<PAGE>

                           PURCHASE AND SALE CONTRACT

                                     between

                           CANAL CENTER PROPERTIES LLC

                                       and

                               TRANSPOTOMAC V LLC

                                   as SELLERS

                                       and

                         CARRAMERICA REALTY CORPORATION

                                    as BUYER

                               as of May 28, 2002

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                               TABLE OF CONTENTS

ARTICLE 1.
   Description of Property

ARTICLE 2.
   Sale Subject to Leases

ARTICLE 3.
   Purchase Price and Payment

ARTICLE 4.
   Form of Conveyance

ARTICLE 5.
   Closing

ARTICLE 6.
   Approvals and Conditions to Buyer's Obligations

ARTICLE 7.
   Conditions to Closing

ARTICLE 8.
   Default

ARTICLE 9.
   Certain Property Matters

ARTICLE 10.
   Entire Agreement Herein

ARTICLE 11.
   Damage or Destruction: Condemnation

ARTICLE 12.
   Representations and Warranties of Seller

ARTICLE 13.
   Maintenance; New Leases

ARTICLE 14.
   Apportionment of Taxes and Other Charges

ARTICLE 15.

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   Broker

ARTICLE 16.
   Continuation and Survival of Representations, Warranties, Indemnifications
   and Covenants

ARTICLE 17.
   Recording

ARTICLE 18.
   Notices

ARTICLE 19.
   Captions

ARTICLE 20.
   Successors and Assigns

ARTICLE 21.
   Closing Costs

ARTICLE 22.
   Governing Law

ARTICLE 23.
   Multiple Counterparts

ARTICLE 24.
   Representations and Warranties of Buyer

ARTICLE 25.
   Post-Closing Obligations

ARTICLE 26.
   Duties and Responsibilities of Escrow Agent

ARTICLE 27.
   Disclosure

ARTICLE 28.
   Like Kind Exchange

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Exhibits
--------

Exhibit A      Description of Real Property
Exhibit B      Personal Property
Exhibit C      Leases
Exhibit D      Form of Deed
Exhibit E      Form of Bill of Sale
Exhibit F      Form of Assignment and Assumption Agreement re: Leases
Exhibit G      Form of Assignment and Assumption Agreement re: Contracts
Exhibit H      Form of FIRPTA Affidavit
Exhibit I      Operating Contracts
Exhibit J      Section 6045 Designation
Exhibit K      Form of Estoppel Certificate
Exhibit K-1    Form of Seller's Estoppel Certificate
Exhibit L      List of Environmental Reports
Exhibit M      Seller's Title Insurance Policy
Exhibit N      Violations of Law
Exhibit 0      Loan Documents
Exhibit P      Tenant Inducement Costs and Brokerage Obligations
Exhibit Q      Lobby Renovation Description

<PAGE>

                           PURCHASE AND SALE CONTRACT

     THIS AGREEMENT (the "Contract") is made as of the 28th day of May, 2002, by
and between CANAL CENTER PROPERTIES LLC ("Canal Center") and TRANSPOTOMAC V LLC
("Transpotomac"), both Delaware limited liability companies, having offices c/o
Beacon Capital Partners, One Federal Street, Boston, Massachusetts 02110
(hereinafter together referred to as "Seller"), and CARRAMERICA REALTY
CORPORATION, a Maryland corporation, having its principal place of business at
1850 K Street, Washington D.C., NW 20006 (hereinafter referred to as "Buyer").
The obligations hereunder of the two above named entities comprising Seller are
joint and several. Although this transaction covers multiple properties, this
transaction constitutes a single transaction, and all such properties shall be
bought and sold hereunder in one transaction and closing.

     WITNESSETH THAT, Canal Center owns those certain parcels of land described
as the Canal Center Parcels on Exhibit A hereto and Transpotomac owns the
certain parcel of land described as Transpotomac Parcel on Exhibit A hereto,
together with the buildings and improvements thereon and appurtenances thereto,
all located in Alexandria, Virginia (the "Realty").

     WITNESSETH FURTHER THAT, Seller desires to sell and Buyer desires to
purchase the Property (as hereinafter defined) on the terms and subject to the
conditions set forth herein.

     WITNESSETH FURTHER THAT, for the consideration hereinafter named, and for
other good and valuable consideration, the receipt and sufficiency of which are
acknowledged hereby, the parties do hereby agree as follows:

     ARTICLE 1. Description of Property: Seller agrees to sell and Buyer agrees
to buy upon the terms and conditions hereinafter set forth:

     (a) The Realty together with all right, title and interest of Seller in and
to any land lying in the bed of any street (opened or proposed) adjacent to or
abutting or adjoining such premises, together with all rights, privileges,
rights of way and easements appurtenant to such premises, including, without
limitation, all minerals, oil or gas on or under such premises, development
rights, air rights, water rights and any easements, rights of way or other
interests in, on, or under any land, highway, alley, street or right of way
abutting or adjoining such premises (all of the foregoing, the "Real Property"),
(ii) all buildings and other improvements located thereon (the "Improvements",
and, together with the Real Property, the "Premises"), (iii) all items of
personal property owned by Seller and located on the Premises or used in
connection with the ownership or operation of the Premises, described in Exhibit
B, attached hereto and incorporated herein by reference, including, without
implied limitation, whether or not listed on Exhibit B, all furniture, fixtures,
equipment, machines, apparatus, appliances, supplies and personal property of
every nature and description and all replacements thereof, (collectively, the
"Personal Property"), (iv) the leases in the Property, and (v) to the extent
assignable, any intangible and other property owned by Seller and used in the
ownership or operation of the Premises including, without limitation, all plans
and specifications, surveys, catalogs, booklets,

                                      -1-

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manuals, logs and records with respect to the sale, management, leasing,
promotion, ownership, maintenance, use, occupancy and operation of the Premises,
permits, licenses, approvals, guaranties, warranties, contracts, lease
agreements, utility contracts, to the extent assignable, rights to use of the
names Canal Center and Transpotomac, and other rights relating to the ownership,
use or operation of the Premises (excluding attorney and accountant work
product) (collectively, the "Intangibles"). All items referred to in clauses
(i), (ii), (iii), (iv) and (v) are herein sometimes collectively referred to as
the "Property".

     (b) The Premises owned by Canal Center has the benefit of and is subject to
a Declaration of Covenants, Conditions and Restrictions as described in the
title insurance policy attached as Exhibit M which also creates an owners
association known as the Transpotomac Canal Center Owner's Association, Inc. The
Premises owned by Transpotomac has the benefit of and is subject to a
Declaration of Covenants and Restrictions Affecting Trans Potomac Plaza as
described in the title insurance policies attached as Exhibit M which also
creates an owner's association known as Trans Potomac Plaza Owners Association,
Inc. (Both associations are hereinafter referred to as "the Associations" and
the declarations are hereinafter referred to as the "Declarations"). All of
Seller's right, title and interest in the Associations shall be transferred to
Buyer.

     ARTICLE 2. Sale Subject to Leases: Subject to the provisions of Article 4
hereof, the Property will be conveyed subject to certain leases and licenses
together with any amendments, renewals, modifications, and extensions thereto
and guarantees thereof (hereinafter called the "Leases") described in Exhibit C
attached hereto and incorporated herein by reference, or as hereafter entered
into by Seller pursuant to the provisions of Article 13 hereof.

     ARTICLE 3. Purchase Price and Payment: (a) The total purchase price (the
"Purchase Price") for the Property is One Hundred Forty-Three Million Five
Hundred Thousand and 00/100 Dollars ($143,500,000.00), which shall be payable at
the Closing, as hereinafter defined, by the applicable Buyer entities assuming
the Mortgage Loan (as hereinafter defined) and the Mezzanine Loan (as
hereinafter defined), in each case as further described in paragraph 3(c) below,
with the balance (the Purchase Price less the outstanding principal balance and
accrued interest and other amounts owing under the Loan Documents as of the
Closing Date) after adjustment for prorations, credits and cost allocations
provided for in this Contract paid in lawful currency of the United States of
America by deposit with the Title Company (hereinafter defined) of immediately
available funds for wire transfer upon Closing to an account designated by
Seller, which designation shall be made not less than two (2) days prior to the
Closing.

     (b) As security for Buyer's performance hereunder, on or prior to the
expiration of the Due Diligence Period (defined in Article 6) and as a condition
to Buyer proceeding pursuant to Article 6, Buyer shall deposit Five Million
Dollars ($5,000,000.00) with First American Title Insurance Company ("Escrow
Agent"). The amount deposited with Escrow Agent, together with all interest
earned thereon, is hereinafter referred to as the "Deposit." The Deposit shall
be deposited in a federally insured interest-bearing, money market account. At
the Closing, the Deposit shall be paid to Seller and applied in reduction of the
Purchase Price payable at the Closing.

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     (c) The Property is presently encumbered by a first mortgage loan
originally in favor of Morgan Stanley Dean Witter Mortgage Capital Inc. in the
original principal sum of Seventy-Two Million Dollars ($72,000,000), currently
serviced by Wells Fargo Bank, N.A. and having an outstanding principal balance
of $63,500,000 (the "Mortgage Loan"). In addition, ALEXMEZZ LLC ("ALEXMEZZ" or
"Seller's Owner"), a Delaware limited liability company and the sole member of
each of Canal Center and TransPotomac, is the borrower under a mezzanine loan
originally in favor of Morgan Stanley Dean Witter Mortgage Capital Inc. and
CTMPII FC TransPotomac (MS) in the original aggregate principal sum of
Twenty-Five Million Dollars ($25,000,000), currently held by Fleet National Bank
and CTMPII FC TransPotomac (MS) and having an aggregate outstanding principal
balance of $33,500,000, which loan is secured by a pledge of the membership
interests of ALEXMEZZ in each of Canal Center and TransPotomac (the "Mezzanine
Loan"; the Mortgage Loan and the Mezzanine Loan are hereinafter collectively
referred to as the "Loan" or "Loans"). From and after the date hereof, the
parties shall endeavor to obtain the consent of the holder of the Mortgage Loan
(the "Mortgage Loan Lender") to the sale of the Property and the assumption of
the Mortgage Loan by the Buyer entities on the same terms and conditions as in
the documents evidencing, securing and otherwise governing the Mortgage Loan
(the "Mortgage Loan Documents"), and the consent of the holders of the Mezzanine
Loan (the "Mezzanine Loan Lender"; the Mortgage Loan Lender and the Mezzanine
Loan Lender are hereinafter collectively referred to as the "Lender") to the
sale of the Property and the assumption of the Mezzanine Loan by the Buyer
entities on the same terms and conditions as in the documents evidencing,
securing and otherwise governing the Mezzanine Loan (the "Mezzanine Loan
Documents"; the Mortgage Loan Documents and the Mezzanine Loan Documents are
hereinafter collectively referred to as the "Loan Documents"). Seller and Buyer
agree to reasonably cooperate with each other (but without cost to Seller except
for Seller's attorney's fees and any separate consideration required by the
Lender in connection with the release of Seller, ALEXMEZZ and Seller's
Responsible Party under the Loan Documents as set forth below) in seeking the
Lender's consent to the assumption of the Loan, including Buyer providing, on a
timely basis, such financial and other information as the Lender or any rating
agency(ies) may require concerning Buyer, the subsidiary of Buyer (the first
tier subsidiary, or mezzanine borrower) and the subsidiaries of the first tier
subsidiary (the second tier subsidiaries, or title holding entities) that Buyer
will form for this transaction to take title to the Property and to pledge the
interests of such second tier subsidiaries under the Mezzanine Loan. Subject to
Buyer's right to review the Loan Documents and make its determination to proceed
or to terminate this Contract pursuant to Article 6, Buyer will provide certain
"recourse carve-out", environmental indemnities and other indemnity obligations
to the Lender in the same form as previously provided by Beacon Capital
Strategic Partners, L.P. ("Seller's Responsible Party"), but, except for the
environmental indemnities, only to the extent such obligations relate to events,
acts or omissions first arising from and after the Closing Date. It shall be a
condition to the parties' obligation to close that the consent of the Lender is
obtained on or prior to the Closing for (i) the Buyer's second tier
subsidiaries' assumption of the Mortgage Loan on the same terms and conditions
as are set forth in the Mortgage Loan Documents, (ii) Buyer's first tier
subsidiary's assumption of the Mezzanine Loan on the same terms and conditions
as are set forth in the Mezzanine Loan Documents, (iii) Buyer's assumption of
all obligations of Seller's Responsible Party under the Loan Documents on the
same terms and conditions as are set forth in the Loan Documents, but, in the
case of this clause (iii) and except for the environmental indemnities, only to
the extent such obligations relate to events, acts or omissions first arising

                                      -3-

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from and after the Closing Date, and (iv) the release of Seller, ALEXMEZZ,
Seller's Responsible Party and their respective affiliates by the Lender of all
obligations of such parties under the Loan Documents or otherwise relating to
the Loan, including, without limitation, any "recourse carve-out", environmental
indemnities or other indemnity obligations contained in the Loan Documents that
relate to events, acts or omissions first arising from and after the Closing
Date. In the event the Lender does not provide the releases set forth in
subsection (iv), and Seller elects to terminate this Contract as a result
thereof in accordance with Article 7(a)(iii) and (b), Seller shall reimburse
Buyer its third party out-of-pocket costs in connection with the transaction up
to a maximum of $200,000.

