DEED OF LEASE

by and between


PETULA ASSOCIATES, LTD.

("Landlord")

and

GOVERNMENT TECHNOLOGY SERVICES, INC.

("Tenant")































'11/13/97

<PAGE>
TABLE OF CONTENTS

Section Page


1.    DEMISE
      ..................................................
      1

2.    TERM...................................................
      .     1

3.    RENT...................................................
      .     7

4.    PERMITTED
      USE...........................................              13

5.    EXPENSES
      ...............................................             14

6.    ADDITIONAL
      RENT..........................................              17

7.    SORTING AND SEPARATION OF REFUSE AND
      TRASH...............          19

8.    HAZARDOUS
      SUBSTANCES.....................................             20

9.    INSURANCE..............................................
      ..    22

10.   DAMAGE OR
      DESTRUCTION....................................             10

11.   INDEMNIFICATION........................................
      ..    25

12.   ASSIGNMENT AND
      SUBLETTING................................            27

13.   CARE OF
      PREMISES.........................................           33

14.   ALTERATION BY
      TENANT.....................................           33

15.   CONDEMNATION...........................................
      ..    35

16.   SUBORDINATION..........................................
      ..    35

17.   ACCESS TO
      PREMISES.......................................             38

18.   RULES AND
      REGULATIONS....................................             39

19.   COVENANTS OF RIGHT TO
      LEASE..............................             39

20.   MECHANICS
      LIENS..........................................             39

21.   EXPIRATION OF LEASE AND SURRENDER OF
      POSSESSION..........          40

22.   DEFAULT-REMEDIES.......................................
      .     41

23.   RE-ENTRY BY
      LANDLORD.....................................               48

24.   ADDITIONAL RIGHTS TO
      LANDLORD............................            49

25.   SUCCESSORS, ASSIGNS AND
      LIABILITY........................         49

26.   NOTICES................................................
      ..    49

27.   MORTGAGEE'S
      APPROVAL.....................................               50

28.   ESTOPPEL
      CERTIFICATES....................................            51

29.   DEFAULT RATE OF
      INTEREST.................................             51

30.   EXCULPATORY
      PROVISIONS...................................               51

31.   MORTGAGEE
      PROTECTION.....................................             52

32.   RECIPROCAL COVENANT ON NOTIFICATION OF ADA
      VIOLATIONS....    52

33.   LAWS THAT
      GOVERN.........................................             53

34.   FINANCIAL
      STATEMENTS.....................................             53

35.   PARKING................................................
      ..    53

36.   SIGNAGE................................................
      ..    54

37.   RECORDATION............................................
      ..    55

38.   FORCE
      MAJEURE............................................
      55

39.   LANDLORD'S
      LIEN..........................................              56

40.   BROKERS................................................
      ..    57

41.   CONFIDENTIALITY........................................
      ..    57

42.   LEASE/DEED OF
      LEASE......................................           58

43.   RIGHT OF FIRST
      OFFER.....................................            58

44.   MISCELLANEOUS..........................................
      ..    59

45.   ROOF-TOP
      EQUIPMENT......................................             60


EXHIBIT A   -     Land
EXHIBIT B   -     Work Agreement
EXHIBIT B-1       -     Current Site Plan
EXHIBIT B-2       -     Form of Environmental Certification
EXHIBIT B-3       -     Current Specification
EXHIBIT C   -     Declaration of Lease Commencement
EXHIBIT D   -     Rules and Regulations
EXHIBIT E   -     Avion (R) Signage Program
EXHIBIT F   -     License Agreement
EXHIBIT F-1       -     Location of License Area
EXHIBIT F-2       -     Intentionally Deleted
EXHIBIT F-3       -     Minimum Equipment Requirements
EXHIBIT F-4       -     Contractor Insurance Requirements
EXHIBIT G         Non-Disturbance Agreement

<PAGE>
DEED OF LEASE

      THIS DEED OF LEASE ("Lease") is made this 10th day of
December, 1997, by and between PETULA ASSOCIATES, LTD.,
whose address for the purpose of this Lease shall be 711
High Street, Des Moines, Iowa 50392-1370, Attn: CRE
Equities/Mid-Atlantic Team, hereinafter referred to as
"Landlord", and GOVERNMENT TECHNOLOGY SERVICES, INC.,
hereinafter referred to as "Tenant".

IT IS AGREED AS FOLLOWS:

1.    DEMISE.

      Landlord does hereby lease to Tenant and Tenant does
      hereby  lease from Landlord the premises  consisting of
      the Improvements to be constructed upon the land
      ("Land") described on Exhibit A attached hereto and
      made a part hereof and any selected parking located on
      the Land which Tenant is entitled to utilize  pursuant
      to Section 35 hereof (the Improvements, together with
      the portion of the Land on which the Improvements and
      any related parking are located, is herein referred to
      as the "Premises" or the "Property").

      Improvements.  The Improvements (also referred to in
      Exhibit B as the "Base Building Work") shall mean the
      building to be constructed on the Land in accordance
      with the Work Agreement attached hereto as Exhibit B,
      to contain approximately one hundred thousand five
      hundred (100,500) rentable square feet as defined by
      the Building Owners and Managers Association
      International's Standard Method for Measuring Floor
      Area in Office Buildings dated June 7, 1996, as
      approved by the American National Standards Institute,
      Inc. (ANSI/BOMA Z65.1-1996) (the "BOMA method").  Upon
      substantial completion of the Improvements, the
      rentable area of the Improvements shall be determined
      in accordance with the BOMA method by the Architect (as
      herein defined).  The rentable area of the Improvements
      as so determined shall be controlling for purposes of
      establishing the Rent hereunder.

2.    TERM.

      (A)   Initial Term

            (1)   The term of this Lease ("Lease Term") shall,
                  subject to Section 2(C) hereof and Section
                  10(c) of Exhibit B hereto, be for a period of
                  120 months, commencing on the date of
                  Substantial Completion of the Improvements
                  and the Tenant Work (all as more fully set
                  forth in Exhibit B) ("Commencement Date") and
                  ending at 11:59 p.m. on the day ("Expiration
                  Date") immediately preceding the tenth (10th)
                  anniversary of the Commencement Date;
                  provided that, if the Commencement Date is a
                  day other than the first (1st) day of a
                  calendar month, the Expiration Date shall be
                  the last day of the month in which the tenth
                  (10th) anniversary of the Commencement Date
                  shall occur.  Except as provided below,
                  Tenant shall not be obligated to pay Rent
                  until possession of the Premises is tendered
                  to Tenant with the Improvements and the
                  Tenant Work therein Substantially Complete.
                  If the Commencement Date is a date other than
                  the first day of the month, Rent for the
                  month in which the Commencement Date occurs
                  shall be prorated on a daily basis.

            (2)   If Tenant occupies the Premises prior to the
                  Commencement Date, other than for purposes of
                  installation of telephones, cabling, special
                  equipment, trade fixtures and furniture in
                  accordance with Section 12(a) of Exhibit B,
                  such occupancy shall be subject to all
                  provisions hereof and shall not advance the
                  last day of the Lease Term, and Tenant shall
                  pay Rent for such period at the initial
                  monthly rate set forth below.

            (3)   If Landlord is delayed in Substantially
                  Completing the Landlord's Work (as defined in
                  Exhibit B) or in tendering possession of the
                  Premises with the Landlord's Work therein
                  Substantially Complete, in whole or part, by
                  a Tenant Delay, Rent and Additional Rent
                  shall, nonetheless, commence on that date on
                  which the Improvements and the Tenant Work
                  would have been Substantially Completed but
                  for the Tenant Delay (e.g., if there are two
                  (2) days of Tenant Delay and the Premises are
                  tendered to Tenant with the Improvements and
                  the Tenant Work Substantially Complete on
                  December 15, Rent and Additional Rent shall
                  accrue from December 13th).

            (4)   Subject to the terms of the last sentence of
                  this Section 2(a)(4), notwithstanding
                  anything herein contained to the contrary, if
                  construction of the Improvements has not
                  commenced on or before the Commencement
                  Deadline, Tenant shall have the right to
                  terminate this Lease by written notice
                  ("Tenant's Commencement Termination Notice")
                  delivered to Landlord not earlier than the
                  Commencement Deadline and not later than ten
                  (10) calendar days after the Commencement
                  Deadline (but in all events not later than
                  commencement of construction of the
                  Improvements), in which event (i) this Lease
                  shall cease and terminate without payment to
                  Tenant of any penalty, compensation or any
                  portion of the Allowance (as herein defined),
                  and without reimbursement of any costs,
                  damages, expenses or fees suffered or
                  incurred by or on behalf of Tenant, as if the
                  date on which Tenant's Commencement
                  Termination Notice is delivered to Landlord
                  was the Expiration Date, and (ii) Landlord
                  shall return to Tenant any Security Deposit
                  and any prepaid Rent.  As used herein, the
                  term "Commencement Deadline" shall mean
                  August 1, 1998 [subject to a day-for-day
                  extension for each day of delay attributable
                  to Tenant Delays, which Commencement Deadline
                  shall not be subject to delay for "Force
                  Majeure" (as defined in Section 38 below)];
                  provided that, if Tenant fails to timely
                  terminate this Lease pursuant to this Section
                  2(A)(4), then for purposes of Section
                  2(A)(5), the term "Commencement Deadline"
                  shall mean the date on which the Permit (as
                  defined in Exhibit B) is issued by Fairfax
                  County.  Despite the foregoing, in the event
                  that the "Construction Lender" (as defined in
                  Section 16(B)(3) below) has foreclosed upon
                  the Property or has accepted a deed in lieu
                  of foreclosure, and, subject to the
                  provisions of Section 38 below, is diligently
                  pursuing completion of the work to be
                  performed by Landlord under Exhibit B hereto,
                  Tenant shall not have the right to terminate
                  the Lease pursuant to the provisions of this
                  Section 2(A)(4).

            (5)   Notwithstanding anything herein contained to
                  the contrary, if the Landlord's Work
                  (exclusive of "long-lead" items and Punch
                  List Work items, as defined herein) is not
                  Substantially Complete within eleven (11)
                  months after the Commencement Deadline
                  (subject to a day-for-day extension for each
                  day of delay which occurs after the
                  Commencement Deadline and is attributable to
                  Tenant Delays, the "Completion Deadline")
                  and, as a result, Tenant is unable to
                  lawfully (and, in fact, does not) occupy the
                  Premises and use the Premises for the uses
                  permitted hereby, Tenant shall have the right
                  to deliver a sixty (60) day written notice of
                  termination ("Tenant's Completion Termination
                  Notice") delivered to Landlord not earlier
                  than the Completion Deadline nor later than
                  ten (10) calendar days after the Completion
                  Deadline (but in all events not later than
                  commencement of the Tenant's Work).  If
                  Tenant timely delivers the Tenant's
                  Completion Termination Notice and the
                  Landlord's Work (exclusive of "long-lead"
                  items and Punch List Work items, as defined
                  herein) is not Substantially Complete within
                  sixty (60) days after delivery of Tenant's
                  Completion Termination Notice (subject to a
                  day-for-day extension for each day of delay
                  which occurs after such delivery of Tenant's
                  Completion Termination Notice and which is
                  attributable to Tenant Delays), and, as a
                  result, Tenant is unable to lawfully (and, in
                  fact, does not) occupy the Premises and use
                  the Premises for the uses permitted hereby ,
                  this Lease shall automatically cease and
                  terminate without payment of penalty or
                  compensation as if the date on which such 60-
                  day period (as the same may be extended as
                  aforesaid) expires was the Expiration Date,
                  and Landlord shall return to Tenant any
                  Security Deposit and any prepaid Rent.

      (B)   Commencement Certificate.

                  At the request of Landlord at any time after
                  the Commencement Date has occurred, Tenant
                  hereby agrees to execute a declaration in the
                  form attached hereto as Exhibit C
                  ("Declaration") as incorporated herein by
                  reference.  Tenant's failure to execute the
                  Declaration shall not affect the Commencement
                  Date or the Lease Term, as same are
                  determined by the terms of this Lease.

      (C)   Extension Period.

            (1)   Provided no Event of Default is in existence
                  under this Lease at the time of the exercise
                  of the Extension Option or thereafter
                  (through and including the commencement date
                  of the Extension Period), and provided that
                  this Lease shall not theretofore have been
                  terminated, Tenant shall have one (1) non-
                  recurring option (the "Extension Option") to
                  extend the Expiration Date of the Lease Term
                  for a  period of five (5) consecutive years
                  (the "Extension Period").   The Extension
                  Period shall commence on the day following
                  the Expiration Date determined under Section
                  2(A) [as the same may be extended pursuant to
                  Section 10(c) of Exhibit B hereto] and end on
                  the fifth (5th) anniversary of the scheduled
                  Expiration Date determined under Section 2(A)
                  [as the same may be extended pursuant to
                  Section 10(c) of Exhibit B hereto].  The
                  Extension Period shall be upon the same terms
                  and conditions contained herein except that
                  (A) the Rent payable in the Extension Period
                  shall be adjusted on the first (1st) day of
                  the Extension Period to equal one hundred
                  percent (100%) of the then-prevailing fair
                  market rental rate for the Premises (the "New
                  Rental Rate"), and shall thereafter be
                  subject to adjustment in accordance with the
                  provisions of Section 3(B) hereof and (B)
                  Tenant shall have no option to extend the
                  Expiration Date of the Lease Term beyond the
                  last day of the Extension Period.

            (2)   Tenant may exercise the Extension Option only
                  by delivering binding written notice (the
                  "Extension Option Notice") to Landlord of
                  Tenant's election to exercise the Extension
                  Option not later than twelve (12) months
                  prior to the commencement of the Extension
                  Period; provided that (i) Tenant's Extension
                  Option Notice shall be ineffective unless the
                  same designates Tenant's broker for purposes
                  of arbitration if the parties are unable to
                  agree on the New Rental Rate, and (ii) if
                  Tenant delivers its Extension Option Notice
                  to Landlord more than twelve (12) months in
                  advance, Tenant may elect to rescind its
                  Extension Option Notice at any time which is
                  at least three hundred fifteen (315) days
                  prior to the commencement of the Extension
                  Period (and in all events prior to the
                  execution of a binding agreement to extend
                  this Lease for the Extension Period), on the
                  condition that Tenant reimburses Landlord
                  upon demand for any out-of-pocket costs
                  incurred by or on behalf of Landlord in
                  connection with the determination of the New
                  Rental Rate and/or preparation of a lease
                  amendment extending this Lease for the
                  Extension Period.  Landlord and Tenant agree
                  to negotiate in good faith for a period of
                  thirty (30) days to attempt to reach
                  agreement on the New Rental Rate applicable
                  to the Extension Period, promptly following
                  delivery of Tenant's Extension Option Notice.
                  If the parties fail to agree on such New
                  Rental Rate within said thirty (30) day
                  period, the determination of fair market
                  rental rate for the Premises shall be
                  arbitrated by brokers as set forth below
                  (each party hereby agreeing to submit the
                  determination of the fair market rental rate
                  for the Premises to arbitration in the manner
                  provided herein, if the parties are unable to
                  agree on the New Rental Rate within said
                  thirty (30) day period). Landlord shall
                  designate the broker appointed by it within
                  ten (10) business days after the expiration
                  of the aforesaid thirty (30) day period, and
                  each party shall by written notice (a copy of
                  which shall be provided to the other party
                  hereto) instruct their respective brokers to
                  commence such arbitration within ten (10)
                  business days after the expiration of the
                  aforesaid thirty (30) day period.

            (3)   In the event the Tenant designates a broker
                  and the Landlord fails to so designate a
                  broker within the aforesaid ten (10) business
                  day period, the broker appointed by the
                  Tenant shall proceed to make his valuation,
                  in which case the fair market rental rate of
                  the Premises shall be as determined by such
                  broker (such determination to be binding on
                  Landlord and Tenant).  In the event each
                  party designates a broker as aforesaid, each
                  broker shall proceed to make an independent
                  determination of the then-prevailing fair
                  market rental rate of the Premises within
                  thirty (30) days after appointment of
                  Landlord's broker.

            (4)   Each broker shall render a separate written
                  report, within thirty (30) days after
                  appointment of Landlord's broker, of such
                  broker's estimate of the then-prevailing fair
                  market rental rate for the Premises as of the
                  commencement of the Extension Period.  If the
                  values contained in the written reports
                  differ by five percent (5%) or less of the
                  greater of such values, the New Rental Rate
                  shall be one hundred percent (100%) of the
                  arithmetic average of such values (such
                  determination to be binding on Landlord and
                  Tenant).  If the values contained in the
                  written reports differ to a greater extent
                  than set forth above, the brokers shall,
                  within five (5) days, promptly jointly
                  appoint a third broker.  If the two brokers
                  so appointed shall fail to agree upon the
                  selection of a third broker within ten (10)
                  days after the expiration of such 30-day
                  period, then either party, upon written
                  notice to the other, may request such
                  appointment by the American Arbitration
                  Association (or any organization successor
                  thereto).  The parties shall cooperate to
                  expedite such appointment.  Within twenty
                  (20) days of his appointment, the third
                  broker shall render a written report of his
                  opinion of the value of the then-prevailing
                  fair market rental rate for the Premises as
                  of the commencement of the Extension Period.
                  One hundred percent (100%) of the arithmetic
                  average of the values in the three (3)
                  evaluation reports shall then be the New
                  Rental Rate for the Extension Period (which
                  determination shall be binding on Landlord
                  and Tenant); provided, however, that if the
                  lowest or highest of the three (3)
                  evaluations, or both, varies by more than ten
                  (10%) from the middle evaluation, such
                  evaluation or evaluations so varying shall be
                  disregarded in computing said average.

            (5)   In the event the New Rental Rate has not been
                  determined on or before the commencement of
                  the Extension Period, the Rent payable by
                  Tenant until such determination shall be
                  deemed equal to the Rent payable by Tenant
                  pursuant to Section 3(A) immediately prior to
                  the commencement of the Extension Period (as
                  the same may be adjusted hereunder);
                  provided, however, within fifteen (15) days
                  of such determination, Tenant shall pay
                  Landlord the excess of (i) the monthly
                  installments of monthly Rent as calculated
                  for the first (1st) year of the Extension
                  Period, above (ii) the monthly installments
                  of Rent actually paid by the Tenant, in
                  respect of each month commencing on or after
                  the commencement of the Extension Period but
                  prior to such determination, or Landlord
                  shall credit Tenant for any excess rent paid
                  by Tenant if the rental rate has declined,
                  and Tenant shall thereafter pay Rent for such
                  Extension Period as determined and adjusted
                  hereunder.

            (6)   All valuations of the fair market rental rate
                  of the Premises shall be in writing and shall
                  be expressed in terms of an annual rent.
                  Each broker's determination shall be based on
                  all relevant factors affecting fair market
                  rental rate, including, but not limited to
                  (and without limiting the scope of such
                  relevant factors), other terms of this Lease
                  which are applicable to the Extension Period
                  (including, but not limited to, the services
                  provided by Landlord and those which are
                  provided by Tenant, and the absence of any
                  concessions such as free rent or construction
                  allowance), the duration of the Extension
                  Period, the age and quality of the Building
                  (as defined in Exhibit B) and the Premises,
                  current "market" concessions, the fact that
                  the determination is for a renewal, the fact
                  that the determination is for a renewal as of
                  a future date, and (if true) that no
                  brokerage commission will be payable with
                  respect to the Extension Period.  To the
                  extent a reasonable sample is available, each
                  broker shall use as a basis for comparison
                  the rent for leases entered into for
                  comparable space in comparable buildings in
                  the submarket of Chantilly, Virginia in which
                  the Premises is located, within the period
                  which commences twelve (12) months prior to
                  the date of such determination, which leases
                  shall commence at approximately the same time
                  as the Extension Period.

