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                         SUBORDINATION, NON-DISTURBANCE
                            AND ATTORNMENT AGREEMENT

                       METROPOLITAN LIFE INSURANCE COMPANY
                                   ("LENDER")

              UNITED STATES OF AMERICA-GENERAL SERVICES ADMINISTRATION
                                   ("TENANT")

                                      AND

                      ARLINGTON SQUARE LIMITED PARTNERSHIP
                                  ("LANDLORD")

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

                         DATED: AS OF NOVEMBER 25, 1998

                         LOCATION: 4401 NORTH FAIRFAX DRIVE
                                   ARLINGTON, VIRGINIA
                                   BLOCK:   ARLINGTON SQUARE
                                   LOT:     PARCEL A
                                   COUNTY:  ARLINGTON
                                   STATE:   VIRGINIA

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

                         RECORD AND RETURN TO:

                         MAYER, BROWN & PLATT
                         2000 PENNSYLVANIA AVENUE, N.W.
                         WASHINGTON, D.C. 20006-1882
                         ATTENTION: KEITH J. WILLNER


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                         SUBORDINATION, NON-DISTURBANCE
                            AND ATTORNMENT AGREEMENT

         This SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT (this
"Non-Disturbance Agreement") made as of the 25TH day of NOVEMBER, 1998, by
and among METROPOLITAN LIFE INSURANCE COMPANY, having an office at 200 Park
Avenue, 12th Floor, New York, New York 10166 ("LENDER"), UNITED STATES OF
AMERICA-GENERAL SERVICES ADMINISTRATION, having an office at 7TH AND D
STREET, S.W., WASHINGTON, D.C. 20407 ("TENANT") and ARLINGTON SQUARE LIMITED
PARTNERSHIP, having an office at 4650 EAST-WEST HIGHWAY, SUITE 251,
BETHESDA, MARYLAND 20814 ("LANDLORD").

                                   WITNESSETH:

     WHEREAS, Lender has made or is about to make a loan (the "L0AN") of
$21,500,000.00 to Landlord;

     WHEREAS, the Loan is or will be evidenced by a promissory note (the
"NOTE") made by Landlord to order of Lender and is or will be secured by,
among other things, mortgage, security agreement and fixture filing
(collectively, the "MORTGAGE") made by Landlord to or for the benefit of
Lender covering, among other things, the land (the "LAND") described on
SCHEDULE A hereto and all improvements (the "IMPROVEMENTS") now or hereafter
located on the Land (the Land and the Improvements hereinafter collectively
referred to as the "PREMISES");

     WHEREAS, by an agreement of lease COMMENCING OCTOBER 1, 1998, AND ENDING
ON SEPTEMBER 30, 2008 (the "LEASE"), Landlord has leased or will lease to
Tenant a portion of the Premises BEING ALL OF THE LEASABLE PREMISES LOCATED
WITHIN THE BUILDING KNOWN AS "ARLINGTON SQUARE", as more particularly
described therein;

     WHEREAS, a memorandum of the Lease is to be recorded in the official
records of the CLERK OF THE CIRCUIT COUNTY OF ARLINGTON COUNTY, VIRGINIA prior
to the recording of this Non-Disturbance Agreement; and

     WHEREAS, the parties hereto desire to make the Lease subject and
subordinate to the Mortgage.

     NOW, THEREFORE, the parties hereto, in consideration of the covenants
contained herein and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, hereby agree as follows:

