EXHIBIT 10.50

1


                              1550 WILSON BOULEVARD

                                  DEED OF LEASE

THIS  DEED OF LEASE  (the  "Lease")  is made and  entered  into this 29th day of
August 1999, by and between TRIZECHAHN CENTERS,  INC., a California  corporation
d/b/a  TRIZECHAHN 1550 WILSON BLVD.  MANAGEMENT  ("Landlord")  and HAGLER BAILLY
SERVICES, INC., a Delaware corporation ("Tenant"').

In consideration of the Rent hereinafter reserved and the agreements hereinafter
set forth, Landlord and Tenant mutually agree as follows:

1.            DEFINITIONS.

Except as otherwise expressly provided or unless the context otherwise requires,
the following terms shall have the meanings assigned to them in this Section:

A.   Alterations:   Any   improvements,   alterations,   fixed   decorations  or
modifications,  structural  or otherwise,  to the Premises,  the Building or the
Land,  as  defined  below,  including  but not  limited to the  installation  or
modification of carpeting,  partitions, counters, doors, air conditioning ducts,
plumbing,  piping,  lighting fixtures,  wiring,  hardware,  locks,  ceilings and
window and wall coverings.

B.   Base Year: Calendar year 1999.

C.   Building:  The  building  located at 1550 Wilson  Boulevard  in  Arlington,
     Virginia, in which the Premises are located.  Except as expressly indicated
     otherwise, the term "Building" shall include all portions of said building,
     including but not limited to the Premises, the Common Areas and the garage.

D. Common  Areas:  Those areas of the Building  and/or Land, as the case may be,
made available by Landlord for use by Tenant in common with the Landlord,  other
tenants of the Building and the  employees,  agents and invitees of Landlord and
of such other tenants.

E.  Consumer Price Index (Regular and Base): [intentionally omitted.]

F. Default Rate: That rate of interest which is five (5) percentage points above
the annual rate of interest  which is publicly  announced by NationsBank of D.C.
or its successor  entity, if applicable  ("Nations Bank"),  from time to time as
its "prime"  rate of interest,  irrespective  of whether such rate is the lowest
rate of interest  charged by NationsBank to commercial  borrowers.  In the event
that NationsBank ceases to announce such a prime rate of interest,  Landlord, in
Landlord's reasonable discretion,  shall designate the prime rate of interest by
another bank located in the Washington,  D.C.  metropolitan area, which shall be
the prime rate of interest used to calculate the default rate.

     G. Fiscal Year: Each  consecutive  twelve (12) month period during the Term
of this  Lease  that  commences  on  January  1 and  concludes  on  December  31
inclusive.

H. Ground Leases:  All ground and other underlying  leases from which Landlord's
title to the Land  and/or  the  Building  is or may in the  future  be  derived.
"Ground  Lessors" shall denote those persons and entities holding such ground or
underlying leases.

I. Holidays: New Years Day, Presidents' Day, Martin Luther King, Jr.'s Birthday,
Memorial  Day,  Independence  Day,  Labor  Day,  Columbus  Day,  Veteran's  Day,
Thanksgiving  Day,  Christmas  Day  and  any  other  holidays  designated  by an
executive order of the President of the United States or by Act of Congress.

     J. Land:  The real estate that  supports the Building,  and all  associated
easements.

     K.  Tenant's  Work:  All work to be  performed  by Landlord  under the Work
Agreement,  including Additional Tenant Work (as defined in Exhibit C).
 L. Lease
Commencement  Date:  The date this Lease  commences,  as determined  pursuant to
Subsection 2.A. below.

M. Lease  Year:  That  period of twelve (12)  consecutive  calendar  months that
commences on the first day of the calendar month in which the Lease Commencement
Date  occurs,  and each  consecutive  twelve (12) month period  thereafter.  The
earliest  such twelve (12) month period shall be referred to as the "first Lease
Year," and each of the  following  Lease Years shall  similarly  be numbered for
identification purposes.

N. Mortgages:  All mortgages,  deeds of trust and similar  security  instruments
which may now or in the future encumber or otherwise  affect the Building or the
Land,  including mortgages related to both construction and permanent financing.
"Mortgagees"  shall denote those  persons and entities  holding such  mortgages,
deeds of trust and similar security instruments.

O. Operating  Expenses:  All costs and expenses  incurred by Landlord during any
Fiscal Year, as defined in Subsection  1.G.  above,  in managing,  operating and
maintaining  the Building and the Land,  as determined by Landlord in accordance
with generally accepted accounting principles  established and regularly applied
by Landlord.  Such costs and expenses shall include,  but not be limited to, the
cost  of  water,  gas,  sanitary  sewer,  storm  sewer,  electricity  and  other
utilities,  trash removal,  telephone services,  insurance,  janitorial and char
services and supplies, security services, labor costs (including social security
taxes and  contributions  and fringe  benefits),  charges under  maintenance and
service contracts  (including but not limited to chillers,  boilers,  elevators,
window and security services), central heating and air conditioning,  management
fees (not to exceed the rate for any comparable building in Arlington,  Virginia
which Landlord identifies to Tenant, if the management agent is not an affiliate
of Landlord),  business taxes,  license fees, public space and vault rentals and
charges,  costs,  charges  and  other  assessments  made  by or for  any  entity
operating  a business  improvement  district  in which the  Building is located,
condominium fees, assessments,  dues, expenses, and other charges which are paid
by Landlord as a result of the  Building,  the Land or part or all of both being
part of a  condominium,  and the cost of any  equipment or services  provided by
Landlord in connection with the servicing,  operation,  maintenance,  repair and
protection  of the  Building  and the Land and  related  exterior  appurtenances
(whether or not provided on the Lease  Commencement  Date).  Operating  Expenses
shall  include  the cost of capital  improvements  made by  Landlord  to manage,
operate or maintain the Building which (i) Landlord reasonably contemplates will
reduce Operating  Expenses or reduce the rate of increase in Operating  Expenses
from what it  otherwise  would  have been with  respect to the item which is the
subject of the capital  improvement  or (ii) are  necessary to comply with laws,
regulations or utility company  requirements,  except for conditions existing in
violation thereof on the Lease  Commencement  Date,  together with any financing
charges  incurred in  connection  therewith,  provided  that such costs shall be
amortized  over  the  useful  life of the  improvements  and  only  the  portion
attributable to the Fiscal Year shall be included in Operating  Expenses for the
Fiscal Year, except that no portion thereof which is attributable to any capital
improvement  which is completed at any time prior to the  expiration of the Base
Year shall be included in Operating Expenses for any Fiscal Year (including, but
not limited to, the Base Year).  Operating Expenses shall not include:  (i) Real
Estate Tax Expenses, (ii) payments of principal and interest on any Mortgages or
any  financing  costs   (including   points)  and  broker  fees,  (iii)  leasing
commissions,  (iv)  costs of  preparing,  improving  or  altering  any  space in
preparation for occupancy of any new or renewal tenant, (v) ground rents and any
and all other payments  associated with a Ground Lease, (vi) any and all special
services rendered by Landlord which are not made available to all office tenants
at the  Building,  (vii) those  expenses  attributable  to retail  tenants only,
(viii)  original   construction  costs  of  the  Building,   (ix)  interest  and
amortization  of funds  borrowed  by  Landlord,  except as  provided  above with
respect to capital  improvements,  (x)  reserves for  repairs,  maintenance  and
replacements,  except to the extent  actually  utilized for such purposes,  (xi)
salaries,  wages,  or  other  compensation  paid to  employees  of any  property
management organization being paid a fee by Landlord for its services (or to any
employees  of  Landlord  who  are not  assigned  to the  operation,  management,
maintenance  or  repair  of  the  Building,  including  accounting  or  clerical
personnel and other  overhead  expenses of Landlord) or any executive  above the
level of property manager,  except to the extent included in any management fee,
(xii)  amounts  paid to any  partners,  shareholders,  officers or  directors of
Landlord, for salary or other compensation,  (xiii) costs of electricity outside
normal  business  hours sold to tenants of the Building by Landlord or any other
special  service to tenants in excess of that furnished to Tenant whether or not
Landlord receives reimbursement from such tenants as an additional charge, (xiv)
expenses  for repairs,  replacements  or  improvements  arising from the initial
construction  of the  Building  to the  extent  such  expenses  either  (a)  are
reimbursed to Landlord by virtue of warranties from  contractors or suppliers or
(b) result by reason of deficiencies in design or workmanship,  (xv) any amounts
paid to any person, firm or corporation related to or otherwise  affiliated with
Landlord or any general  partner,  officer or director of Landlord or any of its
general partners, to the extent the same exceeds arm's-length competitive prices
paid in Washington,  D.C. for the services or goods  provided,  (xvi) legal fees
and other costs  incurred in connection  with (a) the  negotiation  of leases of
space in the Building,  (b) the  enforcement  of the rent payment  provisions of
leases in the Building or in connection  with a tenant  dispute  concerning  the
rent payment  provisions of leases;  and (c) disputes with prospective  tenants,
employees,  purchasers  or  mortgagees  of  the  Building,  (xvii)  professional
accounting fees in connection  with the preparation of, or disputes  concerning,
Landlord's income tax returns,  (xviii) costs relating to maintaining Landlord's
existence,  either  as a  corporation,  partnership  or  other  entity,  such as
trustee's fees,  partnership  organization or administration  expenses, and deed
recordation  expenses,   (xix)  interest  or  penalties  arising  by  reason  of
Landlord's  failure  to timely pay any  Operating  Expenses  or Real  Estate Tax
Expenses,  (xx) compensation paid to clerks,  attendants,  salespersons or other
persons on or in commercial concessions operated in the Building, or costs which
are the  responsibilities of the garage operator,  (xxi) capital improvements to
the  Building  other than those  permitted  by this Section 1.0, or (xxii) costs
incurred in making the Building Year 2000 compliant.  In the event that,  during
any Fiscal Year or portion  thereof during the Term,  Landlord shall furnish any
utility or service which is included in the definition of Operating  Expenses to
less than one  hundred  percent  (100%)  of the  rentable  area of the  Building
because (i) less than all of the rentable area of the Building is occupied, (ii)
any such  utility or service is not desired or required by any tenant,  or (iii)
any tenant is itself  obtaining or providing  any such utility or service,  then
the  Operating  Expenses  for such Fiscal Year shall be  increased  to equal the
total  expenses  that  Landlord  reasonably  estimates it would have incurred if
Landlord  had provided all such  utilities  and services to one hundred  percent
(100%) of the  rentable  area of the Building  for the entire  Fiscal Year.  For
example,  if the average  occupancy rate of the Building during a Fiscal Year is
eighty percent (80%), the electrical contractor's charges are $1.00 per occupied
rentable  square foot per year, and the Building  contains one hundred  thousand
(100,000)  rentable  square  feet of  space,  then it  would be  reasonable  for
Landlord to estimate  that, if the Building had been one hundred  percent (100%)
occupied during the entire Fiscal Year,  electrical charges for such Fiscal Year
would have been One  Hundred  Thousand  Dollars  ($100,000)  and to compute  the
Operating  Expenses  for such  Fiscal  Year  accordingly.  In no event shall the
provisions  of this  paragraph  be used to enable  Landlord to collect  from the
tenants of the Building  more than one hundred  percent  (100%) of the costs and
expenses  incurred  by Landlord  in  managing,  operating  and  maintaining  the
Building and the Land.

P.  Premises:  20,477  square feet of rentable area on the fourth (4th) floor of
the Building,  known as suite(s) 400, as shown on the floor plan attached hereto
as Exhibit A. However, the area and plan of the Premises may change in the event
of the  exercise of any option to expand or contract  the  Premises set forth in
this Lease.  The rentable area of the Premises has been determined in accordance
with the Greater Washington Commercial  Association of REALTORS@ Standard Method
of Measurement dated June 13, 1995.

     Q.  Premises'  Standard  Electrical   Capacity.   The  electrical  capacity
sufficient to support Tenant's balanced consumption of
five (5) watts per square foot of rentable area.

R. Real  Estate Tax  Expenses:  All taxes and  assessments,  general or special,
ordinary or extraordinary, and foreseen or unforeseen, that are assessed, levied
or  imposed  upon the  Building  and/or  the Land,  under any  current or future
taxation or assessment  system or  modification  of, or supplement or substitute
for,  such  system,  whether  or not based on or  measured  by the  receipts  or
revenues from the Building or the Land  (including all taxes and assessments for
public  improvements  or any other  purpose  and any gross  receipts  or similar
taxes).  Real Estate Tax Expenses  also shall  include all  reasonable  expenses
incurred by Landlord in  obtaining  or  attempting  to obtain a reduction of any
such taxes,  rates or assessments,  including but not limited to legal fees, but
shall not  include  any taxes on Tenant's  Personal  Property or other  tenants'
personal property,  which taxes are the sole obligation of each tenant. Under no
circumstances   shall  Real  Estate  Taxes  include  any  inheritance,   estate,
succession, transfer, or gift tax, or capital levy or any abatements, reductions
or credits  received by Landlord  and any federal or state tax which is assessed
upon Landlord's net income (i.e. any tax which will directly vary based upon the
amount of Landlord's net income (for example,  the present  District of Columbia
Unincorporated Business Tax). The foregoing exclusion is not intended to exclude
a tax which is based upon an assessment  which takes into  consideration,  among
other factors, the Landlord's net rents or net income, which latter tax shall be
included in Real Estate Tax Expenses).

S.  Rent: All Base Rent and Additional Rent.
         (1) Base Rent: The amount payable by Tenant pursuant to Subsection 4.A.
         (2) Additional  Rent:  Ali sums of money payable by Tenant  pursuant to
         this  Lease  other  than  Base  Rent.   (3)  Monthly  Rent:  A  monthly
         installment of Base Rent and Additional Rent, if any, which shall equal
         one-twelfth
                  (1/12th) of Base Rent and Additional Rent then in effect.

T. Tenant's Personal Property: All equipment,  improvements,  furnishings and/or
other property now or hereafter installed or placed in or on the Premises by and
at the sole  expense  of  Tenant or with  Tenant's  permission  (other  than any
property of  Landlord),  with  respect to which  Tenant has not been granted any
credit or allowance by Landlord,  and which: (i) is removable  without damage to
the Premises,  the Building and the Land,  and (ii) is not a replacement  of any
property of Landlord,  whether such  replacement is made at Tenant's  expense or
otherwise.  Notwithstanding any other provision of this Lease, Tenant's Personal
Property  shall not include any  improvements  or other  property  installed  or
placed in or on the Premises as part of Tenant's  Work,  whether or not any such
property was purchased or installed at Tenant's expense.

U. Unavoidable  Delay: Any delays due to strikes,  labor disputes,  shortages of
material, labor or energy, acts of God, governmental restrictions, enemy action,
civil  commotion,  fire,  unavoidable  casualty or any other  causes  beyond the
control of Landlord.

     V. Work Agreement: Exhibit C, which terms are hereby expressly incorporated
in this Lease.

2.  TERM.

A. Term of Lease:  The term of this Lease (the "Term") shall  commence on a date
(the "Lease  Commencement  Date"),  as defined  below,  and shall  terminate  at
midnight  on the day  preceding  the  seventh  (7th)  anniversary  of the  Lease
Commencement  Date,  or such  earlier  date on which  this  Lease is  terminated
pursuant  to the  provisions  hereof (the "Lease  Expiration  Date").  The Lease
Commencement Date shall be the earlier of (i) the earlier of (a) the date Tenant
commences  occupancy  of any part of the  Premises,  or (b)  that  date on which
Landlord  notifies  Tenant that  Tenant's Work is  "substantially  complete," as
defined  in  paragraph  6 of the Work  Agreement.  Landlord  hereby  leases  the
Premises to Tenant and Tenant  hereby  leases the Premises from Landlord for the
Term; or (ii) October 1, 1999.

     B.  Declarations:  If  requested  by  Landlord at any time during the Term,
Tenant  promptly  will  execute a  declaration  in the form  attached  hereto as
Exhibit B.

C. Effective Date: The rights and  obligations  set forth in this Lease,  except
for the obligation to pay Rent and as otherwise  specifically provided herein to
the  contrary,  shall become  effective  on the date of final  execution of this
Lease.

3.  WORK AGREEMENT.

Landlord  agrees to improve the Premises in accordance  with the Work Agreement,
but shall have no other  obligation to make any  improvements  or alterations to
the Premises.

4. RENT.

From and after the Lease  Commencement  Date,  Tenant shall pay to Landlord such
Base Rent and Additional  Rent as are set forth in this Section 4 and in Section
5 below.

A.  Base Rent: Base Rent shall equal the following amounts:
<TABLE>
<CAPTION>

                                     Base Rent
        Lease                     Per Square Foot                 Base Rent                    Monthly
         Year                         Per Annum                  Per Annum                      Base Rent
<S>      <C>                         <C>                       <C>                            <C>
           1                           $20.00                    $409,540.00                   .$34,128.33
           2                           $20.60                    $421,826.20                   $35,152.18
           3                           $21.22                    $434,521.94                   $36,210.16
           4                           $21.86                    $447,627.22                   $37,302.27
           5                           $22.52                    $461,142.04                   $38,428.50
           6                           $23.20                    $475,066.40                   $39,588.87
           7                           $23.90                    $489,400.30                   $40,783.36
</TABLE>

Tenant shall pay Base Rent to Landlord in equal monthly  installments  ("Monthly
Base Rent") in advance on the first day of each calendar  month during the Term,
without notice,  except that the first monthly installment of Base Rent shall be
paid upon execution of this Lease.  If the Lease  Commencement  Date occurs on a
date other than the first day of a calendar month, Tenant shall receive a credit
equal to the Monthly Base Rent multiplied by the number of days in said calendar
month prior to the Lease  Commencement Date and divided by the number of days in
such month, which credit shall be applied toward the installment of Monthly Base
Rent  next  due  hereunder.  If the  Lease  Expiration  Date  occurs  after  the
expiration of the last numbered  Lease Year set forth above in this Section 4.A.
for which an amount of Monthly  Base Rent is  specified,  then Monthly Base Rent
shall continue to be payable by Tenant at such rate for each month or portion of
a month thereafter which is prior to the Lease Expiration Date.

