Exhibit 2.1
                           PURCHASE AND SALE AGREEMENT


     THIS AGREEMENT is made as of the 20th day of September, 1996 by and between
DANIEL W. CUMMINGS,  STUART L. SCOTT, ROBERT C. SPOERRI and LYNN C. THURBER, not
personally,  but as Trustees  under that  certain  Declaration  of Trust,  dated
October 1, 1983,  creating  LASALLE FUND II, a group trust,  acting  through its
agent and manager,  LaSalle Advisors Limited (hereinafter called "Seller"),  and
BEACON PROPERTIES, L.P., a Delaware limited partnership ("Purchaser").


                              W I T N E S S E T H:


     WHEREAS,  Seller owns the office buildings  located at 1616 North Fort Myer
Drive  (the  "1616  Building")  and 1300  North  Seventeenth  Street  (the "1300
Building") in Rosslyn, Virginia; and

     WHEREAS,  Seller desires to sell its interest in such office  buildings and
Purchaser  desires  to  purchase  such  interest  from  Seller  on the terms and
conditions set forth below;

     NOW,  THEREFORE,  in  consideration  of the  premises  and  the  respective
undertakings of the parties hereinafter set forth, it is hereby agreed:

     SECTION 1.  DEFINITIONS.  Wherever  used in this  Agreement,  the words and
phrases set forth below shall have the meanings set forth below or in an Exhibit
to this  Agreement  to which  reference  is made,  unless  the  context  clearly
requires otherwise.

     A. "Closing" means the closing at which Seller conveys title to the Project
to Purchaser and Purchaser pays Seller the purchase price described in Section 2
herein below.

     B.  "Closing  Date" means the date  mutually  agreed upon by Purchaser  and
Seller for the Closing  provided  the Closing  Date shall be no earlier than two
(2) business days after the Due Diligence  Deadline (defined below) and no later
than thirty  (30)  business  days after the Due  Diligence  Deadline;  provided,
however,  the Closing  Date may be extended  either (i) by mutual  agreement  of
Purchaser and Seller or (ii) pursuant to the terms hereof.

     C. "Improvements" means all buildings, structures, fixtures and other
improvements now or hereafter located or erected on the Land (other than any
trade fixtures owned by tenants).

     D. "Land" means the real property described on Exhibit A, including all
adjacent roadways, rights-of-way and alleys to the


extent Seller has an interest therein, all oil, gas and other mineral rights and
all easements and other rights appurtenant to such real property.

     E. "Permitted  Exceptions" means  non-delinquent real property taxes on the
Project  and any  other  title  exceptions  set  forth on the  Title  Commitment
(defined  below) which are not objected to by Seller  within the time period set
forth in Paragraph 6(1) below.

     I. "Personal  Property" means all tangible and intangible personal property
now or hereafter  owned by the Seller and used in connection  with the operation
of the Project, including, without limitation, (i) all building and construction
materials,  equipment,  appliances  and  machinery  owned by Seller  and used in
connection  with the  operation  of the  Project,  (ii) all  permits,  licenses,
certificates and approvals issued in connection with the Project,  and (iii) the
personal property listed on Exhibit K attached hereto.  The Purchaser and Seller
may revise Exhibit K by mutual agreement prior to the Due Diligence Deadline.

     J. "Project" means the Land, the Improvements and the Personal Property.

     K. "Title Company" means Commonwealth Land Title Insurance Company.

     SECTION 2. EARNEST MONEY; AGREEMENT TO SELL AND PURCHASE.

     A. Earnest Money. Purchaser has deposited $2,000,000 with the Title Company
(which,  together with any interest earned thereon, is herein referred to as the
"Earnest  Money").  The  Earnest  Money  shall be held by the Title  Company  in
accordance  with the terms hereof and invested in  accordance  with  Purchaser's
direction,  subject to the reasonable  approval of Seller.  If this Agreement is
terminated due to Purchaser's default hereunder, the Earnest Money shall be paid
to Seller as liquidated  damages and as Seller's sole and exclusive  remedy.  If
the Closing  occurs  hereunder,  the  Earnest  Money shall be paid to Seller and
credited against the Purchase Price. If the Closing does not occur hereunder for
any reason other than Purchaser's default hereunder,  the Earnest Money shall be
refunded to Purchaser or Purchaser shall have the remedy of specific performance
as provided below.

     B. Purchase and Sale. On the Closing Date Seller shall convey the Project
to Purchaser on the terms and conditions set forth herein. On the Closing Date
the Purchaser shall accept title to the Project from Seller on the terms and
conditions set forth herein and shall pay to the Seller the purchase price
("Purchase Price") of ONE HUNDRED MILLION DOLLARS ($100,000,000), subject to
prorations as set forth below, by wire transfer of immediately available funds.
The Purchase Price shall be

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allocated as follows: $40,000,000 to the 1616 Building and $60,000,000 to the
1300 Building.

     SECTION 3. REPRESENTATIONS AND WARRANTIES BY SELLER. Seller hereby
represents and warrants to, and covenants and agrees with, Purchaser as follows:

     A. Due Organization. Seller is a group trust duly organized and validly
existing under the laws of the State of Illinois; Seller has full power and
authority, and is duly authorized, to execute, enter into, deliver and perform
this Agreement and its obligations hereunder.

     B. Power.  LaSalle  Advisors Limited has full power and authority on behalf
of Seller to execute this Agreement and all other  agreements,  instruments  and
documents  required to be executed or delivered by Seller pursuant hereto.  This
Agreement and all other  agreements,  instruments  and documents  required to be
executed  or  delivered  by  Seller  pursuant  hereto  have been or (if and when
executed)  will be duly  executed and delivered by LaSalle  Advisors  Limited on
behalf of Seller,  and are or will be legal,  valid and binding  obligations  of
Seller.  No consents and  permissions  are required to be obtained by Seller for
the execution and  performance of this  Agreement and the other  documents to be
executed by Seller hereunder. The consummation of the transactions  contemplated
herein and the  fulfillment  of the terms  hereof will not result in a breach of
any of the terms or provisions of, or constitute a default under,  any agreement
or  document  to which the  Seller  is a party or by which it is  bound,  or any
order,  rule or  regulation  of any court or of any federal or state  regulatory
body  or  any  administrative  agency  or any  other  governmental  body  having
jurisdiction over the Seller or the Project.

     C. No  Proceedings.  Except as set  forth in  Exhibit  B,  there is not now
pending or, to  Seller's  actual  knowledge,  threatened,  any  action,  suit or
proceeding before any court or governmental agency or body against the Seller or
the Project which might have any material adverse result to the Project. Without
limiting the  generality of the  foregoing,  Seller has not received any written
notices from any  governmental  entities of violations or alleged  violations of
any laws, rules, regulations or codes, including,  without limitation,  building
codes,  land use, zoning,  hazardous wastes and other  environmental  laws, with
respect to the Project which have not been corrected to the  satisfaction of the
governmental agency issuing such notices.