     1. The Lease, as the same may hereafter be modified, amended or
extended, and all of Tenant's right, title and interest in and to the
Premises (including, without limitation, any option, right of first refusal
or other rights to acquire all or any portion of the Premises), are and shall
be subject and subordinate to the Mortgage and the lien thereof, to all the
terms, conditions and provisions of the Mortgage to the extent that such do
not conflict with the terms of the Lease, and to each and every advance made
or hereafter made under the Mortgage, and to all renewals, modifications,
consolidations, replacements, substitutions and extensions of the Mortgage,
so that at all times the Mortgage shall be and remain a lien on the Premises
prior and superior to the Lease for all purposes; PROVIDED, HOWEVER, and
Lender agrees, that so long as (a) no default by Tenant has occurred which
has continued to exist for such period of time (after notice, if any,
required by the Lease) as would entitle Landlord to terminate the Lease, (b)
neither the rent nor any other charges or expenses payable by Tenant under
the Lease shall have been reduced in any way except as allowed under the
Lease, (c) Tenant shall pay to Lender or its successor or assign all rental
and other payments payable to Landlord under the Lease in the amounts and at
the times set forth in the Lease, (d) Tenant shall duly confirm its
attornment to Lender or its successor or assign by written instrument as set
forth in PARAGRAPH 2 hereof or enter into the New Lease (as such term is
hereinafter defined) as set forth in such PARAGRAPH 2, (e) Lender or its
successors or assigns shall not be liable under any warranty of construction
contained in the Lease or any implied warranty of construction, (f) Tenant
shall have performed all of its covenants contained herein, and (g) all
representations and warranties made herein by Tenant shall be true and
correct as of the date of such attornment or New Lease; then, and in such event
(i) Lender shall not join Tenant as a party defendant in any foreclosure
action or proceeding which may be instituted or taken by Lender under the
Mortgage by reason of any default thereunder, unless such joinder is
necessary to foreclose the Mortgage and then only for such purpose and not
for the purpose of terminating the Lease, (ii) Tenant's leasehold estate under
the Lease shall not be terminated or disturbed and Lender will accept the
attornment of Tenant or, if Lender

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so elects, the New Lease, pursuant to PARAGRAPH 2 hereof, and (iii) other than
as set forth herein, none of Tenants rights under the Lease shall be affected
in any way by reason of any default under the Mortgage.

     2. Without limitation of any of the provisions of the Lease, Tenant
hereby agrees that in the event of any act, omission or default by Landlord
or Landlord's agents, employees, contractors, licensees or invitees which
would give Tenant the right, either immediately or after the lapse of a
period of time, to terminate the Lease, or to claim a partial or total
eviction, unless the act, omission or default occasioning such termination or
claim presents a health, safety or life-threatening situation, Tenant will
endeavor to provide, in advance of any action by Tenant, written notice of
such act, omission or default to Lender by delivering notice of such act,
omission or default, addressed to Lender at Lender's address as given hereby
or at the last address of Lender furnished to Tenant in writing, or to any
successor to Lender's interest under the Mortgage, provided that Lender or
such successor notifies Tenant of the name and address of the party Tenant is
to notify; provided, however, Tenant's failure to deliver such notice shall
not constitute a breach of this Non-Disturbance Agreement and shall have no
legal effect on the terms and conditions of this Non-Disturbance Agreement or
the rights and obligations of the parties hereunder or under the Lease.

     3. Without limitation of any of the provisions of the Lease, in the
event that, by reason of any default under the Mortgage on the part of
Landlord, Lender or its successors or assigns shall succeed to the interest
of Landlord or any successor to Landlord, then, subject to the provisions of
this Non-Disturbance Agreement, including, without limitation, PARAGRAPH I
above, the Lease shall nevertheless continue in full force and effect and
Tenant shall and does hereby agree to attorn to and accept Lender as its
successors or assigns and to recognize Lender or its successors or assigns as
its Landlord under the Lease for the then remaining balance of the term
thereof, and upon request of Lender or its successors or assigns, Tenant
shall execute and deliver to Lender or its successors or assigns an agreement
of attornment satisfactory to Lender or any such successor or assign.
Alternatively, upon the written request of Lender or its successors or
assigns, Tenant shall enter a new lease (the "New Lease") of the Premises
with Lender or such successor or assign for the then remaining term of the
Lease, upon the same terms and conditions as contained in the Lease.

     4. Lender and its successors or assigns shall have no personal liability
as successor to Landlord and Tenant shall look only to the estate and
property of Lender or its successors or assigns in the Premises for the
satisfaction of Tenants remedies for the collection of a judgment (or other
judicial process) requiring the payment of money in the event of any default
by Lender or its successors or assigns as Landlord under the Lease, and no
other property or assets of Lender or its successors or assigns shall be
subject to levy, execution or other enforcement procedure for the
satisfaction of Tenants remedies under or with respect to the Lease, the
relationship of Landlord and Tenant thereunder or Tenants use or occupancy of
the Premises.

      5. Tenant agrees that no prepayment of rent or additional rent due
under the Lease of more than one month in advance shall be made.