     With respect to Buyer's and Buyer's subsidiaries' assumption of liability
under the Loan Documents relating to periods prior to the Closing Date,
excluding the Claims released in Section 6(f), Seller agrees to defend,
indemnify and hold harmless Buyer and Buyer's first and second tier subsidiaries
from and against any claim, loss or liability (including attorney's fees and
costs) incurred by Buyer or such subsidiaries to Lender under the Loan Documents
arising from any tort claim by a third party with respect to an event first
occurring prior to the Closing Date or for any monetary obligation owing to
Lender by Seller, ALEXMEZZ or Seller's Responsible Party thereunder accruing
prior to the Closing Date other than principal and interest under the Loan and
other amounts prorated or credited under Article 14. The indemnity in the
previous sentence is referred to in Article 16 as the "Seller's Loan Documents
Indemnity".

     Except as provided above with respect to (i) Seller's attorney's fees and
(ii) obtaining the release by Lender of Seller, ALEXMEZZ or Seller's Responsible
Party under the Loan Documents, any and all fees, charges, costs and expenses
(including, without limitation, assumption, administrative or processing fees
and legal fees) imposed or incurred by the Lender or any rating agency(ies) in
connection with the sale of the Property, obtaining the Lender's consent thereto
and/or the assumption of the Loan shall be borne by Buyer.

     ARTICLE 4. Form of Conveyance: (a) The Property shall be conveyed by a
special warranty deed (the "Deed") in substantially the form attached hereto as
Exhibit D, running to the applicable Buyer entities as Buyer designates by
notice to Seller at least three (3) business days before the Closing. The Deed
shall convey title to the Property, free from all liens, encumbrances and
encroachments from or on the Property except (i) the "Permitted Title
Exceptions" (as hereinafter defined) and (ii) the Leases. The Deed shall be in
proper form for recording and shall be duly executed, acknowledged and delivered
by Seller at the Closing.

     (b) The Personal Property shall be conveyed free of all encumbrances by one
or more bills of sale (the "Bill of Sale") in substantially the form attached
hereto as Exhibit E to be delivered by Seller to Buyer at Closing.

     ARTICLE 5. Closing: (a) The closing of the transactions contemplated
hereunder (the "Closing") shall take place through a closing escrow established
by the Title Company at 10:00 a.m. July 9, 2002, (such date, as the same may be
extended pursuant to the terms of this Contract, the "Closing Date"), at the
offices of Goulston & Storrs, P.C., 1717 Pennsylvania Avenue, Washington, DC
20006, or at such other location in metropolitan Washington, DC as Buyer shall
designate by five (5) business days prior written notice to Seller.
Notwithstanding the foregoing,

                                      -4-

<PAGE>

if approval of the assumption of the Mortgage Loan and Mezzanine Loan has not
been received by the original Closing Date or if the tenant estoppel condition
has not been met (Article 7(a)(ii)), either party, by written notice to the
other, given on or before the Closing Date, may extend the Closing for not more
than thirty (30) days, as specified in such notice. If the Closing Date shall
fall on Saturday, Sunday or holiday, the Closing Date shall automatically be
extended to the next business day.

     (b) At the Closing, Seller shall deliver the following documents, in the
form attached hereto, and, if not attached, reasonably satisfactory in form and
substance to Buyer and Buyer's counsel properly executed and acknowledged as
required (reference to Buyer as the assignee or grantee of any assignments means
the applicable Buyer entity):

          (i)       The Deed;

          (ii)      The Bill of Sale;

          (iii)     An original of an Assignment and Assumption Agreement
                    relating to the Leases and Security Deposits (hereinafter
                    defined) in the form attached hereto as Exhibit F (the
                    "Lease Assignment");

          (iv)      Originals (or true and complete copies certified by Seller
                    as such, if originals are not in Seller's possession or
                    control) of all Leases, any renewals thereof, all amendments
                    thereto, all guarantees thereof, and copies of all records
                    and correspondence relating thereto;

          (v)       An original of an Assignment and Assumption Agreement in the
                    form attached hereto as Exhibit G relating to the Operating
                    Contracts (as hereinafter defined) (the "Contract
                    Assignment") and originals (or true and complete copies, if
                    originals are not in Seller's possession or control) of
                    those Operating Contracts so assigned;

          (vi)      Originals or copies in Seller's possession or control of all
                    unexpired warranties, guaranties and operating manuals, if
                    any, with respect to the Property or Leases, including
                    without limitation, any from any contractors,
                    subcontractors, suppliers or materialmen in connection with
                    any construction, repair or alteration of the Improvements,
                    systems or any tenant improvements;

          (vii)     Originals or copies of all land use, environmental, traffic
                    and building permits, certificates of occupancy, licenses,
                    variances and the like relating to the Property in Seller's
                    possession or control;

          (viii)    A certification of non-foreign status in the form attached
                    hereto as Exhibit H;

                                      -5-

<PAGE>

          (ix)      Evidence satisfactory to Buyer and to Buyer's title
                    insurance company (the "Title Company") that all necessary
                    approvals and/or consents by Seller and any constituent
                    person of Seller otherwise required under Seller's
                    organizational documents, have been delivered and such other
                    evidence reasonably satisfactory to Buyer and the Title
                    Company of Seller's authority and the authority of the
                    signatory on behalf of Seller to convey the Property
                    pursuant to this Contract;

          (x)       Evidence of notice of termination of all Operating Contracts
                    as requested by Buyer in accordance with the provisions of
                    Article 12(a)(v);

          (xi)      Affidavits reasonably sufficient for the Title Company to
                    delete any exceptions for parties in possession (other than
                    tenants or permitted subtenants or assignees claiming
                    through tenants under the Leases as tenants only without any
                    option to purchase or acquire an interest in the Property)
                    and mechanics' or materialmen's liens (other than liens
                    arising from any tenant improvement work assumed by Buyer
                    pursuant to Article 14), and otherwise in form sufficient
                    for the Title Company to issue a standard extended coverage
                    owner's title insurance policy subject only to the Permitted
                    Title Exceptions; and a standard gap indemnity;

          (xii)     A certificate restating as of the Closing Date all of
                    Seller's representations and warranties contained herein
                    modified in accordance with Article 12(b) and including the
                    update described in (xiii) below;

          (xiii)    An update of the lease schedule attached hereto as Exhibit
                    C, certified by Seller to the extent provided in Article 12;

          (xiv)     An original of a closing statement setting forth the
                    Purchase Price and the closing adjustments and prorations
                    (the "Closing Statement") in form reasonably satisfactory to
                    Buyer and Seller;

          (xv)      Original tenant notification letters (notifying tenants of
                    the transfer of the Property to Buyer) for each tenant under
                    a Lease or other occupant of any portion of the Property,
                    and original notification letters to all parties to
                    operating and other contracts assigned to Buyer, each in
                    form reasonably satisfactory to Buyer;

          (xvi)     A Designation of Person Responsible for Tax Reporting under
                    Internal Revenue Code Section 6045 in the form of Exhibit J
                    annexed hereto designating Seller's attorney as the party
                    responsible for making the returns required under Internal
                    Revenue Code Section 6045;

          (xvii)    Evidence of payment to the Broker (hereinafter defined);

          (xviii)   Keys to all locks at the Property in Seller's possession or
                    control;

                                      -6-

<PAGE>

          (xix)     Resignations of all persons appointed by Seller as officers
                    or directors of either Association, together with any
                    assignments reasonably satisfactory to Buyer to effectively
                    assign to Buyer all developer or declarant rights, if any,
                    related to the Associations or the Declarations to the
                    extent Seller holds such rights;

          (xx)      Notice to the Associations of transfer of ownership;

          (xxi)     Counterparts signed by Seller and Seller's Owner, as
                    applicable, of the Loan Assumption Documents (defined in
                    Article 7);

          (xxii)    Written termination, confirmed in writing by the property
                    manager, of any property management and leasing agreements
                    affecting the Property,and, except as set forth in Article
                    12(a)(iv), payment by Seller of any costs related to such
                    termination.

          (xxiii)   A certificate that Seller and applicable Seller entities are
                    not (i) an "employee benefit plan" subject to Title I of the
                    Employee Retirement Income Security Act of 1974, as amended,
                    or a "plan" subject to Section 4975 of the Internal Revenue
                    Code of 1986, as amended (each an "ERISA Plan") or (ii) an
                    entity deemed to hold "plan assets" of any ERISA Plan within
                    the meaning of 29 C.F.R. Section 2510.3-10; and

          (xxiv)    Such other instruments as Buyer may reasonably request
                    consistent with the terms of this Contract.

     (c) At the Closing, Buyer shall deliver, or cause to be delivered, the
following payment and documents, reasonably satisfactory in form and substance
to Seller and Seller's counsel properly executed and acknowledged as required:

          (i)       The Purchase Price adjusted in accordance with the terms
                    hereof;

          (ii)      An original of the Lease Assignment;

          (iii)     An original of the Contract Assignment;

          (iv)      An original of the Closing Statement;

          (v)       A certificate that Buyer and applicable Buyer entities are
                    not (i) an "employee benefit plan" subject to Title I of the
                    Employee Retirement Income Security Act of 1974, as amended,
                    or a "plan" subject to Section 4975 of the Internal Revenue
                    Code of 1986, as amended (each an "ERISA Plan") or (ii) an
                    entity deemed to hold "plan assets" of any ERISA Plan within
                    the meaning of 29 C.F.R. Section 2510.3-10; and

                                      -7-

<PAGE>
          (v)       Counterparts signed by Buyer, and the first and second tier
                    subsidiaries, as applicable, of the Loan Assumption
                    Documents.

     (d) All Closing deliveries and deposits shall be made into the Closing
escrow established by the Title Company. Once all documents and deposits of
funds have been properly delivered and deposited to the satisfaction of the
parties and all Closing conditions have been met, the Title Company shall make
all applicable deliveries and payments to the parties and record the all
appropriate documents.