     D. Eminent Domain. There are no pending, or to Seller's actual knowledge,
threatened condemnation, eminent domain or similar proceedings relating to the
Project or any portion thereof or any interest or estate therein.

                                       3


     E. Zoning;  Taxes.  There are no pending or, to Seller's actual  knowledge,
threatened  zoning  changes or variances  with  respect to the Project;  nor has
Seller initiated any request or application for a zoning change or variance with
respect to the Project.  There are no pending or, to Seller's actual  knowledge,
threatened  reassessments or special tax assessments  against the Project except
for normal  reassessments  applicable generally to properties in the area of the
Project.

     F. Service  Contracts.  Attached hereto as Exhibit C is a true, correct and
complete  list of all contracts or agreements to which Seller is a party for the
providing  of services to or  management  of the Project  (which  contracts  and
agreements, together with the contracts and agreements entered into with respect
to the Project  after the date hereof with the consent of Purchaser  pursuant to
Section  6  below,   are  herein   referred  to  collectively  as  the  "Service
Contracts").  To Seller's actual knowledge,  all of the Service Contracts are in
full force and effect and free from material default, and Seller has received no
written  notice of material  default under the Service  Contracts from the other
parties thereto.

     G.  Tenant  Leases.  Attached  hereto as Exhibit D is a true,  correct  and
complete  list of all  outstanding  leases or  agreements  pursuant to which any
person occupies, or has the right to occupy, space in the Project (which leases,
agreements and other documents,  together with the lease documents  entered into
with respect to the Project  after the date hereof with the consent of Purchaser
pursuant to Section 6 below,  are herein referred to collectively as the "Tenant
Leases"). Seller has delivered to Purchaser true, correct and complete copies of
the Tenant  Leases.  Except as shown on such  exhibit,  (a) to  Seller's  actual
knowledge, there are no material defaults under any of the Tenant Leases and the
Tenant Leases are in full force and effect,  (b) there are no security  deposits
nor any  rights to  refunds of rents  previously  paid  under the Tenant  Leases
except for year-end  reconciliations  of 1996 operating expenses and real estate
taxes, (c) there are no brokerage  commissions or fees due now or payable in the
future in connection with the Tenant Leases,  (d) Seller has received no written
notice of material default under the Tenant Leases from the lessees  thereunder,
(e) there are no prepaid  rents except for the current  month,  (f) there are no
outstanding rent arrearages or, to Seller's actual knowledge, offset rights, (g)
there are no tenant improvement expenditures or tenant improvement reimbursement
obligations  which  are  currently  outstanding,  and  (h)  there  are no  other
brokerage   agreements  in  effect  with  respect  to  the  Project.   Purchaser
understands and agrees,  however,  that Seller is not making any representations
or  warranties  with  respect  to any  information  on  Exhibit  D which  is not
expressly  referenced in this paragraph and that such information is included on
Exhibit D solely as a matter of convenience for Purchaser.

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     H. Labor Contracts. Seller has no employees working at the Project. All
persons working on behalf of Seller at the Project are employees of Seller's
managing agent for the Project, and Purchaser will be under no obligation to use
or hire such employees or such managing agent for the Project after Closing.

     I. Limitations on Representations and Warranties.  As used herein, the term
"Seller's actual  knowledge" means the conscious  knowledge of Jana L. Langston,
Joe Donovan,  Trina Santry, and Karen Schumacher,  and such persons shall not be
obligated to perform any due diligence  investigations in connection with making
any  representations or warranties herein. All representations and warranties of
Seller in this  Agreement  shall  terminate  one (1) year after the  Closing and
Seller shall have no liability  thereafter with respect to such  representations
and warranties except to the extent Purchaser has filed a lawsuit against Seller
during such one (1) year period for breach of any representation or warranty. If
Purchaser has actual  knowledge (as such term is defined in Section 4(E) hereof)
at  Closing  that any of the  Seller's  representations  or  warranties  in this
Agreement are not true as of the Closing and  Purchaser  elects  nonetheless  to
close,  Purchaser  shall be deemed to have  waived  any claim for breach of such
representation  or  warranty.  In  addition,  Seller  shall be  relieved  of any
liability for the  representations  and  warranties  contained in Paragraph 3(G)
with  respect  to any Tenant  Lease to the  extent  Purchaser  has  received  an
estoppel certificate  expressly covering the matters set forth in Paragraph 3(G)
from the party who is the tenant under such Tenant  Lease.  Seller shall have no
liability for the breach of any  representations or warranties set forth in this
Agreement  except to the extent the loss  suffered by  Purchaser  as a result of
such breaches exceeds $100,000 in the aggregate.

     J. Disclaimer. EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, PURCHASER
ACKNOWLEDGES AND AGREES THAT SELLER HAS NOT MADE, DOES NOT MAKE AND SPECIFICALLY
NEGATES AND DISCLAIMS ANY REPRESENTATIONS, WARRANTIES, PROMISES, COVENANTS,
AGREEMENTS OR GUARANTIES OF ANY KIND OR CHARACTER WHATSOEVER, WHETHER EXPRESS OR
IMPLIED, ORAL OR WRITTEN, PAST, PRESENT OR FUTURE, OF, AS TO, CONCERNING OR WITH
RESPECT TO (A) THE VALUE, NATURE, QUALITY OR CONDITION OF THE PROJECT,
INCLUDING, WITHOUT LIMITATION, THE WATER, SOIL AND GEOLOGY, (B) THE INCOME TO BE
DERIVED FROM THE PROJECT, (C) THE SUITABILITY OF THE PROJECT FOR ANY AND ALL
ACTIVITIES AND USES WHICH PURCHASER OR ANY TENANT MAY CONDUCT THEREON, (D) THE
COMPLIANCE OF OR BY THE PROJECT OR ITS OPERATION WITH ANY LAWS, RULES,
ORDINANCES OR REGULATIONS OF ANY APPLICABLE GOVERNMENTAL AUTHORITY OR BODY, (E)
THE HABITABILITY, MERCHANTABILITY, MARKETABILITY, PROFITABILITY OR FITNESS FOR A
PARTICULAR PURPOSE OF THE PROJECT, (F) THE MANNER OR QUALITY OF THE CONSTRUCTION
OR MATERIALS, IF ANY, INCORPORATED INTO THE PROJECT, (G) THE MANNER, QUALITY,
STATE OF REPAIR OR LACK OF REPAIR OF THE PROJECT, OR (H) COMPLIANCE WITH ANY
ENVIRONMENTAL PROTECTION, POLLUTION OR LAND USE LAWS, RULES, REGULATIONS,

