Company will timely file such reports
     pursuant to the 1934 Act as are necessary in order to make generally
     available to its securityholders as soon as practicable an earnings
     statement for the purposes of, and to provide the benefits contemplated by,
     the last paragraph of Section 11(a) of the 1933 Act.

                 (h)   Use of Proceeds. The Company will use the net proceeds
     received by it from the sale of the Securities in the manner specified in
     the Prospectuses under "Use of Proceeds".

                 (i)   Listing. The Company will use its best efforts to effect
     the listing of the Common Stock (including the Securities) on the New York
     Stock Exchange.

                 (j)   Restriction on Sale of Securities. During a period of one
     year from the date of the Prospectuses, the Company and the Operating
     Partnership will not, without the prior written consent of the Global
     Coordinators, (i) directly or indirectly, offer, pledge, sell, contract to
     sell, sell any option or contract to purchase, purchase any option or
     contract to sell, grant any option, right or warrant to purchase or
     otherwise transfer or dispose of any share of Common Stock or OP Units, or
     any securities convertible into or exercisable or exchangeable for Common
     Stock or OP Units, or file any registration statement under the 1933 Act
     with respect to any of the foregoing or (ii) enter into any swap or any
     other agreement or any transaction that transfers, in whole or in part,
     directly or indirectly, the economic consequence of ownership of the Common

                                       18
<PAGE>
 
     Stock, whether any such swap or transaction described in clause (i) or (ii)
     above is to be settled by delivery of Common Stock or such other
     securities, in cash or otherwise.  The foregoing sentence shall not apply
     to (A) the Securities to be sold hereunder or under the International
     Purchase Agreement or (B) any shares of Common Stock issued or options to
     purchase Common Stock granted pursuant to existing employee benefit plans
     of the Company referred to in the Prospectuses or any employee benefit
     plans of the Company which have been approved by the requisite vote of the
     stockholders of the Company at a duly called meeting of stockholders.

                 (k)   Lock-up Agreements. The Company will use its best efforts
     to cause each holder of Common Stock or OP Units issued in connection with
     the Formation Transactions to enter into a written agreement, in form and
     substance satisfactory to Merrill Lynch and Goldman, Sachs, on behalf of
     the Underwriters, to the effect set forth in Exhibit A hereto.

                 (l)   Qualification as a REIT.  The Company will use its best
     efforts to meet the requirements to qualify, for the taxable year ending
     December 31, 1997, as a REIT under the Code.

                 (m)   Compliance with NASD Rules. The Company hereby agrees
     that it will ensure that the Reserved Securities will be restricted as
     required by the National Association of Securities Dealers, Inc. (the
     "NASD") or the NASD rules from sale, transfer, assignment, pledge or
     hypothecation for a period of three months following the date of this
     Agreement. The Underwriters will notify the Company as to which persons
     will need to be so restricted. At the request of the Underwriters, the
     Company will direct the transfer agent to place a stop transfer restriction
     upon such securities for such period of time. Should the Company release,
     or seek to release, from such restrictions any of the Reserved Securities,
     the Company agrees to reimburse the Underwriters for any reasonable
     expenses (including, without limitation, legal expenses) they incur in
     connection with such release.

                 (n)   Compliance with Rule 463.  The Company will file with the
     Commission such reports on Form SR as may be required pursuant to Rule 463
     of the 1933 Act Regulations.

     SECTION 4.  Payment of Expenses.  (a)  Expenses.  The Company will pay all
                 -------------------                                           
expenses incident to the performance of its obligations under this Agreement,
including (i) the preparation, printing and filing of the Registration Statement
(including financial statements and exhibits) as originally filed and of each
amendment thereto, (ii) the preparation, printing and delivery to the
Underwriters of this Agreement, any Agreement among Underwriters and such other
documents as may be required in connection with the offering, purchase, sale,
issuance or delivery of the Securities, (iii) the preparation, issuance and
delivery of the certificates for the Securities to the Underwriters, including
any stock or other transfer taxes and any stamp or other duties payable upon the
sale, issuance or delivery of the Securities to the Underwriters and the
transfer of the

                                       19
<PAGE>
 
Securities between the U.S. Underwriters and the International Managers, (iv)
the fees and disbursements of the Company's counsel, accountants and other
advisors, (v) the qualification or registration (or exemption therefrom) of the
Securities under securities laws in accordance with the provisions of Section
3(f) hereof, including filing fees and the reasonable fees and disbursements of
counsel for the Underwriters in connection therewith and in connection with the
preparation of the Blue Sky Survey and any supplement thereto, (vi) the printing
and delivery to the Underwriters of copies of each preliminary prospectus, any
Term Sheets and of the Prospectuses and any amendments or supplements thereto,
(vii) the preparation, printing and delivery to the Underwriters of copies of
the Blue Sky Survey and any supplement thereto, (viii) the fees and expenses of
any transfer agent or registrar for the Securities and (ix) the filing fees
incident to, and the reasonable fees and disbursements of counsel to the
Underwriters in connection with, the review by the NASD of the terms of the sale
of the Securities, (x) the fees and expenses incurred in connection with the
listing of the Securities on the New York Stock Exchange and (xi) all costs and
expenses of the Underwriters, including the fees and disbursements of counsel
for the Underwriters, in connection with matters related to the Reserved
Securities which are designated by the Company for sale to employees and others
having a business relationship with the Company.