     ARTICLE 6. Approvals and Conditions to Buyer's Obligation: (a) Seller
acknowledges the Buyer intends to conduct an investigation of the Property. In
order to facilitate Buyer's investigations, Seller shall deliver or make
available to Buyer within three (3) business days from the date hereof or, as
soon thereafter as is reasonably practicable, copies of the following
(collectively, the "Due Diligence Items"):

          (i)       The Leases;

          (ii)      The Operating Contracts;

          (iii)     Income, expense and other operating statements for the
                    Property for the period of Seller's ownership;

          (iv)      To the extent in Seller's possession or control, all
                    unexpired warranties with respect to the Premises and final
                    as-built plans and specifications for the Premises;

          (v)       To the extent in Seller's possession or control, all
                    licenses and permits of a material nature required for the
                    use and operation of the Property, including occupancy
                    permits/certificates;

          (vi)      All surveys of the Premises or any part thereof in Seller's
                    possession or control;

          (vii)     A copy of any and all traffic studies, reports relating to
                    toxic and/or hazardous materials or substances including
                    without limitation asbestos, asbestos containing materials,
                    lead paint, radon gas, petroleum products, urea-formaldehyde
                    and other similar or dissimilar chemical or materials
                    relating to the Premises and prepared by or on behalf of
                    Seller or its affiliates, within Seller's possession or
                    control;

          (viii)    Copies of all invoices to tenants for operating expenses,
                    taxes, insurance and other "pass-throughs" for the period of
                    Seller's ownership of the Property;

          (ix)      Copies of bills for all real estate taxes and assessments of
                    the Property for the period of Seller's ownership of the
                    Property;

                                      -8-

<PAGE>

          (x)       To the extent they are in Seller's possession or control,
                    copies of all statements of gross sales for any tenants
                    required to pay percentage rent and for all tenants who
                    provide such information to Seller during Seller's
                    ownership;

          (xi)      The Loan Documents; and

          (xii)     To the extent in Seller's possession (Buyer acknowledging
                    that Seller has owned the Property for less than one (1)
                    year), copies of: operating expense reconciliations and
                    billings for the prior 36 months; if available, audited
                    financial statements for the prior 3 years; fixed asset and
                    accumulated depreciation schedules; operating budgets for
                    the current and prior years with supporting assumptions;
                    operating statements for the current year in comparison to
                    budget; list of outstanding receivables and age receivable
                    report; general ledger for the current and prior years;
                    account summaries for prior 3 years for all tenants; all
                    previously prepared lease summaries; and a summary of
                    current lease negotiations.

     (b) Commencing on the date hereof, Buyer shall have the right to perform
and conduct such examinations and investigations of the Property as Buyer may
desire, which may include, without limitation, examination of all structural and
mechanical aspects thereof, review of documentation, income and expenses, all
Leases and tenant files, records of repairs and capital improvements (excluding
any materials of a proprietary nature, such as internal valuation analysis,
projections, software and other materials constituting the work product of
Seller or its agents), examination of the title to the Property, conducting
tests to determine the presence or absence of hazardous waste, asbestos, lead
paint, radon and other similar materials and substances, reviewing a current
as-built survey thereof, and determining the compliance of the Property with all
applicable laws, rules, codes and regulations, and determining whether, and the
extent to which, additional improvements may be constructed on the Real
Property. In connection with such examination, Seller shall make available (at
reasonable times and places) for Buyer's review Seller's books and records
relating to the Property. If the expiration of the Due Diligence Period shall
fall on Saturday, Sunday or holiday, the Due Diligence Period shall
automatically be extended to the next business day. Notwithstanding anything
herein to the contrary, nothing herein shall authorize Buyer, nor shall Buyer be
permitted to conduct, any subsurface or groundwater environmental testing or any
other invasive tests or samplings on or relating to the Property without
Seller's prior written consent, which consent may be withheld or denied for any
or no reason.

     (c) The "Due Diligence Period" shall mean the thirty (30) day period
commencing on the date hereof and ending on June 24, 2002, at 5:00 p.m. eastern
daylight time. Notwithstanding anything to the contrary contained in this
Contract, Seller acknowledges the Buyer shall have the right in its sole and
absolute discretion, either based upon its disapproval of any of the information
it receives, for any other reason whatsoever or for no reason, to terminate this
Contract by written notice delivered to Seller on or before 5:00 p.m. eastern
daylight time June 24, 2002. In the event Buyer notifies Seller prior to the
expiration of the Due Diligence

                                      -9-

<PAGE>

Period that it elects to terminate this Contract, this Contract shall Ipso Facto
be deemed to have been terminated, in which event the entire Deposit, shall be
returned to Buyer forthwith and all obligations (other than the obligations of
Buyer under Article 6(d), Article 6(g), and Article 27(a)) of the parties hereto
shall cease and this Contract shall be terminated and the parties shall be
without further recourse or remedy hereunder. Failure to provide such notice to
the Seller within the time specified above shall be deemed an election by Buyer
to waive its right to terminate the Contract pursuant to this Article 6.

     (d) Seller shall, upon reasonable notice and at reasonable times, make the
Property available to Buyer and its agents, consultants and engineers for such
inspections and tests as Buyer deems appropriate, including for Buyer's
engineering inspection(s), environmental compliance inspections (but excluding
any invasive tests or samplings), site evaluations, and such other inspections
and tests as Buyer deems appropriate but excluding any invasive or destructive
tests, at Buyer's sole cost and expense. Seller shall have the right to have a
representative present during all or any of Buyer's inspections and tests. Buyer
hereby agrees to indemnify and hold Seller harmless from and against any and all
loss, cost or damage arising out of damage to persons or property resulting from
actions taken by Buyer or its agents, engineers or consultants. Buyer shall
provide to Seller prior to its entry on the Property certificates of liability
insurance insuring Buyer and Seller in an amount not less than Three Million
Dollars ($3,000,000.00). Buyer shall promptly repair all damage to the Property
arising from any such inspections or tests and shall restore the Property to the
same condition existing immediately prior to such inspections and tests. In the
event Buyer discovers any matter during the course of its investigations and
tests which may be reportable under applicable law, Buyer acknowledges and
agrees that it shall not undertake any such reporting, but shall notify Seller
immediately of any such discovery, and shall not thereafter make any report
unless failure to do so would breach applicable law. In performing any such
inspections or tests, Buyer shall not unreasonably interfere with the activities
on the Property of any tenant under the Leases. The indemnification, repair and
restoration obligations of Buyer under this Article 6(d) shall survive the
termination of this Contract. Buyer may conduct interviews with tenants but only
upon two (2) business days prior written notice to Seller and Seller shall be
entitled to have a representative present at such interviews.

     (e) Buyer shall obtain each of the following at its own cost and expense on
or before the expiration of the Due Diligence Period: (i) a current ALTA Survey
of the Property (the "Survey") certified to Seller, Buyer and First American
Title Insurance Company (the "Title Company") and (ii) a title insurance
commitment (or specimen policy) for the Property issued by the Title Company
(the "Title Commitment"), containing such endorsements, affirmative coverages
and reinsurance agreements as Buyer shall require, and specifying the Title
Company's requirements relating to the issuance of such title policy (the "Title
Requirements"). On or before the fourth (4th) business day prior to the
expiration of the Due Diligence Period Buyer shall give Seller notice ("Buyer's
Title Notice") of Buyer's disapproval of any of the title exceptions contained
in the Title Commitment (or of any matter disclosed on the Survey) and
specifying those Title Requirements, if any, contained in the Title Commitment
which are to be performed by or on behalf of Seller. Seller, by written notice
to Buyer ("Seller's Title Notice") given within two (2) business days of receipt
of Buyer's Title Notice, shall notify Buyer of the Title Requirements and other
title objections which Seller agrees to use its reasonably efforts to

                                     -10-

<PAGE>

satisfy or cure. If Seller does not agree to cure or satisfy all such matters
identified in Buyer's Title Notice, Buyer may terminate this Contract by written
notice to Seller given within two (2) business days of receipt of Seller's Title
Notice or otherwise be deemed to have waived any matter Seller has not agreed to
use its reasonable efforts to cure or satisfy. If Seller does not respond to
Buyer's Title Notice as provided above, Seller shall be deemed not to have
agreed to satisfy or cure the matters set forth therein. Buyer shall be deemed
to have accepted those matters appearing as exceptions in Buyer's Title
Commitment and those matters appearing on the Survey to which Buyer has not
objected in Buyer's Title Notice (or which Buyer is deemed to have waived), and
each such matter shall be deemed a "Permitted Title Exception". Likewise,
nothing herein shall obligate Seller to deliver the Property to Buyer at the
Closing free and clear of the encumbrances, restrictions, easements and other
specific exceptions identified on the existing owner's title insurance policies
of Seller identified on Exhibit M attached hereto and incorporated herein by
reference. Each of such encumbrances, easements, restrictions and matters being
hereinafter also included as a "Permitted Title Exception." In the event this
Contract is terminated under this Section 6(e), all obligations, liabilities and
rights of the parties under this Contract shall terminate (other than Buyer's
obligations under Article 6(d), Article 6(g) and Article 27 hereof, which shall
remain in effect), and the Deposit shall be returned to Buyer. If Seller has
elected to cure any matter or to satisfy any Title Requirement, such matter
shall be cured or satisfied by Seller prior to the Closing Date, and Buyer shall
be given a reasonable opportunity to verify that such matter has been cured or
satisfied to Buyer's reasonable satisfaction. Notwithstanding the foregoing, the
Permitted Title Exceptions shall not include, and Seller shall be obligated to
release or remove, (i) other than the Loan Documents, any mortgages or other
voluntary monetary encumbrances which Seller has caused to be recorded against
the Property and any encumbrances which Seller has created after the date of
this Contract in breach of the terms hereof and (ii) mechanics and materialman's
liens (other than liens arising from any tenant improvement work assumed by
Buyer pursuant to Article 14).

     (f) Except for the Surviving Obligations (defined in Article 16), Buyer
acknowledges and agrees that Buyer is acquiring the Property strictly on an "as
is", "where is" and "with all defects" basis and without representation or
warranty, express, implied or statutory, of any kind, including, without
limitation, representation or warranty as to title, condition (structural,
mechanical or otherwise), construction, development, income, compliance with
law, habitability, tenancies, merchantability or fitness for any purpose, all of
which are hereby disclaimed and which Buyer hereby waives. Except for the
Surviving Obligations, Buyer acknowledges that all materials furnished by Seller
to Buyer are informational only without warranty or representation as to its
truth or accuracy, and that Buyer is relying on its own due diligence. Except
for the Surviving Obligations and with reservation by Buyer and the first and
second tier subsidiaries of Buyer of any defense or right of contribution or
indemnity against Seller or any other party released hereunder in connection
with a claim against Buyer or any subsidiary of Buyer for actual (but not
consequential) damage to persons or property brought by a non-governmental third
party in or within three (3) years from Closing, by accepting and recording the
Deed, Buyer hereby releases and forever discharges Seller, and their partners,
beneficial owners, officers, directors, employees and agents from any and all
claims, acts, debts, demands, actions, causes of action, suits, sums of money,
guaranties, bonds, covenants, contracts, accounts, agreements, promises,
representations, restitution, omissions, variances, damages, obligations, costs,
response actions, fees (including, without limitation, attorneys, consultants
and experts fees) and

                                     -11-

<PAGE>

liabilities of every name and nature whatsoever, both at law and in equity
(collectively, "Claims"), which Buyer and its successors and assigns may now or
hereafter have against Seller or its partners, members, beneficial owners,
officers, directors, employees or agents, arising in connection with any and all
liabilities or obligations relating to environmental matters, (including,
without limitation, all liabilities and obligations relating to Hazardous
Materials located at, on, in or under the Property or migrating from the
Property), regardless of whether such Hazardous Materials are located on, under
or in the Property prior to, or after the date hereof. For the purposes hereof,
the following terms shall have the meanings set forth below:

          (i)       the term "Environmental Laws" means all federal, state, or
                    local laws, rules or regulations (whether now existing or
                    hereafter enacted or promulgated) and any judicial or
                    administrative interpretation thereof, including any
                    judicial or administrative orders or judgments, relating to
                    the protection of human health, safety and the environment;

          (ii)      the term "Hazardous Materials" includes any substance,
                    chemical, compound, product, solid, gas, liquid, waste,
                    byproduct, pollutant, contaminant or material which is
                    hazardous, toxic, ignitable, corrosive, carcinogenic or
                    otherwise dangerous to human, plant or animal life or the
                    environment or which are defined, determined or identified
                    as such in any Environmental Laws or which are regulated or
                    subject to clean-up authority under any Environmental Laws,
                    including, but not limited to materials defined as (A)
                    "hazardous waste" under the Federal Resource Conservation
                    and Recovery Act (B) "hazardous substances" under the
                    Federal Comprehensive Environmental Response, Compensation
                    and Liability Act, (C) "pollutants" under the Federal Clean
                    Water Act; (D) "toxic substances" under the Toxic Substances
                    Control Act; and (E) "oil or hazardous materials" under
                    state law.