                                       5



ORDERS  OR  REQUIREMENTS,  INCLUDING  THE  EXISTENCE  IN OR ON THE  PROPERTY  OF
HAZARDOUS  MATERIALS (AS DEFINED  BELOW) OR (I) ANY OTHER MATTER WITH RESPECT TO
THE PROJECT, ADDITIONALLY, NO PERSON ACTING ON BEHALF OF SELLER IS AUTHORIZED TO
MAKE, AND BY EXECUTION HEREOF OF PURCHASER ACKNOWLEDGES THAT NO PERSON HAS MADE,
ANY  REPRESENTATION,   AGREEMENT,   STATEMENT,  WARRANTY,  GUARANTY  OR  PROMISE
REGARDING  THE  PROJECT  OR THE  TRANSACTION  CONTEMPLATED  HEREIN;  AND NO SUCH
REPRESENTATION, WARRANTY, AGREEMENT, GUARANTY, STATEMENT OR PROMISE IF ANY, MADE
BY ANY PERSON  ACTING ON BEHALF OF SELLER  SHALL BE VALID OR BINDING UPON SELLER
UNLESS  EXPRESSLY SET FORTH HEREIN.  PURCHASER  FURTHER  ACKNOWLEDGES AND AGREES
THAT HAVING BEEN GIVEN THE  OPPORTUNITY  TO INSPECT THE  PROJECT,  PURCHASER  IS
RELYING  SOLELY  ON  ITS  OWN  INVESTIGATION  OF  THE  PROPERTY  AND  NOT ON ANY
INFORMATION  PROVIDED OR TO BE PROVIDED BY SELLER  EXCEPT AS EXPRESSLY SET FORTH
IN THIS AGREEMENT, AND AGREES TO ACCEPT THE PROJECT AT THE CLOSING AND WAIVE ALL
OBJECTIONS OR CLAIMS AGAINST SELLER (INCLUDING, BUT NOT LIMITED TO, ANY RIGHT OR
CLAIM  OF  CONTRIBUTION)  ARISING  FROM OR  RELATED  TO THE  PROPERTY  OR TO ANY
HAZARDOUS  MATERIALS  ON THE  PROPERTY  EXCEPT  AS  EXPRESSLY  SET FORTH IN THIS
AGREEMENT.  PURCHASER  FURTHER  ACKNOWLEDGES  AND  AGREES  THAT ANY  INFORMATION
PROVIDED OR TO BE PROVIDED  WITH  RESPECT TO THE  PROJECT  WAS  OBTAINED  FROM A
VARIETY OF SOURCES AND THAT SELLER HAS NOT MADE ANY INDEPENDENT INVESTIGATION OR
VERIFICATION  OF  SUCH  INFORMATION  AND  MAKES  NO  REPRESENTATIONS  AS TO  THE
ACCURACY,  TRUTHFULNESS OR COMPLETENESS OF SUCH INFORMATION  EXCEPT AS EXPRESSLY
SET FORTH IN THIS AGREEMENT.  SELLER IS NOT LIABLE OR BOUND IN ANY MANNER BY ANY
VERBAL OR WRITTEN  STATEMENT,  REPRESENTATION  OR INFORMATION  PERTAINING TO THE
PROJECT,  OR THE  OPERATION  THEREOF,  FURNISHED  BY  ANY  REAL  ESTATE  BROKER,
CONTRACTOR,  AGENT,  EMPLOYEE,  SERVANT OR OTHER PERSON. EXCEPT AS EXPRESSLY SET
FORTH IN THIS AGREEMENT,  PURCHASER FURTHER  ACKNOWLEDGES AND AGREES THAT TO THE
MAXIMUM EXTENT  PERMITTED BY LAW, THE SALE OF THE PROJECT AS PROVIDED FOR HEREIN
IS MADE ON AN "AS IS" CONDITION AND BASIS WITH ALL FAULTS.  IT IS UNDERSTOOD AND
AGREED THAT THE PURCHASE PRICE HAS BEEN ADJUSTED BY PRIOR NEGOTIATION TO REFLECT
THAT ALL OF THE PROJECT IS SOLD BY SELLER AND PURCHASED BY PURCHASER  SUBJECT TO
THE  FOREGOING.  THE PROVISIONS OF THIS SECTION SHALL SURVIVE THE CLOSING OR ANY
TERMINATION  HEREOF. IN NO EVENT,  HOWEVER,  SHALL ANY PROVISION OF THIS SECTION
(J) BE INTERPRETED OR APPLIED IN ANY MANNER SO AS TO LIMIT,  IMPAIR OR PREJUDICE
THE  RIGHTS OF  PURCHASER  HEREUNDER  WITH  RESPECT TO THE  REPRESENTATIONS  AND
WARRANTIES  PROVIDED  BY OR ON  BEHALF  OF  SELLER  IN  THIS  AGREEMENT  OR  THE
CONDITIONS TO PURCHASER'S OBLIGATIONS TO CLOSE.

     SECTION 4. REPRESENTATIONS AND WARRANTIES OF PURCHASER. Purchaser hereby
represents and warrants to, and covenants and agrees with, Seller as of the date
hereof and as of the Closing as follows:

     A. Due Organization. Purchaser is a limited partnership organized, validly
existing and in good standing under the laws of the State of Delaware. Purchaser
has full power and


                                       6



authority,  and is duly authorized,  to execute, enter into, deliver and perform
this Agreement and its obligations hereunder.

     B.  Power.  This  Agreement  and  all  other  agreements,  instruments  and
documents required to be executed or delivered by Purchaser pursuant hereto have
been or (if and when executed) will be duly executed and delivered by Purchaser,
and are or will be  legal,  valid  and  binding  obligations  of  Purchaser.  No
consents  and  permissions  are  required to be obtained  by  Purchaser  for the
execution  and  performance  of this  Agreement  and the other  documents  to be
executed  by  Purchaser   hereunder.   The   consummation  of  the  transactions
contemplated herein and the fulfillment of the terms hereof will not result in a
breach of any of the terms or provisions of, or constitute a default under,  any
agreement or document to which  Purchaser is a party or by which it is bound, or
any order, rule or regulation of any court or of any federal or state regulatory
body  or  any  administrative  agency  or any  other  governmental  body  having
jurisdiction over Purchaser.

     C. No Proceedings. There is not now pending or, to Purchaser's actual
knowledge, threatened any action, suit or proceeding before any court or
governmental agency or body which might adversely affect Purchaser's ability to
perform its obligations hereunder.

     D. ERISA. Purchaser is not and is not acting on behalf of an "employee
benefit plan" within the meaning of Section 3(3) of the Employee Retirement
Income Security Act of 1974, as amended ("ERISA"), a "plan" within the meaning
of Section 4975 of the Internal Revenue Code of 1986, as amended (the "Code") or
an entity deemed to hold "plan assets" within the meaning of 29 C.F.R. ss.
2510.3-101 of any such employee benefit plan or plans.