     (b)   Termination of Agreement. If this Agreement is terminated by the U.S.
Representatives in accordance with the provisions of Section 5 or Section
9(a)(i) hereof, the Company shall reimburse the U.S. Underwriters for all of
their out-of-pocket expenses, including the reasonable fees and disbursements of
counsel for the U.S. Underwriters.

     SECTION 5.  Conditions of U.S. Underwriters' Obligations.  The obligations
                 --------------------------------------------                  
of the several U.S. Underwriters hereunder are subject to the accuracy of the
representations and warranties of the Company contained in Section 1 hereof or
in certificates of any officer of the Company or any subsidiary of the Company
delivered pursuant to the provisions hereof, to the performance by the Company
of its covenants and other obligations hereunder, and to the following further
conditions:

                 (a)   Effectiveness of Registration Statement. The Registration
     Statement, including any Rule 462(b) Registration Statement, has become
     effective and at the Closing Time no stop order suspending the
     effectiveness of the Registration Statement shall have been issued under
     the 1933 Act or proceedings therefor initiated or threatened by the
     Commission, and any request on the part of the Commission for additional
     information shall have been complied with to the reasonable satisfaction of
     counsel to the U.S. Underwriters. A prospectus containing the Rule 430A
     Information shall have been filed with the Commission in accordance with
     Rule 424(b) (or a post-effective amendment providing such information shall
     have been filed and declared effective in accordance with the requirements
     of Rule 430A) or, if the Company has elected to rely upon Rule 434, a Term
     Sheet shall have been filed with the Commission in accordance with Rule
     424(b).

                                       20
<PAGE>
 
                 (b)   Opinion of Counsel for Company. At Closing Time, the U.S.
     Representatives shall have received the favorable opinion, dated as of
     Closing Time, of Goodwin, Procter & Hoar LLP, counsel for the Company and
     the Operating Partnership, in form and substance satisfactory to counsel
     for the U.S. Underwriters, together with signed or reproduced copies of
     such letter for each of the other U.S. Underwriters to the effect set forth
     in Exhibit B hereto and to such further effect as counsel to the U.S.
     Underwriters may reasonably request.

           (c)   Opinion of General Counsel of Company. At Closing Time, the
U.S. Representatives shall have received the favorable opinion, dated as of
Closing Time, of Frederick J. DeAngelis, General Counsel of the Company, in form
and substance satisfactory to counsel for the U.S. Underwriters, together with
signed or reproduced copies of such letter for each of the other U.S.
Underwriters to the effect set forth in Exhibit C hereto and to such further
effect as counsel to the U.S. Underwriters may reasonably request.

           (d)   Opinion of Counsel for U.S. Underwriters.  At Closing Time, the
U.S. Representatives shall have received the favorable opinion, dated as of
Closing Time, of Skadden, Arps, Slate, Meagher & Flom LLP, counsel for the U.S.
Underwriters, together with signed or reproduced copies of such letter for each
of the other U.S. Underwriters with respect to the matters set forth in clauses
(i), (x), (xi), (solely as to preemptive or other similar rights arising by
operation of law or under the charter or by-laws of the Company), (xiv) through
(xvi), inclusive, and the penultimate paragraph of Exhibit B hereto.

           In giving the opinions described in paragraphs (b), (c) and (d)
above, each counsel may rely, as to all matters governed by the laws of
jurisdictions other than the law of the State of New York, the Commonwealth of
Massachusetts, the federal law of the United States and the General Corporation
Law of the State of Delaware, upon the opinions of counsel satisfactory to the
U.S. Representatives. Such counsel may also state that, insofar as such opinion
involves factual matters, they have relied, to the extent they deem proper, upon
certificates of officers of the Company and its Subsidiaries and certificates of
public officials.