      6. From and after Tenant's receipt of written notice in accordance with
31 U.S.C. 3727 Assignment of Claims directing Tenant to pay all rent and
additional rent thereafter due under the Lease to Lender (a "RENT PAYMENT
NOTICE") and of a Supplemental Lease Agreement to change the named payee in
the Lease, Tenant shall pay all rent and additional rent to Lender or as
Lender shall direct in writing, until such time as Lender directs otherwise
in writing. Tenant shall comply with any Rent Payment Notice notwithstanding
any contrary instruction, direction or assertion from Landlord. Lender's
delivery to Tenant of a Rent Payment Notice, or Tenants compliance therewith,
shall not be deemed to (a) cause Lender to succeed to or to assume any
obligations or responsibilities as the landlord under the Lease, all of which
shall continue to be performed and discharged solely by Landlord, or (b)
relieve Landlord of any obligations under the Lease. Landlord hereby
irrevocably directs Tenant to comply with any Rent Payment Notice,
notwithstanding any contrary direction, instruction or assertion by Landlord.
Tenant shall be entitled to rely on any Rent Payment Notice. Tenant shall be
under no duty to controvert or challenge any Rent Payment Notice. Tenants
compliance with a Rent Payment Notice shall not be deemed to violate the
Lease. Landlord hereby releases Tenant from, and shall indemnify and hold
Tenant harmless from and against any and all losses, claims, damages,
liabilities, costs or expenses (including the payment of reasonable
attorneys' fees, forum costs and disbursements) arising from any claim based
on Tenants compliance with any Rent Payment Notice. Landlord shall look
solely to Lender with respect to any claims Landlord may have on account of
an incorrect or wrongful Rent Payment Notice. Tenant shall be entitled to
full credit under the

                                        2

<PAGE>


Lease for any Rent paid to Lender pursuant to a Rent Payment Notice to the
same extent as if such Rent were paid directly to Landlord.

     7. Landlord represents and warrants that the Lease was duly executed by
Landlord and all consents, resolutions or other approvals required for
Landlord to execute the Lease were obtained. Tenant represents and warrants
that the Lease was duly executed by Tenant and all consents, resolutions or
other approvals required for Tenant to execute the Lease were obtained. In
the event the Lease was guaranteed pursuant to a guaranty of lease (the
"GUARANTY"), Tenant represents and warrants that the Guaranty was duly
executed by the guarantor named therein and all consents, resolutions and
other approvals required for such named guarantor to execute the Guaranty
were obtained.

     8. Tenant and Landlord shall provide a document similar to this to any
lender making a loan secured by property including the Premises, the proceeds
of which loan are used to repay the Loan in whole or part as may be agreed to
by such lender and subject to such reasonable modifications as may be
requested by such lender.

     9. Tenant agrees that to the extent any assignment of the Lease or
subletting of all or any portion of the Premises by Tenant requires the
consent of Landlord under the Lease, such assignment or subletting shall not
be effective unless Lender's prior written consent shall also have been
obtained. Any assignment or subletting that is permitted under the Lease
without the consent of Landlord shall not require the consent of Lender
hereunder.

    10. Tenant, shall, from time to time, within thirty (30) days after
receipt of a joint written request by Landlord and Lender, execute and
deliver to Landlord a lease status report by Tenant verifying, subject to the
conditions specified in 48 CFR 552.270-35 (a) that the Lease is unmodified
and in full force and effect (or if there have been modifications, that the
same is in full force and effect as modified and stating the modifications),
(b) the amounts of fixed rent, additional rent, percentage rent, or other
sums, if any, which are payable in respect of the Lease and the commencement
date and expiration date of the Lease, (c) the dates to which the fixed rent
additional rent, percentage rent, if any, and other sums which are payable in
respect to the Lease have been paid, (d) whether or not Tenant is entitled to
credits or offsets against such rent, and, if so, the reasons therefor and
the amount thereof, (e) that Tenant is not in default in the performance of
any of its obligations under the Lease and no event has occurred which, with
the giving of notice or the passage of time, or both, would constitute such a
default, (f) whether or not, to the best knowledge of the person certifying
on behalf of Tenant, Landlord is in default in the performance of any of its
obligations under the Lease, and, if so, specifying the same, (g) whether or
not, to the best knowledge of such person, any event has occurred which with
the giving of such notice or passage of time, or both would constitute such a
default, and, if so, specifying each such event, and (h) whether or not, to
the best knowledge of such person, Tenant has any claims, defenses or
counterclaims against Landlord under the Lease, and, if so, specifying the
same. Tenant also shall include in any such statement such other information
concerning the Lease as Lender may reasonably request.