     (g) In the event that Buyer elects to terminate this Contract as provided
in Article 6, or if this Contract otherwise terminates as provided for hereunder
for reasons other than a default by Seller, then Buyer shall promptly deliver to
Seller all written reports, surveys, title commitments, prepared by third
parties for Buyer relating to the Property and in connection therewith
(excluding any proprietary development or marketing materials), such delivery
being without representation or recourse. Buyer hereby agrees that all materials
delivered to it by or on behalf of Seller shall be held in the strictest
confidence and subject to the provisions of Article 27.

     ARTICLE 7. Conditions to Closing: (a) Without limiting any other conditions
to Buyer's obligations to close set forth in this Contract, the obligations of
Buyer under this Contract are subject to the satisfaction at the time of Closing
of each of the following conditions (any of which may be waived in writing in
whole or in part by Buyer or, as applicable, Seller, at or prior to Closing):

          (i)       Seller shall have performed, observed, and complied in all
                    material respects with all covenants and agreements required
                    by this Contract to be

                                      -12-

<PAGE>

                    performed by Seller at or prior to Closing; Seller's
                    representations and warranties in this Contract are true and
                    correct in all material respect as of the date made and
                    re-made, and any updates or modifications to such
                    representations and warranties permitted hereunder do not
                    materially and adversely modify any such representation and
                    warranty. As of the Closing Date, Buyer shall not have
                    knowledge or deemed knowledge of any matter which, but for
                    Buyer having such knowledge or deemed knowledge, Seller
                    would otherwise have liability with respect thereto as a
                    Surviving Obligation pursuant to Article 16.

          (ii)      Original Estoppel Certificates from tenants of the Property
                    ("Tenant Estoppels") sufficient so as to represent
                    seventy-five percent (75%) of the space demised under the
                    Leases as set forth in Exhibit C in the form attached as
                    Exhibit K hereto, including, without limitation, all tenants
                    occupying more than 25,000 rentable square feet of space
                    (such latter group of tenants being "Major Tenants"),
                    provided, however, that if any Lease provides for the form
                    or specifically limits the content of an estoppel letter,
                    Buyer shall accept an estoppel letter as called for under
                    such Lease. Seller shall request Tenant Estoppels from all
                    tenants in the form attached as Exhibit K hereto. To the
                    extent Tenant Estoppels are received for less than seventy
                    five percent (75%) of the space demised under the Leases as
                    set forth in Exhibit C, Seller may, at its election, provide
                    to the extent factually true, a Seller's Estoppel
                    Certificate in the form attached as Exhibit K-1 for tenants
                    to the extent necessary to achieve the seventy five percent
                    (75%) threshold, provided no Seller's Estoppel may be
                    substituted for estoppels from Major Tenants or, in the
                    aggregate, for more than ten percent (10%) of such leased
                    space. If Seller is unable to deliver such Seller's Estoppel
                    Certificate(s) because the required information is untrue in
                    any material respect (such as a tenant being in default),
                    Seller shall not be deemed in default hereunder, but Buyer
                    shall have the right to terminate this Contract by written
                    notice to Seller delivered on the Closing Date, obtain a
                    return of the Deposit and neither party shall have further
                    rights or remedies, except as otherwise provided hereunder.
                    A Seller's Estoppel Certificate will be of no further force
                    or effect as of the date on which there is delivered to
                    Buyer a Tenant Estoppel from a tenant in respect of which
                    such Seller's Estoppel Certificate was given and that
                    conforms to the requirements of this clause (ii). Seller's
                    liability with respect to the Seller's Estoppel Certificates
                    shall be non-recourse, except as set forth in Article 16
                    hereof. The requirement in this subsection (ii) is met for
                    each Lease only if the applicable Tenant Estoppel indicates
                    no default or dispute, is consistent in all material
                    respects with the information in the Rent Roll, and since
                    the date of the estoppel and on or before the Closing Date
                    no material default or dispute has arisen;

                                      -13-

<PAGE>

          (iii)     The Lenders under the respective Loans shall have executed
                    and delivered the Loan Assumption Documents and have
                    certified to the Buyer to their knowledge, in such form as
                    provided under the Loan Documents or otherwise reasonably
                    satisfactory to Buyer, as to the outstanding principal
                    balance and accrued interest and other amounts under the
                    Loans and to their knowledge the absence of any defaults
                    thereunder. For purposes of this Contract, the term "Loan
                    Assumption Documents" shall mean documents reasonably
                    satisfactory to Seller and Buyer by which, subject to and in
                    accordance with Article 3(c): (i) Buyer and the first tier
                    and second tier subsidiaries of Buyer, as applicable, assume
                    all obligations of borrower and Seller's Responsible Party
                    under the Loan Documents on terms no less favorable than
                    those set forth in the Loan Documents, and (ii) a release in
                    favor of Seller and ALEXMEZZ and their respective affiliates
                    of all obligations of Seller, ALEXMEZZ their respective
                    affiliates, respectively, under the Loan Documents accruing
                    from and after Closing, including, without limitation, any
                    "recourse" carve-outs, environmental indemnities or other
                    indemnity obligations of such parties contained therein
                    (except to the extent based on conditions or occurrences
                    existing before Closing) and (iii) otherwise meeting the
                    requirements of Article 3(c).

          (iv)      Upon the sole condition of the payment of the premium, at
                    Closing, the Title Company shall irrevocably commit to issue
                    to Buyer an ALTA Owner's Policy of title insurance, with
                    extended coverage (i.e., with ALTA General Exceptions 1
                    through 5 deleted, or, with respect to parties in possession
                    modified to reflect the Leases, and with respect to survey,
                    modified to reflect those matters shown on the Survey) dated
                    as of the date and time of the recording of the Deed, in the
                    amount of the Purchase Price, insuring Buyer as owner of the
                    Property subject only to those exceptions set forth in the
                    Title Commitment approved or deemed approved by Buyer during
                    the Due Diligence Period and any other Permitted Exceptions.
                    Seller shall have obtained and delivered to Buyer at Closing
                    estoppel certificates from the declarant, association,
                    committee, agent or other person or entity having governing
                    or approval rights under the Declarations, confirming
                    compliance of the Property in all material respects with the
                    Declarations, in form and substance reasonably satisfactory
                    to Buyer. During the Due Diligence Period, Buyer shall be
                    responsible for making arrangements with the Title Company
                    with respect to any endorsements to the title policy that
                    Buyer wishes to obtain, and any reinsurance requirements of
                    Buyer, and obtaining such items shall not be a condition to
                    Buyer's obligation to close.

     (b) If any condition set forth herein is not fully satisfied as of the
Closing Date, Seller may elect to attempt to satisfy or cure any such condition,
and if Seller so elects, Seller shall have a period not exceeding thirty (30)
days after the scheduled Closing Date to satisfy such condition, and the Closing
Date shall be extended accordingly. In addition, Buyer may so extend

                                      -14-

<PAGE>

the Closing for up to thirty (30) days if additional time is needed to satisfy
the conditions in clauses (ii) or (iii) above. The conditions in (i), (ii), and
(iv) are for the sole benefit of Buyer. The condition in (iii) is for the
benefit of each of Buyer and Seller. So long as a party is not in default
hereunder, if any condition benefiting such party has not been satisfied as of
the Closing Date, such party may, in its sole discretion: (i) terminate this
Contract by delivering written notice to the other party on or before the
Closing Date or other applicable date, in which case, subject to Article 8, the
Deposit shall be returned to Buyer and all obligations of the parties hereto
shall cease except those set forth in Articles 6(d), 6(g), 15 and 27; or (ii)
extend the time available for the satisfaction of such condition as provided
above.

     ARTICLE 8. Default: (a) If Seller has failed to perform any of its
obligations hereunder to be performed on or before the Closing, or if Seller
takes action not permitted by this Contract which results in a material
modification of a representation or warranty made by Seller hereunder, Buyer's
sole and exclusive remedy shall be the right to exercise any one of the
following remedies:

          (i)       Buyer shall have the right to terminate this Contract by
                    notice to Seller, in which event the Deposit shall be paid
                    to Buyer, Seller shall reimburse Buyer its third party
                    out-of-pocket costs in connection with the transaction up to
                    a maximum of $200,000 and all obligations of the parties
                    under this Contract shall terminate; or

          (ii)      Buyer shall have the right to waive the breach, or default
                    or other closing condition and proceed to consummate the
                    transaction contemplated hereby without any adjustment of
                    the Purchase Price in accordance with the provisions of this
                    Contract and in which event except for the Surviving
                    Obligations, any default by Seller shall waived; or

          (iii)     Buyer may seek specific performance of Seller's obligations
                    hereunder.

     (b) In the event of a default by Buyer of its obligation to complete the
acquisition hereunder, it would be extremely impracticable and difficult to
estimate the damage and harm which Seller would suffer, and because a reasonable
estimate of the total net detriment that Seller would suffer in the event of
Buyer's default of its obligation to duly complete the acquisition hereunder is
the amount of the Deposit, Seller shall be entitled to receive and retain the
Deposit as and for Seller's sole and exclusive remedy for damages arising from
Buyer's default of its obligation to complete the acquisition in accordance with
the terms hereof, and Seller shall have no further recourse or remedy at law or
in equity for any breach by Buyer hereunder; provided, however that,
notwithstanding anything herein to the contrary, in addition to Seller's ability
to retain the Deposit, Seller shall also have the right to enforce the specific
performance by Buyer of Buyer's obligations under Articles 6(d), 6(g) and 27(a)
hereof. In addition, Seller shall also have the right to sue Buyer for damages
caused by Buyer as a result of Buyer's failure to perform its obligations under
Articles 6(b), 6(d), 6(g), 15 or 27(a) hereof.

     ARTICLE 9. Certain Property Matters: The Canal Center Property abuts a
railroad right of way, which right of way crosses Canal Center Plaza, the public
way which provides access to

                                      -15-

<PAGE>

the Canal Center Property. A railway crossing exists at the point of
intersection of the right of way and the public way. Occasionally, trains make
use of the crossing and no vehicles may pass over the crossing to enter or exit
the Canal Center Property.

     With  respect to the  foregoing,  Buyer  agrees that it shall  evaluate the
matter during its Due Diligence Period set forth in Article 6.

     ARTICLE 10. Entire Agreement Herein: The parties understand and agree that
their entire agreement is contained herein and that no warranties, guarantees,
statements, or representations shall be valid or binding on a party unless set
forth in this Contract. It is further understood and agreed that all prior
understandings and agreements heretofore had between the parties are merged in
this Contract which alone fully and completely expresses their agreement and
that the same is entered into after full investigation, neither party relying on
any statement or representation not embodied in this Contract. This Contract may
be changed, modified, altered or terminated only by a written agreement signed
by the parties hereto.