                 (e)   Officers' Certificate. At Closing Time, there shall not
     have been, since the date hereof or since the respective dates as of which
     information is given in the Prospectuses, any material adverse change in
     the condition, financial or otherwise, or in the earnings, business affairs
     or business prospects of the Company, the Operating Partnership and the
     Subsidiaries considered as one enterprise, whether or not arising in the
     ordinary course of business, and the U.S. Representatives shall have
     received a certificate of the President or a Vice President of the Company
     and of the chief financial or chief accounting officer of the Company and
     appropriate officers of the Company, as General Partner, on behalf of the
     Operating Partnership, dated as of Closing Time, to the effect that (i)
     there has been no such material adverse change, (ii) the representations
     and warranties in Section 1(a) hereof are true and correct in all material
     respects with the same force and effect as though expressly made at and as
     of Closing Time, (iii) the Company has complied in all material respects
     with all agreements and satisfied all

                                       21
<PAGE>
 
     conditions on its part to be performed or satisfied at or prior to Closing
     Time, and (iv) no stop order suspending the effectiveness of the
     Registration Statement has been issued and no proceedings for that purpose
     have been instituted or are pending or are contemplated by the Commission.

                 (f)   Accountant's Comfort Letter. At the time of the execution
     of this Agreement, the U.S. Representatives shall have received from
     Coopers & Lybrand L.L.P. a letter dated such date, in form and substance
     satisfactory to the U.S. Representatives, together with signed or
     reproduced copies of such letter for each of the other U.S. Underwriters
     containing statements and information of the type ordinarily included in
     accountants' "comfort letters" to underwriters with respect to the
     financial statements and certain financial information contained in the
     Registration Statement and the Prospectuses.

                 (g)   Bring-down Comfort Letter. At Closing Time, the U.S.
     Representatives shall have received from Coopers & Lybrand L.L.P. a letter,
     dated as of Closing Time, to the effect that they reaffirm the statements
     made in the letter furnished pursuant to subsection (f) of this Section,
     except that the specified date referred to shall be a date not more than
     three business days prior to Closing Time.

                 (h)   Approval of Listing. At Closing Time, the Securities
     shall have been approved for listing on the New York Stock Exchange,
     subject only to official notice of issuance.

                 (i)   No Objection. The NASD has confirmed that it has not
     raised any objection with respect to the fairness and reasonableness of the
     underwriting terms and arrangements.

                 (j)   Lock-up Agreements. At the date of this Agreement, the
     U.S. Representatives shall have received the agreements described in
     Section 3(k) hereof.

                 (k)   Purchase of Initial International Securities.
     Contemporaneously with the purchase by the U.S. Underwriters of the Initial
     U.S. Securities under this Agreement, the International Managers shall have
     purchased the Initial International Securities under the International
     Purchase Agreement.

                 (l)   Conditions to Purchase of U.S. Option Securities.  In the
     event that the U.S. Underwriters exercise their option provided in Section
     2(b) hereof to purchase all or any portion of the U.S. Option Securities,
     the representations and warranties of the Company contained herein and the
     statements in any certificates furnished by the Company or any subsidiary
     of the Company hereunder shall be true and correct as of each Date of
     Delivery and, at the relevant Date of Delivery, the U.S. Representatives
     shall have received:

                                       22
<PAGE>
 
          (i)    Officers' Certificate.  A certificate, dated such Date of
                 ---------------------                                    
          Delivery, of the President or a Vice President of the Company and of
          the chief financial or chief accounting officer of the Company
          confirming that the certificate delivered at the Closing Time pursuant
          to Section 5(e) hereof remains true and correct as of such Date of
          Delivery.

          (ii)   Opinion of Counsel for Company.  The favorable opinion of
                 ------------------------------                           
          Goodwin, Proctor & Hoar LLP, counsel for the Company and the Operating
          Partnership, in form and substance satisfactory to counsel for the
          U.S. Underwriters, dated such Date of Delivery, relating to the U.S.
          Option Securities to be purchased on such Date of Delivery and
          otherwise to the same effect as the opinion required by Section 5(b)
          hereof.

          (iii)  Opinion of General Counsel of Company.  The favorable opinion
                 -------------------------------------                        
          of Frederick J. DeAngelis, General Counsel of the Company, in form and
          substance satisfactory to counsel for the U.S. Underwriters, dated
          such Date of Delivery, relating to the U.S. Option Securities to be
          purchased on such Date of Delivery and otherwise to the same effect as
          the opinion required by Section 5(c) hereof.

          (iv)   Opinion of Counsel for U.S. Underwriters.  The favorable 
                 ----------------------------------------   
          opinion of Skadden, Arps, Slate, Meagher & Flom LLP, counsel for the
          U.S. Underwriters, dated such Date of Delivery, relating to the U.S.
          Option Securities to be purchased on such Date of Delivery and
          otherwise to the same effect as the opinion required by Section 5(d)
          hereof.

          (v)    Bring-down Comfort Letter.  A letter from Coopers & Lybrand
                 -------------------------                                  
          L.L.P., in form and substance satisfactory to the U.S. Representatives
          and dated such Date of Delivery, substantially in the same form and
          substance as the letter furnished to the U.S. Representatives pursuant
          to Section 5(g) hereof, except that the "specified date" in the letter
          furnished pursuant to this paragraph shall be a date not more than
          five days prior to such Date of Delivery.