     E. Limitations on Representations and Warranties.  As used herein, the term
"Purchaser's  actual  knowledge" means the conscious  knowledge of Erin O'Boyle,
and  such  person  shall  not  be   obligated  to  perform  any  due   diligence
investigations  in  connection  with making any  representations  or  warranties
herein. All  representations and warranties of Purchaser in this Agreement shall
terminate  one year after the  Closing  and  Purchaser  shall have no  liability
thereafter  with respect to such  representations  and warranties  except to the
extent Seller has filed a lawsuit against  Purchaser during such one year period
for breach of any representation or warranty. If Seller is aware at Closing that
any of the Purchaser's  representations  or warranties in this Agreement are not
true as of the Closing and Seller elects  nonetheless to close,  Seller shall be
deemed to have waived any claim for breach of such  representation  or warranty.
Purchaser  shall  have no  liability  for the breach of any  representations  or
warranties set forth in this Agreement except to the extent the

                                       7



loss suffered by Seller as a result of such breaches exceeds $100,000 in the
aggregate.

     SECTION 5. OPERATION OF THE PROJECT PRIOR TO CLOSING. The Seller shall do
all of the following, from and after the date hereof through and including the
Closing Date:

          (a)  operate  and  maintain  the  Project in the same  manner as it is
     currently being operated and shall, subject to damage,  destruction or loss
     to the Project in which event  Purchaser shall have the rights set forth in
     Section 6(I)(3),  cause the Project to be, on the Closing Date, in the same
     condition as exists as of the date of this Agreement  (normal wear and tear
     excepted);

          (b)  maintain,  or  cause to be  maintained,  all  existing  insurance
     carried by Seller on the Improvements;

          (c)  without  the prior  written  consent of  Purchaser,  which may be
     withheld  in  Purchaser's  sole  discretion,  not  enter  into any  service
     contracts  or similar  agreements  affecting  the  Project  which  would be
     binding on Purchaser after Closing, nor modify, amend, terminate, cancel or
     grant concessions regarding any such existing contracts or agreements which
     would be binding on the Purchaser after Closing; provided,  however, Seller
     shall  terminate  prior  to  Closing  any  service   contracts  or  similar
     agreements which Purchaser  elects to have Seller  terminate  provided such
     contracts and agreements are terminable by their terms prior to Closing

          (d) without the prior written consent of the Purchaser  (except in the
     case of  emergencies),  not make, or obligate  itself to make, any material
     alterations or modifications to the Project;  provided,  however,  prior to
     the Due Diligence  Deadline  Seller shall complete the current HVAC upgrade
     project,  which includes  balancing and testing of the system to ensure the
     design CFM requirements and design  temperatures are achieved,  and the new
     roof on  1616  Building  (the  "Pre-Closing  Work").  Seller  shall  notify
     Purchaser when the Pre-Closing Work has been substantially  completed,  and
     Purchaser  shall have five (5) business days in which to exercise the right
     to  determine  that all of the  Pre-Closing  Work  has  been  substantially
     completed to its sole  satisfaction,  including,  without  limitation,  the
     design,  workmanship and adequacy thereof.  If the Pre-Closing Work has not
     been  substantially  completed at least five (5) business days prior to the
     end of the Due Diligence Period, the Due Diligence Period shall be extended
     solely with respect to the  Pre-Closing  Work to the date which is five (5)
     business days after the Pre-Closing Work is substantially completed. If the
     Pre-Closing Work is substantially completed to Purchaser's satisfaction but
     not

                                       8



     100%  completed,  Purchaser  and Seller shall agree on a punchlist of items
     remaining  to be  completed.  At  Purchaser's  option,  Seller shall either
     complete  such  punchlist  prior to Closing or give  Purchaser  a credit at
     Closing for the cost of completing  such  punchlist;  and,  except for such
     punchlist, Seller shall have no obligations with respect to the Pre-Closing
     Work after  Purchaser has accepted the  Pre-Closing  Work as  substantially
     complete; and

          (e) without the prior written  consent of the Purchaser,  not make any
     modifications  or  amendments  to the  Tenant  Leases or enter into any new
     leases.  Purchaser shall not unreasonably  withhold its consent to any such
     modifications or amendments or new leases; and Purchaser shall be deemed to
     have given its consent to any  modification  or  amendment  or new lease if
     Purchaser  does  not  notify  Seller  of its  disapproval  within  five (5)
     business  days after receipt of the proposed  modification  or amendment or
     new lease.  Such five (5)  business day period shall not begin to run until
     Purchaser has received a complete  package of  information  concerning  the
     proposed lease or modification, including appropriate credit information on
     the tenant.  Seller shall give  Purchaser an  opportunity to be involved in
     discussions  leading up to any  proposed  new lease or any  proposed  lease
     modifications  in order to give  Purchaser  an  opportunity  to provide its
     non-binding input to Seller, and Purchaser shall be provided an opportunity
     to submit  contractor  names and proposals for tenant  improvement work for
     Seller's good faith consideration.


     SECTION 6. CONDITIONS TO CLOSING. In addition to the conditions provided in
other  provisions of this Agreement,  the parties'  obligations to perform their
undertakings provided in this Agreement, are each conditioned on the fulfillment
of each of the  following  which is a condition  to such party's  obligation  to
perform  hereunder  (subject to such party's  waiver in strict  accordance  with
Section 8 below):

          (1)  Purchaser  shall  obtain  each of the  following  no  later  than
     September 30, 1996:  (i) a current ALTA survey of the Project  certified to
     Seller,  Purchaser  and the  Title  Company,  and  (ii) a  title  insurance
     commitment  for  the  Project  issued  by the  Title  Company  (the  "Title
     Commitment").  Purchaser  shall have ten (10) days after receipt to approve
     such  items;  and,  if  Purchaser  disapproves  any such items in the Title
     Commitment or Survey,  Seller may at its sole election  either  correct any
     matters which the Purchaser has  disapproved or terminate  this  Agreement.
     Purchaser  shall be deemed to have waived any objections to any matters set
     forth in the Title  Commitment  which  Purchaser  does not notify Seller by
     such date  that it  objects  thereto,  and any  matters  shown on the Title
     Commitment which are not objected to by Purchaser by such

                                       9

     date shall be deemed  "Permitted  Exceptions".  Seller  shall have ten (10)
     days to make the election to cure any matter which  Purchaser  has objected
     to; and, if Seller elects not to cure any such matter, Purchaser may within
     five (5) days  thereafter  elect to waive its objection to such matter,  in
     which case such matter  shall become a Permitted  Exception.  If Seller has
     elected to cure any matter,  such matter  shall be cured by Seller prior to
     Closing,  and Purchaser  shall be given a reasonable  opportunity  prior to
     Closing to verify that such matter has been cured to Purchaser's reasonable
     satisfaction.  Notwithstanding  the  foregoing,  Seller  shall  cause to be
     released any mortgages or other voluntary encumbrances securing the payment
     of money which Seller has caused to be recorded against the Project.