            (7)   Each broker appointed hereunder shall be an
                  independent, licensed real estate broker in
                  the Commonwealth of Virginia, not affiliated
                  with either party, specializing in commercial
                  real estate in Chantilly, Virginia, having
                  not less than ten (10) years relevant
                  experience, and shall be qualified by
                  experience and ability to appraise the fair
                  market rental for the Premises.  The party
                  appointing each broker shall be obligated,
                  promptly after receipt of the valuation
                  report prepared by the broker appointed by
                  such party, to deliver a copy of such
                  valuation report to the other party in the
                  manner provided elsewhere in this Lease for
                  the delivery of notices.  If a third broker
                  is appointed, the third broker shall be
                  directed, at the time of his appointment, to
                  deliver copies of his valuation report,
                  promptly upon its completion, to Landlord and
                  Tenant in the manner provided elsewhere in
                  this Lease for the delivery of notices.  The
                  fees and other costs of each of the first two
                  brokers shall be borne by the party
                  appointing each such broker, with the fees
                  and other costs of the third broker being
                  shared equally by Landlord and Tenant.

            (8)   Unless otherwise agreed in writing by
                  Landlord and Tenant at the time the New
                  Rental Rate is determined, it is understood
                  that the New Rental Rate shall be the initial
                  Rent for the first (1st) Lease Year of the
                  Extension Period, and that such Rent shall be
                  subject thereafter to annual escalations, on
                  each successive anniversary of the
                  commencement of the Extension Period, based
                  on the provisions of Section 3(B).

            (9)   Tenant's failure to timely deliver the
                  Tenant's Extension Option Notice shall render
                  the Extension Option null and void.

3.    RENT.

      (A)   Rent.  Tenant shall pay for the use and occupancy
            of the Premises an annual base rental ("Rent")
            equal to Ten and Fifteen One Hundred Dollars
            ($10.15) per rentable square foot of the
            Improvements payable in equal monthly
            installments.  Rent shall be paid on the first day
            of each month in advance without demand or notice
            (except as otherwise expressly provided herein),
            deduction, offset, or counterclaim during the
            Lease Term.  Rent for any period during the Lease
            Term which is less than one month shall be a pro
            rata portion of the monthly installment, provided
            that if the Commencement Date is not the first
            (1st) day of a calendar month, such pro rata
            portion shall be added to the Rent for the first
            (1st) Lease Year.  Rent shall be payable in lawful
            money of the United States to Landlord at the
            address stated herein or to such other persons or
            at such other places as Landlord may designate in
            writing.

      (B)   Escalation of Rent.  Commencing on the first day
            of the second Lease Year (as hereinafter defined)
            and on the first day of each Lease Year thereafter
            during the Lease Term (each an "Adjustment Date"),
            Tenant shall pay to Landlord on the first day of
            each month as Rent an amount (the "Adjustment
            Amount") equal to the sum of (i) the Rent in
            effect immediately preceding the current
            Adjustment Date plus (ii) three percent (3%) of
            the Rent in effect immediately preceding such
            Adjustment Date.  The Adjustment Amount shall then
            be deemed to be the Rent in effect and shall be
            deemed to be the Rent in effect for purposes of
            calculating the next Adjustment Amount.

            "Lease Year" shall mean the twelve (12) month
            periods within the Lease Term, the first Lease
            Year commencing on the Commencement Date and
            terminating on the last day of the twelfth full
            calendar month after the Commencement Date, with
            each subsequent Lease Year commencing on the date
            immediately following the last day of the
            preceding Lease Year and continuing for a period
            of twelve (12) full calendar months, except that
            the last Lease Year of the Lease Term shall
            terminate on the date this Lease expires or is
            otherwise terminated.

      (C)   Place of Payment.  Rent, Additional Rent and other
            sums owed by Tenant shall be paid to Landlord at
            the offices of Landlord's property manager at 1115
            30th Street, N.W., Washington, D.C. 20007 or at
            such place as Landlord may designate from time to
            time in writing.

      (D)   Late Charge.  Tenant hereby acknowledges that late
            payment by Tenant of Rent, Additional  Rent or
            other sums due hereunder will cause Landlord to
            incur collection costs not contemplated by this
            Lease.  Therefore, if any installment of Rent,
            Additional Rent or any other sum due from Tenant
            shall not be received by Landlord when such amount
            is due, Tenant shall pay to Landlord a late charge
            of five percent (5%) of such overdue amount;
            provided that, Landlord agrees to waive the
            imposition of such late charge on the first (1st)
            occasion in any  twelve (12) month period on the
            conditions that no such late charge waiver has
            been granted or exercised in the preceding twelve
            (12) months, and the overdue payment is paid
            within five (5) business days after notice from
            Landlord that the payment was not paid when due.
            Additionally, Tenant shall pay to Landlord the
            Default Rate (as set forth in Section 29) on all
            sums in default.  Acceptance of such late charge
            and/or the Default Rate by Landlord shall in no
            event constitute a waiver of Tenant's default with
            respect to such overdue amount, or prevent
            Landlord from exercising any other right or remedy
            available to Landlord.

      (E)   Security Deposit.

            (1)   Purpose of Security Deposit.  The Security
                  Deposit shall be held by Landlord as security
                  for Tenant's faithful performance of Tenant's
                  obligations hereunder, with such Security
                  Deposit securing Tenant's obligations
                  hereunder subject to the terms and conditions
                  set forth in this Section 3(E).

            (2)   Required Amount.  Tenant shall, at all times,
                  ensure that the aggregate amount of all
                  Permitted Security (as herein defined) held
                  by Landlord from time to time (the "Security
                  Deposit") is equal to the then-current
                  Required Amount.  If, as a result of the
                  application of all or any part of the
                  Security Deposit in accordance with the terms
                  hereof, the Security Deposit shall be less
                  than the then-current Required Amount, Tenant
                  shall, within fifteen (15) days of Landlord's
                  written demand, provide Landlord with
                  additional Permitted Security equal to the
                  amount of the deficiency.  Tenant's failure
                  to restore the Security Deposit to the then-
                  current Required Amount when and as required
                  hereby shall constitute a material breach of
                  this Lease.  As used herein, the term
                  "Required Amount" shall initially mean the
                  sum of Two Million Dollars ($2,000,000.00).
                  The "Required Amount" shall be reduced on
                  each Reduction Date by Two Hundred Thousand
                  Dollars ($200,000).  "Reduction Date" shall
                  mean the first (1st) day of each Lease Year
                  commencing on or after the first (1st) day of
                  the second (2nd) Lease Year, on which no
                  Event of Default is in existence hereunder.

            (3)   Initial Deposits.  Tenant shall deposit with
                  Landlord upon execution hereof Permitted
                  Security in the amount of Six Hundred
                  Thousand Dollars ($600,000.00).  Landlord
                  agrees to provide Tenant with written notice
                  (the "LC Notice") of the date that
                  construction of the Improvements either (x)
                  is estimated to commence, or (y) has already
                  commenced.  Upon the later to occur of the
                  date that is two (2) days prior to the date
                  construction is scheduled to commence on the
                  Improvements pursuant to the Work Agreement
                  (Exhibit B), or the date which is ten (10)
                  days after the date that Tenant receives the
                  LC Notice, Tenant shall deposit with Landlord
                  additional Permitted Security in the amount
                  of One Million Four Hundred Thousand Dollars
                  ($1,400,000.00), to increase the total amount
                  of Permitted Security to Two Million Dollars
                  ($2,000,000.00).

            (4)   Permitted Security. Tenant shall provide the
                  Security Deposit to Landlord in the form of
                  one or more letters of credit ("LC") meeting
                  the criteria set forth in Section 3(E)(7)
                  ("Permitted Security"); provided that, the
                  aggregate number of LCs forming a part of the
                  Security Deposit shall at no time exceed four
                  (4).  Tenant shall immediately notify
                  Landlord in writing if Tenant acquires actual
                  knowledge (from a source other than Landlord)
                  that any LC provided to Landlord no longer
                  constitutes Permitted Security.

            (5)   Qualified Issuer.  As used herein, the term
                  "Qualified Issuer" shall mean a federally-
                  insured commercial bank or other federally-
                  insured financial institution which has an
                  office (whether of its own or a correspondent
                  bank) located in the greater Washington, D.C.
                  metropolitan area at which Permitted Security
                  (or a sight draft drawn thereon) may be
                  presented for payment (a "DC Payment
                  Office"), and which has a Qualified Credit
                  Rating.  Whether an institution is a
                  Qualified Issuer shall be subject to
                  continuous review (i.e., an institution shall
                  no longer be considered a Qualified Issuer at
                  any time after the loss of federal insurance,
                  the closure of all DC Payment Offices, or
                  loss of a Qualified Credit Rating).  As used
                  herein, the term "Qualified Credit Rating"
                  shall mean at least Prime-2 (or then-current
                  equivalent) by Moody's Investor Services,
                  Inc., at least A-2 (or then-current
                  equivalent) by Standard & Poor's Corporation,
                  or B- by Lace Financial Corporation.
                  Landlord hereby acknowledges that, as of the
                  date of this Lease, Landlord considers
                  Deutsche Bank to be a Qualified Issuer.

            (6)   Substitute Security. If the Security Deposit
                  is, at any time, less than the Required
                  Amount (whether due to application of the
                  Security Deposit pursuant to the terms
                  hereof, the loss of a Qualified Credit Rating
                  by the issuer of some or all of assets
                  delivered to Landlord for purposes of forming
                  a part of the Security Deposit, or
                  otherwise), Tenant shall deliver to Landlord
                  additional Permitted Security sufficient to
                  restore the Security Deposit to the Required
                  Amount, not later than fifteen (15) business
                  days after Landlord's written demand.

            (7)   Special LC Requirements.  Each LC forming all
                  or a part of the Security Deposit shall meet
                  each of the following criteria:

                  (A)   the LC shall be transferable,
                        fully-funded, and run in favor of
                        Landlord;

                  (B)   the LC shall be issued by a Qualified
                        Issuer (as herein defined);

                  (C)   the LC shall be irrevocable for a period
                        of one (1) year, and provide that it is
                        automatically renewable for successive
                        one (1) year periods unless the issuer
                        notifies Landlord by certified mail,
                        return receipt request, at least thirty
                        (30) days in advance of the expiration
                        date thereof, that the issuer will not
                        renew the LC;

                  (D)   the LC shall be in such form, and shall
                        contain such terms, as are reasonably
                        acceptable to Landlord, providing, among
                        other things, in substance that:

                        (1)   Landlord and its successors and
                              assigns shall have the right to
                              draw down an amount up to the then-
                              current face amount of the letter
                              of credit upon presentation to the
                              issuing bank of Landlord's own
                              declaration signed or purportedly
                              signed by or on its behalf, reading
                              as follows:

                              (i)   that the declarant has
                                    authority to make the
                                    declaration on behalf of the
                                    Landlord;

                              (ii)  that the declaration is made
                                    pursuant to the terms of the
                                    letter of credit number; and

                              (iii)       that Landlord is entitled
                                    to draw down the letter of
                                    credit under the terms of
                                    Section 3(E)(9)(A) or
                                    3(E)(9)(B) of the lease made
                                    between Landlord and Tenant.

                        (2)   The LC will be honored by the
                              issuer without inquiry as to the
                              accuracy of the accompanying
                              declaration, and regardless of
                              whether Tenant disputes the content
                              of such declaration; and

                        (3)   In the event of a transfer of
                              Landlord's interest in the
                              Premises, Landlord shall have the
                              right to transfer the LC to the
                              transferee.

                        (4)   Notwithstanding the foregoing,
                              Landlord agrees that the terms of
                              the LC may limit draws upon the LC
                              pursuant to Section 3(E)(9)(A) to
                              not more than Two Hundred Thousand
                              Dollars ($200,000.00) in any period
                              of ten (10) consecutive days.

             (8)  Treatment of Cash Security Deposit.  Any cash
                  sums forming all or a part of the Security
                  Deposit as a result of a draw upon a letter
                  of credit shall be kept in a separately
                  designated security deposit account in a
                  federally-insured bank (which may include
                  other security deposits), with interest
                  thereon accruing forming a part of the
                  Security Deposit.

            (9)   Right to Draw Upon Security Deposit.

                  (A)   Upon the occurrence of any monetary
                        Event of Default, Landlord and its
                        successors and assigns shall have the
                        right to negotiate, present for payment,
                        draw upon, use, apply or retain all or a
                        portion of the Security Deposit for the
                        payment of the Rent, Additional Rent or
                        other charge, payment or sum due to
                        Landlord from Tenant, provided in no
                        event shall the amount of any such draw
                        exceed the amount required to cure such
                        monetary Event of Default.

                  (B)   Upon (i) Tenant's failure, within
                        fifteen (15) business days after
                        delivery of written notice to Landlord
                        from the issuer of an LC forming all or
                        a part of the Security Deposit that the
                        issuer will not renew the LC, to deliver
                        to Landlord additional Permitted
                        Security in an amount equal to the LC
                        which will not be renewed, or (ii)
                        Tenant's failure, within fifteen (15)
                        business days after written notice from
                        Landlord that the some or all of the
                        assets delivered to Landlord to form a
                        part of the Security Deposit no longer
                        meet the criteria to be considered
                        Permitted Security (whether due to a
                        reduction in an LC issuer's credit
                        rating or otherwise), to deliver to
                        Landlord additional Permitted Security
                        sufficient to restore the Security
                        Deposit to the Required Amount, Landlord
                        and its successors and assigns shall
                        have the right to negotiate, present for
                        payment, and/or draw upon any portion of
                        the Security Deposit (or any LC then
                        held by Landlord and formerly
                        constituting a part of the Security
                        Deposit) not in the form of cash, and to
                        hold the proceeds of such negotiation,
                        presentment or draw (together with all
                        cash already forming a part of the
                        Security Deposit) as a cash Security
                        Deposit; provided that, Tenant shall
                        substitute additional Permitted Security
                        for the cash so held upon Landlord's
                        demand (in which event Landlord shall
                        return to Tenant the portion of the cash
                        held equal to the amount of such
                        additional Permitted Security).

            (10)  Transfer of Security Deposit.

                  (A)   Tenant acknowledges and agrees that
                        Landlord shall have the right to
                        transfer the Security Deposit to any
                        assignee or other transferee of
                        Landlord's interest in the Property,
                        subject to the terms hereof, and that
                        the provisions hereof shall apply to
                        every such assignment or transfer to a
                        new Landlord. Upon delivery of the
                        Security Deposit to any assignee or
                        other transferee of Landlord's interest
                        in the Premises, Landlord shall
                        thereupon be discharged from any further
                        liability with respect to the Security
                        Deposit.

                  (B)   Each Permitted Security forming a part
                        of the Security Deposit shall expressly
                        permit transfer of such Permitted
                        Security (whether by endorsement without
                        recourse, delivery, assignment, or re-
                        issuance in the name of the new
                        Landlord), and shall require the issuer
                        to acknowledge and accept the transfer
                        upon execution and delivery of a form of
                        transfer agreement which complies with
                        the issuer's reasonable requirements and
                        payment of a reasonable and customary
                        transfer fee (which fee, if such fee
                        exceeds One Hundred Dollars ($100.00)
                        and is paid by Landlord, shall be repaid
                        by Tenant to Landlord upon demand).  If
                        any issuer fails, within ten (10) days
                        after being notified of such transfer
                        and delivery of the transfer agreement
                        and payment of the transfer fee, to
                        acknowledge and accept the transfer of
                        the Permitted Security which it has
                        issued, Tenant shall deliver to Landlord
                        additional Permitted Security equal to
                        the amount of Permitted Security for
                        which such issuer has failed to
                        acknowledge and accept the transfer
                        (Tenant hereby acknowledging and
                        agreeing that Tenant shall be solely
                        responsible for any and all fees in
                        excess of One Hundred Dollars ($100.00)
                        charged by the issuer of such additional
                        Permitted Security.

            (11)  Return of Security Deposit. If Tenant
                  performs all of Tenant's obligations
                  hereunder, the Security Deposit, or so much
                  thereof as has not theretofore been applied
                  by Landlord, shall be returned with any
                  unpaid interest accrued thereon (if any) to
                  Tenant  (or at Landlord's option, to the last
                  assignee, if any, of Tenant's interest
                  hereunder) within thirty (30) days of the
                  later of (i) the last day of the Lease Term,
                  (ii) the date Tenant vacated the Premises, or
                  (iii) the date Tenant has fulfilled all its
                  obligations hereunder.

            (12)  Covenant Against Assignment or Encumbrance.
                  Tenant further covenants that it will not
                  assign, encumber or otherwise transfer any or
                  all of Tenant's interest in any portion of
                  the Security Deposit, and acknowledges that
                  neither Landlord nor its successors or
                  assigns will be bound by any attempted
                  assignment, encumbrance or other transfer.

            (13)  No Trust Relationship.  No trust relationship
                  is created herein between Landlord and Tenant
                  regarding the Security Deposit.

            (14)  Rights Against Mortgagee.  Tenant hereby
                  agrees not to look to any mortgagee as
                  mortgagee, mortgagee-in-possession or
                  successor in title to the Premises for
                  accountability for the Security Deposit
                  unless (but only to the extent) the Security
                  Deposit has actually been received by said
                  mortgagee as security for Tenant's
                  performance of this Lease.  Notwithstanding
                  the foregoing, this Section 3(E)(14) shall
                  not apply to Principal Mutual Life Insurance
                  Company or any of its wholly-owned
                  subsidiaries, it being understood and agreed
                  that, if Principal Mutual Life Insurance
                  Company or its wholly-owned subsidiaries are
                  the mortgagee-in-possession or successor in
                  title to the Premises, such party shall be
                  responsible to account for and apply the
                  Security Deposit in accordance with the terms
                  of this Lease (regardless of whether such
                  party has actually received the Security
                  Deposit).

4.    PERMITTED USE.

      Tenant covenants that the Premises will be used solely
      (if at all) for the following uses (collectively, the
      "Permitted Use"):  (1) general office purposes;  (2)
      warehouse use; (3) cafeteria use; (4) sales
      presentations; (5) equipment demonstrations; (6)
      seminars; (7) consulting purposes; and (8) catalogue,
      mail and telephone sales.  Tenant further covenants
      that the Premises will not be used or occupied for any
      unlawful purposes.  Tenant agrees to and shall use the
      Premises solely for the purpose of conducting the
      Permitted Use and for no other business or purpose.
      Tenant acknowledges that the Permitted Use is not a use
      granted exclusively to Tenant and that Landlord
      reserves the right to lease premises in the Property to
      others for the same or a similar permitted use.  Tenant
      further acknowledges that it has received no written or
      oral inducements from Landlord or any of Landlord's
      representatives concerning this Lease (other than as
      specifically set forth herein) or that Tenant will be
      granted any such exclusive rights.  Tenant shall not
      commit or allow to be committed any waste upon the
      Premises, or any public or private nuisance.

<PAGE>
5.    EXPENSES.

      (A)   Taxes

            (1)   Landlord shall pay all taxes applicable to
                  the Property which are payable during the
                  Lease Term.