                 (m)   Additional Documents. At Closing Time and at each Date of
     Delivery, counsel for the U.S. Underwriters shall have been furnished with
     such documents and opinions as they may reasonably require for the purpose
     of enabling them to pass upon the issuance and sale of the Securities as
     herein contemplated, or in order to evidence the accuracy of any of the
     representations or warranties, or the fulfillment of any of the conditions,
     herein contained; and all proceedings taken by the Company in connection
     with the issuance and sale of the Securities as herein contemplated shall
     be reasonably satisfactory in form and substance to the U.S.
     Representatives and counsel for the U.S. Underwriters.

                 (n)   Termination of Agreement. If any condition specified in
     this Section shall not have been fulfilled when and as required to be
     fulfilled, this Agreement,

                                       23
<PAGE>
 
     or, in the case of any condition to the purchase of U.S. Option Securities
     on a Date of Delivery which is after the Closing Time, the obligations of
     the several U.S. Underwriters to purchase the relevant Option Securities,
     may be terminated by the U.S. Representatives by notice to the Company at
     any time at or prior to Closing Time or such Date of Delivery, as the case
     may be, and such termination shall be without liability of any party to any
     other party except as provided in Section 4 and except that Sections 1, 6,
     7 and 8 shall survive any such termination and remain in full force and
     effect.

     SECTION 6.  Indemnification.
                 --------------- 

     (a)   Indemnification of U.S. Underwriters.  The Company and the Operating
Partnership jointly agree to indemnify and hold harmless each U.S. Underwriter
and each person, if any, who controls any U.S. Underwriter within the meaning of
Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows:

                 (i)   against any and all loss, liability, claim, damage and
     expense whatsoever, as incurred, arising out of any untrue statement or
     alleged untrue statement of a material fact contained in the Registration
     Statement (or any amendment thereto), including the Rule 430A Information
     and the Rule 434 Information, if applicable, or the omission or alleged
     omission therefrom of a material fact required to be stated therein or
     necessary to make the statements therein not misleading or arising out of
     any untrue statement or alleged untrue statement of a material fact
     included in any preliminary prospectus or the Prospectuses (or any
     amendment or supplement thereto), or the omission or alleged omission
     therefrom of a material fact necessary in order to make the statements
     therein, in the light of the circumstances under which they were made, not
     misleading;

                 (ii)  against any and all loss, liability, claim, damage and
     expense whatsoever, as incurred, arising out of (A) the violation of any
     applicable laws or regulations of foreign jurisdictions where Reserved
     Securities have been offered and (B) any untrue statement or alleged untrue
     statement of a material fact included in the supplement or prospectus
     wrapper material distributed in [Canada] in connection with the reservation
     and sale of the Reserved Securities to eligible employees and persons
     having business relationships with the Company or the omission or alleged
     omission therefrom of a material fact necessary to make the statements
     therein, when considered in conjunction with the Prospectuses or
     preliminary prospectuses, not misleading;

                 (iii) against any and all loss, liability, claim, damage and
     expense whatsoever, as incurred, to the extent of the aggregate amount paid
     in settlement of any litigation, or any investigation or proceeding by any
     governmental agency or body, commenced or threatened, or of any claim
     whatsoever based upon any such untrue statement or omission, or any such
     alleged untrue statement or omission or in connection with any violation of
     the nature referred to in Section 6(a)(ii)(A) hereof; provided that

                                       24
<PAGE>
 
     (subject to Section 6(d) below) any such settlement is effected with the
     written consent of the Company; and

                 (iv)  against any and all expense whatsoever, as incurred
     (including the fees and disbursements of counsel chosen by Merrill Lynch
     and Goldman, Sachs), reasonably incurred in investigating, preparing or
     defending against any litigation, or any investigation or proceeding by any
     governmental agency or body, commenced or threatened, or any claim
     whatsoever based upon any such untrue statement or omission, or any such
     alleged untrue statement or omission or in connection with any violation of
     the nature referred to in Section 6(a)(ii)(A) hereof, to the extent that
     any such expense is not paid under (i), (ii) or (iii) above;

provided, however, that this indemnity agreement shall not apply to any loss,
- --------  -------                                                            
liability, claim, damage or expense to the extent arising out of (A) any untrue
statement or omission or alleged untrue statement or omission made in reliance
upon and in conformity with written information furnished to the Company and the
Operating Partnership by any U.S. Underwriter through the U.S. Representatives
expressly for use in the Registration Statement (or any amendment thereto),
including the Rule 430A Information and the Rule 434 Information, if applicable,
or any preliminary prospectus or the U.S. Prospectus (or any amendment or
supplement thereto) or (B) the fact that such U.S. Underwriter sold Securities
to a person as to whom it shall be established that there was not sent or given,
at or prior to the written confirmation of such sale, a copy of the U.S.
Prospectus or of the U.S. Prospectus as then amended or supplemented in any case
where such delivery is required by the 1933 Act if the Company has previously
furnished copies thereof in sufficient quantity to such U.S. Underwriter and the
loss, claim, damage or liability of such U.S. Underwriter results from an untrue
statement or omission of a material fact contained in any preliminary prospectus
or U.S. Prospectus (or any amendment or supplement thereto), which was corrected
in the U.S. Prospectus or in the U.S. Prospectus as then amended or supplemented
and delivery would have cured the defect giving rise to such loss, claim, damage
or liability.