          (2) As a condition to each party's  obligation  to perform  hereunder,
     the due performance by the other of all  undertakings  and agreements to be
     performed by the other hereunder and the truth in all material  respects of
     each  representation and warranty as set forth herein made pursuant to this
     Agreement by the other at the Closing Date;  provided,  however,  if either
     party cannot remake any of its representations and warranties as of Closing
     in all material  respects  through no fault of its own,  the other  party's
     sole  remedies  shall  either be to terminate  this  Agreement or waive the
     condition  that such  representation  or  warranty be remade as of Closing.
     Purchaser  and Seller  shall each  deliver  to the other a  certificate  at
     Closing (a  "Closing  Certificate")  reaffirming  its  representations  and
     warranties in all material  respects except for matters which have occurred
     after the date hereof  which are listed on the Closing  Certificate  and to
     which the other party has elected to waive its objection in writing.


          (3) As a condition to Purchaser's obligation to perform hereunder (and
     not as a  default),  that there  shall not have  occurred  between the date
     hereof and the Closing Date, inclusive, destruction of or damage or loss to
     the Project  (whether or not covered by insurance  proceeds) from any cause
     whatsoever the cost of which to repair  exceeds  $250,000 in the aggregate;
     provided,  however,  that in the  event  of  such  destruction  or  damage,
     Purchaser  may elect to proceed with the Closing in which case Seller shall
     assign to Purchaser  any claims for proceeds  from the  insurance  policies
     covering  such  destruction  or damage and give  Purchaser a credit for any
     deductibles under such policies.  If the cost of repairing the destruction,
     damage or loss is less than  $250,000 in the  aggregate,  the parties shall
     proceed with the Closing as provided herein and the cost of repair shall be
     deducted from the Purchase Price.

          (4) As a condition of Purchaser's obligation to proceed with Closing
     (and not as a default), Purchaser shall

                                       10



     be satisfied in its sole and  absolute  discretion  with all aspects of the
     Project; provided,  however, if Purchaser does not notify Seller by October
     7, 1996 (the "Due Diligence  Deadline")  that it is not so satisfied,  this
     condition  shall be deemed  waived  by  Purchaser.  Purchaser  shall not be
     required to give its reasons for  terminating  this  Agreement  pursuant to
     this paragraph, and Purchaser's notice shall be conclusive evidence that it
     is dissatisfied with the Project.

          (5) As a condition to Purchaser's obligation to perform hereunder (and
     not as a default),  that there shall not have occurred at any time or times
     on or  before  the  Closing  Date any  taking or  threatened  taking of the
     Project  or  any  part  thereof  or  any  interest  or  estate  therein  by
     condemnation,  eminent domain or similar  proceedings;  provided,  however,
     Purchaser  may elect to waive such  condition  in which case  Seller  shall
     assign to Purchaser at Closing all of Seller's right, title and interest in
     and to any proceeds resulting from any such proceeding.

          (6)  Seller  covenants  and  agrees,  and it shall be a  condition  to
     Purchaser's obligation to perform its undertakings hereunder, that from and
     after the date hereof, at all reasonable times,  Purchaser (and its agents)
     shall be permitted access to the Project and all books, records and reports
     relating to the Tenant  Leases and the physical  condition  and  historical
     financial  statements  for the Project for the purpose of inspecting  same,
     and  Purchaser  (and its agents)  shall have the right to photocopy any and
     all such books, records and information.  Purchaser shall have the right to
     conduct physically  intrusive testing of or under the Project,  provided it
     first  obtains the consent of Seller as to the timing and scope of the work
     to be  performed,  which  consent  shall not be  unreasonably  withheld  or
     delayed.  All  information  relating  to  the  Project  made  available  to
     Purchaser  shall  be  treated  as  confidential,  subject  to  Section  16.
     Purchaser  (and its agents)  shall also have the right to meet with tenants
     in the Project to discuss any matters  relating to their  occupancy  in the
     Project,  provided,  however,  Seller  shall  have  the  right  to  have  a
     representative  in attendance at all such meetings.  Any entry by Purchaser
     and its agents on the  Project  shall be upon  reasonable  prior  notice to
     Seller,  and Purchaser will indemnify and hold Seller harmless  against any
     and all injuries,  claims,  losses, damages and expenses arising out of its
     negligence  in the  performance  of any  such  entry,  inspection  or other
     activities.

     SECTION 7. CLOSING.

          A. Time. The Closing hereunder shall occur on the Closing Date at the
     offices of the Title Company.

                                       11



          B. Actions.  At the Closing,  Seller shall convey good and  marketable
     title to the  Project  to  Purchaser,  free and  clear of all  encumbrances
     except the Tenant Leases,  Permitted  Encumbrances  and those title matters
     which  Purchaser has accepted or has been deemed to accept  pursuant to the
     terms hereof; and Purchaser shall pay to Seller the Purchase Price, plus or
     minus  prorations as set forth  herein.  The Closing shall occur through an
     escrow,  the cost of which shall be shared  equally  between  Purchaser and
     Seller.  Purchaser shall receive full possession of the Project at Closing,
     subject only to the Tenant Leases and Permitted Exceptions.

          C. Deliveries.

          (1) At the Closing,  Purchaser shall receive all of the following,  in
     form and substance reasonably satisfactory to Purchaser (it being agreed by
     Purchaser that the documents  attached hereto as exhibits are  satisfactory
     in form to Purchaser):

               (a) a special warranty deed, with full English covenants,  in the
          form attached hereto as Exhibit E executed by the Seller;

               (b) a bill of sale and assignment for the Personal Property in
          the form of Exhibit F, executed by Seller;

               (c) an  assignment  of the  Service  Contracts,  in the  form  of
          Exhibit G attached  hereto (the  "Assignment  of Service  Contracts"),
          executed by Seller, assigning to Purchaser the Service Contracts;

               (d) an assignment of the Tenant Leases, in the form of Exhibit H
          hereto (the "Assignment of Tenant Leases"), executed by Seller;

               (e) written acknowledgments (the "Tenant Estoppel Certificates"),
          without material deviation from the form of Exhibit I attached hereto,
          dated as of a date not more than  thirty  (30) days prior to  Closing,
          from tenants leasing at least 85% of the occupied rentable square feet
          in the Project,  but including in any event the following tenants (the
          "Major Tenants"): American National Red Cross, Price, Waterhouse, TRW,
          Bolt, Beranek and Newman,  Inc., Bell Atlantic,  Bio-Metric,  NEMA and
          Century Parking, Inc.;

               (f) an assignment in the form of Exhibit J hereto of all
          guaranties and warranties in favor of Seller with respect to the
          Improvements, including any