     ARTICLE 11. Damage or Destruction: Condemnation: (a) The risk of loss,
damage or destruction to the Property by fire or other casualty or the taking of
all or part of the Property by condemnation or eminent domain or by an agreement
in lieu thereof until the Closing is assumed by Seller.

     (b) In the event of partial damage or destruction of the Property of a type
which can, under the circumstances, reasonably be expected to be restored or
repaired at a cost of $3,000,000 (aggregating the damage from all occurrences)
or less, then, Buyer shall (unless such damage has been repaired by Seller in a
good and workmanlike manner prior to Closing) accept title to the Property in
its destroyed or damaged condition. Buyer shall pay the full Purchase Price
without reduction except as provided below, and Seller shall pay over or assign
to Buyer, in form approved by and acknowledged by the insurer, all rights to any
proceeds of insurance payable with respect to such destruction or damage (less
amounts reasonably expended by Seller in repairing the damage prior to the
Closing Date) and Buyer shall have a credit against the Purchase Price in the
amount of any deductible. Notwithstanding the foregoing, in the event of partial
damage or destruction of the Property, which partial damage or destruction is
not covered by insurance and is of a type which can reasonably be expected to be
restored or repaired at a cost of $3,000,000 (aggregating the damage from all
occurrences) or less, then, Seller may elect, within five (5) business days of
such casualty, to (i) repair the damage in a good and workmanlike manner prior
to Closing, or (ii) give Buyer a credit against the Purchase Price in the amount
of such uninsured damage. In the event Seller does not elect either (i) or (ii),
Buyer may terminate this Contract or purchase the Property in accordance with
the terms hereof without reduction in the Purchase Price.

     (c) In the event that the Property shall have been damaged or destroyed,
the cost of repair or restoration of which would, reasonably be expected to
exceed the sum of $3,000,000, (aggregating the damage from all occurrences),
then at Buyer's election, (a) Seller shall, unless Seller has previously
repaired or restored the Property to their former condition, pay over or assign
to Buyer in form approved by and acknowledged by the insurer, at Closing all
amounts recovered or recoverable on account of any insurance, together with
amounts equal to any

                                      -16-

<PAGE>

deductibles thereunder, less any amounts reasonably expended by Seller for
partial restoration or collection of insurance proceeds, or (b) Buyer shall
direct Escrow Agent to return the Deposit to Buyer in which case all other
obligations of the parties hereto shall cease except those set forth in Articles
6(d), 6(g), 15 and 27 and this Contract shall be void and without recourse to
the parties hereto.

     (d) If prior to the Closing Date, all or part of the Property is taken by
condemnation, eminent domain or by agreement in lieu thereof, or any proceeding
to acquire, take or condemn all or part of the Property is threatened or
commenced, Buyer may either terminate this Contract (in which event Buyer shall
be entitled to a return of the Deposit) or purchase the Property in accordance
with the terms hereof, without reduction in the Purchase Price except as
provided below, together with an assignment of Seller's rights to any award paid
or payable by or on behalf of the condemning authority. If Seller has received
payments from the condemning authority and if Buyer elects to purchase the
Property, Seller shall credit the amount of said payments (less Seller's costs
of collection) against the Purchase Price at the Closing.

     (e) Seller shall promptly notify Buyer of any damage or destruction to the
Property or any notice received by it or information or awareness acquired by it
regarding the threatening of or commencement of condemnation or similar
proceedings. If following such damage or destruction the Closing should occur,
the proceeds of any so-called rent insurance shall be apportioned between the
parties as if the same were rent, as and when received by a party.

     ARTICLE 12. Representations and Warranties of Seller: (a) In order to
induce Buyer to enter into this Contract and to consummate the purchase of the
Property, Seller hereby represents and warrants to Buyer as of the date of this
Contract and as of the Closing Date as follows:

          (i)       Seller is a limited liability company duly and validly
                    organized and existing under the laws of the State of
                    Delaware and qualified to do business in the Commonwealth of
                    Virginia. This Contract and all documents that are to be
                    executed by Seller and delivered to Buyer at the Closing are
                    duly authorized, executed and delivered by Seller, are, or
                    at the Closing will be, legal, valid and binding obligations
                    of such party.

          (ii)      Seller has delivered to Buyer true, correct and complete
                    copies of all Leases currently in effect with respect to the
                    Property, a true and correct complete list of which is
                    attached hereto as Exhibit C, and the information set forth
                    on said Exhibit C, is true and correct in all material
                    respects. There are no leases or occupancy agreements
                    affecting the Property except for the Leases as set forth on
                    Exhibit C. Except as set forth on Exhibit P or as provided
                    in Article 9 hereof, Seller has paid in full all
                    concessions, relocation payments, tenant allowance payments
                    and completed all tenant improvement obligations thereunder.
                    Exhibit C sets forth a true and complete list of all
                    security deposits required to be held by Seller under the
                    Leases, and whether held in cash, letter of credit or
                    otherwise. To Seller's knowledge, except with respect to the
                    matters disclosed in Article 9 and on Exhibit C Seller has
                    not received any written notice that it

                                      -17-

<PAGE>

                    currently is in default under any of the Leases.
                    Notwithstanding anything herein to the contrary, Buyer
                    recognizes that the representation and warranty contained in
                    this Article 12(a)(ii) may be modified as set forth in
                    Article 16 hereof.

          (iii)     Except as set forth on Exhibit P attached hereto (i) all
                    commissions and fees which accrued during the period of
                    Seller's ownership of the Property with respect to the
                    current unexpired term of each Lease have been paid in full,
                    and (ii) all commissions and fees which accrued prior to
                    Seller's ownership of the Property with respect to the
                    current unexpired term of each lease have been paid in full,
                    and (iii) Seller has not entered into and is not a party to
                    any agreement with any broker or similar party to pay such
                    broker or party a leasing fee or commission in connection
                    with any renewal, extension or expansion of an existing
                    Lease. Exhibit P, a Schedule of Tenant Inducement Costs
                    which may become due and payable in the future under
                    existing Leases, is true, correct and complete in all
                    material respects.

          (iv)      Exhibit I attached hereto is a complete list of all
                    management, service, operating, listing, brokerage, supply
                    and maintenance agreements, equipment leases, and all other
                    contracts and agreements with respect to or affecting the
                    Property as of the date of this Contract other than the
                    Leases (herein collectively referred to as the "Operating
                    Contracts"). Each of the Operating Contracts is in full
                    force and effect, and, except as specified in Exhibit I, has
                    not been amended, modified, or supplemented. To Seller's
                    knowledge, there is no existing default, beyond applicable
                    grace periods under any of the Operating Contracts, where
                    such default would have a material adverse impact on the
                    value or operation of the Property. Seller shall not modify
                    or terminate the Operating Contracts without the prior
                    written consent of Buyer, which consent shall not be
                    unreasonably withheld, conditioned or delayed, and Seller
                    shall not enter into any new service contract for the
                    Property or any portion thereof without the prior written
                    consent of Buyer, which consent shall not be unreasonably
                    withheld, conditioned or delayed. Failure of Buyer to
                    respond to any request by Seller within three (3) business
                    days shall be deemed approval by Buyer of any such request.
                    By not later than the thirtieth (30th) day prior to the
                    Closing Date, the Buyer may at its option notify the Seller
                    of those Operating Contracts which Buyer desires Seller to
                    send termination notices (to the extent the same are
                    terminable without penalty). At Closing, Seller shall send
                    notices of termination of all Operating Contracts as
                    requested, provided said Operating Contracts are terminable
                    without penalty or liability. Notwithstanding the foregoing,
                    Seller shall terminate effective as of the Closing, any
                    property management agreement and leasing agreement at its
                    sole cost and expense. Buyer acknowledges, however, that
                    said leasing brokerage agreements require payment of
                    commissions in certain circumstances for leases entered into
                    after the

                                      -18-

<PAGE>

                    effective date of a termination of such agreements and Buyer
                    agrees that if Buyer enters into a lease after Closing with
                    a tenant listed on a schedule provided to Buyer by Seller's
                    leasing broker on or prior to Closing and with respect to
                    which lease Seller would have owed such a posttermination
                    leasing commission, Buyer shall assume and be responsible
                    for such commission. The foregoing provision shall survive
                    Closing.

          (v)       To Seller's knowledge and except as set forth on Exhibit N,
                    Seller has not received notice in writing from a
                    governmental agency having jurisdiction that the Property or
                    any part thereof is (as of the date hereof) in violation of
                    any law, ordinance, rule or regulation applicable to the
                    Property which would, if determined adversely to Seller,
                    materially and adversely affect the use or the value of the
                    Property or impose any material liability on the Property or
                    the owner thereof.

          (vi)      There is not now pending nor, to the Seller's best
                    knowledge, has there been threatened, any action, suit or
                    proceeding against or affecting Seller or the Property
                    before or by any federal or state court, commission,
                    regulatory body, administrative agency or other governmental
                    body, domestic or foreign, which would, if determined
                    adversely to Seller, materially and adversely affect the use
                    or the value of the Property or impose any material
                    liability on the Property or the owner thereof.

          (vii)     Attached hereto as Exhibit L is a list of all
                    environmental/hazardous waste studies and reports relating
                    to the Property which are in Seller's possession (the
                    "Environmental Reports"). Complete copies of the
                    Environmental Reports have been furnished to Buyer. Except
                    as set forth in the Environmental Reports, to Seller's
                    actual knowledge, no Hazardous Materials are located on the
                    Premises which would trigger reporting or remediation
                    obligations under applicable law.

          (viii)    Attached as Exhibit O is a list of all Loan Documents
                    (including all amendments), true and complete copies of
                    which have been delivered to Buyer. Neither Seller nor
                    Seller's Owner has received written notice from Lender that
                    it is in default under any of the Loan Documents, and, to
                    the best of Seller's knowledge, neither Seller nor Seller's
                    Owner is in default under any material provision of the
                    Mortgage Loan Documents or Mezzanine Loan Documents,
                    respectively.

     (b) At Closing, Seller shall update such representations and warranties to
include a current Exhibit C and otherwise as necessary to reflect facts which
have changed since the date of execution hereof. Neither party shall have any
liability in connection with this Contract (including under Article 8) by reason
of any inaccuracy of a representation or warranty, if, and to the extent that
such inaccuracy is in fact known by the other party at the time of the Closing,
and such other party elects, nevertheless, to consummate the transaction
contemplated hereby.

                                      -19-

<PAGE>

     (c) For the purposes of this Contract, the term "Seller's knowledge" or
words of similar import, shall refer only to the actual knowledge of Philip
Brannigan and shall not be construed to refer to the knowledge of any other
partner, beneficial owner, officer, employee or agent of Seller, nor shall such
term impose any duty to investigate the matters to which such knowledge, or
absence thereof, pertain. Seller represents that said individual is the person
associated with Seller and Seller's affiliates that is the principal person
responsible for asset management with respect to the Property. There shall be no
personal liability on the part of Philip Brannigan arising out of any
representations or warranties made herein or otherwise. If, after the date
hereof and prior to the Closing, either party obtains knowledge that any of the
representations or warranties made herein by the other are untrue, inaccurate or
incorrect in any material respect, such party shall give the other party written
notice thereof within five (5) business days of obtaining such knowledge and the
party so notified shall have the opportunity to cure such matter prior to the
Closing.