B. Payment:  All Base Rent and Additional Rent due and payable to Landlord under
this Lease shall be made payable to  TrizecHahn  Centers,  Inc. and delivered to
TrizecHahn  Centers,  Inc. at  NationsBank,  P.O.  Box  #631569,  Baltimore,  MD
21263-1569:  provided,  however,  that at Landlord's  sole option,  following at
least thirty (30) days written notice to Tenant,  Tenant shall  thereafter  make
all payments of Base Rent and Additional  Rent due and payable to Landlord under
this Lease by means of  electronic  transfers of funds from  Tenant's  financial
institution to Landlord's  designated  financial  institution.  Payments of Rent
(other than in cash), if initially dishonored,  shall not be considered rendered
until ultimately honored as cash by Landlord's  depository.  Except as expressly
set forth otherwise in this Lease,  Tenant will pay all Rent to Landlord without
demand, deduction, set-off or counter-claim.

C. Late Fee:  If Tenant  fails to make any payment of Rent on or before the date
when payment is due on more than one (1) occasion in any calendar year or if, on
said one (1) occasion, Tenant falls to make full payment of Rent within five (5)
days  after the day on which  payment  is due,  then  Tenant  also  shall pay to
Landlord a late fee equal to five  percent  (5%) of the amount  that is past due
for each  month or part  thereof  until such Rent is fully  paid.  Said late fee
shall  be  deemed  reimbursement  to  Landlord  for its  costs of  carrying  and
processing Tenant's delinquent account.  Acceptance by Landlord of said late fee
shall not waive or release any other rights or remedies to which Landlord may be
entitled on account of such late payment.

D. Arbitration: Any statement provided to Tenant by Landlord pursuant to Section
5 below shall be conclusive  and binding upon Tenant  unless,  within sixty (60)
days after receipt  thereof,  Tenant notifies  Landlord of the respects in which
the statement is claimed to be incorrect.  Unless otherwise mutually agreed, any
such dispute shall be determined by arbitration in the jurisdiction in which the
Premises are located,  in accordance with the then current  commercial  rules of
the American  Arbitration  Association.  The costs of the  arbitration  shall be
divided equally between  Landlord and Tenant,  except that each party shall bear
the  cost  of its own  legal  fees,  unless  (i) the  arbitration  results  in a
determination  that  Landlord's  statement  contained a discrepancy of less than
five  percent  (5%) in  Landlord's  favor,  in which event Tenant shall bear all
costs  incurred  in  connection  with  such  arbitration,   including,   without
limitation,  reasonable  legal  fees  or  (ii)  the  arbitration  results  in  a
determination that Landlord's statement contained a discrepancy of at least five
percent  (5%) in  Landlord's  favor,  in which  event  Landlord  shall  bear all
reasonable  costs  incurred  in  connection  with such  arbitration,  including,
without limitation, reasonable legal fees. Pending determination of any dispute,
Tenant shall pay all amounts due pursuant to the  disputed  statement,  but such
payments shall be without prejudice to Tenant's position.  Upon at least fifteen
(15) days notice to Landlord,  Tenant shall have reasonable access during normal
business  hours and at Tenant's  expense,  to  appropriate  books and records of
Landlord  relating to the amount of expenses covered by the disputed  statement,
for the purpose of verifying the  statement.  Any such review shall be made only
by Tenant's  employees  and/or by an auditor  hired by Tenant who is a Certified
Public Accountant and who is employed on other than a contingent fee basis.

5.  ADDITIONAL RENT.

A. To Cover Consumer Price Index Increases: [intentionally omitted.]


B.  To Cover Increased Operating and Real Estate Tax Expenses:

         (1) Definitions:  As used herein,  "Increased Operating Expenses" shall
         equal the  amount by which  Operating  Expenses  incurred  during  such
         Fiscal  Year exceed the  Operating  Expenses  incurred  during the Base
         Year, and "Tenant's  Share of Increased  Operating  Expenses"  shall be
         that percentage of Increased Operating Expenses which is the equivalent
         of the number of square feet of rentable  area in the Premises  (20,477
         on the Lease Commencement Date) divided by the number of square feet of
         rentable  area of office  space in the  Building  (110,472 on the Lease
         Commencement  Date).  As  used  herein,   "Increased  Real  Estate  Tax
         Expenses"  shall  equal the  amount by which Real  Estate Tax  Expenses
         incurred  during such  Fiscal Year exceed the Real Estate Tax  Expenses
         incurred  during the Base Year,  and 'Tenant's  Share of Increased Real
         Estate Tax Expenses"  shall be that percentage of Increased Real Estate
         Tax  Expenses  which is  equivalent  to the  number of  square  feet of
         rentable  area in the Premises  divided by the number of square feet of
         rentable area (both office and retail) in the Building  (129,289 on the
         Lease  Commencement  Date).  However,  in no  event  shall  any  of the
         aforesaid sums be less than zero.

         (2) Payment of Tenant's Share:  Commencing on the first  anniversary of
         the Lease  Commencement  Date,  in addition to all other Rent set forth
         herein,  for each  Fiscal  Year  during the Term,  Tenant  shall pay to
         Landlord  as  Additional  Rent an amount  equal to the sum of  Tenant's
         Share of Increased  Operating  Expenses and Tenant's Share of Increased
         Real Estate Tax Expenses;  provided, however, that for the Fiscal Years
         during which the Term begins and ends,  Tenant's Share of the aforesaid
         sum shall be prorated based upon the greater of: (1) the number of days
         during  such  Fiscal  Year that this  Lease is in  effect,  or (ii) the
         number  of days that  Tenant  actually  occupies  the  Premises  or any
         portion thereof.

C. Statements:

         (1) [intentionally omitted.]

         (2)   Commencing   with  the  Fiscal  Year  which  includes  the  first
anniversary  of the Lease  Commencement,  and for each Fiscal  Year  thereafter,
Landlord  shall  deliver  to Tenant a  statement  estimating  Tenant's  Share of
Increased  Operating  Expenses and  Increased  Real Estate Tax Expenses for such
Fiscal Year, which Tenant shall pay in equal monthly  installments in advance on
the first day of each  calendar  month  during each Fiscal  Year.  Tenant  shall
continue to pay such estimated  Increased Operating and Real Estate Tax Expenses
until  Tenant  receives the next such  statement  from  Landlord,  at which time
Tenant  shall  commence  making  monthly  payments  pursuant to  Landlord's  new
statement.  With the first  payment of  Additional  Rent herein  which is due at
least  fifteen (15) days after  Tenant's  receipt of a statement  from  Landlord
specifying  Tenant's Share of estimated  Increased Operating and Real Estate Tax
Expenses payable during the Fiscal Year, Tenant shall pay the difference between
its monthly share of such sums for the  preceding  months of the Fiscal Year and
the monthly  installments  which  Tenant has  actually  paid for said  preceding
months.

D. Retroactive Adjustments:  After the end of the Fiscal Year which includes the
first  anniversary  of the Lease  Commencement  Date,  and after the end of each
Fiscal Year thereafter,  Landlord shall determine the actual Increased Operating
Expenses and Increased  Real Estate Tax Expenses for such Fiscal Year,  Landlord
shall  calculate the  foregoing  sums and shall provide to Tenant a statement of
Tenant's  Share of Increased  Operating  Expenses and Increased  Real Estate Tax
Expenses for the Fiscal Year,  which shall be  substantially  in the form of the
statement which is attached  hereto as Exhibit F and made a part hereof.  Within
thirty  (30) days after  delivery  of any such  statement,  Tenant  shall pay to
Landlord any deficiency  between the amount shown as Tenant's Share of Increased
Operating  and Real Estate Tax  Expenses  for the Fiscal Year and the  estimated
payments  made by Tenant.  Tenant  shall be credited  with any excess  estimated
payments toward  subsequent Rent payments by Tenant, or if the Term has expired,
Landlord  shall refund such amount to Tenant within  thirty (30) days  following
the date of issuance of  Landlord's  statement  if Tenant is not then in default
under this Lease.

E. Change In or Contest of Taxes:  In the event of any change by any taxing body
in the period or manner in which any of the Real Estate Tax Expenses are levied,
assessed or imposed,  Landlord shall have the right, in its sole discretion,  to
make equitable  adjustments  with respect to computing  increases in Real Estate
Tax  Expenses.  Real Estate Tax Expenses  which are being  contested by Landlord
shall be included  in  computing  Tenant's  Share of  Increased  Real Estate Tax
Expenses  under this  Section,  but if Tenant shall have paid Rent on account of
contested Real Estate Tax Expenses and Landlord  thereafter receives a refund of
such taxes,  Tenant shall receive a credit toward subsequent Rent payments in an
amount  equal to  Tenant's  Share of such  refund,  or if the Term has  expired,
Landlord  shall refund such amount to Tenant within  thirty (30) days  following
the date of  Landlord's  receipt of such refund if Tenant is not then in default
under this Lease.

F. Sales,  Use or Other  Taxes:  If during the Term any  governmental  authority
having  jurisdiction  over the Building or the Land levies,  assesses or imposes
any tax on Landlord, the Premises, the Building or the Land or the rents payable
hereunder,  in the nature of a sales tax, use tax or any tax except (i) taxes on
Landlord's  income,  (ii) estate or inheritance  taxes, or (iii) Real Estate Tax
Expenses,  then Tenant  shall pay its  proportionate  share to  Landlord  within
fifteen (15) days after receipt by Tenant of notice of the amount of such tax.

6.  USE.

     A.  Permitted  Use:  Tenant  shall use and occupy the  Premises  solely for
office use and for administrative activities directly related thereto and for no
other purpose.

B. Legal and Other  Restrictions  of Tenant's  Use: In its use of the  Premises,
Tenant shall comply with all present and future laws, regulations (including but
not limited to fire and zoning  regulations)  and ordinances of all other public
and  quasi-public  agencies having  jurisdiction  over the Land or the Building.
Tenant  shall not use the Land,  the  Building or use or occupy the Premises for
any  unlawful,  disorderly  or  hazardous  purposes  or in a manner  which  will
interfere with the rights of Landlord, other tenants or their invitees or in any
way injure or annoy any of them.

C. Landlord's  Compliance with Laws:  Landlord shall make reasonable  efforts to
comply with all present and future laws, governmental regulations and ordinances
and shall  correct such  conditions  which may be in violation of any such laws,
regulations  or  ordinances  which may occur with respect to the Building or the
Land,  provided that (a) such compliance is not the  responsibility of Tenant or
of any other  tenant(s) at the  Building  and (b)  Landlord has obtained  actual
knowledge  of  the  existence  of  such   condition   which   constitutes   such
noncompliance with an applicable law, regulation or ordinance.

7.  CARE OF PREMISES.

Tenant  shall at its expense  keep the  Premises  (including  all  improvements,
fixtures and other property  located  therein) in a neat and clean condition and
in good order and  repair,  and will suffer no waste or injury  thereto.  Tenant
shall  surrender  the  Premises  at the end of the  Term in as  good  order  and
condition as they were in on the Lease Commencement Date, ordinary wear and tear
excepted.

B.  ALTERATIONS BY TENANT.

A. Making of Alterations; Landlord's Consent: Tenant shall not make or permit to
be made any Alterations without the prior written consent of Landlord both as to
whether  the  Alterations  may be made and as to how and when they will be made.
Notwithstanding  the foregoing,  (i) Landlord shall not  unreasonably  withhold,
condition or delay its consent to Alterations  which would not affect any of the
structural  components  of the  Building  or any  of the  plumbing,  electrical,
heating,  ventilating or air conditioning  systems of the Building and would not
be visible from the exterior of the  Premises or of the  Building,  and (ii) the
consent of Landlord  shall not be required with respect to painting of the walls
in the Premises,  installation of wall covering in the Premises, and replacement
or installation  of carpeting in the Premises,  provided that, in each instance,
Tenant provides Landlord with written notice of the work which is proposed to be
performed  pursuant to this clause (ii) at least ten (10) days in advance of the
performance  of such  work  and  Tenant's  contractors  comply  with  all of the
Building's  regulations.  Any Alterations shall be made at Tenant's expense,  by
its  contractors  and  subcontractors  and in accordance with complete plans and
specifications  approved  in  advance in  writing  by  Landlord,  and only after
Tenant:  (i) has obtained all necessary  permits from  governmental  authorities
having  jurisdiction  and has  furnished  copies  thereof to Landlord,  (ii) has
submitted  to Landlord an  architect's  certificate  that the  Alterations  will
conform to all applicable laws and regulations,  and (iii) has complied with all
other requirements reasonably imposed by Landlord,  including without limitation
any  requirements  due to the  underwriting  guidelines of Landlord's  insurance
carriers.  Landlord's  consent to any  Alterations and approval of any plans and
specifications  constitutes  approval  of no more  than  the  concept  of  these
Alterations and not a representation  of warranty with respect to the quality or
functioning of such Alterations,  plans and specifications.  Tenant shall be and
is solely responsible for the Alterations and for the proper integration thereof
with the Building,  the  Building's  systems and existing  conditions.  Landlord
shall have the right,  but not the  obligation,  to supervise  the making of any
Alterations.  If any  Alterations  are made without the prior written consent of
Landlord,  or which do not  conform  to plans  and  specifications  approved  by
Landlord or to other  conditions  imposed by Landlord  pursuant to this Section,
Landlord  may,  in its sole but  reasonable  discretion,  correct or remove such
Alterations at Tenant's  expense.  Following  completion of any Alterations,  at
Landlord's request,  Tenant  e4her--shall  deliver to Landlord a complete set of
"as built" plans showing the  Alterations or, if Tenant does not provide same to
Land  lord  with  i n  ten  (10)  business  days  following  completion  of  the
Alterations,  then Tenant shall reimburse  Landlord for any expense  incurred by
Landlord  in  causing  the  Building   plans  to  be  modified  to  reflect  the
Alterations.

B. No Liens:  Tenant shall take all necessary steps to ensure that no mechanic's
or materialmen's liens are filed against the Premises,  the Building or the Land
as a result of any  Alterations  made by the Tenant.  If any mechanic's  lien is
filed,  Tenant  shall  discharge  the lien within ten (10) days  thereafter,  at
Tenant's expense, by paying off or bonding the lien.

9.  EQUIPMENT.

A. Permitted Equipment:  Tenant shall not install or operate in the Premises any
equipment or other  machinery  that, in the aggregate,  will cause Tenant to use
more than the Premises' Standard Electrical Capacity, without: (i) obtaining the
prior  written  consent of Landlord  (which  consent  shall not be  unreasonably
withheld,  conditioned  or  delayed),  who may  condition  its consent  upon the
payment by Tenant of Additional  Rent for  additional  consumption of utilities,
additional  wiring or other  expenses  resulting  therefrom,  (ii)  securing all
necessary  permits  from  governmental  authorities  and utility  companies  and
furnishing  copies  thereof  to  Landlord,  and (iii)  complying  with all other
requirements  reasonably  imposed by Landlord.  Prior to the Lease  Commencement
Date,  Tenant shall provide  Landlord  with a list of all equipment  that Tenant
intends to install or  operate in the  Premises  which  operate on more than one
hundred  twenty (120) volts,  and Tenant shall provide  Landlord with an updated
list  of such  equipment  prior  to the  installation  or use of any  additional
equipment  which  operates on more than one hundred  twenty (120) volts.  Tenant
shall not install any equipment or machinery  which may necessitate any changes,
replacements or additions to or material  changes in the use of water,  heating,
plumbing,  air  conditioning  or  electrical  systems  of the  Building  without
obtaining  the prior  written  consent of Landlord,  which  consent shall not be
unreasonably  withheld,  delayed  or  conditioned,   it  being  agreed  that  in
determining  whether to  consent to any such  change,  replacement  or  addition
Landlord may consider,  inter alia, any noise,  smell,  heat,  cost to Landlord,
liability to Landlord,  or adverse impact on the  marketability  of the Premises
following the  expiration of the Term of this Lease or on the  marketability  of
any other space in the Building during or after the Term of this Lease,  and any
adverse impact of any nature on the operation, maintenance, or management of the
Building or any portion  thereof,  which may result  from the  proposed  change,
replacement or addition.

B.  Payment For Excess  Utility  Usage:  If Tenant's  equipment  shall result in
electrical  demand in  excess of the  Premises'  Standard  Electrical  Capacity,
Landlord shall have the right, in its sole but reasonable discretion, to install
additional  transformers,  distribution  panels,  wiring  and  other  applicable
equipment at the expense of Tenant.  None of the equipment so installed shall be
deemed  to be  Tenant's  Personal  Property.  If at any time  during  the  Term,
Tenant's  connected  electrical  load  from its use of  equipment  and  fixtures
(including  incandescent lighting and power), as estimated by Landlord,  exceeds
the Premises' Standard  Electrical  Capacity,  then Landlord may, at its option:
(i) install  separate  electrical  meter(s)  for the  Premises,  or (ii) cause a
survey to be made by an independent  electrical  engineer or consulting  firm to
determine  the amount of  electricity  consumed by Tenant  beyond the  Premises'
Standard  Electrical  Capacity.  Tenant shall reimburse Landlord for the cost of
the installation of said meter(s) or completion of said meter(s) or survey,  and
shall pay as Additional Rent the cost of any electricity in excess of an average
of the Premises Standard Electrical Capacity, at the rate charged by the utility
company providing such electricity,  assuming  continuous business hours, within
ten (10) days after  receipt of any bill  therefor from Landlord for such excess
utility usage, only if said meter or survey reflects that Tenant's equipment has
resulted in  electrical  demand in excess of the Premises'  Standard  Electrical
Capacity.