     (b)   Indemnification of Company, Directors and Officers.  Each U.S.
Underwriter severally agrees to indemnify and hold harmless the Company, its
directors, each of its officers who signed the Registration Statement, and each
person, if any, who controls the Company within the meaning of Section 15 of the
1933 Act or Section 20 of the 1934 Act against any and all loss, liability,
claim, damage and expense described in the indemnity contained in subsection (a)
of this Section, as incurred, but only with respect to untrue statements or
omissions, or alleged untrue statements or omissions, made in the Registration
Statement (or any amendment thereto), including the Rule 430A Information and
the Rule 434 Information, if applicable, or any preliminary U.S. prospectus or
the U.S. Prospectus (or any amendment or supplement thereto) in reliance upon
and in conformity with written information furnished to the Company by such U.S.
Underwriter through the U.S. Representatives expressly for use in the
Registration Statement (or any amendment thereto) or such preliminary prospectus
or the U.S. Prospectus (or any amendment or supplement thereto).  The Company
and the Operating Partnership acknowledge that the statements set forth in the
last paragraph of the cover page and

                                       25
<PAGE>
 
in the second, fifth and twelfth through fifteenth paragraphs under the caption
"Underwriting" in the Prospectus constitute the only information furnished in
writing by or on behalf of any Underwriter expressly for use in the Registration
Statement relating to the Securities as originally filed or in any amendment
thereof, an related preliminary prospectus or the Prospectuses or in any
amendment thereof or supplement thereto, as the case may be.

     (c)   Actions against Parties; Notification.  Each indemnified party shall
give notice as promptly as reasonably practicable to each indemnifying party of
any action commenced against it in respect of which indemnity may be sought
hereunder, but failure to so notify an indemnifying party shall not relieve such
indemnifying party from any liability hereunder to the extent it is not
materially prejudiced as a result thereof and in any event shall not relieve it
from any liability which it may have otherwise than on account of this indemnity
agreement.  In the case of parties indemnified pursuant to Section 6(a) above,
counsel to the indemnified parties shall be selected by Merrill Lynch and
Goldman, Sachs, and, in the case of parties indemnified pursuant to Section 6(b)
above, counsel to the indemnified parties shall be selected by the Company.  An
indemnifying party may participate at its own expense in the defense of any such
action; provided, however, that counsel to the indemnifying party shall not
(except with the consent of the indemnified party) also be counsel to the
indemnified party.  Notwithstanding the foregoing, if it so elects within a
reasonable time after receipt of such notice, an indemnifying party, jointly
with any other indemnifying parties receiving such notice, may assume the
defense of such action with counsel chosen by it and approved by the indemnified
parties defendant in such action (which approval shall not be unreasonably
withheld), unless such indemnified parties reasonably object to such assumption
on the ground that there may be legal defenses available to them which are
different from or in addition to those available to such indemnifying party.  If
an indemnifying party assumes the defense of such action, the indemnifying party
shall not be liable for any fees and expenses of counsel for the indemnified
parties incurred thereafter in connection with such action, except the
indemnifying party shall be liable for the reasonable costs of investigation
subsequently incurred by the indemnified party in connection with the defense.
In no event shall the indemnifying parties be liable for fees and expenses of
more than one counsel (in addition to any local counsel) separate from their own
counsel for all indemnified parties in connection with any one action or
separate but similar or related actions in the same jurisdiction arising out of
the same general allegations or circumstances.  No indemnifying party shall,
without the prior written consent of the indemnified parties, which consent
shall not be unreasonably withheld, settle or compromise or consent to the entry
of any judgment with respect to any litigation, or any investigation or
proceeding by any governmental agency or body, commenced or threatened, or any
claim whatsoever in respect of which indemnification or contribution could be
sought under this Section 6 or Section 7 hereof (whether or not the indemnified
parties are actual or potential parties thereto), unless such settlement,
compromise or consent (i) includes an unconditional release of each indemnified
party from all liability arising out of such litigation, investigation,
proceeding or claim and (ii) does not include a statement as to or an admission
of fault, culpability or a failure to act by or on behalf of any indemnified
party.