            (2)   As used herein, the term "taxes" shall mean
                  real estate taxes, assessments (whether
                  general or special), sewer rents, rates and
                  charges, transit and transit district taxes,
                  taxes based upon the receipt of Rent or other
                  payments hereunder, and any other federal,
                  state or local governmental charge, general,
                  special, ordinary or extraordinary (but not
                  including income or franchise taxes,
                  inheritance, estate or gift taxes, net profit
                  taxes or any other taxes imposed upon or
                  measured by Landlord's net income or profits,
                  except as provided herein), which may now or
                  hereafter be levied, assessed or imposed
                  against the Property or Premises ("Taxes").
                  If the Property is assessed as part of a
                  larger parcel of land, Taxes shall only
                  include the portion thereof which is
                  allocable to the Property.  The allocation
                  referenced in the preceding sentence shall be
                  based on the ratio of the rentable area of
                  the Improvements to the rentable area of all
                  improvements upon such larger parcel of land,
                  in the following manner: (i) until the
                  construction commences for improvements other
                  than the Improvements on such parcel of land,
                  (A) the assessment for improvements shall be
                  entirely allocated to the Property, and (B)
                  the assessment for the land shall be
                  allocated based on the sum of (1) the
                  rentable area of the Improvements, plus (2)
                  the rentable areas of the other proposed
                  improvements on such land as set forth on
                  that certain site plan which is entitled
                  "Site/Grading Plan, GTSI Headquarters @
                  Avion, Parcel "D-1"," prepared by Rinker-
                  Detwiler & Associates, P.C. as Job Number 97-
                  065-H, dated October ___, 1997, (the "Current
                  Site Plan") attached hereto as Exhibit B-1
                  (as such rentable areas may be modified from
                  time to time)]; and (ii) once the
                  construction of improvements other than the
                  Improvements on such parcel of land has
                  commenced, the assessment for improvements
                  and land shall be allocated as stated on the
                  relevant tax bill(s) or assessor's
                  worksheet(s) (or, if not separately
                  allocated, based on the sum of (1) the
                  rentable area of the Improvements, plus (2)
                  the rentable areas of the proposed
                  improvements on such land for which
                  construction has commenced).  To the extent
                  any Tax may be paid without penalty or
                  interest in installments over a number of
                  years, such Tax shall be included in Taxes
                  for any year only to the extent of the
                  installments allocable to such year (as if
                  Landlord had elected to pay such Tax over the
                  longest possible period, whether or not
                  Landlord has so elected).  Provided Tenant
                  shall timely pay its Pro Rata Share of Taxes,
                  "Taxes" shall exclude any penalties or
                  interest thereon.  As of the date hereof,
                  Landlord estimates that the Taxes for
                  calendar year 1999 will be $80,400.00.
                  Landlord agrees to deliver a copy of each
                  assessment notice on the Property promptly
                  following the receipt thereof.  Additionally,
                  Landlord shall have no obligation to protest
                  Taxes, but if Landlord does protest Taxes,
                  the actual out-of-pocket cost of such protest
                  shall also be deemed Taxes.  Landlord shall
                  advise Tenant upon request (to be made not
                  more than fourteen (14) days in advance of
                  the filing deadline for protest of the
                  current tax assessment) whether Landlord
                  intends to protest the current tax
                  assessment.  If Landlord advises Tenant that
                  Landlord does not intend to protest such
                  current tax assessment, Tenant shall have the
                  right to challenge or appeal such assessment
                  in Landlord's name but at Tenant's sole
                  expense, and Landlord shall cooperate in such
                  challenge or appeal (including executing such
                  forms as may be reasonably necessary to
                  institute and prosecute such action);
                  provided that, Tenant shall have no right to
                  challenge or appeal any Tax assessment during
                  the last two (2) years of the Lease Term.

      (B)   Landlord shall provide insurance for the Property
            as set forth in Subsection 9(A) ("Insurance").  If
            Landlord has a net worth in excess of Fifty
            Million Dollars ($50,000,000.00), Landlord shall
            have the right to self-insure (in which event,
            Operating Expenses shall include the reasonable
            costs which would have been incurred if Landlord
            had obtained the insurance set forth in Section
            9(A) from a third party); provided that, in all
            events Landlord may self-insure the first Fifty
            Thousand Dollars ($50,000.00) of liability risk
            with regard to the Property (whether through
            deductibles, co-insurance or otherwise).

      (C)   (1)   Landlord shall provide for the following
                  throughout the Lease Term as they relate to
                  the Premises: (a) landscaping; (b) property
                  management; and (c) the maintenance, repair
                  and/or replacement of the Premises and
                  Improvements as follows: (i) the roof; (ii)
                  all structural components of the Premises and
                  Improvements; (iii) the parking lot (except
                  as expressly provided in Section 35 hereof),
                  (iv) sidewalks, alleys and any and all access
                  drives, including the removal of snow and ice
                  therefrom (provided that, Tenant shall have
                  the right to perform its own snow removal, at
                  Tenant's sole cost and risk, if Landlord
                  fails to promptly commence snow removal when
                  and as reasonably required to permit access
                  to the Premises); (v) fire sprinkler and fire
                  control systems (if any); (vi) exterior plate
                  glass; (vii) life safety systems and
                  equipment; and (viii) repairs of items under
                  warranty. Landlord agrees to maintain the
                  foregoing systems and components in a first-
                  class manner throughout the Lease Term;
                  provided that, Landlord shall have no
                  liability for failure to maintain or repair
                  the same unless and until Landlord shall fail
                  to perform such maintenance or make such
                  repairs within a reasonable time after
                  acquiring actual knowledge of the need for
                  such maintenance or repairs.

            (2)   Tenant (and not Landlord) shall provide
                  throughout the Lease Term, at Tenant's sole
                  expense, all other maintenance, repair and/or
                  replacement (as and when reasonably required)
                  of the Premises and Improvements (including,
                  but not limited to, (a) heating and air
                  conditioning equipment, lines and fixtures;
                  (b) plumbing equipment, lines and fixtures,
                  excluding fire sprinkler and fire control
                  systems (if any); (c) electrical equipment,
                  lines and fixtures; (d) all other utility
                  equipment, lines and fixtures; and (e) all
                  ingress-egress doors to the Property), all as
                  reasonably required in order to maintain the
                  Improvements and the Tenant Work in good
                  working order and condition.  Notwithstanding
                  the foregoing, Landlord shall perform any of
                  the services listed in this Section 5(C)(2)
                  upon Tenant's written request, in which event
                  all reasonable costs, expenses and fees
                  incurred by or on behalf of Landlord to
                  perform the same shall constitute Operating
                  Expenses.

      (D)   Tenant shall pay all utility bills incurred,
            including, but not limited to, water, gas,
            electricity, fuel, light, heat and power bills,
            when and as due.  If Tenant shall fail to pay any
            utility bill when and as due, Landlord shall have
            the right to pay such utility bill on Tenant's
            behalf (in which event the amount so paid shall be
            deemed Additional Rent which shall be repaid by
            Tenant upon demand). Landlord shall not be liable
            for any failure to furnish, or for any loss,
            injury or damage caused by or resulting from any
            variation, interruption or failure of utility
            services.  In the event of (i) any interruption of
            essential utilities or services due to Landlord's
            gross negligence or willful misconduct, which
            interruption or failure continues for more than
            three (3) consecutive business days, then,
            provided such interruption or failure shall render
            a material portion of the Premises untenantable,
            all Rent and Additional Rent payable hereunder
            with respect to such portion of the Premises shall
            thereafter be abated until such portion of the
            Premises is tenantable.

      (E)   Tenant, at Tenant's sole expense, shall comply
            with all laws, rules, orders, ordinances,
            directions, regulations and requirements of
            federal, state, county, and municipal authorities
            now in force or which may hereafter be in force,
            with respect to the use, repair, replacement,
            maintenance, occupancy or alteration of the
            Premises by Tenant or Tenant's Agents (as herein
            defined); provided that, Tenant shall have no
            obligation to perform structural alterations or
            improvements, unless such structural alterations
            or improvements (i) are required by law as a
            result of Tenant's or Tenant's Agents' specific
            use or manner of use of the Premises, or repair of
            the Premises, or (ii) would not have been required
            to be performed but for additions, alteration,
            improvements or modifications made by or on behalf
            of Tenant.  Landlord shall perform all structural
            alterations or improvements which are not Tenant's
            responsibility pursuant to the terms hereof.

      (F)   Except as otherwise expressly provided herein, the
            Tenant will keep, maintain and preserve the
            Premises in a good condition, ordinary wear and
            tear excepted, and shall provide all services,
            maintenance and repair require to keep the
            Premises in such condition.  Without limiting the
            foregoing, Tenant, at its sole cost and expense,
            will provide janitorial service for the Premises
            and interior and exterior window washing for the
            Premises.  Except as provided in Section 5(C)(1)
            above, Tenant, at the Tenant's sole cost and
            expense, shall also make all interior repairs and
            replacements to the Premises, including, but not
            limited to, interior walls, doors and windows,
            floors, floor coverings and light bulbs.

      (G)   All costs, expenses and fees incurred by or on
            behalf of Landlord in connection with providing
            any of the items in Subsections 5(B) and 5(C), to
            the extent paid by or on behalf of Landlord shall
            be referred to as "Operating Expenses"; provided
            that, the amount of the property management fee
            included in Operating Expenses shall not exceed
            (i) Two Thousand Five Hundred Fifty-One Dollars
            ($2,551.00) per month during the first (1st)
            calendar year of the Lease Term (which amount, as
            of the date of this Lease, is deemed by Landlord
            and Tenant to be the fair market value of the
            goods and services provided in exchange for such
            property management fee), and (ii) in any
            subsequent calendar year, the fair market value of
            the goods and services provided in exchange
            therefor.  For purposes of determining the fair
            market value of the goods and services provided in
            exchange for the property management fee, not more
            often than once every third (3rd) calendar year
            Landlord shall, upon Tenant's written request,
            conduct a survey of the property management fees
            paid to first-class property management companies
            serving the Chantilly, Virginia submarket with
            respect to single-story, single-tenant buildings
            located in a similar office parks in the
            Chantilly, Virginia submarket which are leased
            with similar tenant responsibilities, and shall
            provide to Tenant a copy of such survey.  In the
            event of any dispute between Landlord and Tenant
            on the fair market value of the goods and services
            provide in exchange for the property management
            fee, Landlord and Tenant shall submit such dispute
            to binding arbitration pursuant to the Uniform
            Arbitration Act as adopted by the Commonwealth of
            Virginia, Va. Code Ann. 8.01-581.01 et seq. (as
            the same may be amended from time to time).
            Tenant further acknowledges that the portion
            allocable to the Premises of the reasonable costs
            incurred in connection with the operation and
            management of, and providing and obtaining
            maintenance, landscaping, utilities and repairs
            for Avion (R) Business Park shall constitute
            Operating Expenses.

6.    ADDITIONAL RENT.

      (A)   Tenant shall pay its Pro Rata Share of Taxes and
            Operating Expenses ("Tenant's Share").  As soon as
            practicable each year during the Lease Term,
            Landlord shall furnish to Tenant a detailed
            estimate of Tenant's Share for the timeframe in
            question (broken down on a category by category
            basis).  Tenant acknowledges that Landlord has
            provided Tenant with a non-binding estimate of the
            Tenant's Share for calendar year 1999, prior to
            the execution hereof.  Tenant shall pay to
            Landlord the estimate for Tenant's Share in equal
            monthly installments at the same time and place as
            Rent is to be paid.  Landlord will furnish a
            statement of the actual Tenant's Share no later
            than April 1 of each year during the Lease Term,
            including the year following the year in which the
            Lease expires or is otherwise terminated.  In the
            event that Landlord is, for any reason, unable to
            furnish the statement of the actual Tenant's Share
            within the time specified above, Landlord will
            furnish such statement as soon thereafter as
            practicable with the same force and effect as the
            statement would have had if delivered within the
            time specified above.  Tenant will pay to Landlord
            any deficiency as shown by such statement within
            thirty (30) days of receipt of such statement.
            Provided no Event of Default by Tenant is in
            existence under this Lease, Landlord will refund
            to Tenant any excess as shown by such statement
            within thirty (30) days of the date of the
            statement; provided that, if an Event of Default
            by Tenant is in existence, Landlord shall refund
            to Tenant the amount of such excess at such time
            as all Events of Default have been cured.
            Landlord will keep books and records showing the
            Operating Expenses in accordance with generally
            accepted accounting principles.

      (B)   Any and all payments (other than Rent) required to
            be made by Tenant pursuant to this Lease shall be
            deemed additional Rent ("Additional Rent").
            Landlord shall have the same rights and remedies
            for said payments as for Rent.

      (C)   Pro Rata Share.  Tenant's pro rata share is 100%
            ("Pro Rata Share").

      (D)   Tenant's Right to Audit. If Tenant disputes any
            Operating Expenses or Taxes statement, Tenant must
            provide Landlord with specific written objections
            within one hundred eighty (180) days after
            receiving the statement (failing which, the
            statement will be deemed conclusive).  Within 30
            days after receiving these objections, Landlord
            will either adjust the disputed statement in
            response to Tenant's objection(s) and credit any
            overpayment to Tenant as stated above, or notify
            Tenant that it believes Tenant's objection is
            without merit (it being agreed that, if Landlord
            fails to respond within such 30-day period,
            Landlord shall be deemed to have agreed to adjust
            the disputed statement in response to Tenant's
            objection(s) and credit any overpayment to Tenant
            as stated above).  If Tenant timely disputes a
            statement and Landlord notifies Tenant that
            Tenant's objection is without merit, Tenant may --
            if no Event of Default by Tenant is then in
            existence -- cause (i) qualified accounting
            employees of Tenant, or (ii) an independent,
            certified public accountant ("CPA") to audit the
            supporting data for the disputed statement (in
            which event, such supporting data shall be made
            available to the employee or CPA).  However,
            Tenant may not exercise its audit right unless the
            audit commences within thirty (30) days after
            Landlord notifies Tenant that Tenant's objection
            is without merit, nor may Tenant audit any
            statement more than once (it being understood that
            the foregoing prohibition against multiple audits
            of the same statement shall not be deemed to
            prohibit the examination of the same documents
            more than once in the course of the same audit).
            Any CPA selected by Tenant to conduct an audit
            must have least 5 years experience performing
            operating expense pass-through audits for
            commercial office buildings in the metropolitan
            Washington, D.C. area, and must be approved by
            Landlord.  Landlord's approval will not be
            unreasonably withheld or delayed, if such CPA (a)
            is not compensated on a contingency fee basis, and
            (b) signs a confidentiality agreement in form
            reasonably acceptable to Landlord (Landlord hereby
            agreeing that no such confidentiality agreement
            shall prohibit the disclosure, in any action or
            suit instituted by Tenant against Landlord with
            regard to the audited Operating Expenses or Taxes,
            of information required to institute or prosecute
            such action or suit, but such confidentiality
            agreement may require Tenant and the CPA to agree
            to reasonable protective orders in connection
            therewith).  Each audit under this Section 6(D)
            must be conducted at Landlord's property manager's
            Washington, D.C. area office.  If Landlord does
            not agree with the audit results of the CPA Tenant
            selects, or Tenant's employee(s), Landlord and
            Tenant will endeavor to resolve their differences
            (failing which, the dispute will be conclusively
            determined based on an independent audit by a
            third-party CPA selected by the parties or,
            failing agreement, appointed by the American
            Arbitration Association or any recognized
            successor thereto upon application by either
            party).  The parties will make any necessary
            adjustments in accordance with the third-party CPA
            audit.  Tenant must pay all costs and expenses of
            Tenant's audit (including, but not limited to,
            reasonable copying charges), unless the amounts
            paid by Tenant to Landlord for the year in
            question exceeded the amounts to which Landlord
            was entitled by more than 6%, in which event
            Landlord will reimburse Tenant for the reasonable
            costs incurred in connection with Tenant's audit.
            If the third-party CPA audit shows Tenant has
            underpaid Operating Expenses or Taxes (or both),
            in addition to paying to Landlord the underpayment
            amount, Tenant shall reimburse Landlord upon
            demand for all reasonable costs, expenses and fees
            incurred by Landlord in connection with such
            dispute.  If a third-party CPA ultimately resolves
            the dispute, the losing party shall pay the costs
            incurred in connection with the third-party CPA
            audit (including, but not limited to, reasonable
            copying charges).  Tenant has no right to withhold
            or reduce any performance by Tenant under the
            Lease pending or based upon any audit under this
            Section 6(D).

7.    SORTING AND SEPARATION OF REFUSE AND TRASH.

      Tenant shall be responsible for contracting for all
      trash removal services.  Tenant covenants and agrees,
      as its sole cost and expense, to comply with all
      present and future laws, orders and regulations of all
      state, federal, municipal and local governments,
      departments, commissions and boards regarding the
      collection, sorting, separation and recycling of waste
      products, garbage, refuse and trash.  Tenant shall pay
      all costs, expenses, fines, penalties or damages that
      may be imposed on Landlord or Tenant by reason of
      Tenant's failure to comply with the provisions of this
      Section 7, and, at Tenant's sole cost and expense,
      shall indemnify, defend and hold Landlord harmless
      (including legal fees and expenses) from and against
      any actions, claims and suits arising from such
      noncompliance, utilizing counsel reasonably
      satisfactory to Landlord.

8.    HAZARDOUS SUBSTANCES.

      (A)   The term "Hazardous Substances" shall mean
            pollutants, contaminants, toxic or hazardous
            wastes, or any other substances, the use and/or
            the removal of which is required or the use of
            which is restricted, prohibited or penalized by
            any "Environmental Law", which term shall mean any
            federal, state or local law, regulation, order,
            ordinance or other statute of a governmental or
            quasi-governmental authority relating to pollution
            or protection of the environment.  Tenant hereby
            agrees that (A) no activity will be conducted on
            the Premises that will produce any Hazardous
            Substances, except for such activities that are
            part of the ordinary course of Tenant's business
            activities (the "Permitted Activities") provided
            said Permitted Activities are conducted in
            accordance with all Environmental Laws and have
            been acknowledged and consented to in advance in
            writing by Landlord (such consent not to be
            unreasonably withheld); Tenant shall be
            responsible for obtaining any required permits and
            paying any fees and providing any testing required
            by any governmental agency in connection with the
            Permitted Activities; (B) the Premises will not be
            used in any manner for the storage of any
            Hazardous Substances except for the temporary
            storage of such materials (the "Permitted
            Materials") that are used in the ordinary course
            of the Permitted Activities, provided such
            Permitted Materials are properly stored in a
            manner and location meeting all Environmental Laws
            and acknowledged and consented to in advance in
            writing by Landlord (such consent not to be
            unreasonably withheld); Tenant shall be
            responsible for obtaining any required permits and
            paying any fees and providing any testing required
            by any governmental agency in connection with the
            Permitted Materials; (C) no portion of the
            Premises will be used as a landfill or a dump; (D)
            Tenant will not install any underground tanks of
            any type; (E) Tenant will not cause any surface or
            subsurface conditions to exist or come into
            existence that constitute, or with the passage of
            time may constitute a public or private nuisance;
            (F) Tenant will not knowingly or negligently
            permit any Hazardous Substances to be brought onto
            the Premises by or on behalf of Tenant, except for
            the Permitted Materials described above, and if so
            brought thereon, the same shall be immediately
            removed, with proper disposal, and all required
            cleanup procedures shall be diligently undertaken
            pursuant to all Environmental Laws.  Landlord or
            Landlord's representative shall have the right but
            not the obligation to enter the Premises for the
            purpose of inspecting the storage, use and
            disposal of Permitted Materials to ensure
            compliance with all Environmental Laws.  Should it
            be determined, in Landlord's sole (but reasonable)
            opinion, that said Permitted Materials are being
            improperly stored, used, or disposed of, then
            Tenant shall immediately take such corrective
            action as is reasonably requested by Landlord.
            Should Tenant fail to take such corrective action
            within ten (10) days (or such shorter period as is
            reasonable under the circumstances), Landlord
            shall have the right to perform such work and
            Tenant shall promptly reimburse Landlord for any
            and all actual, out-of-pocket costs associated
            with said work.  If at any time during or after
            the Lease Term, the Premises are found to be
            contaminated by Hazardous Materials as a
            consequence of the acts or omissions of Tenant or
            any of Tenant's Agents, or any surface or
            subsurface conditions exist at the Property as a
            consequence of the acts or omissions of Tenant or
            any of Tenant's Agents, Tenant shall diligently
            institute proper and thorough cleanup procedures
            at Tenant's sole cost, and Tenant agrees to
            indemnify, defend and hold harmless Landlord, its
            lenders, any managing agents and leasing agents of
            the Property, and their respective agents,
            partners, officers, directors and employees, from
            all claims, demands, actions, liabilities, costs,
            expenses, penalties (whether civil or criminal),
            damages (actual or punitive) and obligations of
            any nature arising from or as a result of such
            contamination or conditions.  The foregoing
            indemnification and the responsibilities of Tenant
            shall survive the termination or expiration of
            this Lease.

      (B)   Except with regard to the use, storage and
            disposal, in accordance with applicable law, of
            Hazardous Substances utilized in the ordinary
            course of the maintenance, repair and/or operation
            of the Property ("Landlord's Permitted
            Substances"), Landlord agrees that it will be
            fully responsible for all costs, expenses, damages
            or liabilities which may occur from the use,
            storage, disposal, release, spill or discharge of
            Hazardous Substances by Landlord or its agents,
            representatives, employees or contractors while
            acting within the scope of their employment, and
            it shall indemnify, defend and hold harmless
            Tenant and its agents, employees, partners,
            officers, directors, invitees, assignees,
            sublessees, contractors and others for whose
            actions Tenant is responsible (collectively,
            "Tenant's Agents") from all claims, demands,
            actions, liabilities, reasonable costs, reasonable
            expenses, penalties (whether civil or criminal),
            damages (actual or punitive) and obligations of
            any nature to the extent arising from or as a
            result of any violation of this Section 8(B). The
            foregoing indemnification and the responsibilities
            of Landlord shall survive the termination or
            expiration of this Lease.