C. Noise;  Vibration;  Floor Load:  Business machines and equipment belonging to
Tenant,  which cause noise or vibration  that may be  transmitted to any part of
the  Building  to such a degree as to be  objectionable  to  Landlord  or to any
tenant of the Building,  shall be installed and maintained by Tenant at Tenant's
expense on devices  that  eliminate  the noise and  vibration.  Tenant shall not
place any load upon the floor of the Premises  which exceeds the per square foot
load the floor was  designed  to carry  (eighty  (80) pounds per square foot for
live loads and twenty (20) pounds per square foot for dead loads).

10.  OWNERSHIP AND REMOVAL OF PROPERTY.

A.  Landlord's  Property:   Any  Alterations  and  other  improvements  and  any
equipment,  machinery,  furnishings and other property,  installed or located in
the  Premises,  the  Building or the Land by or on behalf of Landlord or Tenant,
except for Tenant's Personal Property: (i) shall immediately become the property
of Landlord,  and (ii) shall be  surrendered  to Landlord with the Premises as a
part  thereof  at the end of the  Term;  provided,  however,  that  if  Landlord
requests Tenant to remove any  Alterations  installed by or on behalf of Tenant,
Tenant  shall cause the same to be removed at Tenant's  expense on or before the
Lease Expiration Date, or shall reimburse Landlord for the cost of such removal,
as elected by Landlord (unless Landlord expressly waives in writing the right to
require such removal at the time Landlord give its consent to the making of such
Alterations). Notwithstanding the foregoing, (1) with respect to all Alterations
made pursuant to the Office Space Work Agreement  attached  hereto as Exhibit C,
Landlord  shall  specify  which,  if any, of such  Alterations  Tenant  shall be
required  to remove  at the end of the Term at the time  Landlord  approves  the
plans and  specifications  for such  Alterations,  and (ii) with  respect to all
other Alterations,  Tenant, upon submitting its request to Landlord to make such
Alterations,  shall  have the right to request  therein  that  Landlord  specify
whether  and  to  what  extent  Landlord  will  require  Tenant  to  remove  the
Alterations  in question at the end of the Term. If Tenant shall fall to request
such information in its request to make any Alterations specified in clause (ii)
in the  preceding  sentence,  such right shall be deemed null and void as to the
Alterations in question, and all such Alterations shall thereafter be subject to
the exercise of Landlord's  rights and to Tenant's  obligations set forth in the
first  sentence of this  Section  10.A.  If Tenant  submits its request for such
information in accordance with the foregoing provisions and Landlord consents to
the Alterations requested, Landlord shall, together with its consent, specify in
writing  whether  and to what  extent  it will  require  Tenant  to  remove  the
Alterations  in  question at the end of the Term,  and if  Landlord  fails so to
specify, Tenant shall have no further obligation to remove the Alterations which
were the subject of Tenant's request.

B.  Removal of  Property  At End of Term:  Tenant  shall  remove all of Tenant's
Personal Property, and all computer cabling and wiring installed by or on behalf
of Tenant  (irrespective of whether such cabling and wiring constitutes Tenant's
Personal Property under the terms of this Lease, and at Tenant's expense,  using
a contractor approved in advance by Landlord in writing),  from the Building and
the Land on or before the Lease Expiration Date. Any personal property belonging
to Tenant or to any other  person or entity  which is left in the Building or on
the Land after the date this Lease is terminated  for any reason shall be deemed
to have been  abandoned.  In such event,  Landlord shall have the right to store
such property at Tenant's  sole cost and/or to dispose of it in whatever  manner
Landlord considers  appropriate,  without waiving its right to claim from Tenant
all expenses and damages caused by Tenant's failure to remove such property, and
Tenant and any other person or entity shall have no right to  compensation  from
or any other claim against Landlord as a result.

11.  LANDLORD'S ACCESS TO PREMISES.

Landlord  may at any  reasonable  time upon  reasonable  prior  notice to Tenant
(which  notice  maybe given orally and which notice shall not be required in the
event of an emergency)  enter the Premises to examine them, to make  alterations
or repairs thereto or for any other purposes which Landlord considers  necessary
or advisable; however, in the case of any emergency, Landlord and its agents may
enter  the  Premises  at any time and in any  manner.  Tenant  shall  allow  the
Premises  to  be  exhibited  by  Landlord:   (i)  at  any  reasonable   time  to
representatives  of lending  institutions  or to  prospective  purchasers of the
Building,  and (ii) at any  reasonable  time to persons who may be interested in
leasing  the  Premises.  Landlord  reserves  the right  and  shall be  permitted
reasonable  access to the Premises to install  facilities within and through the
Premises and to install and service any systems deemed  advisable by Landlord to
provide  services or utilities to any tenant of the Building,  provided that (a)
the square  footage of the Premises is not reduced,  and (b) Tenant's use of the
Premises is not materially  adversely affected during the time in which Landlord
performs such service or makes any installation.

12  SERVICES AND UTILITIES.

     A. Services  Provided:  As long as Tenant is not in Default,  as defined in
Subsection 19.A. below, Landlord shall provide the following to Tenant,  without
additional  charge,  except as otherwise  provided  herein  (including,  but not
limited to, as provided in Sections 5 and 1.0. hereof):

     (1)  Elevator  service  for  common  use,  subject  to call  at all  times,
including  Sundays and Holidays.  (2) Central heating and air conditioning  from
8:00 a.m.  until 6:00 p.m.  on  weekdays  and from 8:00 a.m.  until 1:00 p.m. on
Saturdays,  exclusive of Holidays, during the seasons of the year and within the
temperature  ranges usually furnished in comparable office buildings in the city
(or, if not a city, other local  jurisdiction) in which the Building is located,
such  that,  during  the hours  from 8:00 a.m.  to 6:00 p.m.  on  weekdays,  the
temperature  in the Premises shall not exceed 75 degrees  Fahrenheit  with fifty
percent  (50%)  relative  humidity  in the Summer and shall not be lower than 70
degrees  Fahrenheit  in  the  Winter.   Landlord  shall  provide  heat  and  air
conditioning  at other times at Tenant's  expense,  provided  that Tenant  gives
Landlord  notice by 1:00 p.m. on  weekdays  for  after-hour  service on the next
weekday,  two (2)  business  days'  notice  before a Holiday for service on such
Holiday and two (2) business days' notice for after-hour  service on Saturday or
Sunday.  Landlord shall charge Tenant for such  after-hour,  Holiday and special
weekend  service at the prevailing  rates  necessary for Landlord to recover its
actual direct cost of providing such service, including, but not limited to, the
cost of  compensation  and all fringe  benefits  for  employees  providing  such
service;  provided,  however,  that Landlord  shall provide Tenant with up to an
aggregate of eight (8) hours of after-hour  HVAC service  during each Lease Year
of the Term at no  additional  charge from time to time to other  tenants of the
Building.

(3)               Cleaning and char services in Landlord's standard manner after
                  6:00 p.m. on weekdays (other than Holidays), and in accordance
                  with the specifications attached hereto and made a part hereof
                  as Exhibit G.

(4)               Electrical   facilities  to  furnish  electricity  up  to  the
                  Premises'   Standard   Electrical   Capacity   (including  the
                  replacement  of  Building  standard  light  bulbs in  Building
                  standard  light  fixtures,  it being  agreed  that if Landlord
                  replaces any other light bulbs in the  Premises,  Tenant shall
                  pay  Landlord  the  cost of such  bulbs  and all  labor  costs
                  incurred by Landlord in connection  therewith  within  fifteen
                  (15) days after Landlord's written demand therefor).

(5)      Rest room facilities.

(6)               Routine maintenance,  painting and electrical lighting service
                  for  all  Common  Areas  of the  Building  in such  manner  as
                  provided in comparable buildings in Arlington, Virginia.

(7)               Reasonable  access to the  Premises at all times  (twenty-four
                  (24) hours per day, seven (7) days per week),  subject to such
                  security  procedures,  restrictions  and other  regulations as
                  Landlord may  promulgate.  Landlord  shall  initially  provide
                  Tenant,  at  Landlord's  expense,  with such number of keys or
                  access cards, as the case may be, as are reasonably  requested
                  by  Tenant,  and  thereafter  all  replacements   thereof  and
                  additional  keys or access cards shall be provided by Landlord
                  at Tenant's expense.

(8)      A listing on the Building directory.

B. Failure to Provide  Services:  Landlord  shall have no liability to Tenant or
others  based on any  failure by  Landlord  to  furnish  the  foregoing,  due to
Unavoidable  Delays,  repair or maintenance  work or any other reason,  and such
failure shall  neither  render  Landlord  liable for damages to either person or
property,  nor be construed as an eviction of Tenant,  nor cause a diminution or
abatement of Rent nor relieve Tenant of any of Tenant's  obligations  hereunder.
Notwithstanding the foregoing, if any of the services described in Section 12.A.
hereof is suspended and such suspension  renders all or substantially all of the
Premises  untenantable and continues for more than five (5) business consecutive
days, then all Rent due hereunder  shall be abated for the period  commencing on
the sixth (6th) business day of such  suspension and concluding on the date that
Landlord gives Tenant written notice that the service has been restored.

C.  Conservation:  Tenant hereby  agrees to comply with all energy  conservation
procedures,  controls and  requirements  instituted by Landlord  pursuant to any
government  regulations  or otherwise,  including but not limited to controls on
the permitted  range of  temperatures,  the volume of energy  consumption or the
hours of operation of the Building. Institution by Landlord of such controls and
requirements shall not entitle Tenant to terminate this Lease or to an abatement
of any Rent payable hereunder.

D. Recycling:  Without limiting the foregoing,  Tenant covenants and agrees,  at
its sole cost and expense,  to comply with all present and future laws,  orders,
and regulations of the  jurisdiction in which the Building is located and of the
federal, municipal, and local governments,  departments,  commissions,  agencies
and boards having jurisdiction over the Building to the extent that they or this
Lease impose on Tenant duties and  responsibilities  regarding  the  collection,
sorting,  separation,  and  recycling  of 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
12.D., 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,  using  counsel
reasonably satisfactory to Landlord.

13.  RULES AND REGULATIONS.

Tenant shall abide by and observe the rules and  regulations  attached hereto as
Exhibit D and such other rules and  regulations  as may be made by Landlord from
time to time as are generally  applicable to all office tenants in the Building,
provided that such rules and  regulations  shall not be materially  inconsistent
with the  provisions  of this Lease.  Nothing  contained in this Lease or in any
rules  and  regulations  shall  be  interpreted  to  impose  upon  Landlord  any
obligations  to enforce  against  any tenant its rules and  regulations,  or the
provisions of any lease with any other tenant,  and Landlord shall not be liable
to Tenant or any other entity for any  violation of said rules,  regulations  or
lease provisions.

14.  REPAIR OF DAMAGE CAUSED BY TENANT: INDEMNIFICATION.

A. Repairs:  Except as otherwise  expressly  provided in this Lease, all injury,
breakage and damage to the Land, the Building or the Premises, caused by any act
or  omission of Tenant  shall be repaired by and at the sole  expense of Tenant,
except that in the event that Tenant fails to make such repairs  within the time
designated  by  Landlord,  which shall be not less than five (5)  business  days
following written notice by Landlord to Tenant or such shorter period of time as
Landlord,   in  its  sole  discretion,   determines  is  appropriate  under  the
circumstances,  then,  in such  event,  Landlord  shall have the  right,  at its
option,  to make such  repairs and to charge  Tenant for all costs and  expenses
incurred in connection therewith as Additional Rent payable within ten (10) days
after the rendering of a bill therefor. Tenant shall notify Landlord promptly of
any injury, breakage or damage to the Land, the Building, or the Premises caused
by Tenant.

B. Indemnification: Tenant hereby agrees to indemnify and hold Landlord harmless
from and against all costs, damages, claims, liabilities and expenses, including
reasonable attorneys' fees, suffered by or claimed against Landlord, directly or
indirectly,  based on,  arising out of or resulting  from:  (i) Tenant's use and
occupancy  of the  Premises  or the  business  conducted  by Tenant  therein  or
Tenant's  presence  in the  Building or on the Land (ii) the making by Tenant of
any Alterations, (iii) any act or omission of Tenant or its employees, agents or
invitees,  and (iv) any  breach  or  default  by  Tenant  in the  observance  or
performance  of its  covenants  and  obligations  under  this  Lease;  provided,
however,  that Tenant's  obligations  to indemnify  and hold  Landlord  harmless
pursuant to this Section 14.B. shall not extend to (a) any actions by any person
who is not an agent, employee,  independent contractor,  or invitee of Tenant or
Landlord,  or (b) any  actions  of  Landlord's  agents,  employees,  independent
contractors,  or invitees unless they are the result of an effort by Landlord to
cure a Default by Tenant  under this Lease or to exercise  any right of Landlord
to replace,  remove or repair any unauthorized Alteration by Tenant, to take any
action that Tenant was  obligated to take under this Lease but did not take,  to
correct  any  violation  by Tenant of any of the  Rules and  Regulations,  or to
otherwise enforce the provisions of this Lease.

15  LIMITATION ON LANDLORD LIABILITY.

A.  Liability  Standard:  Landlord  shall  not be  liable to Tenant or any other
individual or entity for any damage,  loss or claim whatsoever,  except damages,
losses and claims that are the direct result of Landlord's  gross  negligence or
willful  misconduct;   however,  in  no  event  shall  Landlord  be  liable  for
consequential damages.

B. Limitation on Total  Liability:  Notwithstanding  any other provision of this
Lease,  it is  expressly  understood  and  agreed  that the total  liability  of
Landlord  arising out of or in connection with this Lease,  the  relationship of
Landlord and Tenant  hereunder  and/or  Tenant's use of the  Premises,  shall be
limited to the estate of Landlord in the Building.  No other  property or assets
of  Landlord  or any  partner  or owner of  Landlord  shall be  subject to levy,
execution,  or other  enforcement  proceedings or other judicial process for the
satisfaction  of any judgment or any other right or remedy of Tenant arising out
of or in connection  with this Lease,  the  relationship  of Landlord and Tenant
hereunder and/or Tenant's use of the Premises.




16.  FIRE AND OTHER CASUALTY.

If the  Premises  shall be  damaged by fire or other  casualty,  other than as a
result of the repeated  negligence  or any act of willful  misconduct of Tenant,
the Lease shall not terminate and, upon adjustment of insurance claims, Landlord
shall repair the damage,  provided  that  Landlord  shall have no  obligation to
repair  damage to or replace  Tenant's  Personal  Property.  Except as otherwise
provided herein, if any part of the Premises are rendered untenantable by reason
of any such damage, Rent shall abate from the date of the damage to the date the
damage is repaired,  as determined by Landlord,  in the proportion that the area
of the  untenantable  part  bears  from  time to time to the  total  area of the
Premises.  No  compensation  or  reduction  of Rent shall be paid or allowed for
inconvenience,  annoyance or injury to Tenant or Tenant's  business arising from
any damage to or repair of the Premises or the Building.

Notwithstanding the foregoing, if Landlord does not receive sufficient insurance
proceeds to fully  repair the  damage,  or if the  Building  shall be so damaged
that, as determined by Landlord,  substantial  reconstruction of the Premises or
the Building is required  (whether or not the Premises have been damaged),  then
(i) Landlord,  at its option, may give Tenant,  within sixty (60) days after the
casualty,  written notice of  termination of this Lease,  and this Lease and the
Term shall terminate (whether or not the Term has commenced) upon the expiration
of thirty (30) days from the date of the notice,  with the same effect as if the
new  expiration  date had been the date  initially  fixed for  expiration of the
Term,  and all Rent shall be  apportioned  as of such date, and (ii) if Landlord
determines that the repairs and restoration  cannot be  substantially  completed
within two  hundred  twenty-five  (225)  days  after the date of such  damage or
destruction, Landlord shall notify Tenant of such determination. For a period of
thirty  (30) days  after  such  determination,  Tenant  shall  have the right to
terminate  this Lease by giving  written  notice to Landlord,  provided that the
damage or destruction  was not caused by the act or omission of Tenant or any of
its employees or agents.  If this Lease is terminated  pursuant to the foregoing
provisions,  then  this  Lease  shall  terminate  (whether  or not the  Term has
commenced)  upon the  expiration  of  thirty  (30)  days  after  the date of the
termination notice, with the same effect as if the termination date had been the
date initially  fixed for the expiration of the Term, and all Rent from the date
of the casualty,  damage or  destruction  shall be apportioned  and,  subject to
abatement as aforesaid, shall be paid to the date of termination.

If the Premises or the Building  shall be damaged by fire or other  casualty due
to the negligence or misconduct of Tenant: (i) Landlord shall have no obligation
to repair the Premises or the  Building,  (ii) this Lease shall,  at  Landlord's
option, not terminate, (iii) Landlord may at Tenant's expense repair the damage,
and (iv) Landlord may pursue any legal and equitable remedies available to it.

17.  TENANT INSURANCE.

A.  Types of  Insurance  Required:  Tenant,  at its  expense,  shall  obtain and
maintain in effect at all times  during the Term an insurance  policy  providing
the following coverage:

(1)           An "all risk" insurance  policy covering all of Tenant's  Personal
              Property within, and improvements and alterations to, the Premises
              for not less than the full replacement value thereof. All proceeds
              of such insurance  shall be used to repair or replace the items so
              insured.
(2) A commercial  general  liability  policy on an  occurrence  basis,  with the
following limits:
<TABLE>
<CAPTION>

<S>                                                                                     <C>
         Each occurrence limit for bodily injury and property damage                    $1,000,000
         General aggregate                                                              $2,000,000
         Product/completed operations aggregate                                         $2,000,000
         Fire damage legal liability                                                       $50,000
         Medical payments (any one person)                                                  $5,000
</TABLE>

Said insurance shall name Landlord (in care of Landlord's  management  agent and
referring  to the  Building by its  address),  Landlord's  management  agent and
Mortgagee  as  an  additional  insured.   The  policy  shall  protect  Landlord,
Landlord's  management agent, and the Mortgagee against any liability for bodily
injury,  personal  injury,  death or property damage occurring upon, in or about
the  Premises,  the  Building  or the Land or arising  out of or relating to any
risks  against  which  Tenant is  required  to  indemnify  Landlord,  Landlord's
management agent and the Mortgagee.  From time to time during the Term, Landlord
may require  Tenant to increase  said limits of said  insurance to the limits of
liability  insurance then  customarily  required of tenants of other  comparable
office  buildings in the city (or, if not a city,  other local  jurisdiction) in
which the Building is located.