                                       26
<PAGE>
 
     (d)   Settlement without Consent if Failure to Reimburse. If at any time an
indemnified party shall have requested an indemnifying party to reimburse the
indemnified party for fees and expenses of counsel, such indemnifying party
agrees that it shall be liable for any settlement of the nature contemplated by
Section 6(a)(i)(iii) effected without its written consent if (i) such settlement
is entered into more than 45 days after receipt by such indemnifying party of
the aforesaid request, (ii) such indemnifying party shall have received notice
of the terms of such settlement at least 30 days prior to such settlement being
entered into and (iii) such indemnifying party shall not have reimbursed such
indemnified party in accordance with such request prior to the date of such
settlement.

     (e)   Indemnification for Reserved Securities. In connection with the offer
and sale of the Reserved Securities, the Company agrees, promptly upon a request
in writing, to indemnify and hold harmless the Underwriters from and against any
and all losses, liabilities, claims, damages and expenses incurred by them as a
result of the failure of eligible employees and persons having business
relationships with the Company to pay for and accept delivery of Reserved
Securities which, by the end of the first business day following the date of
this Agreement, were subject to a properly confirmed agreement to purchase.

     SECTION 7.  Contribution.  If the indemnification provided for in Section 6
                 ------------                                                   
hereof is for any reason unavailable to or insufficient to hold harmless an
indemnified party in respect of any losses, liabilities, claims, damages or
expenses referred to therein, then each indemnifying party shall contribute to
the aggregate amount of such losses, liabilities, claims, damages and expenses
incurred by such indemnified party, as incurred, (i) in such proportion as is
appropriate to reflect the relative benefits received by the Company and the
Operating Partnership on the one hand and the U.S. Underwriters on the other
hand from the offering of the Securities pursuant to this Agreement or (ii) if
the allocation provided by clause (i) is not permitted by applicable law, in
such proportion as is appropriate to reflect not only the relative benefits
referred to in clause (i) above but also the relative fault of the Company and
the Operating Partnership on the one hand and of the U.S. Underwriters on the
other hand in connection with the statements or omissions, or in connection with
any violation of the nature referred to in Section 6(a)(ii)(A) hereof, which
resulted in such losses, liabilities, claims, damages or expenses, as well as
any other relevant equitable considerations.

     The relative benefits received by the Company and the Operating Partnership
on the one hand and the U.S. Underwriters on the other hand in connection with
the offering of the U.S. Securities pursuant to this Agreement shall be deemed
to be in the same respective proportions as the total net proceeds from the
offering of the U.S. Securities pursuant to this Agreement (before deducting
expenses) received by the Company and the total underwriting discount received
by the U.S. Underwriters, in each case as set forth on the cover of the U.S.
Prospectus, or, if Rule 434 is used, the corresponding location on the Term
Sheet, bear to the aggregate initial public offering price of the U.S.
Securities as set forth on such cover.

     The relative fault of the Company and the Operating Partnership on the one
hand and the U.S. Underwriters on the other hand shall be determined by
reference to, among other things,

                                       27
<PAGE>
 
whether any such untrue or alleged untrue statement of a material fact or
omission or alleged omission to state a material fact relates to information
supplied by the Company, the Operating Partnership or by the U.S. Underwriters
and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission or any violation of
the nature referred to in Section 6(a)(ii)(A) hereof.

     The Company, the Operating Partnership and the U.S. Underwriters agree that
it would not be just and equitable if contribution pursuant to this Section 7
were determined by pro rata allocation (even if the U.S. Underwriters were
treated as one entity for such purpose) or by any other method of allocation
which does not take account of the equitable considerations referred to above in
this Section 7.  The aggregate amount of losses, liabilities, claims, damages
and expenses incurred by an indemnified party and referred to above in this
Section 7 shall be deemed to include any legal or other expenses reasonably
incurred by such indemnified party in investigating, preparing or defending
against any litigation, or any investigation or proceeding by any governmental
agency or body, commenced or threatened, or any claim whatsoever based upon any
such untrue or alleged untrue statement or omission or alleged omission.

     Notwithstanding the provisions of this Section 7, no U.S. Underwriter shall
be required to contribute any amount in excess of the amount by which the total
price at which the U.S. Securities underwritten by it and distributed to the
public were offered to the public exceeds the amount of any damages which such
U.S. Underwriter has otherwise been required to pay by reason of any such untrue
or alleged untrue statement or omission or alleged omission.

     No person guilty of fraudulent misrepresentation (within the meaning of
Section 11(f) of the 1933 Act) shall be entitled to contribution from any person
who was not guilty of such fraudulent misrepresentation.

     For purposes of this Section 7, each person, if any, who controls a U.S.
Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of
the 1934 Act shall have the same rights to contribution as such U.S.
Underwriter, and each director of the Company, each officer of the Company who
signed the Registration Statement, and each person, if any, who controls the
Company within the meaning of Section 15 of the 1933 Act or Section 20 of the
1934 Act shall have the same rights to contribution as the Company.  The U.S.
Underwriters' respective obligations to contribute pursuant to this Section 7
are several in proportion to the number of Initial U.S. Securities set forth
opposite their respective names in Schedule A hereto and not joint.