    11. This Non-Disturbance Agreement may be executed in two or more
counterparts, each of which shall be deemed an original but all of which
together shall constitute and be construed as one and the same instrument.
Signature and acknowledgment pages may be detached from multiple separate
counterparts and attached to a single counterpart so that all signature and
acknowledgment pages are physically attached to the same instrument.

    12. All remedies which Lender may have against Landlord provided herein,
if any, are cumulative and shall be in addition to any and all other rights
and remedies provided by law and by other agreements between Lender and
Landlord or others. If any party consists of multiple individuals or
entities, each of same shall be jointly and severally liable for the
obligations of such party hereunder.

    13. The reasonable cost of attorneys' fees and disbursements for any
legal action or arbitration between or among the parties arising out of any
dispute or litigation relating to enforcement of this NON-DISTURBANCE AGREEMENT
shall be borne by the party or parties against whom a final decision is
rendered, where so directed by Federal law.

    14. Any notice, demand, statement, request or consent made hereunder
shall be effective and valid only if in writing, referring to this
Non-Disturbance Agreement, signed by the party giving such notice, and
delivered either personally to such other party, or sent by nationally
recognized overnight courier delivery service or by certified mail

                                        3

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of the United States Postal Service, postage prepaid, return receipt
requested, addressed to the other party as follow (or to such other address
or person as either party or person entitled to notice may by notice to the
other party specify):

     To Lender:        Metropolitan Life Insurance Company
                       Real Estate Investments
                       200 Park Avenue, 12th Floor
                       New York, New York 10166
                       Attention: Senior Vice President

     with a copy to:   Metropolitan Life Insurance Company
                       Real Estate Investments
                       200 Park Avenue, 12th Floor
                       New York, New York 10166
                       Attention: Law Department

     To Tenant:        GENERAL SERVICES ADMINISTRATION
                       7TH AND D STREETS, S.W.
                       WASHINGTON, D.C., 20407
                       Attention: CONTRACTING OFFICER FOR 4401 NORTH
                       FAIRFAX DRIVE, ARLINGTON, VIRGINIA

     To Landlord:      ARLINGTON SQUARE LIMITED PARTNERSHIP
                       4650 EAST-WEST HIGHWAY, SUITE 251
                       Bethesda, Maryland 20815
                       Attention: William N. Demas

Unless otherwise specified, notices shall be deemed given as follows: (i) if
delivered personally, when delivered, (ii) if delivered by nationally recognized
overnight courier delivery service, on the day following the day such material
is sent, or (iii) if sent by certified mail, three (3) days after such notice
has been sent by Lender, Landlord or Tenant.

     15. This Non-Disturbance Agreement shall be interpreted and construed in
accordance with and governed by Federal law and by the laws of the State of
New York, without regard to conflict of laws principles, where no Federal law
addresses the dispute.

     16. This Non-Disturbance Agreement shall apply to, bind and inure to the
benefit of the parties hereto and their respective successors and permitted
assigns. As used herein "Lender" shall include any subsequent holder of the
Mortgage.

                   [BALANCE OF PAGE INTENTIONALLY LEFT BLANK]


                                        4


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                                    SCHEDULE A

                                LEGAL DESCRIPTION

Parcel A, Arlington Square, as duly dedicated, platted and recorded in Deed
Book 2210, at page 994, among the Land Records of Arlington County, Virginia.


<PAGE>


     IN WITNESS WHEREOF, the parties hereto have duly executed this
Non-Disturbance Agreement as of the day and year first above written.


                                  METROPOLITAN LIFE INSURANCE COMPANY

                                  By: /s/ Michael Curran
                                     --------------------------------
                                     Name: Michael Curran
                                     Title: AVP


                                  ARLINGTON SQUARE LIMITED PARTNERSHIP,
                                  a VIRGINIA LIMITED PARTNERSHIP
                                  BY: ARLINGTON SQUARE, INC., GENERAL PARTNER


                                  By: /s/ William N. Demas
                                     ----------------------------------------
                                     Name:  William N. Demas
                                     Title: President

                                  UNITED STATES OF AMERICA
                                  BY: GENERAL SERVICES ADMINISTRATION


                                  By: /s/ Monica R. Sias
                                     ----------------------------------------
                                     Name:  Monica R. Sias
                                     Title: Contracting Officer