B.  Required  Provisions  of Policies:  All  insurance  policies  required to be
maintained by Tenant under this Lease must: (i) be issued by insurance companies
approved  by  Landlord in its  reasonable  discretion;  (ii) be in form and have
content  satisfactory  to Landlord;  (iii) be written as primary policy coverage
and not  contributing  to or in excess of any  coverage  which  Landlord  or the
Mortgagees may carry; (iv) contain an express waiver of any right of subrogation
by the insurance company against Landlord, the Mortgagees and the Landlord's and
the Mortgagees' employees and agents; and (v) provide that the policy may not be
cancelled or permitted to lapse  unless  Landlord  shall have  received at least
fifteen (15) days prior written notice of cancellation  or  non-renewal.  Tenant
shall deliver to Landlord (in care of Landlord's  management agent and referring
to the Building by its address)  certificates  at least ten (10) days before the
Lease  Commencement Date and at least thirty (30) days before the renewal of any
policies  and shall  provide a copy of the  original  policy if so  requested by
Landlord.  Any  insurance  required of Tenant  under this Section may be carried
under a blanket policy,  provided that said policy shall  specifically set forth
the amount of insurance allocated to this Lease.

C. Effect of  Tenant's  Activities  on  Insurance:  Tenant  shall not conduct or
permit to be  conducted  any  activity,  or place any  equipment in or about the
Land, the Building or the Premises which will increase the rate of, or make void
or voidable, any fire or other insurance maintained or required to be maintained
by Landlord or any  Mortgagee on the  Building,  the Land or the  property  kept
thereon  or  therein,  which  will  conflict  with  the  provisions  of any such
insurance  policy or which will make it  impracticable  for  Landlord  to obtain
insurance  covering  any  risks  against  which  Landlord  reasonably  deems  it
advisable to obtain  insurance.  In the event any increases in the rates of such
insurance are, in Landlord's  reasonable  judgment,  due to Tenant's presence in
the  Building,  to any  activity  conducted  or property  installed or placed by
Tenant on or about the Land,  the  Building or the  Premises  or to  Alterations
installed by Tenant or at Tenant's request,  Tenant shall reimburse Landlord for
the amount of such increases  promptly upon demand  therefor.  Statements by the
applicable  insurance company or insurance rating bureau that such increases are
due to any  activity,  property  or  improvements  shall be  conclusive  for the
purposes of determining Tenant's liability hereunder.

D. Termination Right: Landlord shall have the right to terminate this Lease upon
thirty (30) days notice to Tenant in the event Landlord receives notice from any
of  Landlord's  insurance  carriers  that such  carrier  intends  to cancel  its
insurance on the  Building,  or to increase  the cost of such  insurance by more
than  one  hundred   percent  (100%)  above  the  premium  payable  by  Landlord
immediately  prior  to such  notice,  due to the  activities  of  Tenant  or the
presence of Tenant in the Building.  However,  Landlord shall not terminate this
Lease in the  event  Landlord  is  a-ble,  with good  faith  efforts,  to obtain
equivalent  insurance from an insurance  carrier  satisfactory  to Landlord at a
premium not more than one hundred  percent  (100%)  greater than the premium for
the cancelled  insurance;  provided that Tenant shall reimburse Landlord for all
additional  premiums  charged to Landlord by such new insurance  carrier.  It is
expressly  understood  that Landlord  shall not have the right to terminate this
Lease pursuant to this Subsection D. if any cancellation or rate increase is due
to factors generally  applicable to the insurance or rental market,  rather than
to Tenant's activities or presence in the Building.

E. Waiver. Except for gross negligence and intentional acts, Landlord and Tenant
hereby each waive and release  each other from any and all  liabilities,  claims
and losses for which Landlord or Tenant is or may be held liable,  to the extent
either party: (i) receives  insurance  proceeds on account  thereof,  or (ii) is
required to maintain insurance pursuant to this Section, whichever is greater.

F.  Landlord's  Insurance:  Landlord  shall obtain and maintain in effect at all
times  during  the Term,  fire and  extended  coverage  insurance  insuring  the
Building  (exclusive  of  footings  and  foundations)  (but not the  property or
equipment of Tenant, its employees, agents, licensees, or invitees) against loss
or damage by fire either with  "all-risk"  property  insurance or with  extended
coverage, in an amount sufficient to prevent Landlord from becoming a co-insurer
within the terms of the applicable policy or applicable law, issued by a company
or  companies  licensed to do  business  in the  Commonwealth  of  Virginia,  by
policies  that shall provide that the proceeds  payable in  connection  with the
loss, if any, shall be payable to Landlord or Landlord's  Mortgagee.  Landlord's
insurance  policy  shall  contain  a  waiver  of any  right  of  subrogation  by
Landlord's insurance company against Tenant, its agents or insurance companies.

18.  CONDEMNATION.

A. Landlord's  Right to Terminate:  If a substantial  part of the Premises,  the
Building or the Land is taken or condemned by any governmental authority for any
purpose or is granted to any authority in lieu of condemnation (collectively,  a
"taking"),  Landlord  shall have the right in its sole  discretion  to terminate
this Lease by written notice to Tenant,  and upon the giving of such notice, the
Term shall terminate as of the date title vests in the authority, and Rent shall
be abated as of that date. For purposes of this Section,  a substantial  part of
the  Premises,  the Land or the Building  shall be considered to have been taken
if, in the sole  opinion of Landlord,  the taking  shall render it  commercially
undesirable  for  Landlord  to permit  this  Lease to  continue  or to  continue
operating the Building.

B.  Adjustment  of Rent: If a portion of the Premises is taken and Landlord does
not elect to terminate this Lease pursuant to the preceding paragraph, then Rent
shall be equitably adjusted as of the date title vests in the authority and this
Lease shall otherwise continue in full force and effect.

C. Division of Award: Tenant shall have no claim against Landlord arising out of
or related to any  taking,  or for any portion of the amount that may be awarded
as a result,  and Tenant  hereby  assigns to Landlord all its rights,  title and
interest in and to any such award; provided, however, that Tenant may assert any
claim it may have against the authority for compensation  for Tenant's  Personal
Property and for any relocation expenses compensable by statute, as long as such
awards  shall be made in addition to and stated  separately  from the award made
for the Land, the Building and the Premises.

19.  DEFAULT.

     A. Default of Tenant:  The following events shall be a default by Tenant (a
     "Default") under this Lease:

     (1) Failure of Tenant to pay Rent as and when due, if the failure continues
     for five (5) days after notice from Landlord specifying the failure.

(2)           Failure  of Tenant to  comply  with or  perform  any  covenant  or
              obligation of Tenant under this Lease, other than those concerning
              the payment of Rent, if the failure continues for thirty (30) days
              after  notice from  Landlord  to Tenant  specifying  the  failure;
              provided, however, that with respect to any failure to comply with
              or perform any covenant or obligation  which is not curable within
              such 30 day period, if (i) Tenant has  expeditiously  commenced to
              cure same, (ii) the failure does not adversely affect the Building
              or other tenants  therein and does not result in any liability to,
              or expenditure of funds by, Landlord,  and (iii) Tenant diligently
              pursues  the  cure of such  condition,  the cure  period  shall be
              extended  to the  time  necessary  to cure the  condition,  not to
              exceed a total of sixty (60) days  (inclusive  of the  original 30
              days).
(3)           If, in  Landlord's  reasonable  opinion,  Tenant's  activities  or
              presence in the Premises  results in a significant,  continuing or
              repeated  threat of physical  danger to other tenants and/or users
              of the Building,  whether or not Tenant is capable of  controlling
              such threat.

     (4)  If  Tenant,  any  guarantor  of  Tenant's  performance   hereunder  (a
     *Guarantor)  or,  if  Tenant  is  a  partnership,  any  partner  of  Tenant
     ("Partner"),  shall file a voluntary  petition in bankruptcy or insolvency,
     shall be  adjudicated  bankrupt  or  insolvent  or shall file a petition or
     answer seeking any reorganization,  arrangement, composition, readjustment,
     liquidation,  dissolution  or similar  relief  under any  present or future
     federal, state or other law, or shall make an assignment for the benefit of
     creditors,  or shall seek or acquiesce in the  appointment  of any trustee,
     receiver or  liquidator  of Tenant or of any Guarantor or Partner or of all
     or any part of the property of Tenant or of such Guarantor or Partner.

     (5) If, within thirty (30) days after the  commencement  of any  proceeding
     against  Tenant or a  Guarantor  or  Partner,  whether  by the  filing of a
     petition   or   otherwise,   seeking   any   reorganization,   arrangement,
     composition, readjustment, liquidation, dissolution or similar relief under
     any  present  or  future  applicable  federal,  state  or other  law,  such
     proceeding  shall not have been  dismissed or if,  within  thirty (30) days
     after the  appointment of any trustee,  receiver or liquidator of Tenant or
     any  Guarantor or Partner,  or of all or any part of the property of Tenant
     or of any Guarantor or Partner, without the acquiescence of such individual
     or  entity,  such  appointment  shall not have been  vacated  or  otherwise
     discharged,  or if any  execution  or  attachment  shall  have been  issued
     against the property of Tenant or of any Guarantor or Partner,  pursuant to
     which the  Premises  shall be taken or occupied or attempted to be taken or
     occupied.

     (6) If  Tenant  fails  to take  possession  of the  Premises  on the  Lease
     Commencement  Date or vacates or abandons the  Premises  prior to the Lease
     Expiration  Date,  with or without an intention  of paying Rent;  provided,
     however,  that if (i) Tenant gives Landlord at least thirty (30) days prior
     written notice that it intends to vacate the Premises, (11) Tenant pays the
     full amount of all Rent due under this Lease while the Premises are vacant,
     (111) the fact that the Premises are vacant does not  adversely  affect the
     Building or other tenants  therein and does not result in any liability to,
     or expenditure of funds by,  Landlord,  and (iv) Tenant leaves the Premises
     in a condition  satisfactory  to Landlord  and  continues  to maintain  the
     Premises in a condition  satisfactory to Landlord  throughout the remainder
     of the Term, then, and in such event only, Tenant shall not be deemed to be
     in Default under this Section  19.A.(6) and Landlord  shall have the right,
     exercisable by sending written notice to Tenant,  to sublet from Tenant for
     the balance of the Term of this Lease all or any  portion of the  Premises,
     or to terminate this Lease as to all or any portion of the Premises,  which
     rights of Landlord as to subletting and termination shall be exercisable by
     Landlord in its sole discretion.

     B. Remedies Upon Default: Upon the occurrence of a Default,  Landlord shall
     have the right, then or at any time thereafter.

     (1) Without demand or notice,  to reenter and take possession of all or any
     part of the Premises, to expel Tenant and those claiming through Tenant and
     to remove any property  therein,  either by summary  proceedings  or by any
     other action at law, in equity or  otherwise,  with or without  terminating
     this Lease,  without being deemed guilty of trespass and without  prejudice
     to any other remedies of Landlord for breach of this Lease, and/or

(2)           To give Tenant  written  notice of Landlord's  intent to terminate
              this  Lease,  and on the  date  specified  in  Landlord's  notice,
              Tenant's  right to possession of the Premises shall cease and this
              Lease shall terminate.

If Landlord elects to terminate this Lease,  everything  contained in this Lease
on the part of Landlord to be done shall cease,  without prejudice to Landlord's
right to recover  from Tenant all Rent,  as set forth in  Subsections  C. and D.
below.  If  Landlord  elects to reenter  pursuant  to  Subsection  B.(1)  above,
Landlord may  terminate  this Lease,  or, from time to time without  terminating
this  Lease,  may relet all or any part of the  Premises as the agent of Tenant,
for such term, at such rental and upon such other  provisions as Landlord  deems
acceptable,  with the right to make any  alterations and repairs to the Premises
that Landlord deems appropriate,  at Tenant's expense. No such reentry or taking
of  possession  of the  Premises  shall be construed as an election to terminate
this Lease,  unless  notice of such  intention is given  pursuant to  Subsection
B.(2)  above,  or  unless  termination  be  decreed  by  a  court  of  competent
jurisdiction  at the instance of Landlord.  Landlord  shall in no event be under
any obligation to relet any part of the Premises.

C.  Liability  of Tenant:  If Landlord  terminates  this Lease or  reenters  the
Premises (with or without  terminating  this Lease),  Tenant shall remain liable
(in  addition  to all other  liabilities  of Tenant  accrued  at the time of the
Default)  for  the sum of (i) any  unpaid  Rent  accrued  prior  to the  time of
termination  and/or reentry,  as the case may be, plus interest thereon from the
due date at the Default Rate,  (ii) all Base Rent and  Additional  Rent provided
for in this Lease from the time of termination  and/or reentry,  as the case may
be,  until the date this Lease would have  expired  had a Default not  occurred,
plus interest  thereon from the due date at the Default Rate,  (iii) any and all
expenses (including but not limited to reasonable attorneys' and brokerage fees)
incurred by Landlord in reentering and repossessing the Premises,  in correcting
any default,  in painting,  altering or repairing the Premises in order to place
the Premises in first-class  rentable condition (whether or not the Premises are
relet), in protecting and preserving the Premises and in reletting or attempting
to relet  the  Premises,  and (iv) any other  amounts  necessary  to  compensate
Landlord for any other injury or detriment caused by the Default,  minus the net
proceeds (after deducting any rental abatements,  tenant improvement  allowances
and other concessions and inducements)  actually  received by Landlord,  if any,
from any  reletting to the extent  attributable  to the period prior to the date
this Lease would have expired had a Default not  occurred.  Landlord  shall have
the option to recover any damages  sustained  by Landlord  either at the time of
reletting,  if any, or in  separate  actions  from time to time as said  damages
shall have been made more easily  ascertainable by successive  relettings or, at
Landlord's  option,  to defer any such recovery  until the date this Lease would
have expired in the absence of a Default,  in which event Tenant  hereby  agrees
that the cause of action shall be deemed to have accrued on the aforesaid  date.
The  provisions  of this Section  shall be in addition to, and shall not prevent
the enforcement of, any claim Landlord may have for anticipatory  breach of this
Lease.

D. Liquidated  Damages:  In addition to Landlord's rights pursuant to Subsection
C. above, if Landlord  terminates  this Lease,  Landlord shall have the right at
any time, at its sole option, to require Tenant to pay to Landlord on demand, as
liquidated damages,  the sum of (i) the total of the Base Rent,  Additional Rent
and all other sums which would have been payable  under this Lease from the date
of Landlord's demand for liquidated damages ("Landlord's Demand") until the date
this Lease would have  terminated  in the absence of the Default,  discounted to
present value at the rate of five percent (5%) per annum (the "Discount  Rate"),
(ii) all  unpaid  Rent  accrued  prior to the time of  Landlord's  Demand,  plus
interest  thereon  from  the due date at the  Default  Rate,  (iii)  any and all
reasonable expenses (including but not limited to attorneys' and brokerage fees)
incurred by Landlord in reentering and repossessing the Premises,  in correcting
any default,  in painting,  altering or repairing the Premises in order to place
the Premises in first-class  rentable condition (whether or not the Premises are
relet), in protecting and preserving the Premises and in reletting or attempting
to relet  the  Premises,  and (iv) any other  amounts  necessary  to  compensate
Landlord for any other injury or detriment caused by the Default;  minus the sum
of (a) the net fair market rental value of the Premises for the period  referred
to in Subsection D.(i) above,  discounted to present value at the Discount Rate,
and (b) any sums actually  paid by Tenant to Landlord  pursuant to Subsection C.
above-,  provided,  however,  that if said damages  shall be limited by law to a
lesser  amount,  Landlord  shall be  entitled  to  recover  the  maximum  amount
permitted by law. The "net fair market rental  value"  referred to in Subsection
D.(a) above shall be the fair market rental value of the Premises at the time of
Landlord's  Demand,  reduced  by  any  rental  abatements,   tenant  improvement
allowances and other concessions and inducements generally provided by landlords
seeking to lease comparable  commercial  property in the area of the Premises at
the time of Landlord's Demand. If reletting is accomplished  within a reasonable
time after Lease termination,  the "net fair market rental value" referred to in
Subsection  D.(a) above shall be deemed prima facie to be the net rental  income
(after deducting any rental abatements,  tenant improvement allowances and other
concessions and inducements) realized upon such reletting.

E. Waiver:  Tenant,  on its own behalf and on behalf of all persons and entities
claiming  through  Tenant,  including  but not limited to  creditors  of Tenant,
hereby  waives  any and all rights and  privileges  which  Tenant and such other
persons and entities  might  otherwise have under any present or future law: (i)
to redeem the Premises,  (ii) to reenter or repossess the Premises,  or (iii) to
restore the operation of this Lease, with respect to any dispossession of Tenant
by judgment or warrant of any court,  any reentry by Landlord or any  expiration
or  termination  of this Lease,  whether by  operation of law or pursuant to the
provisions of this Lease.  Tenant hereby expressly waives receipt of a Notice to
Quit.