      (C)   During and after the Lease Term, Tenant and
            Landlord shall each promptly provide the other
            with copies of all summons, citations, directives,
            information inquiries or requests, notices of
            potential responsibility, notices of violation or
            deficiency, orders or decrees, claims, complaints,
            investigations, judgments, letters, notices of
            environmental liens, and other communications,
            issued or threatened in writing, from the United
            States Environmental Protection Agency,
            Occupational Safety and Health Administration, the
            Commonwealth of Virginia Department of
            Environmental Quality, or other federal, state or
            local agency or authority, or any other entity or
            individual, whether public or private, concerning
            (i) any Hazardous Substance regarding the Property
            or the Premises; (ii) the imposition of any
            environmental lien on the Property or the
            Premises; or (iii) any alleged violation of or
            responsibility under any Environmental Law, with
            respect to the Property.

9.    INSURANCE.

      (A)   INSURANCE BY LANDLORD.

            Landlord shall, during the Lease Term, procure and
            keep in force the following insurance (it being
            understood that the cost of commercially
            reasonable premiums and deductibles incurred or
            paid by or on behalf of Landlord in connection
            therewith will be deemed Additional Rent payable
            by Tenant pursuant to Section 5 and Section 6
            (Tenant hereby acknowledging that, as of the date
            hereof, Landlord's deductible in connection with
            its casualty insurance is $10,000 per occurrence,
            and such deductible is commercially reasonable)):

            (1)   Property insurance insuring the Premises and
                  Improvements and rental income insurance
                  (i.e., loss of rents insurance) for perils
                  covered by the causes of loss - special form
                  (all risk) and in addition coverage for
                  flood, earthquake and boiler and machinery
                  (if applicable).  Such coverage (except for
                  flood and earthquake) shall be written on a
                  replacement cost basis equal to ninety
                  percent (90%) of the full insurable
                  replacement value of the foregoing and shall
                  not cover Tenant's equipment, trade fixtures,
                  inventory, fixtures or personal property
                  located on or in the Premises.

            (2)   Commercial general liability insurance
                  against any and all claims for death, bodily
                  injury and property damage occurring in or
                  about the Premises or the land.  Such
                  insurance shall have a combined single limit
                  of not less than One Million Dollars
                  ($1,000,000) per occurrence per location with
                  a Two Million Dollars ($2,000,000) aggregate
                  limit, and shall name Tenant as an additional
                  insured.

            (3)   Such other insurance as Landlord deems
                  reasonably necessary and prudent, consistent
                  with the insurance customarily maintained by
                  comparable buildings in the Chantilly
                  submarket of Fairfax County, Virginia, or as
                  reasonably required by Landlord's
                  beneficiaries or mortgagees of any deed of
                  trust or mortgage encumbering the Premises.

      (B)   INSURANCE BY TENANT.

            Tenant shall, during the Lease Term, procure and
            keep in force the following insurance:

            (1)   Commercial general liability insurance naming
                  Landlord and Landlord's managing agent for
                  the Premises as additional insureds against
                  any and all claims for death, bodily injury
                  and property damage occurring in, or about
                  the Premises arising out of Tenant's use and
                  occupancy of the Premises.  Such insurance
                  shall have a combined single limit of not
                  less than One Million Dollars ($1,000,000)
                  per occurrence with Two Million Dollars
                  ($2,000,000) aggregate limit and excess
                  umbrella liability insurance in the amount of
                  Two Million Dollars ($2,000,000).  If Tenant
                  has other locations that it owns or leases,
                  the policy shall include an aggregate limit
                  per location endorsement conforming to the
                  foregoing.  Such liability insurance shall be
                  primary and not contributing with any
                  insurance available to Landlord and
                  Landlord's insurance shall be in excess
                  thereto.  In no event shall the limits of
                  such insurance be considered as limiting the
                  liability of Tenant under this lease.

            (2)   Personal property insurance insuring all
                  equipment, trade fixtures, inventory,
                  fixtures and personal property located on or
                  in the Premises for perils covered by the
                  cause of loss - special form (all risk) and
                  in addition, coverage for flood, earthquake
                  and boiler and machinery (if applicable).
                  Such insurance shall be written on a
                  replacement cost basis in an amount equal to
                  ninety percent (90%) of the full replacement
                  value of the aggregate of the foregoing.

            (3)   Workers' compensation insurance in accordance
                  with statutory law and employers' liability
                  insurance with a limit of not less than
                  $100,000 per accident, $500,000 for a disease
                  policy limit, and $100,000 for disease limit
                  for each employee.

            (4)   Business interruption insurance in such
                  amounts, if any, that Tenant in its prudent
                  business judgment, elects to maintain, from
                  time to time, it being understood and agreed
                  that if there is any conflict between the
                  provisions of this Section 9(B)(4) and the
                  provisions of Section 9 (B)(5),the provisions
                  of this Section 9(B)(4) shall govern and
                  control.

            (5)   Such other insurance as Landlord deems
                  necessary and prudent, consistent with the
                  insurance customarily required to be
                  maintained by tenants of comparable buildings
                  in the Chantilly submarket of Fairfax County,
                  Virginia, or as reasonably required by
                  Landlord's beneficiaries or mortgagees of any
                  deed of trust or mortgage encumbering the
                  Property.

            The policies required to be maintained by Tenant
            and the policies required to be maintained by
            Landlord shall each be issued by companies rated
            AX or better in the most current issue of Best's
            Insurance Reports.  Insurers shall be licensed or
            authorized to do business in the state in which
            the Premises is located and domiciled in the
            United States.  Any deductible amounts under any
            of Tenant's insurance policies required hereunder
            shall not exceed $10,000.  Certificates of
            insurance (certified copies of the policies shall
            be provided upon Landlord's request) shall be
            delivered to Landlord prior to the Commencement
            Date and annually thereafter at least thirty (30)
            days prior to the expiration date of the old
            policy.  Tenant shall have the right to provide
            insurance coverage which it is obligated to carry
            pursuant to the terms hereof in a blanket policy,
            provided such blanket policy expressly affords
            coverage to the Premises, and to Landlord, as
            required by this Lease.  Each policy of insurance
            shall provide notification to Landlord at least
            ten (10) days prior to any cancellation or
            modification to reduce the insurance coverage.  In
            the event Tenant does not purchase the insurance
            required by this Lease or fails to keep the same
            in full force and effect, Landlord may (but shall
            not be obligated to), upon forty-eight (48) hours
            notice (or, in the case of the lapse of Tenant's
            general liability insurance, without notice),
            purchase the required insurance and pay the
            premium.  The Tenant shall repay to Landlord, as
            Additional Rent the amount so paid promptly upon
            demand.  In addition, Landlord may recover from
            Tenant and Tenant agrees to pay, as Additional
            Rent, any and all reasonable expenses (including
            reasonable attorneys' fee) and damages which
            Landlord may sustain by reason of the failure of
            Tenant to obtain and maintain such insurance.

      (C)   SUBROGATION.

            Landlord and Tenant mutually waive their
            respective rights of recovery against each other
            for any loss of, or damage to, either parties'
            property, to the extent that such loss or damage
            is insured by an insurance policy required to be
            in effect at the time of such loss or damage.
            Each party shall obtain any special endorsements,
            if required by its insurer, whereby the insurer
            waives its rights of subrogation against the other
            party.  This clause shall not apply in those cases
            where waiver of subrogation would cause either
            parties' insurance to be voided or otherwise made
            uncollectible.

10.   DAMAGE OR DESTRUCTION.

      If (i) the Premises shall be materially damaged or
      destroyed during the last year of the Lease Term (it
      being agreed that, if the Extension Option was
      exercised prior to such damage or destruction and
      Tenant's right of rescission thereof has lapsed or is
      waived in writing by Tenant not later than the earlier
      of (x) 315 days in advance of the Expiration Date, or
      (y) thirty (30) days after the date of such damage or
      destruction, the last year of the Lease Term shall be
      deemed to be the last year of the Extension Period), or
      (ii) the Premises is damaged or destroyed to such
      extent that the damage or destruction cannot be
      repaired within a period of three hundred sixty-five
      (365) days of the date of such damage or destruction,
      either Landlord or Tenant may terminate this Lease by
      written notice (the "Damage Notice") delivered to the
      other within sixty (60) days of the date of such damage
      or destruction (and in such event this Lease shall
      terminate as of date of such damage or destruction as
      if such date were the Expiration Date hereof).  In
      addition, Landlord, at its sole option, shall have the
      right to cancel and terminate this Lease, by written
      notice (the "Section 10 Notice") delivered to Tenant
      not later than sixty (60) days after the date of damage
      or destruction, in the event (i) the Premises is
      materially damaged or destroyed, (ii) the unexpired
      portion of the Lease Term which will remain after
      completion of rebuilding or restoration of the Premises
      (based on the estimated time for rebuilding or
      restoration from a reputable, independent contractor)
      is less than forty-two (42) months [it being agreed
      that, for purposes of the foregoing calculation, if the
      Extension Option was exercised prior to such damage or
      destruction and Tenant's right of rescission thereof
      has lapsed or is waived in writing by Tenant not later
      than the earlier of (x) 315 days in advance of the
      Expiration Date, or (y) thirty (30) days after the date
      of such damage or destruction, less than forty-two (42)
      months of the Extension Period will remain unexpired
      after completion of rebuilding or restoration of the
      Premises, based upon the estimated time for such
      rebuilding or restoration], and (iii) Tenant shall fail
      to execute and deliver to Landlord within thirty (30)
      days after the date that Tenant received the Section 10
      Notice an extension of the Lease Term equal to the
      amount of time by which the remaining Lease Term
      (which, if the Extension Option is not exercised prior
      to such damage or destruction or if Tenant's right of
      rescission thereof has not lapsed or is not waived in
      writing by Tenant within thirty (30) days after the
      date of such damage or destruction, shall exclude the
      Extension Period, and in all events shall exclude the
      estimated time to rebuild or restore the Premises) is
      less than forty-two (42) months, upon the same terms
      and conditions set forth herein except that the Rent
      for the period of such extension shall equal the
      then-escalated Rent in effect immediately prior to the
      expiration of the Lease Term, subject to escalation in
      the same manner in effect immediately prior to the
      expiration of the Lease Term.  If Landlord delivers
      neither the Damage Notice or the Section 10 Notice to
      Tenant within sixty (60) days after the date of the
      damage or casualty, Landlord shall be deemed to have
      waived its right to terminate this Lease in connection
      with such damage or destruction.  If this Lease is not
      terminated, then Landlord shall repair and restore the
      Premises (exclusive of Tenant's equipment, trade
      fixtures, inventory, fixtures and personal property)
      with all reasonable speed (but in all events not later
      than twelve (12) months after the date of the damage)
      to substantially the same condition as immediately
      prior to such damage or destruction, and the Rent and
      Additional Rent or a just and proportionate part
      thereof, according to Tenant's ability to utilize the
      Premises in its damaged condition, shall be abated
      until the Premises shall have been repaired and
      restored by Landlord.

11.   INDEMNIFICATION.

      (A)   Subject to the terms of Section 9(C), Tenant shall
            and does hereby indemnify, hold harmless, and
            defend Landlord (except for Landlord's gross
            negligence or willful misconduct) against all
            costs, damages, injury, claims, liabilities or
            expenses (including, but not limited to,
            reasonable attorneys' fees), losses and court
            costs with respect to injury or death to any
            person or for damage to or loss of use of any
            property arising out of any occurrence in, on or
            about the Property or on account of the use,
            condition, occupational safety or occupancy of the
            Property, to the extent caused or contributed to
            by Tenant or Tenant's Agents, or arising out of
            any occurrence in, upon or at the Premises, or on
            account of the use, condition, occupational safety
            or occupancy of the Premises.  To the fullest
            extent permitted by applicable law, it is the
            intent of the parties hereto that the indemnity
            contained in this Section shall not be limited or
            barred by reason of any ordinary negligence on the
            part of Landlord or Landlord's agents, but nothing
            herein contained shall be deemed to require Tenant
            to indemnify Landlord against the negligence of
            Landlord or Landlord's agents except to the extent
            Tenant is insured against liability arising
            therefrom. Such indemnification shall include and
            apply to (but shall not be limited to) reasonable
            attorneys' fees, investigation costs, and other
            costs actually and reasonably incurred by
            Landlord.  Subject to the terms of Section 9(C),
            Tenant shall and does hereby further indemnify,
            defend and hold harmless Landlord from and against
            any and all costs, damages, injury, claims,
            liabilities or expenses arising from any breach or
            default in the performance of any obligation on
            Tenant's part to be performed under the terms of
            this Lease.  The provisions of this Section shall
            survive the expiration or termination of this
            Lease with respect to any damage, injury, death,
            breach or default occurring prior to such
            expiration or termination.  This Lease is made on
            the express conditions that, except as expressly
            set forth in this Lease, Landlord shall not be
            liable for, or suffer loss by reason of, injury to
            person or property, from whatever cause, in any
            way connected with the condition, use,
            occupational safety or occupancy of the Premises
            specifically including, without limitation, any
            liability for injury to the person or property of
            Tenant or Tenant's Agents.

      (B)   Subject to the terms hereof (including, but not
            limited to, Section 9(C) hereof), Landlord shall
            and does hereby indemnify and hold harmless Tenant
            from and against all costs, damages, injury,
            claims, liabilities, expenses (including, but not
            limited to, reasonable attorneys' fees), losses
            and court costs to the extent caused by or
            contributed to by any gross negligence or willful
            misconduct of Landlord or its agents or employees
            acting within the scope of their employment.  Such
            indemnification shall include and apply to (but
            shall not be limited to) reasonable attorneys'
            fees, investigation costs, and other costs
            actually and reasonably incurred by Tenant.
            Subject to the terms of Section 9(C), Landlord
            shall further and does hereby indemnify, defend
            and hold harmless Tenant from and against any and
            all costs, damages, injury, claims, liabilities or
            expenses arising from any breach or default in the
            performance of any obligation on Landlord's part
            to be performed under the terms of this Lease.  To
            the fullest extent permitted by applicable law, it
            is the intent of the parties hereto that the
            indemnity contained in this paragraph shall not be
            limited or barred by reason of any ordinary
            negligence on the part of Tenant or Tenant's
            Agents, but nothing herein contained shall be
            deemed to require Landlord to indemnify Tenant
            against the negligence of Tenant or Tenant Agents
            except to the extent Landlord is insured against
            liability arising therefrom. The provisions of
            this Section shall survive the expiration or
            termination of this Lease with respect to any
            damage, injury, death, breach or default occurring
            prior to such expiration or termination.  This
            Lease is made on the express conditions that,
            except as expressly set forth in this Lease,
            Tenant shall not be liable for, or suffer loss by
            reason of, injury to person or property, from
            whatever cause, in any way connected with the
            condition, use, occupational safety or occupancy
            of the common areas of Avion (R) Business Park
            specifically including, without limitation, any
            liability for injury to the person or property of
            Landlord or Landlord's agents or employees.

12.   ASSIGNMENT AND SUBLETTING.

       (A)  Tenant shall not assign, encumber, mortgage,
            pledge, license, hypothecate or otherwise transfer
            the Premises or this Lease, in whole or in part,
            or sublease all or any part of the Premises, or
            permit the use or occupancy of any part of the
            Premises by any person or entity other than Tenant
            and its employees, without the prior written
            consent of Landlord, which may be granted or
            withheld in Landlord's sole discretion; provided
            that, subject to Landlord's termination right as
            set forth below, Landlord agrees not to
            unreasonably withhold, delay or condition its
            consent to any sublease or assignment (each a
            "Transfer").  Notwithstanding anything herein
            contained to the contrary, it shall be deemed
            reasonable for Landlord to withhold its consent to
            a proposed Transfer if Landlord reasonably
            determines that: (1) the proposed Transferee or
            its business is not of a type and quality suitable
            for a building of comparable quality and type, (2)
            the proposed Transferee is a governmental or
            quasi-governmental authority, a foreign government
            or international agency or other organization
            entitled to sovereign or other immunity, (3) the
            proposed operations of the proposed assignee or
            subtenant would materially and adversely interfere
            with the ability of other tenants of the Building
            to utilize their premises for the uses
            ("Comparable Uses") that are consistent with the
            type of uses found in buildings that are of
            similar quality and type as the Building, (4) the
            proposed assignee has not been demonstrated to
            Landlord's satisfaction to have sufficient
            financial capability and stability to perform its
            obligations under such proposed assignment, or (5)
            the proposed Transferee is proposing to engage in
            a use which (i) is not a Permitted Use, (ii) is
            not permitted pursuant to applicable law to be
            conducted by the proposed Transferee or within the
            Premises (or such lesser portion as is being
            sublet) or both, (iii) will violate any covenant,
            condition, restriction or other matter of record
            affecting title to the Property, or (iv) will
            violate any "exclusive use" or other restrictive
            covenant of any other lease of any portion of the
            Property (so long as such exclusive use or
            restrictive covenant does not restrict the ability
            of Tenant to engage in the Permitted Use).

      (B)   (1)   Tenant must request Landlord's consent to an
                  assignment or sublease in writing at least
                  thirty (30) days prior to the commencement
                  date of the proposed sublease or assignment,
                  which request must include (a) the name and
                  address of the proposed assignee or
                  subtenant, (b) the nature and character of
                  the business of the proposed assignee or
                  subtenant, (c) financial information
                  (including financial statements) of the
                  proposed assignee or subtenant, and (d) a
                  copy of the proposed sublet or assignment
                  agreement, which must be in substance and
                  form reasonably acceptable to Landlord.
                  Tenant shall also provide any additional
                  information Landlord reasonably requests
                  regarding such proposed assignment or
                  subletting.

            (2)   Within twenty-one (21) days after Landlord
                  receives Tenant's request for consent to a
                  proposed assignment or subletting (with all
                  required information included), Landlord
                  shall have the option: (i) to grant its
                  consent to such proposed assignment or
                  subletting, or (ii) to deny or condition its
                  consent to such proposed assignment or
                  subletting (it being understood that such
                  consent will not, subject to Landlord's right
                  of termination, be unreasonably withheld,
                  conditioned or delayed), or (iii) at
                  Landlord's sole discretion, to terminate this
                  Lease effective as of the commencement date
                  of such proposed assignment, or, if a
                  sublease, to sublease the portion of the
                  Premises proposed to be subleased, on the
                  same terms and conditions set forth in the
                  proposed sublease for which Landlord's
                  consent is sought. If Landlord fails to
                  respond to Tenant within such period of time,
                  Tenant may deliver to Landlord a second (2nd)
                  request for such consent, which notice shall
                  specifically state that the failure by
                  Landlord to respond within five (5) business
                  days shall be deemed Landlord's election to
                  grant its consent thereto, and in the absence
                  of a response to such second (2nd) notice,
                  Landlord shall be deemed to have granted its
                  consent thereto.  Landlord acknowledges that
                  as of the date of this Lease, Tenant has
                  delivered to Landlord a list containing the
                  names of the entities identified by Tenant as
                  Tenant's current direct competitors.  At
                  least seven (7) days prior to the date that
                  Landlord enters into a lease or grants any
                  party (other than Tenant) the right to use
                  any portion of the Premises, Landlord shall
                  deliver a written notice (the "Competitor
                  Request Notice") to Tenant which requests
                  that Tenant provide Landlord with a written
                  list of Tenant's then direct competitors.  If
                  within seven (7) days after the date that
                  Tenant receives a Competitor Request Notice,
                  Tenant delivers to Landlord a list of direct
                  competitors, then such list shall be deemed
                  the then-current "Competitor List", provided
                  that if Tenant fails to deliver to Landlord
                  such list within seven (7) days after the
                  date Tenant receives a Competitor Request
                  Notice, then the then current Competitor List
                  shall be deemed to be the most recent list of
                  direct competitors that has been delivered to
                  Landlord by Tenant.  Landlord acknowledges
                  and agrees that, so long as (x) GTSI is the
                  Tenant hereunder, and (y) GTSI utilizes the
                  Premises for sales, marketing or training
                  purposes or for its executive offices,
                  Landlord may not (i) lease space recaptured
                  pursuant to the foregoing clause
                  12(B)(2)(iii) or the following Section
                  12(B)(3) to any direct competitor of GTSI on
                  the then current Competitor List or (ii)
                  permit any direct competitor of GTSI on the
                  then current Competitor List to use any
                  portion of the Premises.  For purposes of
                  this Section 12(B)(2) and Section 12(E), (i)
                  the term "GTSI" shall include Government
                  Technology Services, Inc. and any
                  organization successor thereto by means of
                  merger, consolidation or reorganization, and
                  (ii) the terms "direct competitor" and
                  "direct competitors" shall mean business
                  operations that have been identified by
                  Tenant in writing on the most recent
                  Competitor List as direct competitors in
                  accordance with the foregoing provisions,
                  which operations engage in the resale of
                  computers to the United States government (it
                  being understood that computer manufacturers,
                  and any division of any company which
                  otherwise qualifies as a direct competitor of
                  GTSI but the division of which is to be
                  located within the recaptured space does not
                  engage in the resale of computers to the
                  United States government, shall not be
                  prohibited by the preceding provisions of
                  this Section 12 (B)(2)).