     (d) To the extent a Tenant Estoppel Certificate satisfying the requirements
of Article 7(a)(ii) is provided to Buyer which sets forth information with
respect to any item as to which Seller has made a representation or warranty,
then Seller's representation and warranty with respect to such information will
thereafter be null and void and of no further force and effect and Buyer shall
rely on the information in the Tenant Estoppel Certificate.

     ARTICLE 13. Maintenance: New Leases: Between the date hereof and the
Closing, Seller covenants as follows: (a) Seller shall operate the Premises or
cause the Premises to be operated in the ordinary course of business and
consistent with past procedures heretofore followed by it in connection with
such operation, provided, however, that, other than as provided in Article 14,
Seller shall not be obligated to make any capital improvements, capital repair
or capital replacements prior to Closing; and Seller shall perform or cause to
be performed its material obligations under Leases, the Loan Documents and other
agreements affecting the Property.

     (b) Seller shall not (i) permit the removal of any material item of the
Personal Property from the Premises unless the same is obsolete and is replaced
by tangible personal property of equal or greater utility and value or (ii)
transfer, modify or otherwise dispose of any intangible property that is to be
assigned hereunder.

     (c) (i) At any time between the date hereof and the Closing, with respect
to leases of 10,000 square feet or more of net rentable area, and (ii) after the
Due Diligence Period with respect to all other leases, Seller shall not (a)
enter into any lease, (b) amend, modify, or cancel any Lease (or guaranty
thereof) (other than in the case of a tenant default) or (c) grant any consents
under, or waive any provisions of, any Lease, in each case without the prior
written consent of Buyer, which consent shall not be unreasonably withheld,
conditioned or delayed. Any consent requested by Seller pursuant to the
preceding sentence shall be deemed to have been given if Buyer shall fail to
respond to such request within three (3) business days after its receipt of such
request. Seller shall keep Buyer informed of leasing activity at the Property
with respect to leases of less than 10,000 square feet of net rentable area and
shall provide Buyer with copies of executed letters of intent with respect
thereto. From time to time, and in any case no later than two (2) business days
prior to expiration of the Due Diligence Period, Seller shall

                                      -20-

<PAGE>

provide Buyer with copies of all executed leases, licenses and letters of intent
executed during the Due Diligence Period as well as then outstanding written
proposals to tenants.

     Notwithstanding the foregoing, Buyer acknowledges that Seller shall have
the right, before or after the expiration of the Due Diligence Period, without
Buyer's consent so long as such actions are in all material respects in
accordance with the lease summaries provided to Buyer by Seller hereunder, to
enter into the pending lease renewal with Onyx of Alexandria, Inc. and leases
with J & M Printing, Inc., T/A Kwik-Kopy Printing and with Robbins Gioia, Inc.,
a pending amendment to the lease with Wisnewski Blair and Associates, Ltd.
correcting the square footage of the demised premises, and pending storage
leases with Effinity and with the United States of America.

     Additionally, The Village Foundation, a tenant at the Premises, has been in
default under its lease. Rent is presently being collected from its subtenant,
The Taubman Company. Buyer hereby agrees that Seller may enter into an agreement
with The Taubman Company and terminate the lease with The Village Foundation.
Said attornment agreement shall require The Taubman Company to continue to pay
rent at a rate no less than that presently being paid by it. Furthermore, Buyer
agrees that the Estoppel Certificate with respect to the Premises covered by
said lease may be delivered by The Taubman Company.

     (d) Seller shall not, without the prior written consent of Buyer, which
consent may be withheld, conditioned or delayed in Buyer's sole discretion,
enter into any contract which could bind Buyer or the Property after the
Closing, encumber the Property or create or modify any exceptions to title to
the Property, or initiate or consent to any action with respect to zoning or
other Property entitlements or permits.

     (e) After the date hereof, Seller shall not apply any security deposits
paid under the Leases (the "Security Deposits") which term shall include any
interest earned thereon or required to be paid thereon pursuant to the Leases or
applicable laws) to the obligations of any tenant who is or may be in possession
at the Closing without promptly notifying Buyer thereof, which notification
shall specify the reasons for such application.

     ARTICLE 14. Apportionment of Taxes and Other Charges: (a) All normal and
customarily proratable items, including without limitation, real estate and
personal property taxes and assessments, utility bills (except as hereinafter
provided), assessments and common area costs under the Declaration, collected
rents and other income, and Operating Contract payments (under Operating
Contracts assumed by Buyer), shall be prorated as of the Closing Date, Seller
being charged and credited for all of the same relating to the period up to the
Closing Date and Buyer being charged and credited for all of the same relating
to the period on and after the Closing Date. If the amount of any such item is
not known at the time of the delivery of the Deed, such item shall be
apportioned on the basis of the comparable period of the prior year with a
reapportionment within ninety (90) days of the Closing Date or as soon
thereafter as the amount of the item is actually determined. No proration shall
be made in relation to delinquent rents, common area expense charges or tax
payments, (collectively, "Delinquent Rents") existing, if any, as of the Closing
Date. To the extent that such Delinquent Rents and tenant reimbursement
obligations are paid or payable after Closing, Buyer agrees to use reasonable

                                      -21-

<PAGE>

efforts to secure said Delinquent Rents and reimbursement obligations (with no
obligation, however, to incur any additional out-of-pocket costs with respect
thereto) and as soon as the same are received by Buyer, said receipts shall be
apportioned between Seller and Buyer so that Seller shall be entitled to the
portion allocable to the period prior to Closing and Buyer shall be entitled to
the balance. Any Delinquent rent paid to Seller after Closing shall be held in
trust by Seller and applied in accordance with this Contract. All street,
drainage, betterment and like assessments (or portions thereof) assessed against
the Premises prior to Closing relating to periods prior to Closing, shall be
paid by Seller at Closing.

     With respect to percentage rent payable under the Leases for any lease year
ending prior to Closing, any and all percentage rent shall belong to Seller. To
the extent that any such percentage rent is received by Buyer, Buyer shall
promptly pay over the same to Seller. With respect to any lease year during
which the Closing shall take place, Seller shall be entitled to that portion
thereof represented by multiplying such percentage rent by a fraction, the
numerator of which is the number of days of such lease year occurring prior to
Closing and the denominator of which is 365. Buyer shall be entitled to the
balance thereof. Buyer agrees to use reasonable efforts to collect such
percentage rent (with no obligation, however, to incur any additional
out-of-pocket Costs with respect thereto) and promptly after receipt thereof by
Buyer, the same shall be allocated as aforesaid and paid to Seller.

     Seller, as landlord under the Leases, is currently collecting from tenants
under the Leases additional rent to cover taxes, insurance, utilities,
maintenance and other operating costs and expenses (collectively, "Operating
Expense Pass-throughs") incurred by Seller in connection with the ownership,
operating, maintenance and management of the Property. If Seller collected
estimated prepayments of Operating Expense Pass-throughs in excess of any
tenant's share of such expenses, then if the excess can be determined by the
Closing, Buyer shall receive a credit for the excess or, if the excess cannot be
determined at Closing, Buyer shall receive a credit based upon an estimate, and
the parties shall make an adjusting payment between them when the correct amount
can be determined. In either event, Buyer shall be responsible for crediting or
repaying those amounts to the appropriate tenants. If Seller collected estimated
prepayments of Operating Expense Pass-throughs attributable to any period after
Closing, Seller shall pay or credit any such amounts to Buyer at Closing. Within
sixty (60) days after Closing, Seller shall prepare and present to Buyer a final
calculation of Operating Expense Pass-throughs for Seller's period of ownership.
Such final calculation shall include a general ledger pertaining to the portion
of the year under Seller's ownership along with supporting documentation of
tenant's calculations and base year determinations (if applicable). Buyer shall
have sixty (60) days from receipt to review said calculations of Operating
Expense Pass-throughs. If Seller collected payments of Operating Expense
Pass-throughs in excess of any tenant's share of such expense, Buyer shall
receive a credit for the excess. If Seller under-collected payments of Operating
Expense Pass-throughs for any tenant's share of such expenses, an adjustment
will be made between the parties after year-end billing to and receipt from said
tenants.

     Accrued interest on the Loan shall be apportioned as of the Closing Date.
Seller shall be credited with any escrow balances of Seller's funds maintained
in connection with the Loan, all of which shall be assigned to Buyer.

                                      -22-

<PAGE>

     Except as set forth below, Brokerage and leasing commissions, inducements
and contributions and allowances for tenant improvement work; (i) for Leases
entered into prior to the execution date of this Contract shall be borne by
Seller, and Seller shall remain responsible for payment of all such costs and
expenses; and (ii) for Leases entered into during the term of this Contract in
accordance with Article 13(c) shall be borne by Buyer, and with respect to such
new Leases to the extent Seller has actually made any payment for such items
prior to Closing, Buyer shall reimburse Seller at Closing for such payments. In
addition:

          (i)       Attached hereto as Exhibit P is a Schedule of Tenant
                    Inducement Costs and Brokerage Obligations which may become
                    due and payable in the future under existing Leases. Buyer
                    hereby agrees to assume all liability for performance and
                    payment of such obligations identified thereon as Buyer's
                    responsibility and Seller shall either pay at or prior to
                    Closing or credit Buyer at Closing with the amounts of those
                    identified as Seller's responsibility thereunder.

          (ii)      As set forth in Exhibit P, Seller shall pay for all tenant
                    improvement costs and for all brokerage commissions in
                    connection with (a) the renewal of the Onyx of Alexandria,
                    Inc. lease, (b) the lease with Wisnewski Blair and
                    Associates, Ltd. (as well as for the cost of building out
                    the corridor in Building 44 as required by such lease), and
                    (c) the lease expansion with Robbins Gioia, Inc. if such
                    lease is executed.

          (iii)     As set forth in Exhibit P, if the proposed lease with J & M
                    Printing, Inc. T/A Kwik-Kopy Printing is executed, Buyer
                    shall pay for all tenant improvement costs and brokerage
                    commissions in connection with such lease.

     To the extent Seller has performed any tenant improvement work pursuant to
the foregoing, which is Buyer's obligation, Buyer shall reimburse Seller for the
cost thereof at Closing. Similarly, to the extent any work which is Seller's
obligation as aforesaid has not been completed as of the date of Closing, Seller
shall credit Buyer with the remaining costs to complete such work.

          (iv)      Pursuant to its lease, the Hawthorne Group, L.C. has
                    exercised its right to terminate its lease on the fourth
                    floor of the Premises owned by Transpotomac. A termination
                    fee is due from the tenant in December 2002. Buyer shall be
                    entitled to receive such fee.

     Seller is in the process of renovating the lobby of the Improvements owned
by Transpotomac. The scope of work of the renovation is described in Exhibit O.
All of such work shall be performed at Seller's cost, and if such work is not
completed at the time of Closing, Buyer shall receive a credit for the remaining
amounts due to complete such work and Seller shall assign to Buyer in form
reasonably satisfactory to Buyer the outstanding contracts related thereto.