F. Lien on Personal  Property:  Landlord shall have alien upon Tenant's Personal
Property and other  Property  brought  onto the  Premises by Tenant,  as and for
security for the Rent and other obligations of Tenant herein provided.  Landlord
may, at any time after a Default,  seize and take possession of any and all such
property, excluding files (hard and electronic),  records and computer disks. If
Tenant fails to redeem the property so seized by payment of whatever sums may be
due Landlord pursuant to this Lease,  then Landlord shall have the right,  after
twenty  (20) days  written  notice to Tenant to sell such  personal  property at
public or private sale and upon such terms and  conditions  as Landlord may deem
advantageous, and after the payment of all proper charges incident to such sale,
apply the  proceeds  thereof  to the  payment  of any  balance  due to  Landlord
hereunder and pay any remaining  balance to Tenant.  The exercise by Landlord of
the foregoing  remedy shall not  discharge  Tenant from any  deficiency  owed to
Landlord, nor shall it preclude the exercise by Landlord of any other rights and
remedies.  Landlord  shall not be liable to Tenant,  or other owners of property
seized, for damages,  general or special, if Landlord reasonably believed it was
acting lawfully in seizing property located in the Premises.

     G. Right of Distress:  Landlord shall, to the extent permitted by law, have
     a right of distress for Rent.

H. Right of Landlord to Cure: If Tenant defaults in the making of any payment or
in the doing of any act  required to be made or done by Tenant under this Lease,
then  Landlord  may, at its option,  make such  payment or do such act,  and the
expenses thereof,  with interest thereon at the Default Rate, from the date paid
by Landlord,  shall  constitute  Additional  Rent  hereunder  due and payable by
Tenant with the next payment of Monthly Base Rent.

I. Attorneys' Fees: In the event of any Default  hereunder,  Tenant shall pay to
Landlord all reasonable  attorneys' fees incurred by Landlord in connection with
such Default or the  enforcement  of  Landlord's  rights or remedies  arising in
connection therewith, whether or not this Lease is terminated and whether or not
Landlord  institutes any lawsuit against Tenant as a result of such Default.  In
addition to the foregoing, whether or not this Lease is terminated, Tenant shall
pay to Landlord all other costs incurred by Landlord with respect to any lawsuit
instituted or action taken by Landlord to enforce the provisions of this Lease.

J. Survival:  Tenant's  liability  pursuant to this Section 19 shall survive the
termination of this Lease,  the  institution of summary  proceedings  and/or the
issuance of a warrant thereunder.

20.  NO WAIVER.

No failure or delay by Landlord in enforcing its right to strict  performance by
Tenant of every  provision  of this Lease or in  exercising  any right or remedy
hereunder,  and no  acceptance  by Landlord  of full or partial  rent during the
continuance  of any Default,  shall  constitute a waiver of the provision or the
Default,  and no  provision  shall be  waived  or  modified  except by a written
instrument  executed by Landlord.  No payment by Tenant, or receipt by Landlord,
of a lesser amount than the full Rent shall be deemed to be other than a payment
on account,  notwithstanding any endorsement or statement on any check or letter
accompanying  any payment of any Rent. No waiver of any Default or settlement of
any  proceeding  instituted  on account of any claimed  Default  shall affect or
alter this Lease or constitute a waiver of any of Landlord's rights hereunder.

21.  HOLDING OVER.

If Tenant shall be in possession of the Premises after termination of this Lease
(whether by normal  expiration of the Term or otherwise) and Tenant's request to
hold over made by at least  sixty  (60) days prior  written  notice has not been
approved by Landlord,  then, at Landlord's  option: (i) Landlord may deem Tenant
to be occupying the Premises as a tenant from month-to-month,  at the sum of one
hundred  fifty  percent  (150%) of the Monthly  Base Rent in effect for the last
full month of the Term, plus the monthly installment of Additional Rent which is
then payable  pursuant to Section 5.C. of this Lease,  and subject to all of the
other  provisions of this Lease, as applicable to a month-to-month  tenancy,  or
(ii)  Landlord  may  exercise  any or all remedies for Default and at law and in
equity,  including but not limited to an aciion  against  Tenant for  wrongfully
holding over.

22.  SUBORDINATION.

A. Lease Subordinate: This Lease shall be subject and subordinate to the lien of
any  and all  Mortgages  and to any  Ground  Leases,  and any and all  renewals,
extensions,  modifications,  recastings and  refinancings  thereof.  This clause
shall be  self-operative,  without execution of any further  instrument;  but if
requested  by  Landlord  or any  Mortgagee,  Tenant  shall  promptly  execute  a
certificate or other document  evidencing and providing for such  subordination.
Landlord  shall have the right to execute  said  document on behalf of Tenant if
Tenant fails to do so within five (5) days after receipt of the request.  Tenant
agrees that,  if any Mortgage is  foreclosed  or Ground Lease  terminated,  upon
request by the purchaser at the foreclosure  sale or Ground Lessor,  as the case
may be,  Tenant shall attorn to and  recognize the purchaser or Ground Lessor as
the landlord under this Lease and shall make all payments required  hereunder to
such new  landlord  without  any  deduction  or set-off of any kind  whatsoever.
Tenant  waives the  provisions  of any law or  regulation,  now or  hereafter in
effect,  which may give or purport  to give  Tenant  any right to  terminate  or
otherwise  affect this Lease or the obligations of Tenant hereunder in the event
that any such foreclosure,  termination or other proceeding is filed, prosecuted
or completed. Notwithstanding anything herein to the contrary, any Mortgagee may
at any time  subordinate the lien of its Mortgage to the operation and effect of
this Lease without  Tenant's  consent.  by giving Tenant  written notice of such
subordination,  in which  event this Lease  shall be deemed to be senior to such
Mortgage,  and thereafter  such Mortgagee shall have the same rights as it would
have had if this Lease had been  executed,  delivered  and recorded  before said
Mortgage. Upon Landlord's receipt of Tenant's written request therefor, Landlord
shall use reasonable  efforts to obtain a  non-disturbance  and quiet  enjoyment
agreement from each future Mortgagee and Ground Lessor, and Tenant shall pay all
third party costs associated with obtaining the agreement, but in no event shall
the fact  that a  non-disturbance  agreement  is not  obtained  from any  future
Mortgagee or Ground Lessor affect in any manner the  subordination  provided for
in Section 22.A. hereof.

B. Modifications to Lease: in the event any of Landlord's  insurance carriers or
any  Mortgagee  requests  modifications  to this Lease,  Tenant shall  execute a
written amendment  incorporating such requested modifications within thirty (30)
days after the same has been submitted to Tenant by Landlord, provided that such
modifications do not materially adversely affect Tenant's use or quiet enjoyment
of the Premises as herein  permitted or any rights of Tenant  hereunder  against
Landlord or increase the rentals and other sums payable by Tenant hereunder.  In
the event Tenant refuses or fails to execute such  amendment  within thirty (30)
days,  Landlord  shall  have the  right,  at its sole  option,  in  addition  to
Landlord's  other  remedies for Default,  to terminate  and cancel this Lease by
written notice to Tenant specifying the date on which this Lease will terminate.
From and after said termination date, both Landlord and Tenant shall be relieved
of any and all further obligations  hereunder,  except liabilities arising prior
to the date of termination.

23.  ASSIGNMENT AND SUBLETTING.

A. No Transfer Without Consent:  Except as hereinafter provided in Section 23.E.
hereof,  Tenant shall not, without the prior written consent of Landlord in each
instance  (which  consent  may be  withheld  in  Landlord's  sole  and  absolute
discretion) (i) assign,  mortgage or otherwise encumber this Lease or any of its
rights  hereunder;  (ii) sublet the  Premises or any part  thereof or permit the
occupancy  or use of the Premises or any part thereof by any persons or entities
other  than  Tenant;  or (iii)  permit  the  assignment  of this Lease or any of
Tenant's  rights  hereunder  by  operation  of law.  Any  attempted  assignment,
mortgaging or encumbering of this Lease or any of Tenant's rights  hereunder and
any  attempted  subletting or grant of a right to use or occupy all or a portion
of  the  Premises  in  violation  of  the  foregoing  sentence  shall  be  void.
Notwithstanding  the foregoing,  Landlord agrees that it shall not  unreasonably
withhold, condition or delay its consent to a proposed subletting, provided that
all of the following conditions are satisfied:  (a) there shall be no default at
the  time of the  proposed  subletting,  (b) the  proposed  subtenant  shall  be
creditworthy, (c) the proposed subtenant shall not be a governmental entity or a
person or entity enjoying sovereign or diplomatic  immunity,  (d) the use of the
Premises by the proposed subtenant shall not attract a volume, frequency or type
of  visitor  or  employee  to the  Building  which  is not  consistent  with the
standards of a high-quality  office building,  (e) the proposed  subtenant shall
specifically  covenant and agree to perform the obligations of Tenant  hereunder
and to occupy the  Premises  subject to the  provisions  of this Lease,  and (f)
Tenant remains liable for the faithful performance of this Lease.

B. Take-Back Rights:  In addition,  Tenant may not assign this Lease, nor sublet
(or permit  occupancy  or use of) the  Premises,  or any part  thereof,  without
giving Landlord  thirty (30) days prior written notice thereof.  For thirty (30)
days  following  receipt of said notice if Tenant  intends to sublease more than
fifty percent (50%) of the Premises or to assign this Lease, Landlord shall have
the right,  exercisable by sending  notice to Tenant,  to sublet from Tenant for
the  balance  of the Term of this  Lease  (i) all of the  Premises  in the event
Tenant notified  Landlord of its desire to assign this Lease, or (ii) so much of
the Premises as Tenant intends to sublet in the event Tenant  notified  Landlord
of its desire to sublet the Premises or permit  another to make use thereof,  at
the same rental Tenant is obligated to pay to Landlord  hereunder.  In the event
Landlord  does not  exercise the  aforesaid  right within said thirty (30) days,
Tenant may attempt to assign,  sublet or permit use of this Lease or such space;
provided that Tenant shall obtain the prior  written  consent of Landlord as set
forth in  Subsection  A.  above;  provided  that Tenant  shall  obtain the prior
written  consent of Landlord as set forth in Subsection A. above,  which consent
shall be granted or withheld by the  expiration of the thirty (30) day take-back
period.  In the event that Tenant defaults  hereunder,  Tenant hereby assigns to
Landlord the Rent due from any assignee or subtenant and hereby  authorizes each
such party to pay said Rent to Landlord.

C. Transfer of Stock: If Tenant and/or any Guarantor is a corporation,  then the
sale,  issuance  or  transfer  of any  voting  capital  stock of  Tenant  or any
Guarantor,  by the person,  persons or entities  owning a  controlling  interest
therein as of the date of this  Lease,  which  results in a change in the voting
control of Tenant or the  Guarantor,  shall be deemed an  assignment  within the
meaning of this Section 23. If Tenant and/or any Guarantor is a partnership, the
sale or transfer  of the  partnership  share,  or any  portion  thereof,  of any
general partner shall be deemed an assignment of this Lease.

D.  Expenses and Profits; Effect of Consent:

     (1) In the event  Landlord  permits  Tenant  to  assign or sublet  all or a
     portion of the Premises to a third party,  one-half (1/2) of the profits to
     Tenant from such assignment or subletting  (that is, the sums that are paid
     by such third party for the right to occupy the Premises,  in excess of (i)
     the Rent  then in  effect,  (ii) all  costs  and  expenses  paid by  Tenant
     pursuant to Section 23.D.(2) hereof, and (iii) all other costs and expenses
     actually   incurred  by  Tenant  in  connection  with  such  assignment  or
     subletting  for  brokerage  commissions,   improvements  to  the  Premises,
     advertising  costs,  attorney's fees, tenant  allowances,  and professional
     fees), shall be paid by Tenant to Landlord on a monthly basis as Additional
     Rent.

(2)           Tenant shall be responsible for all reasonable costs and expenses,
              including attorneys' fees, incurred by Landlord in connection with
              any   proposed  or  purported   assignment   or  sublease  and  an
              administrative   fee  of  Two  Thousand   Five   Hundred   Dollars
              ($2,500.00).

(3)           The consent by  Landlord to any  assignment  or  subletting  shall
              neither be  construed  as a waiver or  release of Tenant  from any
              covenant  or  obligation  of  Tenant  under  this  Lease,  nor  as
              relieving  Tenant from giving  Landlord the aforesaid  thirty (30)
              days notice of, or from  obtaining the consent of Landlord to, any
              further assignment or subletting.  The collection or acceptance of
              Rent from any such  assignee or subtenant  shall not  constitute a
              waiver or release of Tenant  from any  covenant or  obligation  of
              Tenant under this Lease, except as expressly agreed by Landlord in
              writing.

E. Permitted Assignments; Permitted Licensees:

Notwithstanding  the foregoing  provisions of this Section 23,  Landlord  agrees
that:

     (1) So long as (a) no Default is then continuing beyond any applicable cure
     period,  (b) no  circumstance  shall have occurred which with the giving of
     notice,  the passage of time, or both would constitute a Default by Tenant,
     and (c) Tenant or its permitted subtenant or assignee named herein shall be
     occupying the entire Premises and actively conducting business therein, the
     provisions  of this  Section 23 shall not be  applicable  with regard to an
     assignment  of this  Lease or a  subletting  of the  Premises  to  Tenant's
     Affiliate (as  hereinafter  defined),  so long as (1) Tenant gives Landlord
     prior  written  notice of any such  subletting  or  assignment  to Tenant's
     Affiliate (as  hereinafter  defined);  (2) Tenant  originally  named herein
     shall remain  primarily liable under this Lease,  notwithstanding  any such
     assignment  or  subletting;  and (3) no  other  or  further  assignment  or
     subletting shall be permitted without Landlord's prior written consent.  An
     Affiliate,  as used herein,  shall be a person or entity that directly,  or
     indirectly  through one or more  intermediaries,  controls or is controlled
     by, or is under common control with,  the Tenant.  "Control" as used herein
     shall mean the  possession,  direct or indirect,  of the power to direct or
     cause the direction of the  management  and policies of a person or entity,
     whether through ownership of voting securities,  by contract, or otherwise;
     and

(2)           Provided  that  Tenant  delivers  written  notice to  Landlord  of
              occupancy of a portion of the Premises by a Permitted Licensee (as
              hereinafter  defined)  within five (5) business days following the
              commencement  of each such  occupancy  and,  only with  respect to
              Permitted  Licensees  who  are  described  in  clause  (i) of this
              Section  23.E.(2),  Tenant delivers a copy of a revocable  license
              agreement  with such Permitted  Licensee  within five (5) business
              days  following  the  commencement  of such  Permitted  Licensee's
              occupancy  of any  portion of the  Premises,  Tenant  shall not be
              required to obtain  Landlord's  prior written consent for any such
              occupancy  by a  Permitted  Licensee  (which  occupancy  shall  be
              permitted as a matter of right) and such  occupancy by a Permitted
              Licensee  shall not constitute a sublease for the purposes of this
              Section 23. As used  herein,  a  "Permitted  Licensee"  shall mean
              either (i) a retired  officer or retired  employee of Tenant,  any
              person or party who is a client or a  consultant  of Tenant (or an
              officer  or  employee  thereof),  and any person or party who is a
              client or consultant of any client or consultant (or an officer or
              employee  thereof),  which  party uses or  occupies,  but does not
              sublease,  a portion of the Premises either in conjunction with or
              to support the  carrying on of Tenant's  regular  business or as a
              result of an ongoing business  relationship between Tenant and any
              client of Tenant, and (ii) any employee of Hagler Bailly,  Inc., a
              Delaware  corporation,  or PHB  Hagler  Bailly,  Inc.,  a Delaware
              corporation; provided, however, that a Permitted Licensee may only
              be a natural person and not any corporation,  partnership, limited
              liability company or other form of business entity.




24.  TRANSFER BY LANDLORD.

Landlord (and any successor or affiliate of Landlord) may freely sell, assign or
transfer all or any portion of its interest in this Lease or the  Premises,  the
Building or the Land and, in the event of any such sale, assignment or transfer,
shall be relieved of any and all obligations under this Lease from and after the
date of the sale, assignment or transfer. From and after said date, Tenant shall
be bound to such purchaser, assignee or other transferee, as the case may be, as
though the latter had been the original  Landlord  hereunder,  provided that the
purchaser,  assignee or transferee  agrees to assume the obligations of Landlord
hereunder.

25.  INABILITY TO PERFORM.

Except as provided in Section 12.B. hereof, t4:his Lease and Tenant's obligation
hereunder  shall in no way be  affected,  impaired or excused,  nor shall Tenant
have  any  claim  against  Landlord  for  damages,   because  Landlord,  due  to
Unavoidable  Delays,  is unable to  fulfill  any of its  obligations  under this
Lease,  including,  but not limited to, any obligations to provide any services,
repairs, replacements, alterations or decorations or to supply any improvements,
equipment or fixtures.

26.  ESTOPPEL CERTIFICATES.

Tenant shall, without charge, within ten (10) business days after receipt of any
request  therefor,  execute and deliver to Landlord a certificate  stating:  (i)
whether this Lease is unmodified  and in full force and effect (or if there have
been modifications, that the Lease is in full force and effect and setting forth
all such modifications);  (ii) whether there then exist any defenses against the
enforcement of any right of Landlord  hereunder (and, if so, specifying the same
in detail);  (iii) the dates to which rent and any other charges  hereunder have
been paid by Tenant;  (iv) that  Tenant  has no  knowledge  of any then  uncured
defaults  under this Lease (or, if Tenant has  knowledge  of any such  defaults,
specifying  the same in detail);  (v) that Tenant has no  knowledge of any event
that will or may result in the  termination of this Lease (or if Tenant has such
knowledge,  specifying the same in detail); (vi) the address to which notices to
Tenant are to be sent;  and (vii) such other  information  as may be  reasonably
requested.  It is  understood  that any such  certificate  may be relied upon by
Landlord,  any Mortgagee,  prospective  Mortgagee,  Ground  Lessor,  prospective
Ground  Lessor,  or  purchaser  or  prospective  purchaser  of the  Land  or the
Building.  Landlord shall,  without charge, on not more than one (1) occasion in
each  Fiscal  Year,  within ten (10)  business  days after  receipt of a request
therefor  from  Tenant,  execute  and  deliver  to  Tenant a  certificate  which
addresses  the matters  described in clauses (1) through  (vi) of the  preceding
sentence.