            (3)   Tenant shall additionally have the right to
                  deliver to Landlord advance written notice
                  (each an "Intent Notice") of Tenant's intent
                  to assign or sublease before Tenant
                  identifies the proposed assignee or
                  sublessee.  Each Intent Notice shall include
                  the terms and conditions upon which Tenant
                  proposes to assign or sublease.  Landlord may
                  exercise its recapture right pursuant to the
                  foregoing Section 12(B)(2)(iii), with respect
                  to the space Tenant intends to sublet or
                  assign as identified in Tenant's Intent
                  Notice, within twenty-one (21) days after
                  delivery of Tenant's Intent Notice, but if
                  Landlord fails to exercise such right within
                  such 21-day period, Landlord shall have no
                  right to exercise such recapture right, with
                  respect to any proposed assignment or sublet
                  of the space identified in Tenant's Intent
                  Notice on the terms and conditions described
                  in such Intent Notice, during the sixty (60)
                  day period following the expiration of such
                  21-day recapture period (or any earlier date
                  on which Landlord notifies Tenant that it
                  will not exercise its recapture right at that
                  time).

      (C)   Each sublease and/or assignment is also subject to
            all of the following terms and conditions:

            (1)   Tenant shall pay to Landlord as Additional
                  Rent fifty percent (50%) of the amount (the
                  "sublet profit"), if any, by which the rent
                  (net of any rent abatements), any additional
                  rent and any other sums paid by the assignee
                  or subtenant to Tenant under such assignment
                  or sublease (after deducting therefrom the
                  reasonable out-of-pocket costs incurred by
                  Tenant in the subject transaction, including,
                  but not limited to, brokerage commissions,
                  hard and soft construction expenses, tenant
                  concessions (exclusive of non-cash
                  concessions, such as free rent), and
                  reasonable legal fees) exceeds the total of
                  (i) the Rent plus (ii) any Additional Rent
                  payable by Tenant hereunder, which is
                  allocable to the portion of the Premises
                  and/or the Lease Term which is the subject of
                  such assignment or sublease.  The foregoing
                  payments shall be made on a monthly basis by
                  Tenant in each month in which a sublet profit
                  is received.  In the event that Tenant
                  receives any consideration in connection with
                  a  merger, consolidation, reorganization of
                  Tenant, or in connection with a sale of all
                  or substantially all of Tenant's assets or
                  stock, then the provisions of this Section
                  12(c)(1) shall not be applicable to such
                  consideration.

            (2)   No consent to any assignment or sublease
                  shall constitute a further waiver of the
                  provisions of this Section, and all
                  subsequent assignments or subleases may be
                  made only upon the terms and conditions of
                  this Section 12 and, where required, with the
                  prior written consent of Landlord in
                  accordance herewith.  In no event shall any
                  consent by Landlord be construed to permit
                  reassignment or resubletting by a permitted
                  assignee or sublessee.

            (3)   No sublease or assignment by Tenant shall
                  relieve Tenant of any liability hereunder.

            (4)   Any assignment or sublease made without
                  Landlord's prior written consent (if such
                  consent is required) shall be void, and
                  shall, at the option of the Landlord,
                  constitute an Event of Default under this
                  Lease.

            (5)   No assignment or sublease shall be granted
                  for any term which extends beyond the Lease
                  Term.

            (6)   Tenant shall reimburse Landlord upon demand
                  for all reasonable costs, expenses and fees
                  incurred by or on behalf of Landlord in
                  connection with any proposed assignment or
                  sublease by Tenant (including, but not
                  limited to, Landlord's reasonable attorneys
                  fees and out-of-pocket expenses, if any), up
                  to a maximum of One Thousand Five Hundred
                  Dollars ($1,500.00) per proposed Transfer.

      (D)   The following events also constitute an
            "Assignment" which is subject to the terms of this
            Section and for which Landlord's prior written
            consent is required:  (i) if Tenant is a
            corporation and any part or all of Tenant's shares
            of stock, or the shares of stock or other
            ownership interests of any corporation or other
            entity owning shares of Tenant's stock, shall in
            any one or more instances be issued, or
            transferred by sale, assignment, conveyance,
            operation of law (including, but not limited to,
            transfer as a result of or in conjunction with any
            merger, reorganization or recapitalization) or
            other disposition, or otherwise changed, so as to
            result in less than fifty-one (51%) of such
            shares, or other ownership interests, or less than
            fifty-one percent (51%) of any class of such
            shares or other ownership interests, being owned
            by the present (i.e., as of the date hereof)
            owners thereof; (ii) if Tenant is a partnership
            and any general partnership interest(s), or the
            stock or other ownership interests of any
            corporation or other entity owning any such
            general partnership interests(s), in the
            partnership shall in any one or more instances be
            issued, or transferred by sale, assignment,
            conveyance, operation of law (including, but not
            limited to, transfer as a result of or in
            conjunction with any merger, reorganization or
            recapitalization) or other disposition, or
            otherwise changed, so as to result in less than
            fifty-one percent (51%) of such general
            partnership interests(s), stock (or any class of
            such stock) or other ownership interests being
            owned by the present (i.e., as of the date hereof)
            owners thereof; (iii) if Tenant is a limited
            liability company or any other type of entity, and
            any interest(s) of any member or other equity
            owner, or the ownership interests of any entity
            owning any membership interest(s) or other equity
            interest in the Tenant, shall in any one or more
            instances be issued, or transferred by sale,
            assignment, conveyance, operation of law
            (including, but not limited to, transfer as a
            result of or in conjunction with any merger,
            reorganization or recapitalization) or other
            disposition, or otherwise changed, so as to result
            in less than fifty-one percent (51%) of such
            membership interests or other such equity and/or
            ownership interests being owned by the present
            (i.e., as of the date hereof) owners thereof; or
            (iv) if effective control of the corporation,
            partnership, limited liability company or other
            form of Tenant shall be taken from those
            exercising such control as of the date hereof.
            Notwithstanding anything herein contained to the
            contrary, this Section 12(D) shall not be deemed
            to apply to Tenant if Tenant is a corporation the
            shares of which are traded on a
            nationally-recognized exchange and which is
            required to make public disclosures regarding
            ownership and financial condition.

      (E)   Notwithstanding any other provision of this Lease
            to the contrary, GTSI (as defined in Section
            12(B)(2)), while it is the Tenant and no Event of
            Default is in existence hereunder, shall have the
            right to (1) assign this Lease or to sublet all or
            any portion of the Premises, in either case
            without the consent of Landlord, to any successor
            to GTSI by merger, consolidation or
            reorganization, and to any affiliate that is
            wholly-owned by or under common ownership with
            GTSI (as part of a single group of interlocking
            companies), or to any wholly-owned and controlled
            division or sub-entity of GTSI, or (2) sublet up
            to twenty percent (20%) of the Premises in the
            aggregate (collectively, the "Permitted
            Sublettings") without the consent of Landlord,
            subject to the satisfaction of the following
            conditions: (a) the proposed assignee or sublessee
            (the "Transferee") and its business shall be of a
            type and quality suitable for a building of
            comparable quality and type, (b) the proposed
            Transferee shall not be a governmental or
            quasi-governmental authority, a foreign government
            or international agency or other organization
            entitled to sovereign or other immunity, (c) the
            proposed operations of the proposed assignee or
            subtenant will not materially and adversely
            interfere with the ability of other tenants of the
            Building to utilize their premises for the
            Comparable Uses, (d) GTSI shall notify Landlord
            not less than ten (10) days in advance of the
            effective date of such assignment or sublease of
            GTSI's intent to enter into such assignment or
            sublease (failing which, Landlord shall be
            entitled, and GTSI shall pay to Landlord as
            liquidated damages, the sum of Five Hundred
            Dollars ($500.00) for each failure to so notify
            Landlord), (e) occupancy of the Premises by such
            Transferee will not violate existing law, (f)
            there will be no use of the Premises in violation
            of the terms hereof, (g) with respect to an
            assignment, such Transferee shall expressly assume
            all of the obligations of the Tenant hereunder on
            a form reasonably acceptable to Landlord, and (h)
            no such assignment or subletting shall relieve
            GTSI of any agreement, covenant, duty, liability
            or obligation hereunder.  Landlord acknowledges
            and agrees that Landlord's right to recapture
            pursuant to this Section 12 shall not apply to any
            assignment or sublease to any successor to GTSI by
            merger, consolidation or reorganization, or to
            affiliate that is wholly-owned by or under common
            ownership with GTSI (as part of a single group of
            interlocking companies), or to any wholly-owned
            and controlled division or sub-entity of GTSI,
            which may be made without Landlord's consent under
            the terms hereof, nor to the Permitted
            Sublettings.

      (F)   Tenant hereby assigns to the Landlord absolutely
            the rent due from each assignee and subtenant and
            Tenant hereby authorizes each such assignee and
            subtenant to pay said rent directly to Landlord
            for credit, as and when collected by the Landlord
            (and net of the Landlord's reasonable collection
            costs), against the Rent and Additional Rent
            payable hereunder; provided that, for all periods
            in which no Event of Default shall be in existence
            hereunder, Landlord shall permit Tenant to
            continue to collect the rent from such assignees
            and subtenants.

13.   CARE OF PREMISES.

      Except to the extent the obligation of Landlord
      pursuant to the express terms hereof, Tenant covenants
      and agrees that during the Lease Term it will keep the
      Premises and every part thereof in good order,
      condition and repair (subject to reasonable wear and
      tear, and damage by fire or other casualty which is not
      Tenant's obligation to repair),and that it will in all
      respects and at all times duly comply with all
      applicable laws, and all covenants, conditions and
      restrictions applicable to the Property.

14.   ALTERATION BY TENANT.

      (A)   Tenant is hereby given the right, at its sole cost
            and expense, at any time during the Lease Term, to
            make non-structural alterations or improvements to
            the interior of the Improvements which Tenant
            deems necessary or desirable for its purposes;
            provided, however, that no alterations or
            improvements shall be made without the prior
            written approval of Landlord, which written
            approval shall not be unreasonably withheld,
            conditioned or delayed so long as the proposed
            alterations do not affect the structure of the
            Property or the systems serving the same, do not
            require any alterations to be made to portions of
            the Property outside the Premises, and will not
            materially and adversely interfere with the
            ability of other tenants of the Building to
            utilize their premises for the Comparable Uses.
            Landlord's approval of any plans, specifications
            or work drawings shall create no responsibility or
            liability on the part of the Landlord for their
            completeness, design sufficiency or compliance
            with any laws, rules and regulations of
            governmental agencies or authorities.
            Notwithstanding the foregoing, Landlord's consent
            shall not be required for purely cosmetic
            decorations nor for non-structural alterations
            costing less than Twenty-Five Thousand Dollars
            ($25,000.00) in the aggregate, so long as (1)
            Tenant notifies Landlord of its intent to carry
            out such alterations at least ten (10) days in
            advance, (2) the proposed alterations do not
            affect the structure of the Property or the
            systems serving the same, do not require any
            alterations to be made to portions of the Property
            outside the Premises, do not require the issuance
            of a building permit, and will not adversely
            affect any other tenant or occupant of the
            Property, and (3) Tenant provides Landlord with
            reasonable assurances against the attachment of
            any mechanics' or materialmen's liens to the
            Property.  Landlord agrees to respond to any
            request for consent to any alteration costing less
            than Fifty Thousand Dollars ($50,000) within five
            (5) business days after delivery to Landlord of
            Tenant's request for consent accompanied by
            detailed plans and specifications for the proposed
            alteration.

      (B)   All work herein permitted shall be done and
            completed by the Tenant in a good and workmanlike
            manner and in compliance with all requirements of
            law and of governmental rules and regulations.
            Tenant agrees to and does hereby indemnify the
            Landlord against all mechanics' or other liens
            arising out of any of such work, and also against
            any and all costs, damages, injury, claims,
            liabilities or expenses which arise out of any
            such work.  The Landlord agrees to join with the
            Tenant in applying for all permits necessary to be
            secured from governmental authorities and to
            promptly execute such consents as such authorities
            may reasonably require in connection with any of
            the foregoing work.

      (C)   Upon written notice to Tenant within ninety (90)
            days after expiration of the Lease Term, Landlord
            may require that Tenant remove, at Tenant's sole
            cost and expense, any or all alterations,
            improvements or additions to the Improvements, and
            restore the Improvements to their prior condition.
            Notwithstanding the foregoing, Landlord shall have
            no right to require removal of the Tenant Work, or
            any subsequent alteration, addition, improvement
            or modification in or to the Premises for which
            Landlord's consent is required, unless Landlord
            expressly reserves (in writing) the right to
            require such removal at the time Landlord's
            consent to the plans and specifications therefor
            is given. Unless Landlord requires their removal
            in accordance with the foregoing, all alterations,
            additions and improvements which may be made on
            the Improvements (other than video/surveillance
            equipment installed by or on behalf of Tenant at
            Tenant's expense, exclusive of the Tenant's
            Allowance) shall become the property of Landlord
            and remain upon and be surrendered with the
            Improvements.  Tenant shall also repair any damage
            to the Improvements or Tenant Work caused by the
            installation or removal of Tenant's trade
            fixtures, furnishings and equipment, or any
            alterations or other improvements made to the
            Improvements or Tenant Work by or on behalf of
            Tenant.

15.   CONDEMNATION.

      (A)   If the Premises shall be wholly taken by exercise
            of right of eminent domain, then this Lease shall
            terminate from the day the possession of the whole
            of the Premises shall be required under the
            exercise of such power of eminent domain.  Any
            award for the taking of all or part of the
            Premises under the power of eminent domain or any
            payment made under threat of the exercise of such
            power shall be the property of the Landlord.
            Tenant reserves such separate rights as it may
            have against the condemning authority to claim
            damages for loss of its trade fixtures and the
            cost of removal and relocation expense, provided
            such Tenant rights do not, in any way, diminish
            the award to which Landlord would otherwise be
            entitled or reduce the amounts payable to Landlord
            pursuant to this subsection.

      (B)   If such part of the Improvements shall be
            condemned so as to substantially and materially
            hamper the operation of Tenant's business, then
            the Rent and Additional Rent payable hereunder
            shall be reduced in the proportion that the
            remaining area of the Improvements bears to the
            original area of the Improvements.

16.   SUBORDINATION.

      (A)   Provided that (i) Landlord enters into a mortgage
            which encumbers all or any portion of the
            Property, and (ii) Landlord's mortgagee shall have
            executed and delivered to Tenant a written
            subordination, attornment and non-disturbance
            agreement meeting the criteria set forth in
            Section 16(B)(the "Approved Agreement"), (x) this
            Lease shall be subject and subordinate to the lien
            of such mortgage (and to any and all advances made
            thereunder); however, Landlord's mortgagee shall
            have the right, without Tenant's consent, to
            require this Lease be superior to any such
            mortgage, and (y) Tenant agrees to execute such
            Approved Agreement.  Notwithstanding anything
            herein to the contrary, if Principal Mutual Life
            Insurance Company ("PMLIC") or any party that is
            related to or affiliated with PMLIC is the
            mortgagee, the form of the subordination and
            non-disturbance agreement that will be entered
            into shall be the form that is attached hereto as
            Exhibit G.

      (B)   (1)   The subordination of this Lease to any
                  mortgage shall be conditioned upon Landlord
                  obtaining from the holder of such mortgage a
                  commercially reasonable form of written
                  non-disturbance agreement which provides (A)
                  in the event of a foreclosure or other action
                  taken under the mortgage by the holder
                  thereof, this Lease and the rights of Tenant
                  hereunder shall not be disturbed but shall
                  continue in full force and effect so long as
                  Tenant shall not be in default hereunder
                  beyond the applicable notice and cure period
                  (if any), and (B) such holder will agree that
                  in the event it shall be in possession of the
                  Premises, that so long as Tenant shall
                  observe and perform all of the obligations of
                  Tenant to be performed pursuant to this Lease
                  (subject to applicable notice and cure
                  rights), such Mortgagee will perform all
                  obligations of Landlord required to be
                  performed under this Lease.

            (2)   Tenant hereby acknowledges that it has been
                  informed that Principal Mutual Life Insurance
                  Company currently is the beneficiary of a
                  deed of trust which encumbers the Land.
                  Tenant further acknowledges and agrees that
                  the form of subordination, non-disturbance
                  and attornment agreement attached hereto as
                  Exhibit G (the "Approved SNDA") constitutes a
                  commercially reasonable form of
                  non-disturbance agreement.  Landlord hereby
                  agrees that, if Principal Mutual Life
                  Insurance Company fails to execute and
                  deliver the Approved SNDA to Tenant within
                  five (5) days after Landlord and Tenant
                  execute and deliver this Lease, Tenant may
                  deliver to Landlord a five (5) day written
                  notice of termination (the "SNDA Termination
                  Notice") within ten (10) days after the
                  expiration of the first 5-day period.
                  Provided the Tenant's SNDA Termination Notice
                  is timely delivered, and further provided
                  that such SNDA Termination Notice shall
                  state, inter alia, that the failure by
                  Principal Mutual Life Insurance Company to
                  execute and deliver the Approved SNDA within
                  five (5) days after delivery of the SNDA
                  Termination Notice will result in a
                  termination of this Lease, if Principal
                  Mutual Life Insurance Company fails to
                  execute and deliver the Approved SNDA to
                  Tenant within five (5) days after delivery of
                  the SNDA Termination Notice this Lease shall
                  cease and terminate without payment of
                  penalty or compensation as if the fifth (5th)
                  day after the date on which Tenant's SNDA
                  Termination Notice is delivered to Landlord
                  was the Expiration Date, and Landlord shall
                  return to Tenant any Security Deposit and any
                  prepaid Rent.

            (3)   Tenant hereby acknowledges that it has been
                  informed that Landlord intends to obtain a
                  construction loan to finance the construction
                  of the Improvements and/or the Tenant Work
                  from a third-party construction lender (the
                  "Construction Lender").  Landlord hereby
                  agrees that, if the Construction Lender fails
                  to execute and deliver to Tenant a
                  commercially reasonable form of
                  non-disturbance agreement (a "Construction
                  SNDA", which form shall provide, inter alia,
                  that if the Construction Lender forecloses
                  upon the Property or accepts a deed to the
                  Property in lieu of foreclosure, the
                  Construction Lender will, subject to the
                  provisions of Section 38 below, diligently
                  pursue completion of the construction of the
                  Improvements and the Tenant Work beginning
                  upon the Construction Lender's obtaining
                  possession of the Property, provided that (i)
                  Tenant attorns to the Construction Lender as
                  substitute landlord, (ii) Tenant agrees not
                  to terminate this Lease, provided that,
                  subject to the provisions of Section 38
                  below, the Construction Lender is diligently
                  pursuing completion of the work to be
                  performed by Landlord under Exhibit B, and
                  (iii) Tenant is not in default beyond the
                  expiration of any applicable cure period, on
                  or before August 1, 1998, Tenant may deliver
                  to Landlord a five (5) day written notice of
                  termination (the "Construction SNDA
                  Termination Notice") on or before August 11,
                  1998.  Provided the Tenant's Construction
                  SNDA Termination Notice is timely delivered,
                  and further provided that such Construction
                  SNDA Termination Notice shall state, inter
                  alia, that the failure by the Construction
                  Lender to execute and deliver the
                  Construction SNDA within five (5) days after
                  delivery of the Construction SNDA Termination
                  Notice will result in a termination of this
                  Lease, if the Construction Lender fails to
                  execute and deliver the Construction SNDA to
                  Tenant within five (5) days after delivery of
                  the Construction SNDA Termination Notice this
                  Lease shall cease and terminate without
                  payment of penalty or compensation as if the
                  fifth (5th) day after the date on which
                  Tenant's Construction SNDA Termination Notice
                  is delivered to Landlord was the Expiration
                  Date, and Landlord shall return to Tenant any
                  Security Deposit and any prepaid Rent.