                                       12


          guaranties and warranties with respect to the Pre-Closing Work;

               (g)  notices  to each of the  tenants  under the  Tenant  Leases,
          notifying  them of the sale of the Project and  directing  them to pay
          all future rent as Purchaser may direct;

               (h) a closing statement setting forth all prorations and credits
          required hereunder;

               (i) an affidavit from Seller that it is not a "foreign person" or
          subject to withholding  requirements  under the Foreign  Investment in
          Real Property Tax Act of 1980, as amended;

               (j) the original of all Leases and Service Contracts to the
          extent they are in the possession of Seller or its agents;

               (k) all keys and combinations to locks located at the Project;

               (l) All soil reports,  engineering  studies,  consultant reports,
          plans and specifications,  books and records and permits and approvals
          relating to the Project  which are in the  possession of Seller or its
          managing agent;

               (m) a termination of the existing management agreement for the
          Project;

               (n) to the extent  the  Seller can obtain the same,  (i) a letter
          from the installer of the original roof on the Project confirming that
          any  warranties  and  guaranties  applicable to the original roof will
          remain in effect  notwithstanding  the  Pre-Closing  Work;  and (ii) a
          letter from the  manufacturer of the new roof membrane being installed
          as part of the Pre-Closing  Work confirming that the roof work done as
          part of the Pre-Closing  Work is in compliance with any warranty given
          by such manufacturer.

               (o) the Closing Certificate from Seller referred to in Section
          6(2) above;

               (p) evidence  that any fees or payments  due LaSalle  Partners in
          connection with the transactions set forth herein have been paid;

               (q) an affidavit in the form attached hereto as Exhibit M; and

                                       13

               (r) an  assignment in the form of Exhibit N (the  "Assignment  of
          Art Agreements") of (i) that certain  Agreement,  dated June 19, 1991,
          between  Arlington County and Seller and (ii) that certain  Commission
          Agreement, dated June 17, 1990, between Chris Gardner and Seller.

     In the event  Seller is unable to obtain the Tenant  Estoppel  Certificates
required herein without  material  deviation from the  information  contained in
this  Agreement,  Purchaser  shall  have the  option  as its sole and  exclusive
remedies of (i) terminating this Agreement or (ii) proceedi with the Closing and
waiving the requirement that it receive the Tenant Estoppel Certificates, as the
case may be, without material deviation.  Seller shall also use its best efforts
(without  the  expenditure  of any  material  sums) to obtain  prior to  Closing
subordination,  attornment and non-disturbance agreements from the Major Tenants
in the form attached hereto as Exhibit L; but receipt of such  agreements  shall
not be a condition of Closing.

     (2) Seller shall have received from Purchaser all of the following, in form
and substance reasonably  satisfactory to Seller (it being agreed by Seller that
the  documents  attached  hereto as  exhibits  are  satisfactory  in form to the
Seller):

          (a) payment of the Purchase Price, plus or minus prorations;

          (b) copies of the Assignment of Service Contracts, the Assignment of
     Tenant Leases and the Assignment of Art Agreements, executed by Purchaser;
     and

          (c) the Closing Certificate from Purchaser referred to in Section 6(2)
     above.

     D. Prorations. The Purchase Price for the Property shall be subject to
prorations and credits as follows to be determined as of 12:01 A.M. on the
Closing Date, the Closing Date being a day of income and expense to Purchaser:

          1. Rents payable under Tenant Leases. Purchaser shall receive a credit
     at Closing  for all rents  collected  by Seller  prior to the  Closing  and
     allocable to the period after Closing.  No credit shall be given the Seller
     for accrued and unpaid Rent or any other  non-current sums due from tenants
     unless and until  said sums are paid.  Any  portion of any rents  collected
     subsequent  to the Closing Date and properly  allocable to periods prior to
     the Closing Date shall be paid,  promptly after receipt, to the Seller, but
     subject to all of the  provisions of this Section  hereof;  and any portion
     thereof  properly  allocable to periods  subsequent to the Closing Date, if
     any, shall be paid to Purchaser. Seller shall be solely responsible for


                                       14




     collecting  any rent  under the Tenant  Leases  which is past due as of the
     Closing;  provided,  however, Purchaser shall be responsible for collecting
     any rent due for the month in which  the  Closing  occurs  and shall pay to
     Seller  the  portion  of such  rents  if, as and when  collected  which has
     accrued prior to Closing.  Any security  deposits held by Seller at Closing
     shall be credited to Purchaser on the Closing Date.

          2.  Seller  shall be  entitled  to collect  from  tenants  the monthly
     adjustment rent or escalation  payments payable under the Tenant Leases for
     the  period  prior to  Closing  for taxes and  operating  expenses  for the
     Project,  and Purchaser  shall retain all such monthly rent or payments for
     the period after Closing.  As soon as all such taxes and operating expenses
     for the Project are  finally  determined  for the year in which the Closing
     occurs,  Purchaser  shall be responsible for adjusting with the tenants the
     adjustment  rent or  escalation  payments  paid under the Tenant Leases for
     such  year.  Seller  shall  pay to  Purchaser  Seller's  share  of any such
     adjustment  payments owed to tenants under the Tenant Leases, and Purchaser
     shall remit to Seller Seller's share of any such  adjustment  payments paid
     by tenants;  and Seller  shall  indemnify  and hold  Purchaser  harmless in
     connection  with all claims for Seller's share of the  adjustments  owed to
     tenants,  which indemnity shall survive the Closing.  Seller's share of any
     adjustments shall be determined based on the portion of operating  expenses
     and real estate taxes for the year  incurred by Seller  (after  taking into
     account any prorations pursuant to this Section D).

          3.  Purchaser  shall  receive a credit for any accrued but unpaid real
     estate  taxes  imposed  in respect of the  Project  for the  portion of the
     current year which has elapsed prior to the Closing Date (and to the extent
     unpaid,  for  prior  years).  If the  amount  of any such  taxes  have been
     determined  as of Closing,  such  credit  shall be based on the most recent
     ascertainable  taxes and shall be reprorated upon issuance of the final tax
     bill. Seller shall also give Purchaser a credit for any special assessments
     against the Project which are due and payable prior to Closing.

          4. Utilities and fuel,  including,  without limitation,  steam, water,
     electricity,  gas and oil. The Seller  shall cause the meters,  if any, for
     utilities  to be read the day on which the  Closing  Date occurs and to pay
     the bills rendered on the basis of such  readings.  If any such reading for
     any utility is not available, then adjustment therefor shall be made on the
     basis of the most recently  issued bills  therefor which are based on meter
     readings no earlier than thirty (30) days prior to the Closing Date; and

                                       15

     such adjustment shall be reprorated when the next utility bills are
     received.