27.  COVENANT OF QUIET ENJOYMENT.

Landlord  covenants that it has the right to make this Lease and that, if Tenant
shall pay all Rent and  perform  all of Tenant's  other  obligations  under this
Lease,  Tenant  shall  have  the  right,  during  the Term  and  subject  to the
provisions  of this  Lease,  to quietly  occupy and enjoy the  Premises  without
hindrance by Landlord or its successors and assigns.

28.  WAIVER OF JURY TRIAL.

Landlord  and Tenant  hereby  waive trial by jury in any action,  proceeding  or
counterclaim  brought by either of them  against  the other with  respect to any
matter arising out of or connected with this Lease.

29.  BROKERS.

Landlord and Tenant each  represents  and warrants to the other that,  except as
hereinafter  set forth,  neither of them has employed any broker in procuring or
carrying on any negotiations  relating to this Lease.  Landlord and Tenant shall
indemnify and hold each other harmless from any loss,  claim or damage  relating
to the breach of the foregoing representation and warranty.  Landlord recognizes
only The Fred Ezra Company,  as agent of Tenant,  as broker with respect to this
Lease and agrees to be  responsible  for the payment of any leasing  commissions
owed to said broker.


30.  CERTAIN RIGHTS RESERVED BY LANDLORD.

Landlord shall have the following rights,  exercisable  without notice,  without
liability  for damage or injury to  property,  person or  business  and  without
effecting an eviction, constructive or actual, or disturbance of Tenant's use or
possession of the Premises or giving rise to any claim for set-off, abatement of
Rent or otherwise:

A. To change  the  Building's  name or  street  address.  In the event  Landlord
changes the address or name of the Building,  Landlord shall reimburse  Tenant's
reasonable costs for replacement of Tenant's letterhead, envelopes, and business
cards then on hand.

     B. To affix,  maintain  and  remove any and all signs on the  exterior  and
     interior of the Building.

C. To designate and approve,  prior to installation,  all window shades, blinds,
drapes, awnings, window ventilators,  lighting and other similar equipment to be
installed by Tenant that may be visible from the exterior of the Premises or the
Building.

D. To  decorate  and make  repairs,  alterations,  additions  and  improvements,
whether  structural  or  otherwise,  in, to and about the  Building and any part
thereof,  and  for  such  purposes  to  enter  the  Premises,  and,  during  the
continuance of any such work, to close  temporarily  doors,  entry ways,  Common
Areas in the Building and to interrupt or temporarily  suspend Building services
and facilities, all without affecting Tenant's obligations hereunder, as long as
the Premises remain tenantable,  provided that Landlord gives Tenant such notice
as may be  required  by  Section  11 hereof  and that  there is no  unreasonable
interference with Tenant's access to or use of the Premises.

E. To grant to anyone the exclusive  right to conduct any business or render any
service in the  Building,  provided  Tenant is not  thereby  excluded  from uses
expressly permitted herein.

F. To alter, relocate,  reconfigure and reduce the Common Areas of the Building,
as long as the Premises  remain  reasonably  accessible,  provided that Landlord
gives  Tenant such notice as may be required by Section 11 hereof and that there
is no unreasonable interference with Tenant's access to or use of the Premises.

G. To alter, relocate, reconfigure, reduce and withdraw the Common Areas located
outside  the  Building,  including  parking  and  access  roads,  as long as the
Premises remain reasonably accessible.

H. To erect,  use and maintain  pipes and conduits in and through the  Premises,
provided that Landlord gives Tenant such notice as may be required by Section 11
hereof and that there is no unreasonable interference with Tenant's access to or
use of the Premises.

31.  NOTICES.

No notice, request,  approval,  waiver or other communication which may be or is
required or permitted to be given under this Lease shall be effective unless the
same is in writing and  hand-delivered,  sent by registered  or certified  mail,
return receipt  requested,  first-class  postage  prepaid,  or sent with charges
prepaid by a nationally recognized air courier service. addressed as follows:

If to Landlord:
         c/o TrizecHahn Mid-Atlantic Management Services LLC
         1250 Connecticut Avenue, N.W., Suite 500
         Washington, D.C. 20036
         Attn: Portfolio Manager - 1550 Wilson Boulevard

If to Tenant:
         Hagler Bailly Services, Inc.
         1530 Wilson Boulevard, Suite 300
         Arlington, Virginia 22209
         Attn: Ms. Angela McCluskey

or at any  other  address  of which  either  party  shall  notify  the  other in
accordance  with this  Section.  Such  communications,  if sent by registered or
certified  mail,  shall be deemed to have been given two (2) days after the date
of mailing, or if sent by a nationally recognized air courier service,  shall be
deemed to have been given one (1)  business day after the date of deposit of the
notice with such service.  If any  Mortgagee  shall notify Tenant that it is the
holder of a  Mortgage  affecting  the  Premises,  no  notice,  request or demand
thereafter  sent by Tenant to Landlord  shall be effective  until a copy of same
shall be sent to such Mortgagee in the manner prescribed in this Section at such
address as such Mortgagee shall designate.

32.  MISCELLANEOUS PROVISIONS.

A. Benefit and Burden:  The  provisions of this Lease shall be binding upon, and
shall inure to the benefit of, the parties  hereto and each of their  respective
successors and permitted assigns.

     B.  Governing Law. This Lease shall be construed and enforced in accordance
     with the laws of the jurisdiction in which the Building is located.

C. No Partnership:  Nothing  contained in this Lease shall be deemed to create a
partnership or joint venture between Landlord and Tenant, or to create any other
relationship between the parties other than that of Landlord and Tenant.

D.  Delegation  by Landlord.  Wherever  Landlord  has the  authority to take any
action  under  this  Lease,  Landlord  shall  have the  right to  delegate  such
authority  to others,  and  Landlord  shall be  responsible  for the  authorized
actions of such agents,  employees and others, to the same extent as if Landlord
had taken such action itself.

E. Tenant Responsibility for Agents. In any case where Tenant is responsible for
performing or refraining  from an act or for preventing an action or result from
occurring,  Tenant shall also be responsible for any actions taken or omitted by
Tenant's  agents,   employees,   business  invitees,   licensees,   contractors,
subtenants, family members, guests and any other individuals or entities present
in the Building or on the Land at Tenant's invitation.

F.  Invalidity of Particular  Provisions:  If any provision of this Lease or the
application thereof to any person,  entity or circumstance shall, to any extent,
be held invalid or unenforceable,  the remaining  provisions and the application
of  such  invalid  or   unenforceable   provisions  to  persons,   entities  and
circumstances  other than those as to which it is held invalid or unenforceable,
shall not be affected  thereby.  Each provision of this Lease shall be valid and
enforced to the fullest extent permitted by law.

     G. Counterparts: This Lease may be executed in several counterparts, all of
     which shall constitute one and the same document.

H. Entire  Agreement This Lease,  and any exhibits and addenda  attached hereto,
embody the entire  agreement  of the  parties  hereto,  and no  representations,
inducements or agreements, oral or otherwise,  between the parties not contained
in this Lease or in the exhibits or addenda shall be of any force or effect.  No
rights,  privileges,  easements or licenses are granted to Tenant hereby, except
as expressly set forth herein.

     I.  Amendments:  This Lease may not be  modified in whole or in part in any
     manner other than by an agreement in writing.

     J.  Mortgagee's  Performance:  Tenant  shall accept  performance  of any of
     Landlord's obligations hereunder by any Mortgagee.

K.  Limitation on Interest:  In any case where this Lease provides for a rate of
interest  that is  higher  than the  maximum  rate  permitted  by law,  the rate
specified herein shall be deemed to equal, and the party designated as recipient
of such  interest  shall be entitled to  receive,  the maximum  rate of interest
permitted by law.

     L.  Remedies  Cumulative:  All rights and  remedies  of  Landlord  shall be
     cumulative  and shall not be  exclusive  of any other rights or remedies of
     Landlord hereunder or now or hereafter existing at law or in equity.

M. Annual Financial  Statements:  Within ten (10) business days after Landlord's
written  request  therefor,  but not more often than once per year except in the
event of a proposed sale or financing of the Building,  the Land or both, Tenant
shall submit to Landlord Tenant's most recent annual financial statement.

33.  LENDER APPROVAL.

If the Mortgagee  fails to give its consent to this Lease,  Landlord  shall have
the right, at its sole option,  to terminate and cancel this Lease.  Such option
shall  be   exercisable  by  Landlord  by  written  notice  to  Tenant  of  such
termination,  whereupon this Lease shall be deemed cancelled and terminated, and
both  Landlord  and Tenant  shall be  relieved  of any and all  liabilities  and
obligations hereunder.


34.  PARKING.

Parking will be made available to Tenant pursuant to the provisions of Exhibit E
attached hereto.

35.  SECURITY DEPOSIT.

A. Amount and Uses:  Landlord  acknowledges  receipt from Tenant of  Thirty-Four
Thousand One Hundred Twenty-Eight and 33/100 Dollars ($34,128.33)(the  "Security
Deposit"),  to be held by  Landlord  as  security  for the  payment  of all Rent
payable  by  Tenant  and for the  faithful  performance  by  Tenant of all other
obligations of Tenant under this Lease. Said Security Deposit shall be repaid to
Tenant after the  termination of this Lease (or any renewal  thereof),  provided
Tenant shall have made all such  payments  and  performed  all such  obligations
hereunder.  Landlord shall not be required to maintain the Security Deposit in a
separate  account but shall maintain the Security  Deposit in an account bearing
interest at the rate earned on other  similar  deposits  held by  Landlord.  The
Security Deposit shall not be mortgaged,  assigned, transferred or encumbered by
Tenant without the prior written consent of Landlord,  and any such act shall be
void.  Landlord  may, at  Landlord's  option,  appropriate  and apply the entire
Security Deposit,  or so much thereof as Landlord believes may be necessary,  to
compensate  Landlord for the payment of any past-due Rent and for loss or damage
sustained by Landlord due to any Default. In the event Landlord  appropriates or
applies  the  Security  Deposit in such a manner,  Tenant,  within five (5) days
after notice thereof,  shall pay to Landlord an amount sufficient to restore the
Security Deposit to the original sum deposited.  Tenant's failure to restore any
such deficiency shall constitute a Default hereunder. In the event of bankruptcy
or other debt or creditor proceedings by or against Tenant, the Security Deposit
shall be applied first to the payment of Rent due Landlord for all periods prior
to the  filing  of  such  proceedings.  In  lieu of the  cash  Security  Deposit
hereinabove provided for, Tenant shall have the option to deposit with Landlord,
not later than October 31,1999 a letter of credit (the "Letter of Credit") in an
amount equal to the  Security  Deposit,  which Letter of Credit shall  thereupon
constitute  the  Security  Deposit.  In the event that Tenant does not deposit a
Letter of Credit with Landlord on or before October 31, 1999,  Tenant shall have
no further right to do so. The Letter of Credit shall be  maintained  throughout
the remainder of the Term. Any Letter of Credit  delivered to Landlord by Tenant
shall be an  unconditional,  irrevocable  letter  of credit in a form and from a
financial  institution  located in the Washington,  D.C.  metropolitan  area and
acceptable  to Landlord  in its sole  discretion.  Said  Letter of Credit  shall
provide that it shall expire on the sixtieth  (60th) day  following  the date of
expiration of the Term of this Lease. At Tenant's option,  said Letter of Credit
shall have a term equal to the period  expiring on the first  anniversary of the
date of issuance thereof, in which event Tenant covenants that a renewal of said
Letter of Credit  shall be  delivered  to  Landlord by that date which is thirty
(30) days prior to the expiration date thereof,  and thereafter a renewal of the
Letter of Credit  shall be delivered to Landlord by Tenant by that date which is
thirty (30) days prior to each succeeding anniversary of the original expiration
date of the  Letter of  Credit.  If Tenant  fails to so renew and  deliver  said
Letter of Credit to Landlord by the  thirtieth  (30th) day  preceding  each said
expiration date, such failure shall constitute a Default  hereunder (as to which
no cure period  shall be  applicable)  and  Landlord may draw upon the Letter of
Credit  then in effect  without  the  necessity  of any other  monetary or other
default  hereunder by Tenant,  in which event the proceeds thereof shall be held
by  Landlord.  Said  Letter of  Credit  shall  provide  that  Landlord  shall be
permitted to draw on same on multiple  occasions  following the  occurrence of a
Default by Tenant under this Lease;  provided,  however,  that in the event that
said Letter of Credit would  expire  during the  pendency of any  litigation  to
resolve whether such Default has occurred, Landlord may draw upon said Letter of
Credit prior to the  expiration  thereof.  In the event that Landlord draws upon
the Letter of Credit after a Default by Tenant as aforesaid, Landlord shall use,
apply or retain all or any portion of the  proceeds  thereof for (i) the payment
of any Rent or any other sums as to which Tenant is in default, (ii) the payment
of any amount which  Landlord  may spend or become  obligated to spend to repair
damage  to the  Premises  or the  Building  for which  repairs  Tenant is liable
hereunder,  or (iii)  compensation  to Landlord for any losses which Landlord is
entitled to recover hereunder by reason of Tenant's Default,  including, but not
limited to, any damage or deficiency arising in connection with the reletting of
the Premises and all  associated  reasonable  legal fees.  In the event that the
Letter of Credit is drawn upon by  Landlord  for failure of Tenant to renew said
Letter of Credit as aforesaid, the proceeds thereof shall be held by Landlord in
accordance  with the  provisions  respecting  the  Security  Deposit  under this
Section 36, and, in such event,  within sixty (60) days after the  expiration of
the Term,  and  provided  Tenant has vacated the  Premises and is not in default
hereunder,  Landlord  shall  return such  proceeds to Tenant,  less such portion
thereof as Landlord may be entitled hereunder to apply to satisfy any Default by
Tenant hereunder.  In the event that Tenant is in default upon the expiration of
the Term and  Landlord  does not use all of the  Security  Deposit  to cure such
default,  then,  after such  default has been cured,  Landlord  shall return any
unused  balance  of the  Security  Deposit to Tenant.  The use,  application  or
retention of the proceeds of the Letter of Credit,  or any portion  thereof,  by
Landlord  shall not prevent  Landlord from  exercising any other right or remedy
provided  by this  Lease or by law,  and shall not limit any  recovery  to which
Landlord  may  otherwise  be  entitled.  In the event of the sale or transfer of
Landlord's  interest in the Building or the Land,  Landlord  shall  transfer the
proceeds of the Letter of Credit to the purchaser or transferee,  in which event
Tenant  shall look only to the  purchaser  or  transferee  for the return of the
proceeds  of the Letter of  Credit,  and  Landlord  shall be  released  from all
liability to Tenant for the return of such proceeds.

B. Transferability: In the event of a sale or transfer of Landlord's interest in
the Building or of the interest of any successor or assign of Landlord, Landlord
(or such  successor  or assign)  shall have the right to transfer  the  Security
Deposit  to  any  vendee  or   transferee   and  shall   thereupon  be  released
automatically  from any  liability  therefor.  Tenant  shall look  solely to the
transferee for the return of the Security Deposit.  No Mortgagee or purchaser of
any or all of the Building at any foreclosure  proceeding  shall  (regardless of
whether the Lease is at the time  subordinated  to the lien of said Mortgage) be
liable to Tenant or any other person for any of such  Security  Deposit,  or any
other payment made by Tenant hereunder,  unless Landlord has actually  delivered
said deposit or other such sum to such  Mortgagee or purchaser.  In the event of
any rightful and permitted  assignment of Tenant's  interest in this Lease,  the
Security Deposit shall be deemed to be held by Landlord as a deposit made by the
assignee,  and Landlord  shall have no liability to the assignor with respect to
the return of the Security Deposit.

36.  HAZARDOUS MATERIALS.

A. Definition:  As used in this Lease,  the term "Hazardous  Material" means any
flammable  items,   explosives,   radioactive  materials,   hazardous  or  toxic
substances,  material or waste or related  materials,  including any  substances
defined as or included in the definition of "hazardous  substances",  "hazardous
wastes", "infectious wastes", "hazardous materials" or "toxic substances" now or
subsequently  regulated under any federal,  state or local laws,  regulations or
ordinances including, without limitation, oil, petroleum-based products, paints,
solvents,  lead,  cyanide,  DDT,  printing  inks,  acids,  pesticides,   ammonia
compounds and other chemical products, asbestos, PCBs and similar compounds, and
including any different  products and materials which are subsequently  found to
have adverse effects on the environment or the health and safety of persons.

B. General Prohibition.  Tenant shall not cause or permit any Hazardous Material
to be generated,  produced,  brought upon, used,  stored,  treated,  discharged,
released,  spilled  or  disposed  of on,  in under or about  the  Premises,  the
Building,  or the Land (hereinafter  referred to collectively as the "Property")
by Tenant, its affiliates, agents, employees, contractors, subtenants, assignees
or invitees. Tenant shall indemnify,  defend and hold Landlord harmless from and
against  any  and  all  actions  (including,  without  limitation,  remedial  or
enforcement  actions of any kind,  administrative or judicial  proceedings,  and
orders or  judgments  arising out of or  resulting  therefrom),  costs,  claims,
damages (including without limitation,  attorneys',  consultants',  and experts'
fees,  court  costs and amount  paid in  settlement  of any claims or  actions),
fines,  forfeitures  or  other  civil,  administrative  or  criminal  penalties,
injunctive or other relief (whether or not based upon personal injury,  property
damage,  or contamination  of, or adverse effects upon, the  environment,  water
tables or natural  resources),  liabilities  or losses  arising from a breach of
this  prohibition by Tenant,  its affiliates,  agents,  employees,  contractors,
subtenants, assignees or invitees.