                                       5

<PAGE>


STATE OF DISTRICT OF )
                     ) SS.:
COUNTY OF COLUMBIA   )

         ON THE 24TH DAY OF NOVEMBER IN THE YEAR 1998 BEFORE ME, THE
UNDERSIGNED, A NOTARY PUBLIC IN AND FOR SAID STATE, PERSONALLY APPEARED MICHAEL
CURRAN, PERSONALLY KNOWN TO ME OR PROVED TO ME ON THE BASIS OF SATISFACTORY
EVIDENCE TO BE THE INDIVIDUAL(S) WHOSE NAME(S) IS (ARE) SUBSCRIBED TO THE WITHIN
INSTRUMENT AND ACKNOWLEDGED TO ME THAT HE/SHE/THEY EXECUTED THE SAME IN
HIS/HER/THEIR CAPACITY(IES), AND THAT BY HIS/HER/THEIR SIGNATURE(S) ON THE
INSTRUMENT, THE INDIVIDUAL(S), OR THE PERSON UPON BEHALF OF WHICH THE
INDIVIDUAL(S) ACTED, EXECUTED THE INSTRUMENT.

                                      /s/ Veronica Jenkins
                    ----------------------------------------------------------
                    (SIGNATURE AND OFFICE OF INDIVIDUAL TAKING ACKNOWLEDGEMENT)

                                      VERONICA JENKINS
                              NOTARY PUBLIC DISTRICT OF COLUMBIA
                             MY COMMISSION EXPIRES APRIL 30, 2003


STATE OF VIRGINIA    )
                     ) SS.:
COUNTY OF ARLINGTON  )

         ON THE 19TH DAY OF NOVEMBER IN THE YEAR 1998 BEFORE ME, THE
UNDERSIGNED, A NOTARY PUBLIC IN AND FOR SAID STATE, PERSONALLY APPEARED WILLIAM
N. DEMAS, PERSONALLY KNOWN TO ME OR PROVED TO ME ON THE BASIS OF SATISFACTORY
EVIDENCE TO BE THE INDIVIDUAL(S) WHOSE NAME(S) IS (ARE) SUBSCRIBED TO THE WITHIN
INSTRUMENT AND ACKNOWLEDGED TO ME THAT HE/SHE/THEY EXECUTED THE SAME IN
HIS/HER/THEIR CAPACITY(IES), AND THAT BY HIS/HER/THEIR SIGNATURE(S) ON THE
INSTRUMENT, THE INDIVIDUAL(S), OR THE PERSON UPON BEHALF OF WHICH THE
INDIVIDUAL(S) ACTED, EXECUTED THE INSTRUMENT.

                                        /s/ Priscilla D. Okay
                    ----------------------------------------------------------
                    (SIGNATURE AND OFFICE OF INDIVIDUAL TAKING ACKNOWLEDGEMENT)
                                   My Commission expires 10/31/2002

DISTRICT OF COLUMBIA  )
                      ) SS.:
CITY OF WASHINGTON    )

         ON THE 13TH DAY OF NOVEMBER IN THE YEAR 1998 BEFORE ME, THE
UNDERSIGNED, A NOTARY PUBLIC IN AND FOR SAID STATE, PERSONALLY APPEARED
MONICA SEAS, PERSONALLY KNOWN TO ME OR PROVED TO ME ON THE BASIS OF
SATISFACTORY EVIDENCE TO BE THE INDIVIDUAL(S) WHOSE NAME(S) IS (ARE)
SUBSCRIBED TO THE WITHIN INSTRUMENT AND ACKNOWLEDGED TO ME THAT HE/SHE/THEY
EXECUTED THE SAME IN HIS/HER/THEIR CAPACITY(IES), AND THAT BY HIS/HER/THEIR
SIGNATURE(S) ON THE INSTRUMENT, THE INDIVIDUAL(S), OR THE PERSON UPON BEHALF
OF WHICH THE INDIVIDUAL(S) ACTED, EXECUTED THE INSTRUMENT.

                                        /s/ Paul Jonell
                    ----------------------------------------------------------
                    (SIGNATURE AND OFFICE OF INDIVIDUAL TAKING ACKNOWLEDGEMENT)
                            My Commission expires December 14, 1998