      (C)   In the event any proceedings are brought for
            foreclosure, or in the event of the exercise of
            the power of sale under any mortgage made by the
            Landlord covering the Premises, Tenant shall
            attorn to the purchaser at any such foreclosure,
            or to the grantee of a deed in lieu of
            foreclosure, and recognize such purchaser or
            grantee as the Landlord under this Lease.

      (D)   Tenant hereby agrees that no mortgagee or its
            successor shall be (i) bound by any payment of
            Rent or Additional Rent for more than one (1)
            month in advance, (ii) bound by any amendment or
            modification of this Lease made without the
            consent of Landlord's mortgagee or its successor
            (which consent, if PMLIC is the mortgagee, shall
            not be unreasonably withheld, conditioned or
            delayed), (iii) liable for damages for any breach,
            act or omission of any prior landlord, (iv) bound
            to effect or pay for any construction for Tenant's
            occupancy (it being understood and agreed that
            such mortgagee or its successor shall be obligated
            to perform the initial construction of the
            Improvements in accordance with the provisions of
            Exhibit B to the extent not previously completed),
            or (v) subject to any claim of offset or defenses
            that Tenant may have against any prior landlord.
            Notwithstanding anything herein contained to the
            contrary, (x) the foregoing clause (iv) shall not
            apply to Principal Mutual Life Insurance Company
            or its wholly-owned subsidiaries or to any
            Construction Lender, and (y) with respect to any
            mortgage, secured in whole or part by the
            Property, under which PMLIC or any of its
            wholly-owned subsidiaries is the mortgagee or
            beneficiary, the disposition of any casualty
            proceeds and condemnation awards shall, in the
            first instance, be controlled by the terms of this
            Lease and not such lender's loan documents, and
            such lender will be obligated to return the
            Security Deposit, whether or not received by such
            lender. Upon Tenant's written request, Landlord
            agrees to exercise reasonable efforts (the same
            not to include refinancing, payment of money or
            posting of security by Landlord) to obtain the
            agreement of any future mortgagee (other than
            Principal Mutual Life Insurance Company or its
            wholly-owned subsidiaries or any Construction
            Lender) to include in its non-disturbance
            agreement such mortgagee's agreement that (a)
            clause (iv) of this Section 16(D) will be
            inapplicable, (b) the disposition of any casualty
            proceeds and condemnation awards shall, in the
            first instance, be controlled by the terms of this
            Lease and not such lender's loan documents, and
            (c) the lender will be obligated to return the
            Security Deposit, whether or not received by such
            lender, but the refusal of any such future
            mortgagee to agree to such provisions shall not
            entitle Tenant to refuse to execute a commercially
            reasonable form of written non-disturbance
            agreement which complies with Section 16(B).

      (E)   The word "mortgage" as used herein includes
            mortgages, deeds of trust and any sale-leaseback
            transactions, or other similar instruments, and
            modifications, extensions, renewals, and
            replacements thereof, and any and all advances
            thereunder.

17.   ACCESS TO PREMISES.

      Landlord and its authorized agents shall have access to
      the Premises, upon forty-eight (48) hours' notice (but
      without notice in the event of an emergency) at any and
      all reasonable times to inspect the same, to make any
      repair or alteration to the Premises, to exhibit and
      show the Premises to prospective tenants during the
      last three hundred fifteen (315) days of the Lease
      Term, and for other purposes pertaining to the rights
      of the Landlord. Tenant may require an authorized
      representative of Tenant accompany any entry into the
      Premises, provided Tenant makes such representative
      available upon reasonable prior notice.  Tenant shall
      also have the right to restrict access to secure areas,
      so long as (i) Tenant accepts all responsibility and
      liability arising from Landlord's inability to access
      such areas, and (ii) a senior employee of Landlord or
      Landlord's managing agent is provided access to such
      secure area upon 48-hours' notice for purposes of
      verifying the condition and use thereof.  In exercising
      Landlord's rights under this Section 17, Landlord
      agrees to exercise commercially reasonable efforts to
      avoid any unreasonable interference with the operation
      of Tenant's business in the Premises.

18.   RULES AND REGULATIONS.

      Tenant agrees to comply with the current rules and
      regulations set forth in the attached Exhibit D and
      made a part hereof by reference.  Tenant further agrees
      to comply with future rules and regulations promulgated
      by Landlord concerning the Premises, to the extent (i)
      such future rules and regulations do not increase
      Tenant's obligations or decrease Tenant's rights
      hereunder, (ii) such future rules and regulations are
      not in conflict with the express terms of this Lease,
      and (iii) such future rules and regulations are imposed
      on all comparable tenants in Avion (R) Business Park.

19.   COVENANTS OF RIGHT TO LEASE.

      Landlord covenants that it owns the fee interest in the
      Land subject to existing covenants, conditions and
      restrictions of record, that it has good and sufficient
      right to enter into this Lease, subject to approval
      from Landlord's mortgagee, and that Landlord alone has
      the right to lease the Premises for the Lease Term.
      Tenant acknowledges that Landlord has provided to
      Tenant a current title report for the Land (the "Title
      Report") prior to the date hereof, and Landlord
      represents that, to the best of Landlord's actual
      knowledge as of the date hereof, Landlord has not
      entered into any proffers with respect to the Land that
      are binding upon the Land or the occupants thereof
      which either are not disclosed on the Title Report or
      have not been disclosed in writing to Tenant prior to
      the date hereof.  Landlord further covenants that upon
      Tenant performing the terms and obligations of Tenant
      under this Lease, Tenant shall be entitled to have
      quiet enjoyment of the Premises and the Property
      throughout the Lease Term and any renewal or extension
      thereof, without hindrance or molestation by Landlord
      or anyone lawfully claiming by, through or under
      Landlord, subject to the terms of this Lease; provided
      that, nothing herein contained shall be deemed to
      constitute a guaranty that neighboring tenants will not
      utilize portions of Tenant's parking, but, subject to
      the provisions of Section 36 below, Landlord agrees to
      consult with Tenant on measures to assure Tenant of the
      parking it requires.  Subject to the terms hereof,
      Tenant shall be entitled to use, and will have access
      to, the Premises three hundred sixty-five (365) days
      per year, twenty-four (24) hours per day.

20.   MECHANICS LIENS.

      Neither Tenant nor anyone claiming by, through, or
      under Tenant or this Lease, shall have the right to
      file or place any mechanics lien or other lien of any
      kind or character whatsoever upon the Premises or upon
      any improvement thereon, or upon the leasehold interest
      of Tenant therein.  Notice is hereby given that no
      contractor, subcontractor, or anyone else who may
      furnish any material, service or labor for any Property
      improvements, alteration, repairs or any part thereof,
      shall at any time be or become entitled to any lien
      thereon.  For the further security of Landlord, Tenant
      covenants and agrees to give actual notice thereof in
      advance to any and all contractors and subcontractors
      who may furnish or agree to furnish any such material,
      service or labor.  Tenant shall cause any such lien
      imposed to be released of record by payment or posting
      of the proper bond reasonably acceptable to Landlord
      within ten (10) days after the earlier of imposition of
      the lien or written request by Landlord.  If Tenant
      fails to remove any lien within the ten (10) day
      period, then Landlord, upon ten (10) days prior notice
      to Tenant, may do so at Tenant's expense and Tenant's
      reimbursement to Landlord for such amount, including,
      but not limited to, reasonable attorneys fees and
      costs, shall be deemed Additional Rent.

21.   EXPIRATION OF LEASE AND SURRENDER OF POSSESSION.

      (A)   Holding Over.  Tenant will, at the expiration or
            termination of this Lease by lapse of time or
            otherwise, yield up immediate possession of the
            Premises to Landlord in the condition required
            under this Lease.  If Tenant retains possession of
            the Premises or any part thereof after such
            expiration or termination, then Landlord may, at
            its option, serve written notice upon Tenant that
            such holding over constitutes (i) creation of a
            month-to-month tenancy, upon the terms and
            conditions set forth in this Lease, or (ii)
            creation of a tenancy at sufferance, upon the
            terms and conditions set forth in this Lease;
            provided, however, that the monthly Rent (or daily
            Rent under (ii)) shall, in addition to all other
            sums which are to be paid by Tenant hereunder, be
            equal to one hundred ten percent (110%) of the sum
            of Rent plus Additional Rent owed monthly to
            Landlord under this Lease immediately prior to
            such expiration or termination (prorated in the
            case of (ii) on the basis of a 365 day year for
            each day Tenant remains in possession); provided
            further that, if Landlord shall institute any
            action, case or suit to recover possession of the
            Premises (whether styled as an unlawful detainer
            action or otherwise), the monthly Rent (or daily
            Rent under (ii)) payable pursuant to the preceding
            sentence shall increase, effective as of the date
            on which such action, case or suit is filed with
            the court, to one hundred fifty percent (150%) of
            the sum of Rent plus Additional Rent owed monthly
            to Landlord under this Lease immediately prior to
            such expiration or termination (prorated in the
            case of (ii) on the basis of a 365 day year for
            each day Tenant remains in possession).  If no
            such notice is served, then a tenancy at
            sufferance shall be deemed to be created at the
            Rent in the preceding sentence.  Tenant shall also
            pay to Landlord as Additional Rent all damages
            sustained by Landlord resulting from retention of
            possession by Tenant, including the loss of any
            proposed subsequent tenant for any portion of the
            Premises.  The provisions of this Section shall
            not constitute a waiver by Landlord of any right
            of re-entry as herein set forth; nor shall receipt
            of any Rent or any other act in apparent
            affirmance of the tenancy operate as a waiver of
            Landlord's right to terminate this Lease for a
            breach of any of the terms, covenants, or
            obligations herein on Tenant's part to be
            performed.

      (B)   Subject to Section 14(C) and the following Section
            21(C), upon the expiration of this Lease, by lapse
            of time or otherwise, any and all buildings,
            improvements or additions erected on the Premises
            by Tenant shall, at the option of Landlord, be and
            become the property of the Landlord without any
            payment therefor and Tenant shall, at the option
            of Landlord, surrender said Premises, together
            with all buildings, improvements or additions
            thereon, whether erected by Tenant or Landlord,
            ordinary wear and tear excepted.

      (C)   Tenant may install in the Premises adequate
            furnishings, furniture, equipment (including, but
            not limited to, security cameras on the exterior
            of the Building), fixtures, machinery and other
            personal property for the operation of its
            business (collectively, "Tenant's Property"), and
            upon the expiration or termination of this Lease
            by lapse of time or otherwise, Tenant shall remove
            Tenant's Property at Tenant's sole cost.  Upon
            removal of Tenant's Property, Tenant shall repair
            any damage to the Premises caused by the
            installation or removal thereof at Tenant's sole
            cost.

22.   DEFAULT-REMEDIES.

      (A)   The occurrence of one or more of the following
            events shall constitute a material default and
            breach of this Lease by Tenant ("Event of
            Default"):

            (1)   Failure by Tenant to make payment of any
                  Rent, Additional Rent, or any other payment
                  required to be made by Tenant hereunder, as
                  and when due, and such a failure shall
                  continue for a period of five (5) business
                  days after written notice of such failure
                  from Landlord; provided that, if two (2) such
                  notices have been delivered within the twelve
                  (12) months immediately preceding any failure
                  to make any payment when and as due, such
                  failure shall, without notice or demand, be
                  deemed an Event of Default;

            (2)   The making by Tenant (or any guarantor) of
                  any assignment or arrangement for the benefit
                  of creditors;

            (3)   The levying of an attachment, execution of
                  other judicial seizure upon the Tenant's
                  property in or interest under this Lease,
                  which is not satisfied or released or the
                  enforcement thereof superseded by an
                  appropriate proceeding within sixty (60) days
                  thereafter;

            (4)   The appointment of a receiver or trustee to
                  take possession of the property of Tenant (or
                  any guarantor) or of Tenant's (or any
                  guarantor's) business or assets and the order
                  or decree appointing such receiver or trustee
                  shall have remained in force undischarged for
                  sixty (60) days after the entry of such order
                  or decree;

            (5)   The vacating or abandonment of the Premises,
                  unless (i) Tenant notifies Landlord of its
                  intent to vacate or abandon not less than ten
                  (10) days in advance thereof, (ii) Tenant
                  obtains and maintains all necessary
                  endorsements to ensure that Tenant's
                  insurance shall remain in effect with regard
                  to the Premises, notwithstanding such
                  vacating or abandonment of the Premises, and
                  (iii) Tenant takes all necessary steps to
                  ensure there will be no unauthorized access
                  to the Premises during the period of any such
                  vacancy or abandonment;

            (6)   The failure by Tenant to maintain any
                  insurance required herein, which failure
                  continues for more than two (2) business days
                  after written notice from Landlord advising
                  Tenant of such failure;

            (7)   An assignment, subletting, pledge, mortgage,
                  or other transfer of this Lease or the
                  Premises by Tenant, or any transfer of any
                  interest in the Tenant, in violation of
                  Section 12 of this Lease; and/or

            (8)   The failure by Tenant to perform or observe
                  any other term, covenant, agreement or
                  condition to be performed or kept by the
                  Tenant under the terms, conditions, or
                  provisions of this Lease, which failure is
                  not cured within ten (10) days after written
                  notice thereof from Landlord (or such longer
                  time as may be reasonably required to cure
                  such failure through the exercise of due
                  diligence, unless (i) such failure is a
                  willful repudiation of the Lease authorized
                  by Tenant's Board of Directors, (ii) such
                  failure cannot, based on objective evidence,
                  be cured, (iii) such failure relates to the
                  existence of a generally-recognized, imminent
                  danger to the health or safety of occupants
                  of the Premises due to a hazardous condition
                  on the Premises, or (iv) such failure
                  subjects Landlord to criminal prosecution).

      (B)   If an Event of Default shall have occurred,
            Landlord shall have (in addition to all other
            rights and remedies provided by law or otherwise
            provided by this Lease) the right, at the option
            of the Landlord, then or at any time thereafter
            while such Event of Default  shall continue, to
            elect any one or more of the following:

             (1)  To continue this Lease in full force and
                  effect (so long as Landlord does not
                  terminate this Lease), and Landlord shall
                  have the right to collect Rent, Additional
                  Rent and other charges when due for the
                  remainder of the Lease Term; and/or

            (2)   To cure such default or defaults at its own
                  expense and without prejudice to any other
                  remedies which it might otherwise have; and
                  any reasonable payment made or reasonable
                  expenses incurred by Landlord in curing such
                  default, with interest thereon at the Default
                  Rate (as hereafter defined), to be and become
                  Additional Rent to be paid by Tenant with the
                  next installment of Rent falling due
                  thereafter (but in no event earlier than
                  fifteen (15) days, nor later than thirty (30)
                  days, after the date on which Landlord
                  invoices Tenant for the same); and/or

            (3)   To re-enter the Premises in accordance with
                  applicable law, and dispossess Tenant and
                  anyone claiming through or under Tenant by
                  summary proceedings or otherwise, and remove
                  their effects, and take complete possession
                  of the Premises and either (a) declare this
                  Lease terminated and the Lease Term ended, or
                  (b) elect to continue this Lease in full
                  force and effect, but with the right at any
                  time thereafter that such Event of Default
                  remains uncured to declare this Lease
                  terminated and the Lease Term ended.  In such
                  re-entry, Landlord may, as permitted by
                  applicable law, remove all persons from the
                  Premises, and Tenant hereby covenants in such
                  event, for itself and all others occupying
                  the Premises under Tenant, to peacefully
                  yield up and surrender the Premises to
                  Landlord.  If Landlord elects to terminate
                  this Lease and/or elects to terminate
                  Tenant's right of possession, every
                  obligation of Landlord contained in this
                  Lease shall, upon entry of a final,
                  non-appealable judgment terminating this
                  Lease or Landlord's reentry onto the Premises
                  in accordance with applicable law, cease
                  without prejudice to Tenant's liability for
                  all Rent, Additional Rent, and other sums
                  owed by Tenant herein.

            Should Landlord declare this Lease terminated and
            the Lease Term ended (pursuant to Section
            22(B)(3)(a) above), the Landlord shall be entitled
            to recover from Tenant the Rent, Additional Rent,
            and all other sums due and owing by Tenant to the
            date of termination, plus the reasonable costs of
            curing all Tenant's defaults existing at or prior
            to the date of termination, plus the reasonable
            costs of recovering possession of the Premises,
            plus the reasonable costs of reletting the
            Premises including, but not limited to repairs to
            the Premises, costs to prepare and refinish the
            Premises for reletting, leasing commissions,
            rental concessions, and legal fees and costs, plus
            other actual damages suffered or incurred by
            Landlord due to all Events of Default and any late
            fees or other charges incurred by Landlord under
            any mortgage, plus the deficiency, if any, between
            Tenant's Rent and Additional Rent for the balance
            of the Lease Term and the rent obtained by
            Landlord under another lease for the Premises, for
            the balance of the Lease Term remaining under this
            Lease on the date of termination.

            Should Landlord elect to continue this Lease
            (pursuant to Section 22(B)(3)(b) above), Landlord
            shall be entitled to recover from Tenant the Rent,
            Additional Rent and all other sums due and owing
            by Tenant up to the date of dispossession, plus
            the reasonable costs of curing all Events of
            Default existing at or prior to the date of
            dispossession, plus the Rent, Additional Rent and
            all other sums owed by Tenant on a continuing
            basis as said amounts accrue to the end of the
            Lease Term, less the rental which Landlord
            receives during such period, if any, from others
            to whom the Premises may be relet, plus the
            reasonable cost of recovering possession of the
            Premises, plus the reasonable costs of reletting
            including, but not limited to repairs to the
            Premises, costs to prepare and refinish the
            Premises for reletting, leasing commissions,
            rental concessions, and legal fees and costs.  Any
            suit brought by Landlord to enforce collection of
            such deficiency for any one month shall not
            prejudice Landlord's right to enforce the
            collection of any deficiency for any subsequent
            month in subsequent separate actions, or Landlord
            may defer initiating any such suit until after the
            expiration of the Lease Term (in which event such
            deferral shall not be construed as a waiver of
            Landlord's rights as set forth herein and
            Landlord's cause of action shall be deemed not to
            have accrued until the expiration of the Lease
            Term), and it being further understood that if
            Landlord elects to bring suits from time to time
            prior to reletting the Premises, Landlord shall be
            entitled to its full damages through the date of
            the award of damages without regard to any rent,
            additional rent or other sums that are or may be
            projected to be received by Landlord upon a
            subsequent reletting of the Premises.  In the
            event that Landlord relets the Premises together
            with other premises or for a term extending beyond
            the scheduled expiration of the Lease Term, it is
            understood that Tenant will not be entitled to
            apply against Landlord's damages any rent,
            additional rent or other sums generated or
            projected to be generated by either such other
            premises or the period extending beyond the
            scheduled expiration of the Lease Term.  Landlord
            shall use commercially reasonable efforts to relet
            and rent the Premises with or without advertising
            for the remainder of the Lease Term, or for such
            longer or shorter period as Landlord shall deem
            advisable.