     SECTION 8.  Representations, Warranties and Agreements to Survive Delivery.
                 -------------------------------------------------------------- 
All representations, warranties and agreements contained in this Agreement or in
certificates of officers of the Company, the Operating Partnership or any of the
Subsidiaries submitted pursuant hereto, shall remain operative and in full force
and effect, regardless of any investigation made by or on behalf of any U.S.
Underwriter or controlling person, or by or on behalf of the Company, and shall
survive delivery of the Securities to the U.S. Underwriters.

                                       28
<PAGE>
 
     SECTION 9.  Termination of Agreement.
                 ------------------------ 

     (a)   Termination; General.  The U.S. Representatives may terminate this
Agreement, by notice to the Company, at any time at or prior to Closing Time (i)
if there has been, since the time of execution of this Agreement or since the
respective dates as of which information is given in the U.S. Prospectus, any
material adverse change in the condition, financial or otherwise, or in the
earnings, business affairs or business prospects of the Company and its
subsidiaries considered as one enterprise, whether or not arising in the
ordinary course of business, or (ii) if there has occurred any material adverse
change in the financial markets in the United States or the international
financial markets, any outbreak of hostilities or escalation thereof or other
calamity or crisis or any change or development involving a prospective change
in national or international political, financial or economic conditions, in
each case the effect of which is such as to make it, in the judgment of the U.S.
Representatives, impracticable to market the Securities or to enforce contracts
for the sale of the Securities, or (iii) if trading in any securities of the
Company has been suspended or materially limited by the Commission or the New
York Stock Exchange, or if trading generally on the American Stock Exchange or
the New York Stock Exchange or in the Nasdaq National Market has been suspended
or materially limited, or minimum or maximum prices for trading have been fixed,
or maximum ranges for prices have been required, by any of said exchanges or by
such system or by order of the Commission, the NASD or any other governmental
authority, or (iv) if a banking moratorium has been declared by either Federal
or New York authorities.

     (b)   Liabilities. If this Agreement is terminated pursuant to this
Section, such termination shall be without liability of any party to any other
party except as provided in Section 4 hereof, and provided further that Sections
1, 6, 7 and 8 shall survive such termination and remain in full force and
effect.

     SECTION 10.  Default by One or More of the U.S. Underwriters.  If one or
                  -----------------------------------------------            
more of the U.S. Underwriters shall fail at Closing Time or a Date of Delivery
to purchase the Securities which it or they are obligated to purchase under this
Agreement (the "Defaulted Securities"), the U.S. Representatives shall have the
right, within 24 hours thereafter, to make arrangements for one or more of the
non-defaulting U.S. Underwriters, or any other underwriters, to purchase all,
but not less than all, of the Defaulted Securities in such amounts as may be
agreed upon and upon the terms herein set forth; if, however, the U.S.
Representatives shall not have completed such arrangements within such 24-hour
period, then:

                 (a)   if the number of Defaulted Securities does not exceed 10%
     of the number of U.S. Securities to be purchased on such date, each of the
     non-defaulting U.S. Underwriters shall be obligated, severally and not
     jointly, to purchase the full amount thereof in the proportions that their
     respective underwriting obligations hereunder bear to the underwriting
     obligations of all non-defaulting U.S. Underwriters, or

                 (b)   if the number of Defaulted Securities exceeds 10% of the
     number of U.S. Securities to be purchased on such date, this Agreement or,
     with respect to any

                                       29
<PAGE>
 
     Date of Delivery which occurs after the Closing Time, the obligation of the
     U.S. Underwriters to purchase and of the Company to sell the Option
     Securities to be purchased and sold on such Date of Delivery shall
     terminate without liability on the part of any non-defaulting U.S.
     Underwriter.

     No action taken pursuant to this Section shall relieve any defaulting U.S.
Underwriter from liability in respect of its default.

     In the event of any such default which does not result in a termination of
this Agreement or, in the case of a Date of Delivery which is after the Closing
Time, which does not result in a termination of the obligation of the U.S.
Underwriters to purchase and the Company to sell the relevant U.S. Option
Securities, as the case may be, either the U.S. Representatives or the Company
shall have the right to postpone Closing Time or the relevant Date of Delivery,
as the case may be, for a period not exceeding seven days in order to effect any
required changes in the Registration Statement or Prospectus or in any other
documents or arrangements.  As used herein, the term "U.S. Underwriter" includes
any person substituted for a U.S. Underwriter under this Section 10.