     Buyer shall pay Seller Delinquent Rent as and when collected by Buyer, it
being agreed that Buyer shall not be deemed to have collected any such
arrearages until such time as the

                                      -23-

<PAGE>

tenant is current in the payment of all rents accruing from and after the
Closing. Buyer agrees to bill tenants of the Property for all Delinquent Rents
and to take any additional reasonable actions requested by Seller to collect
Delinquent Rents provided that Buyer shall not be obligated to incur any
material out-of-pocket third party expense in connection with such actions and
Buyer shall not be obligated to take any action to terminate a tenancy. Final
readings and final billings for utilities will be made if possible as of the
Closing Date, in which event no proration shall be made at the Closing with
respect to utility bills. Otherwise a proration shall be made based upon the
parties' reasonable good faith estimate and a readjustment made within thirty
(30) days after Closing or such later date as shall be necessary so that such
readjustment may be based upon actual bills for such utilities. No proration
will be made in relation to insurance premiums and the insurance policies will
not be assigned to Buyer, except to the extent insurance premiums are included
in Common Area expenses, in which event they shall be prorated as provided
above. Seller shall be entitled to receive a return of all deposits presently in
effect with the utility providers, and Buyer shall be obligated to make its own
arrangements for deposits with the utility providers. Buyer shall receive a
credit for all cash Security Deposits then held by Seller and in such event
Buyer shall assume all of Seller's and Seller's Affiliate's obligations to repay
such Security Deposits to Tenants. With respect to any Security Deposits which
are letters of credit, Seller shall, if the same are assignable, deliver to
Buyer at the Closing such letters of credit and shall execute and deliver such
other instruments as the issuers of such letters of credit shall reasonably
require to assign such letters of credit to Buyer. Seller shall cooperate with
Buyer to change the name of the beneficiary under such letters of credit so long
as Seller does not incur any additional cost or expense in connection therewith
other than normal administrative expenses. The provisions of this Article 14
shall survive the Closing for a period of twelve (12) months, and in the event
of any error in performing the prorations contemplated by this Contract or if
information becomes available subsequent to the Closing indicating that the
prorations performed at Closing were not accurate the parties hereto shall be
obligated promptly to reprorate the closing adjustments to correct such errors
and to reflect such new information.

     (b) Seller shall prepare a detailed statement setting forth all closing
adjustments and shall deliver same to Buyer (together with all supporting data)
not less than five (5) business days prior to Closing. Buyer and Seller shall
then jointly prepare the final Closing Statement.

     ARTICLE 15. Broker: (a) Each party represents hereby to the other that it
dealt with no broker in the consummation of this Contract except for Trammell
Crow Company ("Broker") and each party shall indemnify and save the other
harmless from and against any claim arising from the breach of such
representation by the indemnifying party.

     (b) Any commission due Broker shall be paid by Seller, and Seller shall
obtain and provide to Buyer a receipt therefor at Closing.

     (c) The provisions of this Article 15 shall survive the Closing or, if
applicable, the termination of this Contract.

     ARTICLE 16. Continuation and Survival of Representations. Warranties
Indemnifications and Covenants: All representations, warranties,
indemnifications and covenants by Seller in Article 12 hereof (as such
representations, warranties, indemnifications

                                      -24-

<PAGE>

and covenants may be modified pursuant to the next succeeding paragraph of this
Article 16) are intended to be and shall remain true and correct as of the time
of Closing, and, together with Seller's Loan Documents Indemnity, Seller's
liability under any Seller's Estoppel Certificate under Article 7, Seller's
liability and obligations under Articles 13, 14, 15, 21, 25, and 26, and
Seller's representations and warranties and indemnities in favor of Buyer as set
forth in the closing documents executed by Seller at Closing (collectively, the
"Surviving Obligations") shall survive the execution and delivery of this
Contract and the delivery of the Deed and the transfer of title for a period of
one (1) year (except for Seller's Loan Documents Indemnity), and with respect to
any written claim made and delivered by Buyer to Seller within such period, time
being of the essence, until and subject to final unappealable adjudication or
settlement thereof. Any claim must be delivered to Seller on or before that date
which is one (1) year after the Closing Date, time being of the essence, sent by
certified mail, return receipt requested, at the address set forth in Article 18
hereof. No such notice of claim shall be effective unless such notice identifies
such claim with specificity and refers to this Article 16. The Seller's Loan
Documents Indemnity shall survive for the applicable period of limitations with
respect to the underlying liability.

     Beacon Capital Strategic Partners, L.P., by signing this Contract,
covenants and agrees that it shall be jointly and severally liable with Seller
to Buyer and Buyer's successors and assigns and Buyer's first tier and second
tier subsidiaries, for any breach of the Surviving Obligations subject to the
limitations herein set forth.

     To the extent that Buyer knows or is deemed to know, prior to the Closing
Date, that the Seller's representations or warranties in Article 12, in any
Seller's Estoppel Certificate, or elsewhere, are inaccurate, untrue or incorrect
in any way, such representations and warranties shall be deemed modified to
reflect Buyer's knowledge or deemed knowledge, as the case may be. For purposes
of this Contract, Buyer shall be "deemed to know" that a representation or
warranty was untrue, inaccurate or incorrect only to the extent that this
Contract, any estoppel certificate delivered in connection herewith or any
written studies, tests, reports, or analyses prepared by or for Buyer or any of
its employees, agents, representatives or attorneys it utilizes in this
transaction (all of the foregoing being herein collectively called the "Buyer's
Representatives") or otherwise obtained in writing by Buyer or Buyer's
Representatives in the course of their investigation, contains information which
is materially inconsistent with the applicable representation or warranty.
Furthermore, Seller shall have no liability with respect to any Surviving
Obligations or the information in any Seller's Estoppel Certificate to the
extent that, at or prior to Closing, Buyer had knowledge or deemed knowledge, as
described above, of any matter which would give rise to liability with respect
to the particular Surviving Obligation. The waiver with respect to the Surviving
Obligations does not apply to Article 14, 15, 25 or 26.

     Notwithstanding anything in this Contract to the contrary, except for
Seller's obligations to make post-Closing adjustments under Article 14 hereof,
its obligation to indemnify with respect to broker's commissions under Article
15, and to pay closing costs under Article 21, Seller shall be liable to Buyer,
its successors and assigns hereunder, and the first tier and second tier
subsidiaries of Buyer, with respect to the Surviving Obligations only to the
extent of actual damages and only if the actual damages incurred by Buyer or
Buyer's successors and assigns or the first tier and second tier subsidiaries,
as applicable, exceeds $50,000, and, if so, such liability

                                      -25-

<PAGE>

shall include the first dollar of such damage. In addition, except for Seller's
obligations to make post-Closing adjustments under Article 14 hereof, its
obligation to indemnify with respect to broker's commissions under Article 15,
to pay closing costs under Article 21 and under any Seller's Estoppel
Certificate and under Seller's Loan Documents Indemnity (all of which are not
limited by such cap and which do not count against such cap), the maximum
aggregate liability of Seller and the maximum aggregate amount which may be
awarded to and collected by Buyer or Buyer's successors and assigns for all
breaches of the Surviving Obligations shall in no event exceed the lesser of (a)
the actual damages incurred by Buyer or Buyer's successors and assigns and the
first tier and second tier subsidiaries and (b) $2,500,000.00. Buyers acceptance
and recording of the Deed shall be deemed full compliance by Seller of all of
its obligations hereunder other than Seller's Surviving Obligations.

     Except for the Surviving Obligations and with reservation by Buyer and the
first and second tier subsidiaries of Buyer of any defense or right of
contribution or indemnity against Seller or any other party released hereunder
in connection with a claim against Buyer or any subsidiary of Buyer brought by a
third party pursuant to Article 6, Seller or any party released hereunder, by
accepting and recording the Deed, Buyer, for itself and its successors and
assigns hereby releases and forever discharges Seller, and their partners,
beneficial owners, offices, directors, employees, and agents from any and all
claims, acts, debts, demands, actions, causes of action, suits, sums of money,
guaranties, bonds, covenants, contracts, accounts, agreements, promises,
representations, restitutions, omissions, variances, damages, obligations,
costs, response actions, fees and liabilities of every name and nature
whatsoever, both at law and in equity, which Buyer and its successors and
assigns may now or hereafter have with respect to matters existing as of the
Closing Date against Seller, or their partners, beneficial owners, officers,
directors, employees, or agents arising in connection with this Contract, the
Property, or the transaction contemplated hereby.

     ARTICLE 17. Recording: It is agreed that this Contract shall not be filed
for recording in the land records of the City of Alexandria, Virginia. If for
any reason before the Closing Buyer files or records a copy of this Contract
with any such body other than in connection with an action for specific
performance, Seller may elect to terminate this Contract by written notice to
Buyer, and in such event, Seller shall be entitled to the Deposit and upon
receipt of such Deposit, neither party shall thereafter have any further
recourse one to the other hereunder, provided, however, that Buyer shall be
required to fulfill its obligations under Articles 6(b), 6(d), 6(g), 15 and
27(a) hereof.

     ARTICLE 18. Notices: Any notice or communication which may be or is
required to be given pursuant to the terms of this Contract shall be in writing
and shall be sent to the respective party at the address set forth in the first
paragraph of this Contract, (i) postage prepaid, by Certified Mail, Return
Receipt Requested, or (ii) by a nationally recognized overnight courier service
that provides tracing and proof or receipt of items mailed, or to such other
address as either party may designate by notice similarly sent or (iii) by
facsimile, with an original to be sent by either of the aforesaid methods of
delivery. Notices shall be effective upon receipt or attempted delivery if
delivery is refused or the party no longer receives deliveries at said address
and no new address has been given to the other party pursuant to this paragraph.
A copy of any notice to Seller shall also be simultaneously sent to (i) Beacon
Capital Partners, One Federal

                                      -26-

<PAGE>

Street, Boston, MA 02110, Attention: Erin O'Boyle, Senior Vice President, (ii)
Beacon Capital Partners, One Federal Street, Boston, MA 02110, Attention:
William A. Bonn, Senior Vice President and General Counsel, and (iii) Goulston &
Storrs, 400 Atlantic Avenue, Boston, MA 02110-3333, Attention: Jordan P.
Krasnow, Esq. Any notice sent to Buyer shall be sent to (i), CarrAmerica Realty
Corporation, 1850 K Street NW, Suite 500, Washington, D.C. 20006, Attn: Tom Levy
(ii) and a copy shall also be simultaneously sent to Mayer, Brown, Rowe & Maw,
1909 K Street, NW, Washington, D.C. 20006, Attn: Scott Morehouse.

     ARTICLE 19. Caption: The captions in this Contract are inserted only for
the purpose of convenient reference and in no way define, limit or prescribe the
scope or intent of this Contract or any part hereof.

     ARTICLE 20. Successors and Assigns: (a) This Contract shall be binding upon
the parties hereto and their respective successors and assigns.

     (b) Buyer may assign this Contract and the rights or benefits hereof
including, without limitation, the benefit of the representations and warranties
contained in Article 12 hereof, to any party (or parties) of which Buyer owns or
controls not less than fifty-one percent (51%) of the legal and beneficial
interests, and to any qualified intermediary pursuant to Article 28, but in any
case no such assignment shall relieve Buyer of its obligations hereunder. No
such assignment shall be permitted which is inconsistent with any submission to
the holders of the Loan and which would affect any consent to assignment given
by such holders. The first and second tier subsidiaries formed by Buyer in
connection with this transaction are, in addition to Buyer, the beneficiaries of
any rights of Buyer and of any obligations owing by Seller hereunder and under
the closing documents, as applicable.

     ARTICLE 21. Closing Cost: Except as herein specifically provided, Seller
and Buyer shall allocate all closing costs between them in accordance with
standard practice in Alexandria, Virginia. Except for the Exhibits attached
hereto, each of Seller and Buyer shall be responsible for preparing such
documents as it is obligated to deliver pursuant to Article 5 hereof and for its
own legal expenses. Seller shall pay the "Grantor" tax pursuant to Virginia Code
Section 58.1802 and Buyer shall pay any and all other deed, transfer and
recordation taxes and fees other than recording fees for documents to clear
title. Buyer shall pay for its due diligence costs, the fees of its counsel,
title insurance, survey and all assumption fees and other costs associated with
the assumption of the Loan.

     ARTICLE 22. Governing Law: The laws of the Commonwealth of Virginia shall
govern the validity, construction, enforcement and interpretation of this
Contract.

     ARTICLE 23. Multiple Counterparts: This Contract may be executed in any
number of identical counterparts. If so executed, each of such counterparts
shall constitute this Contract. In proving this Contract, it shall not be
necessary to produce or account for more than one such counterpart.