            In lieu of the amounts recoverable by Landlord
            pursuant to the two immediately preceding
            paragraphs, but in addition to other remedies and
            amounts otherwise recoverable by Landlord in this
            Lease, Landlord may, at its sole election, (i)
            terminate this Lease, (ii) collect all Rent,
            Additional Rent, and other sums due and owing by
            Tenant up to the date of termination, and (iii)
            provided Landlord terminates Tenant's right to
            possession of the Premises, accelerate and collect
            the present value of the positive difference (if
            any) between (x) the sum of all Rent, Additional
            Rent and all other sums required to be paid by
            Tenant through the remainder of the Lease Term,
            and (y) the fair market rental value of the
            Premises for the remainder of the Lease Term, net
            of a reasonable vacancy and concession allowance
            determined by Landlord in its reasonable
            discretion (the present value of such difference
            being herein referred to as the "Accelerated
            Rent"), which Accelerated Rent shall be discounted
            to present value using an interest rate equal to
            six and one-half percent (6.5%) per annum
            ("Present Value Accelerated Rent").  In the event
            Landlord is successful in reletting the Premises
            for any part of the remainder of the Lease Term
            prior to payment of the Present Value Accelerated
            Rent, the fair market rental value shall be deemed
            to equal the rents reserved under such reletting,
            and Landlord shall not be obligated to pay over
            the proceeds of such reletting in whole or part.
            In no event shall Landlord be liable for, nor
            shall Tenant's obligations hereunder be diminished
            by reason of, any failure by Landlord to relet all
            or any portion of the Premises or to collect any
            rent due upon such reletting.

      (C)   Tenant, on its own behalf and on behalf of all
            persons claiming through or under Tenant,
            including all creditors, does hereby specifically
            waive and surrender any and all rights and
            privileges, so far as is permitted by law, which
            Tenant and all such persons might otherwise have
            under any present or future law (1) to the service
            of any notice to quit or of Landlord's intention
            to re-enter or to institute legal proceedings,
            which notice may otherwise be required to be
            given, (2) to redeem the Premises, (3) to re-enter
            or repossess the Premises, (4) to restore the
            operation of this Lease, with respect to any
            dispossession of Tenant by judgment or warrant of
            any court or judge, or any re-entry by Landlord,
            or any expiration or termination of this Lease,
            whether such dispossession, re-entry, expiration
            or termination shall be by operation of law or
            pursuant to the provisions of this Lease, or (5)
            which exempts property from liability for debt or
            for distress for rent.  Landlord and Tenant each
            hereby consents to the exercise of personal
            jurisdiction over it by any federal or local court
            in the jurisdiction in which the Premises is
            located.

      (D)   If Tenant fails to take possession of the Premises
            upon the commencement of the Lease Term, Landlord
            and Tenant acknowledge that this Lease Agreement
            may be construed as a contract to or for  lease,
            as opposed to a contract of lease.  Accordingly,
            Landlord and Tenant agree that, if Tenant defaults
            under this Lease (beyond the applicable notice and
            cure period, if any) prior to the Lease
            Commencement Date, or if Tenant fails to accept
            possession of the Premises when tendered by
            Landlord (it being acknowledged and agreed that
            any such failure by Tenant to accept possession of
            the Premises when tendered by Landlord shall be an
            Event of Default hereunder, but that Tenant shall
            not be required to actually occupy the Premises in
            order for Tenant to accept possession thereof),
            Landlord shall be entitled to terminate Tenant's
            right to possession of the Premises pursuant to
            the Lease Agreement and to recover from Tenant,
            subject to the conditions and limitations set
            forth in Section 22(B), contract damages resulting
            from Tenant's default and/or failure to accept
            possession of the Premises in an amount equal to
            all of the rents and other sums required to be
            paid under the Lease (as if Tenant had taken
            possession of the Premises when tendered by
            Landlord) from the date on which Landlord tenders
            possession of the Premises to Tenant until the
            date on which the Premises are relet (if ever) or
            any earlier date on which the Lease would have
            expired by its terms, plus (but without
            duplication) all of the damages reserved to
            Landlord in Section 22(B) of this Lease
            (including, but not limited to, any rent
            deficiency upon any reletting, costs of reletting,
            and court costs and attorneys' fees incurred to
            relet the Premises and/or to enforce Landlord's
            rights under the terms of this Lease).

      (E)   Landlord Default.

            (1)   Subject to the terms hereof, if (i) Landlord
                  shall default in the performance of any
                  covenant or provision of this Lease
                  pertaining to the provision of services by
                  Landlord or performance of repairs or
                  maintenance on Landlord's part to be
                  performed (which default shall not be
                  occasioned by (a) the acts or omissions of
                  Tenant or Tenant's agents, assignees,
                  contractors, employees, invitees, licensees,
                  sublessees or others for whose actions Tenant
                  is responsible or over whose actions Tenant
                  can reasonably be expected to exercise
                  control, or (b) circumstances, events or
                  facts beyond Landlord's reasonable control),
                  (ii) Landlord shall fail to remedy such
                  default within ten (10) days after Tenant
                  shall have given Landlord written notice of
                  such default specifying the same in detail
                  and specifying that the failure to cure the
                  same within ten (10) days shall be deemed a
                  Landlord Default hereunder, and (iii) such
                  default shall substantially impair Tenant's
                  use and enjoyment of the Premises, then upon
                  the expiration of such 10-day cure period the
                  Tenant shall (as Tenant's sole and exclusive
                  remedies) be entitled to exercise the
                  remedies set forth in this Section 22(E).
                  Notwithstanding the foregoing, in the event
                  that any such default is not reasonably
                  susceptible of cure within such ten (10) day
                  cure period, such cure period shall
                  automatically be deemed to be extended for
                  such additional period as shall be reasonably
                  required to cure such default, provided that
                  Landlord commences such cure within such
                  10-day period and diligently pursues such
                  cure thereafter.  Any such default on the
                  part of Landlord which is not cured within
                  such 10-day cure period (as the same may be
                  extended pursuant to the preceding sentence)
                  shall be deemed a "Landlord Default".

            (2)   Subject to the terms hereof, in the event of
                  a Landlord Default, Tenant shall, provided
                  that no Event of Default by Tenant is in
                  existence hereunder, have the right (but not
                  the obligation) to remedy such Landlord
                  Default and charge Landlord for the
                  reasonable cost of such remedy, which charges
                  shall be payable by Landlord within thirty
                  (30) days of Tenant's demand therefor;
                  provided that, (i) Tenant's actions to cure
                  any Landlord Default shall conform and comply
                  in all respects with the terms of this Lease
                  (including, but not limited to, the
                  applicable provisions of Section 14), (ii)
                  the charges payable by Landlord pursuant to
                  this Section 22(E) shall constitute Operating
                  Expenses to the extent the same would
                  constitute Operating Expenses under Section 5
                  hereof if incurred directly by Landlord (it
                  being agreed, however, that any additional
                  incremental increase in such costs which is
                  reasonably attributable solely to the
                  Landlord Default (i.e., if Landlord had
                  performed directly it would have been able to
                  render performance at a lower cost) shall be
                  excluded from Operating Expenses), and (iii)
                  Tenant shall have no right to remedy any
                  Landlord Default if (a) such remedy will or
                  may materially and adversely interfere with
                  the ability of other tenants of the Building
                  to utilize their premises for the Comparable
                  Uses or invalidate or impair any warranty
                  applicable to any portion of the Building,
                  the Building structure or any system serving
                  any of the same, or (b) such Landlord Default
                  arises from or out of, or in connection with,
                  any fire or other casualty damage to, or
                  condemnation of, the Building.

            (3)   In the event Tenant engages in self-help as
                  provided in subparagraph 22(E)(2) above and
                  Landlord disagrees with the propriety of
                  Tenant's actions and/or the level of expenses
                  incurred by Tenant, and refuses to reimburse
                  Tenant for its costs, the parties agree to
                  submit such dispute to arbitration; provided
                  that, this subparagraph 22(E)(3) shall not be
                  deemed to require that Tenant refrain from
                  curing a Landlord Default in compliance with
                  this Section 22(E) until such dispute is
                  submitted to arbitration, nor shall this
                  subparagraph 22(E)(3) be deemed to preclude
                  Landlord from submitting to arbitration,
                  after the exercise of such remedy by Tenant,
                  any dispute regarding the existence of a
                  Landlord Default or arising from the exercise
                  of (or the costs of exercising) such remedy
                  by Tenant.

            (4)   Notwithstanding anything herein contained to
                  the contrary, in the event the Building, or
                  any part thereof, or the land on which the
                  Building is constructed, or the Landlord's
                  estate in the Building, is at any time
                  subject to a mortgage or deed of trust (each
                  a "Mortgage"), and/or (ii) this Lease, or the
                  Rent payable under this Lease, is assigned to
                  a mortgagee or the trustee(s) under a deed of
                  trust (each a "Mortgagee"), then Tenant shall
                  have no right to exercise any remedy under
                  this Section 22(E) unless and until Tenant
                  shall first deliver written notice, in the
                  manner provided elsewhere in this Lease for
                  the delivery of notices, to such Mortgagee,
                  specifying the Landlord Default in reasonable
                  detail, and affording such Mortgagee the same
                  notice and cure period set forth above for
                  the cure of a Landlord Default (it being
                  understood and agreed that no such Mortgagee
                  shall be obligated to cure any Landlord
                  Default).  Tenant further agrees to deliver
                  to each such mortgagee or trustee a copy of
                  any notice delivered to Landlord pursuant to
                  the provisions of this Section 22(E).

23.   RE-ENTRY BY LANDLORD.

      No re-entry by Landlord or any action brought by
      Landlord to remove Tenant from the Premises shall
      operate to terminate this Lease unless Landlord shall
      have given written notice of termination to Tenant, in
      which event Tenant's liability shall be as above
      provided.  Subject to the express limitations and
      conditions set forth herein, no right or remedy herein
      granted to Landlord or Tenant is intended to be
      exclusive of any other right or remedy, and each and
      every right and remedy herein provided shall be
      cumulative and in addition to any other right or remedy
      hereunder or now or hereafter existing in law or equity
      or by statute.  In the event of termination of this
      Lease, Tenant waives any and all rights to redeem the
      Premises either given by any statute now or herein
      enacted.

24.   ADDITIONAL RIGHTS TO LANDLORD.

      (A)   In addition to any and all other remedies,
            Landlord or Tenant may restrain any threatened
            breach of any covenant, condition or agreement
            herein contained, but except as otherwise
            expressly set forth herein the mention herein of
            any particular remedy or right shall not preclude
            the Landlord or Tenant from any other remedy or
            right it may have either at law or equity, or by
            virtue of some other provision of this Lease; nor
            shall the consent to one act, which would
            otherwise be a violation or waiver of or redress
            for one violation either of covenant, promise,
            agreement, undertaking or condition, prevent a
            subsequent act which would originally have
            constituted a violation from having all the force
            and effect of any original violation.

      (B)   Receipt by Landlord of Rent or other payments from
            the Tenant shall not be deemed to operate as a
            waiver of any rights of the Landlord to enforce
            payment of any Rent, Additional Rent, or other
            payments previously due or which may thereafter
            become due, or of any rights of the Landlord to
            terminate this Lease or to exercise any remedy or
            right which otherwise might be available to the
            Landlord, the right of Landlord to declare a
            forfeiture for each and every breach of this Lease
            is a continuing one for the life of this Lease.

      (C)   Intentionally Deleted.

      (D)   Intentionally Deleted.

25.   SUCCESSORS, ASSIGNS AND LIABILITY.

      The terms, covenants, conditions and agreements herein
      contained and as the same may from time to time
      hereafter be supplemented, modified or amended, shall
      apply to, bind, and inure to the benefit of the parties
      hereto and their legal representatives, successors and
      assigns, respectively, subject to Section 12 hereof.
      In the event either party now or hereafter shall
      consist of more than one person, firm or corporation,
      then and in such event all such person, firms and/or
      corporations shall be jointly and severally liable as
      parties hereunder.

26.   NOTICES.

      All notices and demands required to be given to either
      party hereunder shall be in writing and shall be deemed
      to have been given upon the earlier to occur of
      delivery or refusal of delivery (or inability to
      deliver at the last address provided by the recipient
      to the sender), provided that such notice or demand is
      sent by certified United States mail, postage prepaid,
      return receipt requested, or by personal delivery, or
      by a nationally recognized overnight delivery service
      which provides evidence of delivery, delivery prepaid,
      addressed to the party to whom directed at the address
      set forth below or at such other address as may be from
      time to time designated in writing by the party
      changing such address.

      Landlord                            Tenant

      Petula Associates, Ltd.                   If Prior to the
Commencement
      711 High Street                           Date:
      Des Moines, Iowa  50392-1370              Government
Technology
      Attn:       CRE Equities/Mid-Atlantic           4100 Lafayette
Center Drive
            Team                          Chantilly, VA  20151-1200

      With a copy to:                           With a copy to:

      Trammell Crow Real Estate                 Government
Technology
       Services, Inc.                            Services, Inc.
      1115 30th Street, N.W.                    4100 Lafayette
Center Drive
      Washington, D.C.  20007                   Chantilly, Virginia
20151-1200
      Attn:         Property Manager/Avion      Attn:  General
            Counsel

                                          If after the Commencement
                                           Date:

                                          Tenant at the Premises
                                          Attn:       Director of
                                                Facilities

                                          With a copy to:

                                          Tenant at the Premises
                                          Attn:       General Counsel

      Notwithstanding the foregoing, Tenant acknowledges and
      agrees that any motion, pleading or other filing
      (including, but not limited to, any motion to compel
      performance pursuant to 11 U.S.C. 365(d)(3), or any
      proof of claim) by Landlord in any bankruptcy case in
      which Tenant is the debtor shall constitute notice to
      Tenant for purposes of this Lease.

27.   MORTGAGEE'S APPROVAL.

      Tenant hereby agrees that, if Landlord's mortgagee
      shall require modifications of the terms and provisions
      of this Lease, Tenant shall not unreasonably withhold,
      condition or delay its execution and delivery of the
      agreements required to effect such Lease modification
      (it being understood that any such reasonable
      modification(s) shall be executed and delivered within
      thirty (30) days after Landlord's request therefor).
      In no event, however, shall Tenant be required to agree
      to modify any provision of this Lease relating to the
      amount of Rent, Additional Rent or other charges
      reserved herein, the size and/or location of the
      Premises, the Improvements or the Lease Term, or to any
      modification which would conflict with the express
      terms hereof, nor shall any such modification diminish
      Landlord's obligations or Tenant's rights hereunder or
      increase Tenant's obligations hereunder.

<PAGE>
28.   ESTOPPEL CERTIFICATES.

      Within fifteen (15) days after delivery of a written
      request from the other party hereto (the "Requesting
      Party"), the party receiving such request (the
      "Receiving Party") agrees to execute, acknowledge and
      deliver to the Requesting Party (or, if Landlord is the
      Requesting Party, any proposed mortgagee or purchaser)
      a statement in writing, in form reasonably satisfactory
      to the Requesting Party, certifying whether this Lease
      is in full force and effect and, if it is in full force
      and effect, what modifications (if any) have been made
      to this Lease to the date of the certification, whether
      or not any defaults or offsets exist with respect to
      this Lease and, if there are, what they are claimed to
      be, and setting forth the date(s) to which Rent or
      other charges have been paid in advance, if any.  The
      failure of Tenant to execute, acknowledge, and deliver
      to Landlord a statement requested pursuant to this
      Section 28, which failure shall continue for more than
      five (5) days after a second (2nd) written notice from
      Landlord (delivered not earlier than the expiration of
      the initial 15-day period) demanding such statement,
      shall constitute an acknowledgment by Tenant that this
      Lease is unmodified and in full force and effect and
      that the Rent and other charges have been duly and
      fully paid to and including the respective due dates
      immediately preceding the date of Landlord's notice to
      Tenant and shall constitute as to any person, a waiver
      of any defaults which may exist prior to such notice.

29.   DEFAULT RATE OF INTEREST.

      All amounts owed by one party to the other pursuant to
      any provision of this Lease shall bear interest from
      the date due until paid at five percent (5%) per annum
      above the generally prevailing "prime rate" as
      published in the "Money Rates" section of the Wall
      Street Journal (Eastern Edition) on the due date of
      such sum (or, if not a business day, the next business
      day), unless a lesser rate shall then be the maximum
      rate permissible by law, in which event said lesser
      rate shall be charged ("Default Rate"); provided that,
      interest shall not accrue on any payment which is paid
      within five (5) business days after written notice that
      such payment is due and payable, unless two (2) or more
      such notices have been delivered to the party from whom
      payment is due within the twelve (12) months
      immediately preceding the due date of the current
      payment.

30.   EXCULPATORY PROVISIONS.

      It is expressly understood and agreed by and between
      the parties hereto, anything herein to the contrary
      notwithstanding, that each and all of the
      representations, warranties, covenants, undertakings,
      indemnities and agreements herein made on the part of
      Landlord while in form purporting to be the
      representations, warranties, covenants, undertakings,
      indemnities and agreements of Landlord are nevertheless
      each and every one of them made and intended, not as
      personal representations, warranties, covenants,
      undertakings, indemnities and agreements by Landlord or
      for the purpose or with the intention of binding
      Landlord personally, but are made and intended for the
      purpose only of subjecting Landlord's interest in the
      Premises to the terms of this Lease and for no other
      purpose whatsoever, and in case of default hereunder by
      Landlord, Tenant shall look solely to the interests of
      Landlord in the Property.  Landlord shall not have any
      personal liability to pay any indebtedness accruing
      hereunder or to perform any covenant, either express or
      implied, herein contained.  All such personal liability
      of Landlord, if any, is expressly waived and released
      by Tenant and by all persons claiming by, through or
      under Tenant.  Notwithstanding the foregoing, this
      Section 30 shall be inapplicable to any judgment for
      monetary damages entered against Landlord and in favor
      of Tenant, to the extent Tenant's damages were found to
      have been proximately caused by Landlord's fraud or
      Landlord's misapplication of insurance proceeds or a
      condemnation award.

31.   MORTGAGEE PROTECTION.

      Tenant agrees to give any holder of any first mortgage
      or first trust deed in the nature of a mortgage (both
      hereinafter referred to as a "First Mortgage") against
      the Premises, or any interest therein, by registered or
      certified mail, a copy of any notice or claim of
      default served upon Landlord by Tenant, provided that
      prior to such notice, Tenant has been notified in
      writing of the address of such First Mortgage holder.
      Tenant further agrees that if Landlord shall have
      failed to cure any such default within twenty (20) days
      after such notice to Landlord (or if such default
      cannot be cured or corrected within that time, then
      such additional time as may be necessary if Landlord
      has commenced within such twenty (20) days and is
      diligently pursuing the remedies or steps necessary to
      cure or correct such default), then the holder of the
      First Mortgage shall have an additional thirty (30)
      days within which to cure or correct such default (or
      if such default cannot be cured or corrected within
      that time, then such additional time as may be
      necessary if such holder of the First Mortgage has
      commenced with such thirty (30) days and is diligently
      pursuing the remedies or steps necessary to cure or
      correct such default, including the time necessary to
      obtain possession if possession is necessary to cure or
      correct such default).

32.   RECIPROCAL COVENANT ON NOTIFICATION OF ADA VIOLATIONS.

      Within ten (10) days after receipt, Landlord and Tenant
      shall advise the other party in writing, and provide
      the other with copies of (as applicable), any notices
      alleging violation of the Americans with Disabilities
      Act of 1990 ("ADA") relating to any portion of the
      Premises or the Improvements; any claims made or
      threatened in writing regarding noncompliance with the
      ADA and relating to any portion of the Premises or the
      Improvements; or any governmental or regulatory actions
      or investigations instituted or threatened regarding
      noncompliance with the ADA and relating to any portion
      of the Premises or the Improvements.

33.   LAWS THAT GOVERN.

      The terms and conditions of this Lease shall be
      governed by the laws of the jurisdiction in which the
      Premises is located.

34.   FINANCIAL STATEMENTS.

      Within ten (10) business days of Landlord's request,
      Tenant shall deliver to Landlord the current financial
      statements of Tenant, and financial statements for the
      two (2) years prior to the current year.  The financial
      statements shall include a balance sheet, profit and
      loss statement, and statement of cash flows for each
      year, accompanied by an opinion from a certified public
      accountant certifying that the financial statements are
      prepared in accordance with generally accepted
      accounting principles consistently applied.  If Tenant
      fails to deliver such financial statements within two
      (2) business days after Landlord's second (2nd) request
      for such financial statements, an amount equal to $250
      per day shall be charged as Additional Rent for each
      day thereafter on which Tenant fails to deliver to
      Landlord the financial statements required herein.
      Notwithstanding the foregoing, this Section 34 shall
      not be deemed to apply to GTSI or to any other publicly
      traded corporation so long as GTSI or such publicly
      traded corporation, as applicable, publicly discloses
      its financial condition.