C. Notice:  In the event that Hazardous  Materials are  discovered  upon, in, or
under the Property,  and any governmental  agency or entity having  jurisdiction
over the Property requires the removal of such Hazardous Materials, Tenant shall
be responsible for removing those Hazardous  Materials arising out of or related
to the use or  occupancy of the  Property by Tenant or its  affiliates,  agents,
employees,  contractors,  subtenants, assignees or invitees but not those of its
predecessors.  Notwithstanding the foregoing, Tenant shall not take any remedial
action in or about the Property or any portion  thereof  without first notifying
Landlord of Tenant's  intention to do so and affording  Landlord the opportunity
to protect  Landlord's  interest with respect thereto.  Tenant immediately shall
notify Landlord in writing of. (i) any spill, release,  discharge or disposal of
any Hazardous Material in, on or under the Property or any portion thereof; (ii)
any enforcement,  cleanup,  removal or other  governmental or regulatory  action
instituted,  contemplated, or threatened (if Tenant has notice thereof) pursuant
to any laws respecting Hazardous  Materials;  (iii) any claim made or threatened
by any person against Tenant or the Property or any portion thereof  relating to
damage, contribution, cost recovery, compensation, loss or injury resulting from
or claimed to result from any Hazardous Materials;  and (iv) any reports made to
any  governmental  agency or entity  arising  out of or in  connection  with any
Hazardous  Materials  in, on under or about or removed  from the Property or any
portion  thereof,  including  any  complaints,  notices,  warnings,  reports  or
asserted  violations  in  connection  therewith.  Tenant  also  shall  supply to
Landlord as promptly as possible, and in any event within five (5) business days
after Tenant first  receives or sends the same,  copies of all claims,  reports,
complaints,  notices, warnings or asserted violations relating in any way to the
Premises, the Property or Tenant's use or occupancy thereof.

D. Landlord's  Obligations:  Landlord hereby advises Tenant that Landlord has no
actual knowledge of the existence of any Hazardous  Materials in the Premises or
in the structure of the  Building.  In the event that  Landlord  obtains  actual
knowledge  of the  presence of  Hazardous  Materials  in the  Building or in the
Premises in a quantity and of a nature that violates any applicable governmental
laws or regulations and that were not introduced to the Building by or on behalf
of Tenant, Landlord shall take such action, if any, as may be required to comply
with such governmental laws or regulations,  and Landlord shall notify Tenant in
advance of any such  corrective  action by  Landlord  and  advise  Tenant of the
nature of the action to be taken and Landlord's estimate of the approximate time
that such action will take to be completed.

     E. Survival:  The respective  rights and obligations of Landlord and Tenant
     under this Section 36 shall survive the  expiration or earlier  termination
     of this Lease.

37.  RELOCATION OF TENANT. [Intentionally omitted.]

38.  NO RECORDATION.

Tenant shall not record or attempt to record this Lease or any memorandum hereof
in any public records without the prior written approval of Landlord,  which may
be denied in Landlord's sole and absolute discretion. In the event that Landlord
grants its  approval to record this Lease or a memorandum  hereof,  Tenant shall
pay all recordation fees, taxes and charges in connection with such recordation.

39.  TENANT'S OPTION TO TERMINATE.

Notwithstanding anything in this Lease to the contrary,  Hagler Bailly Services,
Inc., a Delaware corporation  ("Hagler"),  shall have the right,  exercisable at
Hagler's  sole  option,  to  terminate  this  Lease,  said right of Hagler to be
exercisable  by giving  written  notice  thereof (the  "Termination  Notice") to
Landlord,  which Termination  Notice shall set forth a date of termination which
is specified to be September 30, 2002 (the "Termination Date"), and which notice
shall be given,  if at all, not later than September 30, 2001. In the event that
Hagler exercises its termination option hereunder,  this Lease shall continue in
full  force and  effect  until the  Termination  Date,  whereupon  Hagler  shall
surrender  possession of the Premises in accordance  with the provisions of this
Lease,  this  Lease  shall  terminate  with  respect to the  Premises  as if the
Termination  Date  were the Lease  Expiration  Date set  forth  herein,  and all
Additional Rent shall be prorated as of the Termination  Date, and neither party
shall  have any  obligations  hereunder  accruing  after the  Termination  Date.
Hagler's right  hereunder to terminate  this Lease shall be exercisable  only if
(1)  Hagler is not then in  default  under this  Lease,  and (2) Hagler  pays to
Landlord,  contemporaneously  with the  giving of its  Termination  Notice,  Two
Hundred  Seventeen  Thousand Two Hundred Sixty and 96/100 Dollars  ($217,260.96)
(the  "Termination  Fee").  The  Termination  Fee  payable by Hagler to Landlord
pursuant to the immediately  preceding sentence shall be in addition to the Rent
coming due between the date of the Termination Notice and the Termination Date.

IN WITNESS  WHEREOF,  Landlord and Tenant have executed this Deed of Lease under
seal as of the day and year first above written.

WITNESS:                   LANDLORD:
                           TRIZECHAHN CENTERS, INC., a California corporation
                           d/b/a TRIZECHAHN 1550 WILSON BLVD. MANAGEMENT

By:                                  Name: /s/ Holly H. Davis


ATTEST:                    TENANT:
[Corporate Seal]           HAGLER BAILLY SERVICES, INC., a Delaware corporation
By: /s/ John R. Armstrong                By: /s/ Stephen V.R. Whitman
                                        Name: Stephen V.R. Whitman
                                  Its: Senior Vice President and General Counsel
















<PAGE>



                                    EXHIBIT A

                          [Description To Be Provided]
















<PAGE>


                                    EXHIBIT A

                       [FLOOR PLAN INTENTIONALLY OMITTED]



<PAGE>


                                    EXHIBIT B

                       DECLARATION BY LANDLORD AND TENANT
                    AS TO DATE OF DELIVERY AND ACCEPTANCE OF
                    POSSESSION, LEASE COMMENCEMENT DATE, ETC.

THIS DECLARATION made this ______ day of ___________, 19 ____ is hereby attached
to and made a part of the Deed of Lease  dated  the ____ day of  ________,  1999
(the  "Lease"),  entered  into  by  and  between  TRIZECHAHN  CENTERS,  INC.,  a
California  corporation  d/b/a  TRIZECHAHN  1550  WILSON  BLVD.  MANAGEMENT,  as
Landlord and HAGLER BAILLY SERVICES, INC., a Delaware corporation, as Tenant.
All terms  used in this  Declaration  have the same  meaning as they have in the
Lease.

     (i) Landlord and Tenant do hereby  declare that  possession of the Premises
     was accepted by Tenant on the _________ day of _________, 19__;

     (ii) As of the date  hereof,  the Lease is in full  force and  effect,  and
     Landlord has fulfilled all of its  obligations  under the Lease required to
     be  fulfilled  by  Landlord  on or  prior to said  date;  (iii)  The  Lease
     Commencement Date is hereby established to be ________,  19__; and (iv) The
     Lease Expiration Date is hereby  established to be  ____________unless  the
     Lease is sooner terminated pursuant to any provision thereof.


WITNESS:                    LANDLORD:
                            TRIZECHAHN CENTERS, INC., a California corporation
                            d/b/a TRIZECHAHN 1550 WILSON BLVD. MANAGEMENT

By:                                                          By:
                                      Name:
                                      Its:

ATTEST:                       TENANT:
[Corporate Seal]            HAGLER BAILLY SERVICES, INC., a Delaware corporation

By:                                                          By:
                                      Name:
                                      Its:

            [NOTE: NOT TO BE EXECUTED AT TIME OF EXECUTION OF LEASE]





<PAGE>


                                    EXHIBIT C

                                 WORK AGREEMENT

THIS WORK  AGREEMENT  is hereby  attached  to and made part of the Deed of Lease
dated August 29, 1999 entered into by and between  TRIZECHAHN  CENTERS,  INC., a
California  corporation  d/b/a  TRIZECHAHN  1550  WILSON  BLVD.  MANAGEMENT,  as
Landlord,  and HAGLER BAILLY SERVICES,  INC., a Delaware corporation,  as Tenant
(the  "Lease).  All terms used in this Work  Agreement  have the same meaning as
they have in the Lease.

1.                      ARCHITECTURAL DESIGN SERVICES.

Tenant shall engage an architect for competitive  market fees to provide a space
plan  and   completed,   finished  and  detailed   architectural   drawings  and
specifications for all work to be provided by Landlord under Paragraph 4 hereof,
which drawings and  specifications  shall be completed at Tenant's sole cost and
expense,  which shall be payable  out of the Tenant  Allowance  (as  hereinafter
defined) to the extent that funds are available therefrom for such purpose.  The
architect who prepares such drawings and specifications is hereinafter  referred
to as the "Space Planner".  Any architectural  drawings and specifications which
are  completed  for  Additional  Tenant Work (as defined in  Paragraph 5 hereof)
shall also be prepared by the Space Planner at Tenant's expense.  All such plans
are expressly subject to Landlord's review and written approval.

2.                    ENGINEERING DESIGN SERVICES.

Tenant,  at Tenant's  sole cost and  expense,  which shall be payable out of the
Tenant Allowance (as hereinafter defined) to the extent that funds are available
therefrom  for that purpose,  shall  provide the design  services of, a licensed
professional  engineer (the  "Engineer"),  to prepare complete Building standard
mechanical and electrical  plans and  specifications,  as necessary for Tenant's
Work  to be  performed  pursuant  to  Paragraph  4  hereof.  Any  mechanical  or
electrical  plans shall be prepared  by the  Engineer at Tenant's  sole cost and
expense,  which shall be payable  out of the Tenant  Allowance  (as  hereinafter
defined) to the extent that funds are available therefrom for that purpose.  All
such plans are  expressly  subject to  Landlord's  review and written  approval,
which shall not be unreasonably withheld, conditioned or delayed.

3.  TENANT'S RESPONSE TIME.

Tenant covenants and agrees to deliver to Landlord and the Engineer on or before
the  fifth  (5th)  day  following  the date of  receipt  by  Tenant of all final
detailed  architectural  plans  and  specifications  and  engineering  plans for
Tenant's Work and Additional Tenant Work, if any,  sufficient to obtain bids for
Tenant's  Work  and  Additional  Tenant  Work,  if any  (the  "Final  Plans  and
Specifications")  Tenant written approval of such Final Plans and Specifications
and, prior thereto,  to provide Landlord and the Space Planner and Engineer with
all  information  requested  by them in order to  complete  the Final  Plans and
Specifications,  within five (5) days of each such request.  Any and all changes
made to the Final  Plans  and  Specifications  subsequent  to  Tenant's  written
approval of same shall be at the sole cost of Tenant.

4.               TENANT'S WORK.

Landlord shall make available for the  performance of Tenant's Work, and for the
other purposes hereinafter  specified,  an allowance (the "Tenant Allowance") in
an amount equal to the product of (i) Five Dollars  ($5.00)  multiplied  by (ii)
the number of rentable  square feet  comprising  the  Premises.  Landlord  shall
perform Tenant's Work and shall pay directly to its general contractor and other
service providers and vendors the cost of performing all improvements  shown and
contemplated by the Final Plans and Specifications ("Tenant's Work"), including,
but  not  limited  to,  the  cost  of  demolition,   permits  and   governmental
inspections, all architectural and engineering fees, and a fee to Landlord in an
amount  equal to five  percent  (5%) of the hard costs of Tenant's  Work and any
Additional  Tenant Work (as  hereinafter  defined),  all of which costs shall be
payable out of the Tenant  Allowance to the extent that the Tenant  Allowance is
sufficient for that purpose,  and any excess amount of which costs shall be paid
by Tenant  within  thirty  (30) days  following  Tenant's  receipt of an invoice
therefor from Landlord.

Landlord  shall  solicit  bids  for  Tenant's  Work  from  at  least  three  (3)
contractors,  one (1) of which may be designated by Tenant,  if so designated by
Tenant within two (2) business days after  Landlord's  request  therefor  (which
request may be made verbally). All general contractor bids shall be submitted to
Tenant for its review,  and Tenant shall have five (5) days following receipt of
the bids within  which to direct that  changes be made in the bid  documents  to
reduce the cost of the work on which the bids were based. The general contractor
selected  to  construct  the  Tenant's  Work  shall (i)  demonstrate  sufficient
experience, in Landlord's reasonable opinion, to complete the Tenant's Work in a
workmanlike manner,  (ii) furnish a certificate of insurance,  and (iii) satisfy
other reasonable industry requirements.

5.  ADDITIONAL TENANT WORK.

Tenant shall be responsible  for  coordinating  at its expense the placement and
installation of all telephone  equipment and outlets. If Tenant shall desire any
work to be performed by Landlord in the Premises, other than Tenant's Work, that
is,  any work the cost of which is in  excess of the  funds  available  for that
purpose from the Tenant  Allowance  ("Additional  Tenant Work"),  all Additional
Tenant Work shall be performed at Tenant's sole expense.

Tenant  shall  not have the right to order  extra  work or  change  orders  with
respect to the  construction  of Tenant's Work without the prior written consent
of Landlord,  which consent shall not be unreasonably  withheld,  conditioned or
delayed.  Tenant shall pay for any  increase in the actual cost of  constructing
Tenant's  Work  occasioned  by a change  to the Final  Plans and  Specifications
requested  by Tenant,  including,  but not  limited  to,  contractors  usual and
customary  overhead  and  profit.  Said  payment by Tenant  shall be made within
thirty  (30)  days  following  Tenant's  receipt  of an  invoice  therefor  from
Landlord,  which  invoice may be issued as early as  Landlord's  approval of the
change order.

The  failure of Tenant to pay any portion of the cost of the  Additional  Tenant
Work within thirty (30) days following  Tenant's  receipt of an invoice therefor
from Landlord shall  constitute a Default under the Lease entitling  Landlord to
exercise  all rights  and  remedies.  In the event of a Default by Tenant  which
results in a  termination  of the Lease,  Landlord  shall  also be  entitled  to
damages in respect of Tenant's Work undertaken on behalf of Tenant.

6. SUBSTANTIAL COMPLETION OF TENANT'S WORK.

Tenant's Work shall be considered  "substantially  complete" for all purposes of
this Work  Agreement  and the  Lease if  Landlord  has  performed  or  completed
substantially  all of Tenant's Work,  except (a) punch list items and details of
construction, decoration or adjustment which do not substantially interfere with
Tenant's  ability to occupy the  Premises,  or to complete  improvements  to the
Premises to be made by Tenant, and/or (b) custom or specialty items requested by
Tenant for Tenant's Work or Additional  Tenant Work and other items which cannot
be completed  until said custom or specialty  items are  delivered,  or Tenant's
Work or Additional Tenant Work requiring use of such items is completed.

7. DATE OF SUBSTANTIAL COMPLETION, NO LIABILITY, ETC.

Landlord shall use reasonable  efforts to substantially  complete  Tenant's Work
within sixty (60) calendar  days after the date set forth for Tenant's  approval
of the Final  Plans and  Specifications  set forth in  Paragraph 3 hereof or the
date on which Landlord  receives from Tenant  Tenant's  written  approval of the
Final Plans and  Specifications  set forth in  Paragraph 3 hereof,  whichever is
later. However, Landlord shall in no event be liable or subject to any claim for
failure to  substantially  complete  Tenant's  Work by such date or for delay or
inability to deliver  possession  of the  Premises to Tenant for any reason.  If
Landlord shall be delayed in substantially completing said work as a result of.

(a)           Tenant's  failure to furnish to  Landlord,  on or before the dates
              and time periods set forth in Paragraphs 3 and 5 hereof, the Final
              Plans  and   Specifications,   information,   requirements  and/or
              approvals for any work to be done hereunder;
(b)           Tenant's  request for changes in plans  subsequent to the date set
              forth for Tenant's approval of the Final Plans and  Specifications
              set forth in Paragraph 3 hereof;
(c)           Tenant's  failure to approve  the  plans,  specifications  or cost
              estimates for  Additional  Tenant Work or make any payment  within
              the time required under Paragraph 5 hereof,
(d)      Tenant's request for materials, finishes or installations; or
(e) The result of Tenant's,  its agents' or employees' acts,  failure to act, or
failure to act in a timely manner;

then,  solely for the purposes of determining the commencement  date of Tenant's
liability for rent and other  charges under the Lease,  such delay shall neither
postpone the Lease  Commencement Date nor the date of substantial  completion by
Landlord or occupancy by Tenant of the Premises.

On or before Tenant takes possession of the Premises,  Landlord and Tenant shall
walk  through  the  Premises  and shall  agree  upon a punch list of items to be
completed  by  Landlord.  Landlord  shall  attempt to complete all items on said
punch list within thirty (30) days after the punch list is completed. The taking
of possession  of the Premises by Tenant shall be  conclusive  evidence that the
Premises are in good and satisfactory condition at the time possession is taken,
that  Tenant's  Work  is  substantially  complete  and  that  Tenant's  Work  is
satisfactory,  with the  exception  of punch list items  remaining to be done or
repaired as of the date Tenant  accepts  possession  and latent  defects,  which
latent defects Landlord shall remain responsible to repair during the first five
(5) years of the initial Term of the Lease.