     ARTICLE 24. Representations and Warranties of Buyer: Buyer hereby
represents and warrants to Seller as of the date hereof and as of the Closing
Date as follows:

                                      -27-

<PAGE>

     (a) This Contract and all documents executed by Buyer that are to be
delivered to Seller at the Closing are, or at the time of Closing will be, duly
authorized, executed and delivered by Buyer. This Contract and such documents
are, or at the Closing will be, legal, valid, and binding obligations of Buyer,
and do not, and, at the time of Closing will not, violate any provisions of any
agreement or judicial order to which Buyer is a party or to which it is subject.

     (b) There are no proceedings pending or, to Buyer's knowledge, threatened
against it in any court or before any governmental authority or any tribunal
which, if adversely determined, would have a material adverse effect on its
ability to purchase the Property or to carry out its obligations under this
Contract.

     (c) Buyer shall indemnify and defend Seller against and hold Seller
harmless from any and all losses, costs, damages, liabilities and expenses
(including, without limitation, reasonable counsel fees) arising out of any
breach by Buyer of its representations and warranties hereunder.

     (d) Buyer has adequate financial resources to fully perform all of its
obligations under this Contract, including payment to Seller of the Purchase
Price.

     ARTICLE 25. Post-Closing Obligation: After the Closing, Seller and Buyer
shall cooperate with one another at reasonable times and on reasonable
conditions and shall execute and deliver such instruments and documents as may
be necessary in order fully to carry out the intent and purposes of the
transactions contemplated hereby. Except for such instruments and documents as
the parties were originally obligated to deliver by the terms of this Contract,
such cooperation shall be without additional cost or liability.

     ARTICLE 26. Duties and Responsibilities of Escrow Agent: Except as
otherwise specifically directed in this Contract, Escrow Agent shall deliver the
Deposit (for purposes of this Article 26, the "Escrow") to Seller or Buyer
promptly after receiving a joint notice from Seller and Buyer directing the
disbursement of the same, such disbursement to be made in accordance with such
direction. If Escrow Agent receives notice from Buyer or Seller that the party
giving such notice is entitled to the Escrow, which notice shall describe with
reasonable specificity the reasons for such entitlement, then Escrow Agent shall
(i) promptly give notice to the other party of Escrow Agent's receipt of such
notice and enclosing a copy of such notice and (ii) subject to the provisions of
the following paragraph which shall apply if a conflict arises, on the fifth
(5th ) day after the giving of the notice referred to in clause (i) above,
deliver the Escrow to the party claiming the right to receive it.

     In the event that Escrow Agent shall be uncertain as to its duties or
actions hereunder or shall receive instructions or a notice from Buyer or Seller
which are in conflict with instructions or a notice from the other party or
which, in the reasonable opinion of Escrow Agent, are in conflict with any of
the provisions of this Contract, it shall be entitled to take any one or more of
the following courses of action:

                                      -28-

<PAGE>

     (a) Hold the Escrow as provided in this Contract and decline to take any
further action until Escrow Agent receives a joint written direction from Buyer
and Seller or any order of a court of competent jurisdiction directing the
disbursement of the Escrow, in which case Escrow Agent shall then disburse the
Escrow in accordance with such direction;

     (b) In the event of litigation between Buyer and Seller, deliver the Escrow
to the clerk of any court in which such litigation is pending; or

     (c) Deliver the Escrow to a court of competent jurisdiction and therein
commence an action for interpleader, the cost thereof to Escrow Agent to be
borne by whichever of Buyer or Seller does not prevail in the litigation.

     Escrow Agent shall not be liable for any action taken or omitted in good
faith and reasonably believed by it to be authorized or within the rights or
powers conferred upon it by this Contract and it may rely, and shall be
protected in acting or refraining from acting in reliance upon an opinion of
counsel and upon any directions, instructions, notice, certificate, instrument,
request, paper or other documents believed by it to be genuine and to have been
made, sent, signed or presented by the proper party or parties. In no event
shall Escrow Agent's liability hereunder exceed the aggregate amount of the
Escrow. Escrow Agent shall be under no obligation to take any legal action in
connection with the Escrow or this Contract or to appear in, prosecute or defend
any action or legal proceedings which would or might, in its sole opinion,
involve it in cost, expense, loss or liability unless, in advance, and as often
as reasonably required by it, Escrow Agent shall be furnished with such security
and indemnity as it finds reasonably satisfactory against all such cost,
expense, loss or liability. Notwithstanding any other provision of this
Contract, Buyer and Seller jointly indemnify and agree to hold harmless Escrow
Agent against any loss, liability or expense incurred without bad faith on its
part and arising out of or in connection with its services under the terms of
this Contract, including the cost and expense of defending itself against any
claim of liability.

     Except under this Article 26 and, as applicable, Article 27, Escrow Agent
is not a party to this Contract. Escrow Agent shall not be bound by any
modification of this Article 26 unless the same is in writing and signed by
Buyer, Seller and Escrow Agent. From time to time on or after the date hereof,
Buyer and Seller shall deliver or cause to be delivered to Escrow Agent such
further documents and instruments that fall due, or cause to be done such
further acts as Escrow Agent may reasonably request (it being understood that
the Escrow Agent shall have no obligation to make any such request) to carry out
more effectively the provisions and purposes of this Contract, to evidence
compliance with this Contract or to assure itself that it is protected in acting
hereunder.

     Escrow Agent shall serve hereunder without fee for its services as escrow
agent, but shall be entitled to reimbursement for expenses incurred hereunder,
which expenses shall be paid and borne equally by Buyer and Seller, unless such
expenses are associated with litigation between Buyer and Seller, in which event
they shall be borne by the party that does not prevail in the litigation. Escrow
Agent agrees that it will not seek reimbursement for the services of its
employees or partners, but only for its actual and reasonably incurred
out-of-pocket expenses. Escrow Agent executes this Contract solely for the
purpose of consent to, and agreeing to be

                                      -29-

<PAGE>

bound by the provisions of this Article 26, and to the extent applicable to
Escrow Agent, Article 3 and Article 27.

     ARTICLE 27. Disclosure.

     (a) Public Disclosure of Contracts. Prior to the Closing, Buyer and its
respective officers, directors, employees, consultants, attorneys, advisors,
underwriter, potential financial sources and agents will hold in confidence,
unless compelled to disclose by judicial or administrative process or applicable
law, all documents and information relating to the transaction contemplated by
this Contract, including, without limitation, any information relating to the
Property provided to Buyer by Seller in connection herewith; provided, however,
that Buyer may, prior to the Closing, disclose such information to its officers,
directors, employees, consultants, attorneys, advisors and agents so long as
such persons are informed by Buyer of the confidential nature of such
information and are directed by Buyer to treat such information confidentially.
If this Contract is terminated prior to the Closing Date, all such confidences
not already disclosed shall continue to be maintained. In the event this
Contract is terminated, whether before or after the Closing, Buyer and its
respective officers, directors, employees, consultants, advisors, attorneys, and
agents shall deliver to the Seller, upon request, all documents and other
materials, and all copies thereof, obtained from Seller or its agents in
connection with this Contract. By execution of this Contract, Escrow Agent
hereby agrees to maintain the existence of this Contract and the nature and
details of the transaction contemplated hereby in confidence, unless Escrow
Agent is required by law to disclose some or all of such information.

     ARTICLE 28. Like Kind Exchange. Buyer may consummate the purchase of the
Property as part of a so-called like kind exchange (the "Exchange") pursuant to
(S) 1031 of the Internal Revenue Code of 1986, as amended (the "Code"), provided
that: (1) the Exchange does not result in an inability to satisfy the Lender's
requirements for the assumption of the Loan, such as, for example, its special
purpose entity requirements; (2) the Closing shall not be delayed or affected by
reason of the Exchange nor shall the consummation or accomplishment of the
Exchange be a condition precedent or condition subsequent to Buyer's obligations
under this Agreement; (3) Buyer shall effect the Exchange through an assignment
of this Agreement, or its rights under this Agreement, to a qualified
intermediary; (3) Seller shall not be required to take an assignment of the
purchase agreement for the relinquished property or be required to acquire or
hold title to any real property for purposes of consummating the Exchange; and
(4) Buyer shall pay any additional, reasonable out of pocket costs that would
not otherwise have been incurred by Seller had Buyer not consummated its
purchase through the Exchange. Seller shall not by this agreement or
acquiescence to the Exchange have its rights under this Agreement affected or
diminished in any manner or be responsible for compliance with or be deemed to
have warranted to Buyer that the Exchange in fact complies with (S) 1031 of the
Code.

                                      -30-

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Contract as an
instrument under seal as of the day and date first written above.

In the presence of   SELLER:

                     CANAL CENTER PROPERTIES LLC, a Delaware limited liability
                     company

                     By: ALEXMEZZ LLC, a Delaware limited liability company,
                         its manager

                         By: Beacon Capital Strategic Partners, L.P., a Delaware
                             limited partnership, its manager

                             By: BCP Strategic Partners, LLC, a Delaware limited
                                 liability company, its general partner

                                 By: Beacon Capital Partners, L.P., a Delaware
                                     limited partnership, its sole member

                                     By: Beacon Capital Partners, Inc., a
                                         Maryland corporation, its general
                                         partner


/s/ KATHLEEN M. McCARTHY                 By: /s/ WILLIAM A. BONN
-------------------------                    -----------------------------------
                                             Name:  WILLIAM A. BONN, ESQ.
                                             Title: Hereunto duly authorized
                                                    Senior Vice President &
                                                    General Counsel

                                      -31-

<PAGE>

                     TRANSPOTOMAC V LLC, a Delaware limited liability company

                     By: ALEXMEZZ LLC, a Delaware limited liability company,
                         its manager

                         By: Beacon Capital Strategic Partners, L.P., a Delaware
                             limited partnership, its manager

                             By: BCP Strategic Partners, LLC, a Delaware limited
                                 liability company, its general partner

                                 By: Beacon Capital Partners, L.P., a Delaware
                                     limited partnership, its sole member

                                     By: Beacon Capital Partners, Inc., a
                                         Maryland corporation, its general
                                         partner


/s/ KATHLEEN M. McCARTHY                 By: /s/ WILLIAM A. BONN
------------------------                     -----------------------------------
                                             Name:  WILLIAM A. BONN, ESQ.
                                             Title: Hereunto duly authorized
                                                    Senior Vice President &
                                                    General Counsel

                                      -32-

<PAGE>

                     BUYER:

                     CARRAMERICA REALTY CORPORATION


                     By: /s/ KAREN B. DORIGAN
                         ------------------------------------


                     ESCROW AGENT:

                     FIRST AMERICAN TITLE INSURANCE COMPANY


                     By: /s/ JAY MELKONIAN
                         ------------------------------------
                         Name: JAY MELKONIAN
                         Title: NATIONAL UNDERWRITING COUNSEL

     Beacon Capital Strategic Partners, L.P. joins in the execution of the above
Contract with respect to its agreements and undertakings set forth in Article
16.

                     Beacon Capital Strategic Partners, L.P., a Delaware limited
                     partnership

                         By: BCP Strategic Partners, LLC, a Delaware limited
                             liability company, its general partner

                             By: Beacon Capital Partners, L.P., a Delaware
                                 limited partnership, its sole member

                                 By: Beacon Capital Partners, Inc., a Maryland
                                     corporation, its general partner


/s/ KATHLEEN M. McCARTHY             By: /s/ WILLIAM A. BONN
------------------------                 ---------------------------------------
                                         Name:  WILLIAM A. BONN, ESQ.
                                         Title: Hereunto duly authorized
                                                Senior Vice President &
                                                General Counsel


                                      -33-