35.   PARKING.

      In connection with construction of the Improvements,
      Landlord shall construct on the Premises in accordance
      with the Work Agreement attached hereto as Exhibit B,
      surface parking at a ratio equal to not less than 4
      spaces per 1,000 square feet of net rentable area in
      the Improvements.  Tenant shall have the right to park
      in the parking facilities free of charge (other than
      payment of Tenant's Pro Rata Share of Operating
      Expenses).  If, after Landlord completes construction
      of the second building (the "Second Building")
      contemplated by the Current Site Plan (as defined
      herein) and executes a lease therefor, Tenant
      determines that use of parking on the Property by third
      parties is leaving Tenant with insufficient parking
      spaces for its employees and visitors, Tenant shall
      have the right to install professional signs and
      stencils on Tenant's parking spaces, identifying such
      spaces as reserved for the exclusive use of Tenant and
      its employees and invitees.  Tenant shall have the
      right, at any time, to install professional signs and
      stencils identifying Tenant's executive and visitor
      parking spaces.  Tenant shall have the right to tow any
      vehicle parked in Tenant's parking spaces in violation
      of Tenant's posted signs, provided that such signs warn
      that violators will be towed and provide such other
      information as is required by law to allow such towing.
      Landlord and Tenant acknowledge that Tenant's parking
      area will be as shown cross-hatched on the Current Site
      Plan (subject to modification in accordance with
      Exhibit B).  Tenant shall, at all times and at Tenant's
      sole expense, maintain its parking signs and stencils
      in a first-class condition.

36.   SIGNAGE.

      (A)   Landlord shall permit Tenant to place two (2)
            signs containing Tenant's logo upon the
            Improvements subject to Landlord's approval as to
            design, method of attachment, placement, size,
            color and style (such approval not to be
            unreasonably withheld, conditioned or delayed), it
            being further agreed that Landlord shall not
            withhold its approval as to the design, color,
            size, or style of such signs to the extent that
            such signs comply with the signage requirements of
            Exhibit E hereto.  So long as Tenant shall occupy
            at least fifty percent (50%) of the Building, no
            other tenant shall be permitted to place signage
            on the Building.

      (B)   So long as Tenant occupies at least seventy-five
            percent (75%) of the Building, Tenant shall also
            have the exclusive right, subject to approval by
            Fairfax County and receipt of all necessary
            approvals, easements, licenses and permits (which
            the parties agree to cooperate to obtain), to
            install and maintain one (1) monument sign
            containing Tenant's name and/or logo on the Land
            adjacent to Stonecroft Boulevard (in a location
            mutually-agreed by Landlord and Tenant [and to be
            tentatively agreed by the parties not later than
            when Landlord's proposed site plan is submitted
            for Fairfax County approval], each hereby agreeing
            to negotiate the same in good faith and further
            agreeing not to unreasonably withhold, condition
            or delay their agreement to the same).  If Tenant
            occupies less than seventy-five percent (75%) of
            the Building, Landlord shall have the right to
            install and maintain its own monument sign on the
            Land adjacent to Stonecroft Boulevard (in a
            location mutually-agreed by Landlord and Tenant,
            each hereby agreeing to negotiate the same in good
            faith and further agreeing not to unreasonably
            withhold, condition or delay their agreement to
            the same).  If Tenant occupies less than
            seventy-five percent (75%) of the Building, and
            Fairfax County does not permit installation of a
            second monument sign on the Land adjacent to
            Stonecroft Boulevard, Tenant agrees to provide
            Landlord with fifty percent (50%) of the signage
            space on its monument sign and Landlord agrees to
            reimburse Tenant for (i) any modifications to such
            monument sign reasonably required in connection
            therewith and (ii) fifty percent (50%) of the
            original cost of constructing and installing the
            monument sign.

      (C)   In the event Landlord, in Landlord's sole
            discretion, installs a monument or directional
            signage at the entrance to the parking areas from
            Avion Parkway, Tenant shall be entitled to have
            sign space on such directional sign equal to that
            of the other tenants occupying improvements on
            Parcel D-1, Avion Development, as shown on plat
            attached to Deed of Division recorded in Deed Book
            7375 at page 562, among the land records of
            Fairfax County, Virginia ("Parcel D-1"); provided
            that, Tenant's signage thereon shall be uppermost
            in location on such directional sign.  Tenant
            shall reimburse Landlord for its proportionate
            share (based on the proportion of signage space
            allowed thereon) of all costs, expenses and fees
            attributable to such directional sign.

      (D)   Tenant shall obtain and pay for all governmental
            approvals, permits and/or licenses required in
            connection with any signage installed by or on
            behalf of Tenant.  In addition, all such signage
            shall be subject to Landlord's prior approval (not
            to be unreasonably withheld, conditioned or
            delayed), and must comply with the established
            signage program at Avion Business Park  (a copy of
            which is attached hereto as Exhibit E) and with
            all covenants, conditions and restrictions of
            record.  The cost of Tenant's signage shall be
            borne by Tenant (it being understood, however,
            that Tenant may elect to be reimbursed from the
            Allowance (as defined in Exhibit B) for the cost
            of Tenant's permitted signage.

      (E)   If any signage (other than signage on the interior
            of the Premises which is not visible from outside
            the Premises) is exhibited without Tenant first
            obtaining the Landlord's written consent thereto,
            Landlord shall have the right, upon ten (10) days
            written notice to Tenant, to remove the same and
            Tenant shall be liable for any and all expenses
            incurred by Landlord in connection with such
            removal. Tenant shall maintain all of its signage
            in a good state of repair and save the Landlord
            harmless from any loss, cost or damage as a result
            of the construction, installation, maintenance,
            existence or removal of the same, and Tenant shall
            repair any damage which may have been caused by
            the construction, installation, operation,
            existence, maintenance or removal of such signage.
            Upon vacating the Premises, Tenant shall remove
            all of its signage and repair all damage caused by
            the installation, operation and/or removal
            thereof, at the Tenant's sole expense.

37.   RECORDATION.

      Except to the extent required by law, Tenant shall not
      record this Lease among or in any public records.

38.   FORCE MAJEURE.

      This Lease and the obligations of the parties hereunder
      shall not be affected or impaired because the Landlord
      or Tenant (as applicable) is unable to fulfill any of
      its obligations hereunder or is delayed in doing so, to
      the extent such inability or delay is caused by reason
      of war, civil unrest, strike, labor troubles, unusually
      inclement weather, governmental delays, inability to
      procure services or materials despite reasonable
      efforts, third party delays, acts of God, or any other
      cause(s) beyond the reasonable control of the Landlord
      or Tenant (as applicable) (which causes are referred to
      collectively herein as "Force Majeure").  The time
      specified for the performance of an obligation of
      Landlord or Tenant (as applicable) in this Lease shall
      be extended one day for each day of delay suffered by
      Landlord or Tenant (as applicable) in the performance
      of such obligation as a result of any Force Majeure
      cause, provided that the party from whom performance is
      due exercises commercially reasonable efforts to
      mitigate the effects of such Force Majeure cause.
      Notwithstanding the foregoing, but subject to the terms
      of the sentence which immediately follows this
      sentence, (i) this Section 38 shall have no application
      to, nor shall the time for the performance of
      Landlord's or Tenant's obligations hereunder be
      extended with respect to, any obligation for the
      payment of money or the surrender of the Premises upon
      the expiration of the Lease Term, and (ii) this Section
      38 shall be disregarded for purposes of determining
      Tenant's termination rights pursuant to Section 2(A)(4)
      and for determining the liquidated damages, if any, to
      which Tenant may be entitled pursuant to Section 10(c)
      of Exhibit B (it being understood that Force Majeure
      shall have no application to Section 2(A)(4), and is
      independently treated in Section 10(c) of Exhibit B).
      Notwithstanding anything herein to the contrary, (x) if
      the Construction Lender has foreclosed upon the
      Property or has accepted a deed in lieu of foreclosure,
      and (y) such Construction Lender is diligently pursuing
      completion of the work to be performed by Landlord
      under Exhibit B hereto, this Section shall apply to
      Tenant's right to terminate pursuant to Section
      2(A)(4).

39.   LANDLORD'S LIEN.

      As security for the performance of Tenant's
      obligations, Tenant grants to Landlord a lien upon and
      a security interest in Tenant's existing or hereafter
      acquired personal property, inventory, furniture,
      furnishings, fixtures, equipment, licenses, permits,
      and all other tangible and intangible property, assets
      and accounts, and all additions, modifications,
      products and proceeds thereof, including, without
      limitation, such tangible property which has been used
      at the Premises, purchased for use at the Premises,
      located at any time in the Premises or used or to be
      used in connection with the business conducted or to be
      conducted in the Premises, whether or not the same may
      thereafter be removed from the Premises.   Such lien
      shall be in addition to all rights of distraint
      available under applicable law.    Within five (5) days
      after request from time to time, Tenant shall execute,
      acknowledge and deliver to Landlord a financing
      statement and any other  document evidencing or
      establishing such lien and security interest which may
      be requested by Landlord.  During the Lease Term,
      Tenant shall not sell, transfer or remove from the
      Premises any of the aforementioned tangible property
      without Landlord's prior written consent, unless the
      same shall be promptly replaced with similar items of
      comparable value.  In order to further assure Tenant's
      performance of its obligations under this Lease, Tenant
      covenants that during the Lease Term, it will not
      convey or otherwise transfer its assets or permit its
      assets to be encumbered to the extent that any such
      conveyance, transfer or encumbrance is not done in the
      ordinary course of Tenant's business or would
      materially and adversely affect the net worth of
      Tenant.  Notwithstanding anything herein to the
      contrary, said lien shall be subordinated to the rights
      of any lessor of any equipment or personal property
      under any equipment lease, the rights of the seller
      under any conditional sales contract, and to the
      properly perfected lien of any bona fide third party
      lender providing financing to Tenant in the ordinary
      course of Tenant's business.  Landlord also shall, to
      the extent permitted by law, have (in addition to all
      other rights) a right of distress for rent as security
      for all Rent, Additional Rent and any other sums
      payable under this Lease.

40.   BROKERS.

      Tenant represents and warrants to Landlord, and
      Landlord represents and warrants to Tenant, that
      neither it nor its officers or agents nor anyone acting
      on its behalf has dealt with any real estate broker
      other than Trammell Crow Real Estate Services, Inc. and
      Cambridge Property Group Limited Partnership in the
      negotiating or making of this Lease, and each agrees to
      indemnify and hold the other party, and its respective
      agents, employees, partners, directors, shareholders
      and independent contractors harmless from all
      liabilities, costs, demands, judgments, settlements,
      claims and losses, including reasonable attorneys fees
      and costs, incurred in conjunction with any such claim
      or claims of any other broker or brokers claiming to
      have interested Tenant in the Property or Premises or
      claiming to have caused Landlord or Tenant to enter
      into this Lease.  Landlord acknowledges that it has
      agreed to pay Trammell Crow Real Estate Services, Inc.
      and Cambridge Property Group Limited Partnership a
      commission with respect to this Lease, pursuant to a
      separate agreement.

41.   CONFIDENTIALITY.

      Tenant agrees that this Lease is confidential and,
      agrees to exercise reasonable, good faith efforts not
      to disclose the contents of this Lease to any third
      party, except Tenant's brokers, lawyers, architects,
      engineers, and other consultants engaged in connection
      with this Lease transaction; provided that, this
      Section 41 shall not prohibit the disclosure of the
      terms of this Lease to the U.S. Government or Tenant's
      lenders, to the extent required by law or contract
      between Tenant and such party.

<PAGE>
42.   LEASE/DEED OF LEASE.

      To the extent required under applicable law to make
      this Lease legally effective, this Lease shall
      constitute a deed of lease executed under seal.

43.   RIGHT OF FIRST OFFER.

      (A)   Subject to the terms hereof and provided no Event
            of Default then remains uncured under the Lease,
            Landlord agrees that it will not sell the Premises
            (or, if the Premises is Landlord's sole asset,
            transfer all of Landlord's capital stock) during
            the Lease Term unless it first extends a bona fide
            offer to sell the Premises to Tenant at a price
            and on such terms and conditions as Landlord may
            describe in a written "offer to sell" given to
            Tenant in the same fashion as notices given
            pursuant to the provisions of Section 26 of this
            Lease.  Landlord shall, not less than fifteen (15)
            days prior to Landlord's general circulation of
            offering materials for the Premises, deliver to
            Tenant the offer to sell ("Sale Offer Notice").
            Tenant shall have fifteen days after receipt of
            the Sale Offer Notice to (i) exercise its right of
            first offer by agreeing to the economic terms of
            the purchase and sale and giving Landlord written
            notice of Tenant's election to acquire the
            Premises ("Sale Election Notice") or (ii) not to
            exercise its right of first offer for the
            acquisition of the premises, it being understood
            and agreed that if no notice is received from
            Tenant during said fifteen day period, Tenant
            shall be deemed not to have elected to purchase
            the Premises.  Within 30 days after receipt of
            Tenant's Sale Election Notice, Landlord will
            provide Tenant with an agreement of purchase and
            sale, which Landlord and Tenant will negotiate and
            execute within thirty (30) days of Tenant's
            delivery of the Sale Election Notice.  In the
            event Tenant fails to execute the agreement of
            purchase and sale within said thirty (30) day
            period after giving its Sale Election Notice or in
            the event Tenant does not deliver the Sale
            Election Notice, then Landlord shall have the
            right thereafter to sell the Premises to any third
            party purchaser free and clear of any rights by
            Tenant under this Section 43; provided that,
            before entering into a contract to sell the
            Premises at a price which is less than ninety-five
            percent (95%) of the price at which the Premises
            was offered to Tenant in Landlord's Sale Offer
            Notice, Landlord shall again offer to sell the
            Premises to Tenant in accordance with this Section
            43 (in which event Tenant shall exercise its
            rights under this Section 43 by delivery of the
            Sale Election Notice within three (3) business
            days after delivery of the Sale Offer Notice).

      (B)   Subject to the terms hereof and provided no Event
            of Default has occurred under the Lease, Landlord
            agrees that, during the first (1st) six and
            one-half (6-1/2) years of the Lease Term, before
            executing any lease for space in any other
            building constructed on Parcel D-1 (an "Adjacent
            Building"), Landlord will provide Tenant with a
            bona fide offer to lease such Adjacent Building at
            a rental rate and on such other terms and
            conditions as Landlord describes in a written
            "offer to lease" (the "Lease Offer Notice")
            delivered to Tenant in the same fashion as notices
            given pursuant to the provisions of Section 26 of
            this Lease.  Tenant shall have fifteen days after
            receipt of the Lease Offer Notice to (i) exercise
            its right of first offer by agreeing to the
            economic terms of the lease and giving Landlord
            written notice of Tenant's election to lease such
            Adjacent Building ("Lease Election Notice") or
            (ii) not to exercise its right of first offer for
            the lease of the Adjacent Building, it being
            understood and agreed that if no notice is
            received from Tenant during said fifteen day
            period, Tenant shall be deemed not to have elected
            to lease the Adjacent Building.  Within 30 days
            after receipt of Tenant's Lease Election Notice,
            Landlord will provide Tenant with a lease
            agreement, which Landlord and Tenant will
            negotiate and execute within thirty (30) days of
            Tenant's delivery of the Lease Election Notice.
            In the event Tenant fails to execute the lease
            agreement within said thirty (30) day period after
            giving its Lease Election Notice or in the event
            Tenant does not deliver the Lease Election Notice,
            then Landlord shall have the right thereafter to
            lease all or any part of the Adjacent Building to
            any third party free and clear of any rights by
            Tenant under this Section 43.  Notwithstanding
            anything herein contained to the contrary, Tenant
            acknowledges that (i) its rights under this
            Section 43(B) are subject and subordinate to any
            now-existing expansion rights in or to such
            Adjacent Building, and to any expansion or renewal
            rights granted to future tenants of such Adjacent
            Building, and (ii) this Section 43(B) shall be
            inapplicable to the initial "lease-up" of any
            "pre-leased" or "build-to-suit" Adjacent Building.

44.   MISCELLANEOUS.

      (A)   In the event that Tenant desires to store or
            maintain the type or character of goods or
            materials in the Premises which cause an increase
            in insurance premiums, Tenant shall first obtain
            the written consent of Landlord and Tenant shall
            reimburse Landlord for any increase in premiums
            caused thereby.

      (B)   Unless the context clearly denotes the contrary,
            the words "Rent" and "Additional Rent" as used in
            this Lease not only includes cash rental for the
            Premises, but also all other payments and
            obligations to pay assumed by the Tenant, whether
            such obligations to pay run to the Landlord or to
            other parties.

       (C)  In any litigation between the parties arising out
            of this Lease, or in connection with any
            consultations with counsel and other actions taken
            or notices delivered in relation to a default by
            any party to this Lease, the non-prevailing party
            shall pay to the prevailing party all reasonable
            expenses and costs including reasonable attorneys'
            fees incurred by the prevailing party in
            connection with the default and/or litigation, as
            the case may be (including fees and costs in
            preparation for and at trial, and on appeal, if
            applicable) ("Legal Costs").  The Legal Costs
            shall be payable on demand, and, if the prevailing
            party is Landlord, the Legal Costs shall be deemed
            Additional Rent, subject to all of Landlord's
            rights and remedies provided herein.

      (D)   It is mutually agreed by and between Landlord and
            Tenant that the respective parties hereto shall,
            and they hereby do, waive trial by jury in any
            action, proceeding or counterclaim brought by
            either of the parties hereto against the other on
            any matter whatsoever arising out of or in any way
            connected with this Lease, the relationship of
            Landlord and Tenant, Tenant's use of or occupancy
            of the Premises or any claim of injury or damage
            and any emergency statutory or any other statutory
            remedy.  If Landlord commences any summary
            proceeding for nonpayment of Rent or Additional
            Rent,  Tenant will not interpose any counterclaim
            of whatever nature or description in any such
            proceeding, unless such counterclaim is a
            mandatory counterclaim which would be waived if
            not interposed in such proceeding.

      (E)   If any term or provision of this Lease is declared
            invalid or unenforceable, the remainder of this
            Lease shall not be affected by such determination
            and shall continue to be valid and enforceable.

      (F)   Landlord and Tenant warrant that this agreement is
            being executed with full corporate authority and
            that the officers whose signatures appear hereon
            are duly authorized and empowered to make and
            execute this Lease in the name of the corporation
            by appropriate and legal resolution of its Board
            of Directors.

      (G)   This Lease contains the entire agreement between
            the parties hereto.  No representations,
            inducements, promises or agreements, oral or
            otherwise, between the parties not embodied herein
            shall be of any force or effect, and all reliance
            by Tenant with respect to any representations,
            inducements, promises or agreements is based
            solely on those contained in this Lease.  Any
            modification to this Lease must be in writing and
            duly executed by the parties hereto.

45.   ROOF-TOP EQUIPMENT.

      Tenant shall have the right to utilize a portion of the
      roof of the Building for purposes of installing and
      operating one or more satellite dishes or antennas,
      subject to the terms of the attached Exhibit F.
      Landlord and Tenant shall each complete, execute and
      deliver to other the attached Exhibit F prior to Tenant
      making any installation upon the Building roof.
      Nothing herein contained shall be deemed to grant
      Tenant the exclusive right to utilize the roof of the
      Building.


      IN WITNESS WHEREOF, Landlord and Tenant have executed
this Lease under seal on this 10th day of December, 1997.

WITNESS/ATTEST:                           LANDLORD:

                                    PETULA ASSOCIATES, LTD., an
                                    Iowa corporation
______________________________
                                    By: /s/ Michael D. Ripson
(Seal)

                                    Title: Vice President

                                    By: /s/ R. L. Minear
(Seal)

                                    Title: Vice President

WITNESS/ATTEST:                           TENANT:

                                    GOVERNMENT TECHNOLOGY
                                    SERVICES, INC.,
_____________________________             a Delaware corporation

                                    By: /s/ M. Dendy Young
(Seal)

                                    Title:  CEO