     SECTION 11.  Notices.  All notices and other communications hereunder shall
                  -------                                                       
be in writing and shall be deemed to have been duly given if mailed or
transmitted by any standard form of telecommunication.  Notices to the U.S.
Underwriters shall be directed to the U.S. Representatives c/o Merrill Lynch,
Pierce, Fenner & Smith Incorporated, North Tower, World Financial Center, New
York, New York 10281-1201, attention of Richard B. Saltzman; and notices to the
Company and the Operating Partnership shall be directed to it at 8 Arlington
Street, Boston, Massachusetts  02116, attention of Frederick J. DeAngelis, Esq.
Notices given by telex or telephone shall be confirmed in writing.

     SECTION 12.  Parties.  This Agreement shall each inure to the benefit of
                  -------                                                    
and be binding upon the U.S. Underwriters and the Company and their respective
successors.  Nothing expressed or mentioned in this Agreement is intended or
shall be construed to give any person, firm or corporation, other than the U.S.
Underwriters and the Company and their respective successors and the controlling
persons and officers and directors referred to in Sections 6 and 7 and their
heirs and legal representatives, any legal or equitable right, remedy or claim
under or in respect of this Agreement or any provision herein contained.  This
Agreement and all conditions and provisions hereof are intended to be for the
sole and exclusive benefit of the U.S. Underwriters and the Company and their
respective successors, and said controlling persons and officers and directors
and their heirs and legal representatives, and for the benefit of no other
person, firm or corporation.  No purchaser of Securities from any U.S.
Underwriter shall be deemed to be a successor by reason merely of such purchase.

     SECTION 13.  GOVERNING LAW AND TIME.  THIS AGREEMENT SHALL BE GOVERNED BY
                  ----------------------                                      
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.  SPECIFIED
TIMES OF DAY REFER TO NEW YORK CITY TIME.

                                       30
<PAGE>
 
     SECTION 14.  Effect of Headings.  The Article and Section headings herein
                  ------------------                                          
and the Table of Contents are for convenience only and shall not affect the
construction hereof.

                                       31
<PAGE>
 
     If the foregoing is in accordance with your understanding of our agreement,
please sign and return to the Company a counterpart hereof, whereupon this
instrument, along with all counterparts, will become a binding agreement between
the U.S. Underwriters and the Company in accordance with its terms.

                                    Very truly yours,

                                    BOSTON PROPERTIES, INC.



                                    By
                                       ----------------------------------
                                       Title:


                                    BOSTON PROPERTIES LIMITED
                                    PARTNERSHIP



                                    By
                                       ----------------------------------
                                       Title:


CONFIRMED AND ACCEPTED,
     as of the date first above written:


MERRILL LYNCH & CO.
Merrill Lynch, Pierce, Fenner & Smith
  Incorporated
GOLDMAN, SACHS & CO.
BEAR, STEARNS & CO. INC.
MORGAN STANLEY & CO. INCORPORATED
PAINEWEBBER INCORPORATED
PRUDENTIAL SECURITIES INCORPORATED
SMITH BARNEY INC.

By:  MERRILL LYNCH, PIERCE, FENNER & SMITH
      INCORPORATED


By 
   -----------------------------------------
             Authorized Signatory

                                       32
<PAGE>
 
By:  GOLDMAN, SACHS & CO.

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

For themselves and as U.S. Representatives of the
other U.S. Underwriters named in Schedule A hereto.

                                       33
<PAGE>
 
                                   SCHEDULE A

<TABLE> 
<CAPTION> 

                                                                     Number of
                                                                      Initial
          Name of Underwriter                                       Securities
          -------------------                                       ----------
     <S>                                                            <C> 
     Merrill Lynch, Pierce, Fenner & Smith
          Incorporated.............................................
     Goldman, Sachs & Co...........................................
     Bear, Stearns & Co. Inc.......................................
     Morgan Stanley & Co. Incorporated.............................
     PaineWebber Incorporated......................................
     Prudential Securities Incorporated............................
     Smith Barney Inc..............................................



                                                                     -----------

     Total.........................................................  25,120,000
                                                                     ==========

</TABLE> 

                                    Sch A-1
<PAGE>
 
                                   SCHEDULE B

                            BOSTON PROPERTIES, INC.
                       25,120,000 Shares of Common Stock
                           (Par Value $.01 Per Share)



          1.  The initial public offering price per share for the Securities,
determined as provided in said Section 2, shall be $_____________.
 
          2.  The purchase price per share for the Securities to be paid by the
several Underwriters shall be $__________, being an amount equal to the initial
public offering price set forth above less $_________ per share; provided that
the purchase price per share for any Option Securities purchased upon the
exercise of the over-allotment option described in Section 2(b) shall be reduced
by an amount per share equal to any dividends or distributions declared by the
Company and payable on the Initial Securities but not payable on the Option
Securities.

                                    Sch B-1
<PAGE>
 
                                   SCHEDULE C

                               Certain Properties


599 Lexington Avenue
One Independence Square
Two Independence Square
Democracy Center
Capital Gallery
2300 N Street
Long Wharf Marriott
Cambridge Center Marriott

                                    Sch C-1