B.  TENANT ACCESS.

Landlord shall permit Tenant and its agents to enter the Premises  fourteen (14)
days prior to the date which Landlord  anticipates to be the Lease  Commencement
Date to enable  Tenant to perform such work and  decorations  as Landlord  shall
approve, provided that (i) Tenant and its agents and contractors shall be deemed
to be bound by all of the terms,  covenants,  provisions  and  conditions of the
Lease,   including   but  not  limited  to  Section  U.B.   regarding   Tenant's
indemnification  obligations,  Section 14.A.  regarding  Tenant's  obligation to
repair injury,  loss or damage which may occur to any of Tenant's  installations
made prior to the Lease Commencement  Date, and Section 17 regarding  insurance,
the same being  installed and maintained  solely at Tenant's risk,  (ii) neither
Tenant  nor any of its  contractors,  employees  or agents  shall in any  manner
interfere  with or delay the  performance  of Tenant's  Work, and (iii) all such
entries prior to the Lease  Commencement  Date shall be  coordinated  in advance
with Landlord's  contractors.  In the event that Landlord does not notify Tenant
of the  opportunity  to enter the  Premises  to perform  cabling and wiring work
prior to the walls of the Premises being enclosed,  Landlord shall provide "ring
and string" for data communication lines in the Premises.

IN WITNESS WHEREOF,  Landlord and Tenant have executed this Work Agreement under
seal as of the day and year first above written.

WITNESS:               LANDLORD:

                    TRIZECHAHN CENTERS, INC., a California corporation
                   d/b/a TRIZECHAHN 1550 WILSON BLVD. MANAGEMENT
By:                                             By: /s/ Holly H. Davis
                                               Name: Holly H. Davis
                                      Its:

ATTEST:                    TENANT:
[Corporate Seal]          HAGLER BAILLY SERVICES, INC., a Delaware corporation

By: /s/ John R. Armstrong                  By: /s/ Stephen V.R. Whitman
                                           Name: Stephen V.R. Whitman
                                  Its: Senior Vice President and General Counsel




<PAGE>


                                    EXHIBIT D

                              RULES AND REGULATIONS

The following  rules and  regulations  have been  formulated  for the safety and
well-being  of all the  tenants of the  Building.  Adherence  to these rules and
regulations  by each and every tenant  contributes  to safe  occupancy and quiet
enjoyment of the Building.  Any violation of these rules and  regulations by any
tenant which  continues after notice from Landlord shall be a Default under such
tenant's lease, at the option of Landlord.

Landlord may, upon request by any tenant, waive compliance by such tenant of any
of the  following  rules and  regulations,  provided that (a) no waiver shall be
effective unless signed by Landlord or Landlord's  authorized agent, (b) no such
waiver shall relieve any tenant from the  obligation to comply with such rule or
regulation in the future, unless expressly consented to by Landlord,  and (c) no
such  waiver  granted to any tenant  shall  relieve  any other  tenant  from the
obligation of complying  with said rule or  regulation  unless such other tenant
has received a similar waiver in writing from Landlord.

1.  The  sidewalks,  entrances,  passages,  courtyards,  elevators,  vestibules,
stairways,  corridors, halls and other parts of the Building not occupied by any
tenant (hereinafter "Common Areas") shall not be obstructed or encumbered by any
tenant or used for any  purposes  other than  ingress and egress to and from the
tenant's  premises.  No tenant shall permit the visit to its premises of persons
in such  numbers  or under  such  conditions  as to  interfere  with the use and
enjoyment of the Common Areas by other tenants.

2. No awnings or other projections shall be attached to the outside walls of the
Building  without the prior  written  consent of  Landlord.  No drapes,  blinds,
shades or screens shall be attached to or hung in, or used in  connection  with,
any window or door of a tenant's premises,  without the prior written consent of
Landlord.  Such  awnings,  projections,  curtains,  blinds,  screens  and  other
fixtures shall be of a quality,  type,  design and color  acceptable to Landlord
and shall be attached in a manner approved by Landlord.

3. No sign,  advertisement,  notice  or  other  lettering  shall  be  exhibited,
inscribed, painted or affixed by any tenant on any part of the outside or inside
if visible from the outside of the tenant's premises of the tenant's premises or
in the Building  without the prior written consent of Landlord.  In the event of
any  violation  of the  foregoing  by any tenant,  Landlord  may remove the same
without any liability and may charge the expense incurred by such removal to the
tenant or tenants responsible for violating this rule. All interior signs on the
doors and  directory  tablet of the  Building  shall be  inscribed,  painted  or
affixed by Landlord at the expense of each tenant, and shall be of a size, color
and style acceptable to Landlord,  except that Landlord shall initially provide,
at  Landlord's  expense,  a  listing  for  Tenant on the  Building's  directory,
replacements for which shall be at Tenant's expense.

4. No show  cases or other  articles  shall be put in front of or affixed to any
part of the exterior of the Building, nor placed in the Common Areas without the
prior  written  consent of  Landlord.  5. The water and wash  closets  and other
plumbing  fixtures shall not be used for any purposes other than those for which
they were constructed, and no sweepings, rubbish, rags or other substances shall
be thrown therein. No tenant shall throw anything out of the doors or windows or
down any corridors of stairs.

6. There shall be no marking, painting,  drilling into or other form of defacing
of or damage to any part of a  tenant's  premises  or the  Building.  No boring,
cuffing or stringing of wires shall be permitted except for affixing  decorative
items such as pictures.  No tenant  shall  construct,  maintain,  use or operate
within its premises or elsewhere  within or on the outside of the Building,  any
electrical device,  wiring or apparatus in connection with a loud speaker system
or other sound  system.  Upon prior written  approval by Landlord,  a tenant may
install Muzak or other internal music system within the tenant's premises if the
music system cannot be heard outside of the premises.

7. No tenant shall make or permit to be made any disturbing noises or disturb or
interfere  with the  occupants  of the  Building  or  neighboring  buildings  or
premises or those having  business with them,  whether by the use of any musical
instrument, radio, tape recorder, whistling, singing or any other way.

8. No bicycles,  vehicles,  animals,  birds or pets of any kind shall be brought
into or kept in or about a tenant's premises or in the Building.

9. No cooking shall be done or permitted by any tenant on its  premises,  except
that, with Landlord's  prior written approval  (including  approval of plans and
specifications  therefor)  (which approval shall not be  unreasonably  withheld,
conditioned or delayed), a tenant may install and operate for convenience of its
employees  a lounge  or  coffee  room  with a stove,  microwave  oven,  sink and
refrigerator;  provided  that in so  doing  the  tenant  shall  comply  with all
applicable  building code  requirements and any insurance or other  requirements
specified  by  Landlord.  No  tenant  shall  cause  or  permit  any  unusual  or
objectionable odors to originate from its premises.

10.  No space  in or  about  the  Building  shall  be used for the  manufacture,
storage, sale or auction of merchandise goods or property of any kind.

11. No tenant shall buy or keep in the Building or its premises any inflammable,
combustible or explosive fluid, chemical or substance.

12. No  additional  locks or bolts of any kind  shall be placed  upon any of the
doors or windows by any tenant,  nor shall any changes be made in existing locks
or the  mechanisms  thereof.  The doors  leading to the  corridors or main halls
shall  be kept  closed  during  business  hours  except  as they may be used for
ingress and egress.  Each tenant  shall,  upon the  termination  of its tenancy,
return to Landlord all keys used in connection with its premises,  including any
keys to the premises, to rooms and offices within the premises, to storage rooms
and closets,  to cabinets and other  built-in  furniture,  and to toilet  rooms,
whether or not such keys were  furnished  by Landlord or procured by the tenant,
and in the event of the loss of such keys, such tenant shall pay to Landlord the
cost of replacing the locks.  On  termination  of a tenant's  lease,  the tenant
shall disclose to Landlord the combination of all locks for safes, safe cabinets
and vault doors, if any, remaining in the premises.

13. All removals, or the carrying in or out of any safes, freight,  furniture or
bulky matter of any description,  must take place in such manner and during such
hours as Landlord may require.  Landlord  reserves the right (but shall not have
the  obligation) to inspect all freight brought into the Building and to exclude
from the Building all freight which violates any of these rules and  regulations
or any provision of any tenant's lease.

14. Any person  employed by any tenant to do janitorial work within the tenant's
premises  must  obtain   Landlord's   approval  (which  approval  shall  not  be
unreasonably  withheld,  conditioned or delayed) prior to commencing  such work,
and such person shall comply with all instructions  issued by the superintendent
of the  Building  while in the  Building.  No  tenant  shall  engage  or pay any
employees on the tenant's  premises or in the  Building,  except those  actually
working for such tenant on said premises.

15. No tenant shall purchase spring water, ice, coffee,  soft drinks,  towels or
other like  merchandise  or  service  from any  company  or person  who has,  in
Landlord's  reasonable opinion committed  violations of Building  regulations or
caused a hazard or nuisance to the Building and/or its occupants.

16.  Landlord  shall have the right to prohibit  any  advertising  by any tenant
which,  in  Landlord's  reasonable  opinion,  tends to impair the  reputation or
desirability  of the Building as a building for offices and, upon written notice
from Landlord, such tenant shall refrain from and discontinue such advertising.

17.  Landlord  reserves  the right to exclude from the Building at all times any
person who is not known or does not properly  identify himself to the Building's
management  or its  agents.  Landlord  may at its  option  require  all  persons
admitted to or leaving the Building to register  between the hours of 6 p.m. and
8 a.m., Monday through Friday, and all times on Saturdays, Sundays and holidays.
Each tenant shall be  responsible  for all persons for whom it authorized  entry
into the Building, and shall be liable to Landlord for all acts of such persons.

18.  Each  tenant  shall see that all lights are turned off before  closing  and
leaving its premises at any time.

19. The requirements of tenants will be attended to only upon application at the
office of the Building.  Building  employees have been instructed not to perform
any work or do anything  outside of their  regular  duties,  except with special
instructions from the management of the Building.

20. Canvassing,  soliciting and peddling in the Building is prohibited, and each
tenant shall cooperate to prevent the same.

21. No water cooler, plumbing or electrical fixture shall be installed by tenant
without Landlord's prior written consent.

22. No hand  trucks,  except those  equipped  with rubber tires and side guards,
shall be used to  deliver  or  receive  any  merchandise  in any space or in the
Common Areas of the Building, either by tenant or its agents or contractors.

23. Access plates to under floor conduits shall be left exposed. Where carpet is
installed, carpet shall be cut around the access plates.

24. Mats, trash and other objects shall not be placed in the public corridors.

25.  [Intentionally omitted.]

26.  Landlord shall not maintain suite finishes which are  non-standard  such as
kitchens,  bathrooms,  wallpaper,  special lights, etc. However, should the need
for repairs  arise,  Landlord  shall arrange for the work to be done at tenant's
expense.

27. Landlord's employees are prohibited from receiving articles delivered to the
Building  and, if any such  employee  receives any article for any tenant,  such
employee shall be acting as the agent of such tenant for such purposes.

28. No smoking  shall be permitted in any of the Common Areas of the Building or
in the tenant's premises.  All cigarettes and related trash shall be disposed of
in trash receptacles and not on the sidewalk, parking lot or grass.





<PAGE>


                                    EXHIBIT E

                                     PARKING


1.  AVAILABILITY; RENT.

Landlord  agrees  that  it will  provide  to  Tenant  sufficient  space  to park
twenty-six  (26)  automobiles,  either  in  the  garage  of the  Building  or as
otherwise  provided.  For each month during the Term, Tenant shall pay, directly
to the garage  operator for the use of such parking  spaces,  an amount equal to
the product  obtained by  multiplying:  (i) the number of parking  spaces herein
designated, by (ii) the market rent for each such space, as determined from time
to time by Landlord or the garage  operator.  No specific parking spaces will be
allocated for use by Tenant.  Landlord  reserves the right to institute either a
valet or self parking system; provided,  however, that if at any time during the
Term of the Lease Landlord  provides to Tenant any additional  spaces,  Landlord
shall at all times have the right to reclaim  such  spaces upon thirty (30) days
notice to Tenant.  Tenant shall have the right to terminate its lease of parking
spaces from time to time  throughout the Term of the Lease upon thirty (30) days
written notice to Landlord or the garage operator, as the case may be, and shall
have the  right to again  lease  such  space(s)  upon at least  sixty  (60) days
written notice to Landlord or the garage  operator,  as the case may be, if such
spaces are then available.

2. REGULATIONS; LIABILITY.

Tenant and its employees,  agents and invitees shall observe  reasonable  safety
precautions  in the use of the garage and shall at all times  abide by all rules
and regulations promulgated by Landlord and/or the garage operator governing use
of the garage. Landlord does not assume any responsibility for, and shall not be
held liable for, any damage or loss to any  automobiles  parked in the garage or
to any personal  property  located  therein,  or for any injury sustained by any
person in or about the garage.



<PAGE>


                                    EXHIBIT F

                           FORM OF OPERATING EXPENSES
                               AND REAL ESTATE TAX
                               EXPENSES STATEMENT

                             [INTENTIONALLY OMITTED]




<PAGE>


                                    EXHIBIT G
                             CLEANING SPECIFICATIONS



CLEANING SPECIFICATIONS

LAVATORIES:

Lavatories - Daily:

Wash:

a. Shelves
b. Brightwork (Handles, Piping, Hinges)
c. Sinks
d. Urinals
e. Toilets
f. Floors
g. Tile Walls - Spot Clean
h. Partitions and Legs
i. Vents
j. Receptacles
k. Mirrors

Stock with supplies furnished by contractor:

a. Handsoap
b. Towels
c. Tissue
d. Sanitary Napkins
e. Seat Covers

Polish to remove water spots:

a. Brightwork
b. Mirrors
c. Shelves
d. Partitions

LAVATORIES - SPECIAL INSTRUCTIONS:

Tile Floors

Tile floors will be mopped daily using a germicidal detergent. Any stained areas
will be machine  scrubbed  daily as required  to maintain a uniform  appearance.
Floors will be stripped and waxed as needed.

Tile Walls

Tile walls will be spot  cleaned  with  disinfectant.  Walls will be  completely
cleaned monthly or as needed.

Partitions

Partitions  will be entirely wiped clean daily.  Supporting legs will be cleaned
and polished as necessary.

Trash Rece2tacles

Trash will be removed  daily.  Plastic liners will be provided and changed daily
in all types of receptacles.

LAVATORIES - SPECIAL INSTRUCTIONS:

Hand Soap Dispensers

Hand soap  dispensers  will be checked daily for adequate supply levels and will
be filled as necessary.

Paper Supplies

All paper dispensers will be filled completely each night. In some areas, it may
be necessary to place extra rolls of wrapped paper so that no shortages occur.

High Dusting

All high fixtures and lights will be dusted as needed.

Carpeted Floors

All carpeted bathroom areas will be vacuumed daily and shampooed as needed.

OFFICES, HALLWAYS, AND PUBLIC AREAS:

Waste Baskets-- Daily

Waste baskets to be emptied daily. Plastic liners to be provided to tenant waste
baskets and changed as needed.  Only remove trash in waste can or clearly marked
"trash".

Ashtrays - Daily

Ashtrays to be emptied and wiped clean daily.  Sand levels will be maintained in
cigarette urns.

Dusting - Daily

All furniture and flat surfaces will be dusted daily with a treated cloth. Desks
and tables not  cleared of paper and work  materials  will only be dusted  where
desk is  exposed.  Papers are not to be moved.  Telephones,  glass desk tops and
tables will be damp wiped.'

Spot Cleaning - Daily

All handprints and spots will be removed from doors and light switches. Woodwork
and interior glass will be spot cleaned as needed.

Vacuuming - Daily/Weekly

All rugs and carpets will be vacuumed daily in all traffic areas.  Hard-to-reach
spots, such as corners,  under desks and chairs,  behind plants,  etc., shall be
vacuumed weekly with accessory  tools,  with light furniture moved to accomplish
cleaning.

Carpet S2ot Cleaning - Daily

An effort will be made to remove carpet spots and stains.

Tile Floors - Daily

All tile floors will be dusted daily and mopped as needed. Extreme care shall be
exercised in all mopping so as to avoid splashing walls,  furniture,  or carpet.
All tile floors will be buffed as required to maintain a finish.

Water Coolers - Daily

Water Coolers shall be cleaned and polished.
Main Lobby and Corridor Floors

Mop floors daily and buff as required to maintain a lustrous finish.

Elevators - Daily

Interior surfaces and all doors to be spot cleaned for fingerprints.

Entrance Door Glass - Daily

All entrance door glass shall be spot cleaned.

Stairways and Landings - Weekly

Spot cleaning of walls and doors will be done weekly.  Handrails,  ledges,  fire
points,  and miscellaneous  hardware will be cleaned weekly.  Day porter will be
responsible for sweeping and mopping stairwells and landings weekly.

Elevators - Monthly

Carpets will be shampooed as needed.

Glass Partitions and Doors - Monthly

All glass  partitions  and doors will be cleaned with ammonia  using a squeegee,
clean rag, or paper towels.

Air Conditioning Grills - Monthly

All areas  around air  conditioning  and return air grills will be cleaned  once
each month or more often, if necessary. Care will be taken so as to prevent dirt
from falling on floor or other surfaces.

Tile Floors - Monthly

Machine  stripping  and/or  scrubbing  shall be accomplished as needed to remove
dirt-embedded finishes, stains, spillage and wax buildup. New wax and sealer, if
required, will then be applied.

Venetian Blinds - Monthly

All venetian blinds will be dusted and/or damp wiped as needed.

Entrance Mats - Monthly

Entrance mats will be shampooed as needed.

High Dusting - Quarterly

Pipes, ledges,  ceilings,  sprinklers,  moldings,  picture frames, etc., will be
dusted every three months or more frequently if necessary.

Lavatories'- Quarterly

Strip and wax tile floors completely.

Carpet "Shampooing" - Annually

All carpeted public areas to be "shampooed".

Special Floor Coverings - As Necessary

     Parquet,  quarry,  ceramic, raised computer floors, and other special floor
     coverings will be treated with  appropriate  methods and materials.  Walls,
     Woodwork and Partitions - As Necessary

All walls and  ceilings  will be brushed down as necessary  with  approved  wall
duster or a vacuum cleaner.