          5. Charges payable under the Service  Contracts  assigned to Purchaser
     pursuant to this Agreement.

          6. Any vault fees or similar payments for the Project.

     At least five (5) days prior to Closing,  Seller shall deliver to Purchaser
copies of all  information  and  records  necessary  to support  the  prorations
hereunder.  In the  event  any  prorations  made  pursuant  hereto  shall  prove
incorrect  for any reason  whatsoever,  either  party  shall be  entitled  to an
adjustment to correct the same,  provided no adjustments shall be requested more
than one (1) year after Closing.

     E. Expenses.  Purchaser shall pay (1) the cost of the Title Policy (defined
below),  (2) the cost of the  survey of the  Project,  (3) any state and  county
transfer taxes or recording  charges payable in connection with the recording of
the Deed, (4) one-half of any escrow or closing charge by the Title Company, and
(5) its own due diligence and legal expenses. Seller shall pay (1) the Grantor's
Tax, (2) one-half of any escrow or closing charge by the Title Company,  and (3)
its own legal expenses.

     F. Title.  At the Closing,  the Title  Company  shall issue to Purchaser an
ALTA Policy of Title Insurance or equivalent (the "Title Policy") with Purchaser
named as insured,  dated as of the Closing Date, with a liability limit equal to
the Purchase  Price,  insuring  that title to the Land and the  Improvements  is
vested in Purchaser, subject only to the Permitted Exceptions and Tenant Leases.
If the Title Policy discloses any liens or encumbrances  which are not Permitted
Exceptions and which the Seller voluntarily  created,  Purchaser may remove such
liens at Closing by paying so much of the  Purchase  Price to the holders of the
liens as is necessary to do so. If the Title Policy discloses any other liens or
encumbrances which are not Permitted Exceptions,  Seller shall have up to thirty
(30)  days in which to cure such new title  exception.  If Seller  does not cure
such new exception within such thirty (30) day period,  Purchaser shall have the
option,  to be  exercised  within ten (10) days after the end of the thirty (30)
day period, to either terminate this Agreement or waive its objection to the new
title  exception;  and,  if  Purchaser  elects to waive its  objection,  the new
exception  shall be deemed a "Permitted  Exception."  If necessary,  the Closing
Date shall be  extended  until the date which is ten (10) days after the date on
which  Seller  cures  such new title  exception  or the date on which  Purchaser
waives its objection to such new title exception.

     G. Leasing Costs. Except as set forth in the following sentence, Seller
shall be responsible for the brokerage


                                       16


commissions,  tenant  improvement  costs and other  leasing  costs to be paid in
connection  with the existing  leases at the Project with American  National Red
Cross   (approximately   75,000  square   feet),   Teledyne   Industries,   Inc.
(approximately 24,000 square feet), John Snow, Inc. (approximately 19,000 square
feet) and TRW, Inc.  (Suites 500 and 1900 totaling  approximately  34,347 square
feet).  Purchaser  shall be responsible  for the brokerage  commissions,  tenant
improvements  and other leasing costs to be paid in connection  with (i) any new
lease at the Project after the date hereof with TRW, Inc. provided Purchaser has
approved such new lease, (ii) the lease with Bell Atlantic International,  Inc.,
dated August 5, 1996, which has been assigned to Bell-Atlantic  Virginia,  Inc.,
(iii) existing options under the Tenant Leases for expansions and renewals which
are  exercised  after August 21,  1996,  which  Purchaser  shall have a right to
review  prior  to the Due  Diligence  Deadline,  and (iv)  new  leases  or lease
amendments  for the Project which are executed  after August 21, 1996, and prior
to Closing provided Purchaser has approved such new leases or amendments.

     H. Existing Mortgages. At Purchaser's election,  Purchaser may seek to have
the existing  mortgages on the Project assigned to Purchaser's lender at Closing
in lieu  of  having  them  satisfied.  If  Purchaser  so  elects,  Seller  shall
reasonably  cooperate with Purchaser's efforts, but such assignment shall not be
a condition of Closing and any assignment  shall be at Purchaser's sole cost and
expense.

     SECTION 8.  WAIVER.  Each party  hereto may,  at any time or times,  at its
election,  waive any of the conditions to its obligations hereunder by a written
waiver  expressly  detailing  the extent of such waiver (and no other  waiver or
alleged waiver by such party shall be effective for any purpose). No such waiver
shall reduce the rights or remedies of such party by reason of any breach by the
other party or parties of any of its or their obligations hereunder.

     SECTION 9. BROKERS. Each party represents and warrants to the other that it
has not hired any brokers or finders in  connection  with the  transactions  set
forth herein except for LaSalle  Partners.  Seller shall be obligated to pay any
commissions or fees due LaSalle Partners and shall indemnify  Purchaser  against
any claims by LaSalle  Partners for such  commissions or fees,  which  indemnity
shall survive the Closing.

     SECTION 10. SURVIVAL;  FURTHER  INSTRUMENTS.  Except as expressly set forth
herein, none of the terms and provisions herein shall survive the Closing.  Each
party  will,  whenever  and as often as it  shall be  requested  so to do by the
other, cause to be executed,  acknowledged or delivered any and all such further
instruments  and  documents  as may be necessary  or proper,  in the  reasonable
opinion of the requesting party, in order to carry out

                                       17



the intent and purpose of this Agreement and as is consistent with this
Agreement.

     SECTION 11. NO THIRD PARTY  BENEFITS.  This  Agreement is made for the sole
benefit of  Purchaser  and Seller and their  respective  successors  and assigns
(subject to the limitation on assignment set forth in Section 13 below),  and no
other person or persons  shall have any right or remedy or other legal  interest
of any kind under or by reason of this  Agreement.  Whether or not either  party
hereto elects to employ any or all the rights,  powers or remedies  available to
it  hereunder,  such party shall have no  obligation or liability of any kind to
any third party by reason of this  Agreement or by reason of any of such party's
actions or  omissions  pursuant  hereto or  otherwise  in  connection  with this
Agreement or the transactions contemplated hereby.

     SECTION 12. REMEDIES. If Purchaser defaults hereunder, Seller's sole remedy
at law or in equity shall be to recover the Earnest Money as liquidated damages.
The parties agree that  Seller's  damages in the event of a default by Purchaser
will be difficult to determine  and that the Earnest Money is a fair estimate of
those damages.  If Seller shall default  hereunder  prior to Closing,  Purchaser
shall be entitled as its sole  remedies  at law or in equity to  terminate  this
Agreement  and  receive a return  of the  Earnest  Money or to sue for  specific
performance of this Agreement.

     SECTION 13.  MISCELLANEOUS.  This Agreement (including all Exhibits hereto)
contains the entire agreement between the parties  respecting the matters herein
set forth and  supersedes  all  prior  agreements  between  the  parties  hereto
respecting  such matters.  The section  headings shall not be used in construing
this  Agreement.  This  Agreement  shall be construed and enforced in accordance
with the laws of the State of  Virginia.  Purchaser  may not  assign  its rights
under this  Agreement  without the prior written  consent of Seller except to an
entity  controlling  Purchaser,  controlled by Purchaser or under common control
with  Purchaser.  Subject to the preceding  sentence,  this  Agreement  shall be
binding  upon and shall  inure to the  benefit of the  parties  hereto and their
respective  successors and assigns.  The provisions of this Agreement may not be
amended,  changed or modified orally, but only by an agreement in writing signed
by the party against whom any amendment,  change or modification is sought. Time
is of the essence with respect to the terms and conditions of this Agreement.

     SECTION 14.  NOTICES.  All notices and other  communications  which  either
party is  required or desires to send to the other shall be in writing and shall
be sent by messenger,  registered or certified  mail,  postage  prepaid,  return
receipt requested. Notices and other communications shall be deemed to have been
given on the earlier of actual  receipt or the third business day after the date
so mailed. Notices shall be addressed as follows:

                                       18


       (a)     To Seller:

                c/o LaSalle Partners Limited
                200 East Randolph Drive
                Chicago, Illinois  60601
                Attention:  Ms. Jana L. Langston

                with copies to:

                LaSalle Partners Limited
                220 East 42nd Street
                New York, New York 10017
                Attention: Mr. Thomas Beneville

                                and

                Hagan & Olian
                200 East Randolph Drive
                Suite 4322
                Chicago, Illinois  60601
                Attention:  Mr. R. K. Hagan

        (b)     To Purchaser:

                c/o Beacon Properties Corporation
                50 Rowes Wharf
                Boston, Massachusetts 02110
                Attention:  Mr. Charles H. Cremens

                with a copy to:

                Goulston & Storrs
                400 Atlantic Avenue
                Boston, Massachusetts 02110
                Attention: Mr. Jordon Krasnow

or to such other person and/or  address as shall be specified by either party in
a notice given to the other pursuant to the provisions of this Paragraph.

     SECTION 15.  ATTORNEYS'  FEES. In the event either party  institutes  legal
proceedings  to  enforce  its rights  hereunder,  the  prevailing  party in such
litigation shall be paid all reasonable expenses of the litigation by the losing
party, including its attorneys' fees.

     SECTION  16.  CONFIDENTIALITY.  Seller  and  Purchaser  agree to keep  this
Agreement  confidential and not disclose or make any public  announcements  with
respect to the subject  matter  hereof  without the consent of the other  party.
Seller acknowledges that Beacon Properties  Corporation,  the general partner of
Purchaser, is a publicly owned corporation subject to regulation by the

                                       19

Securities and Exchange  Commission (the "SEC"), and that the regulations of the
SEC may require that Purchaser  disclose the existence of this Agreement and the
contents  of some or all of the  documents  delivered  by Seller  in  connection
therewith. Accordingly, Seller expressly consents to the disclosure of the terms
and conditions of this Agreement and the transactions contemplated hereby to the
extent that Purchaser in the exercise of its reasonable  judgment has determined
that  the  SEC  requires  such   disclosure.   In  addition  to  the  disclosure
contemplated by the preceding sentence,  and without limitation thereof,  either
party may disclose this Agreement or the contents thereof or of any documents to
be executed and/or delivered in connection  herewith to any partners,  advisers,
underwriters, analysts, employees, affiliates, officers, directors, consultants,
lenders,  accountants  or legal counsel of any of the  foregoing,  provided that
they are  advised  as to the  confidential  nature of such  information  and are
instructed to maintain such  confidentiality.  The foregoing shall  constitute a
modification of any prior  confidentiality  agreement that may have been entered
into by the parties. From and after the Closing,  either Seller or Purchaser may
issue a press  release  with  respect  to this  Agreement  and the  transactions
contemplated  hereby provided the terms of the  transactions are not included in
such press release.

     SECTION 17. AUDIT. To comply with the SEC  regulations  with respect to the
verification of historical information,  Purchaser shall have the right prior to
or for a one (1) year  period  subsequent  to Closing  to  conduct an audit,  at
Purchaser's  sole cost and expense,  of Seller's  books and records for and with
respect to the  respective  Project  for the shorter of (i) three years prior to
Closing or (ii) the period of Seller's ownership  thereof.  Seller hereby agrees
to permit Purchaser and Purchaser's accountants access to such books and records
(including  those  maintained by Seller's  managing  agents) and, at Purchaser's
sole cost and expense, to reasonably cooperate and to cause Seller's accountants
to  cooperate  with  Purchaser to enable such audit to be  performed;  provided,
however,  Purchaser shall not have a right to inspect any confidential documents
such as appraisals or market  studies.  The provisions of this  paragraph  shall
survive the Closing.

     SECTION 18.  LIMITATION  ON  LIABILITY.  This  Agreement is entered into by
LaSalle  Advisors  Limited,  a Delaware limited  partnership,  as duly appointed
agent and investment manager of the above-named  Trustees of LaSalle Fund II and
on the express condition that any obligation of such Trustees or LaSalle Fund II
or LaSalle  Advisors Limited or any affiliate shall be enforceable only against,
and  payable  only out of, the  property  of LaSalle  Fund II, and  neither  the
Trustees  nor any  beneficiary,  officer or  employee  of LaSalle  Fund II or of
LaSalle  Advisors  Limited  or of any  affiliate  shall be held to any  personal
liability  whatsoever.  Seller,  however,  agrees to  maintain a net worth of at
least $5,000,000 until the first anniversary of the Closing.

                                       20


     IN WITNESS WHEREOF,  the parties have executed this Agreement as of the day
and year first above written.


                                   DANIEL W. CUMMINGS, STUART L. SCOTT,
                                   ROBERT C. SPOERRI, and LYNN C. THURBER, not
                                   personally, but as Trustees under that
                                   certain Declaration of Trust, dated
                                   October 1, 1983, creating LASALLE FUND II,
                                   a Group Trust, acting through its
                                   agent and manager:

                                   LASALLE ADVISORS LIMITED


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



                                   BEACON PROPERTIES, L.P., a Delaware
                                      limited partnership

                                   By:  Beacon Properties Corporation, a
                                          Maryland corporation


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

                                       21


                                    EXHIBITS

Exhibit A - Legal Description of Land Exhibit B - Litigation Exhibit C - Service
Contracts  Exhibit D - Tenant  Leases  Exhibit E - Deed Exhibit F - Bill of Sale
Exhibit G - Assignment  of Service  Contracts  Exhibit H - Assignment  of Tenant
Leases Exhibit I - Estoppel  Certificates for Tenant Leases Exhibit J Assignment
of  Guaranties  and  Warranties  Exhibit  K  -  Personal  Property  Exhibit  L -
Subordination,  Attornment and  Non-Disturbance  Agreement  Exhibit M - Seller's
Affidavit Exhibit N - Assignment of Art Agreements

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