<PAGE>




                                  DEED OF LEASE



                                 BY AND BETWEEN



                             HERNDON LINCOLN I LLC,
                                  ("LANDLORD")



                                       AND



                             UNIVERSAL ACCESS, INC.,
                                   ("TENANT")





                                  * * * * * *


                            13900 LINCOLN PARK DRIVE
                                HERNDON, VIRGINIA










                                                  HOLLAND & KNIGHT LLP
                                                  2100 Pennsylvania Avenue, N.W.
                                                  Suite 400
                                                  Washington, D.C. 20037
                                                  (202) 955-3000
                                                  (202) 955-5564 (Fax)


<PAGE>



                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                               Page
<S>                                                                                                            <C>
1.     BASIC LEASE TERMS..........................................................................................1

2.     PREMISES...................................................................................................1

3.     TERM AND COMMENCEMENT OF TERM..............................................................................2

4.     RENT.......................................................................................................3

5.     SECURITY DEPOSIT...........................................................................................7

6.     USE........................................................................................................9

7.     ASSIGNMENT AND SUBLETTING.................................................................................10

8.     IMPROVEMENTS AND FIXTURES.................................................................................12

9.     UTILITIES AND SERVICES....................................................................................13

10.    RIGHTS OF LANDLORD........................................................................................14

11.    LIABILITY.................................................................................................15

12.    INSURANCE.................................................................................................16

13.    FIRE OR CASUALTY..........................................................................................17

14.    EMINENT DOMAIN............................................................................................17

15.    SUBORDINATION AND ESTOPPEL CERTIFICATES...................................................................17

16.    DEFAULT AND REMEDIES......................................................................................18

17.    BANKRUPTCY................................................................................................20

18.    PAYMENT OF TENANT'S OBLIGATIONS BY LANDLORD AND UNPAID RENT...............................................21

19.    VOLUNTARY SURRENDER.......................................................................................21

20.    ABANDONMENT OF PERSONAL PROPERTY..........................................................................21

21.    HOLD-OVER.................................................................................................21

22.    OPTION TO EXTEND TERM.....................................................................................22

23.    PARKING...................................................................................................22

24.    NOTICES...................................................................................................23

25.    BROKERS...................................................................................................23

26.    ENVIRONMENTAL CONCERNS....................................................................................23

27.    LANDLORD'S LIEN...........................................................................................24

28.    ROOFTOP COMMUNICATIONS EQUIPMENT..........................................................................24

29.    EXTERIOR SIGNAGE..........................................................................................25

30.    RULES AND REGULATIONS.....................................................................................25

31.    QUIET ENJOYMENT...........................................................................................26

32.    MISCELLANEOUS PROVISIONS..................................................................................26
</TABLE>


                                       i
<PAGE>

                                LIST OF EXHIBITS

                            EXHIBIT A:       Floor Plan of Premises

                            EXHIBIT B:       Work Agreement

                            EXHIBIT C:       Declaration of Commencement Date

                            EXHIBIT D:       Location of Reserved Parking Spaces

                            EXHIBIT E:       Location of Exterior Sign

                            EXHIBIT E-1:     Dimensions of Exterior Sign

                            EXHIBIT F:       Rules and Regulations


                                      ii
<PAGE>

                                  DEED OF LEASE

         THIS DEED OF LEASE (this "Lease") is made as of the _____ day of April,
2000 (the "Effective Date"), by and between HERNDON LINCOLN I LLC ("Landlord")
and UNIVERSAL ACCESS, INC., a Delaware corporation ("Tenant"), who agree as
follows:

1.   BASIC LEASE TERMS. The following terms shall have the following meanings in
     this Lease:

<TABLE>
<S><C>
          a.       PREMISES:                                    Approximately 41,957 rentable
                                                                square feet of space comprising
                                                                the entire fourth (4th)
                                                                floor of the Building
                                                                (described in Section 1b,
                                                                below), all as outlined on the
                                                                floor plan attached hereto
                                                                as EXHIBIT A.

         b.       BUILDING:                                     13900 Lincoln Park Drive, Herndon, Virginia
                                                                (the "Building"), containing approximately
                                                                201,376 rentable square feet of space.

         c.       COMMENCEMENT DATE:                            June 1, 2000*

                          [*subject to adjustment as provided for in this Lease]

                  TERM:                                         Ten (10) years

         d.       INITIAL ANNUAL BASE RENT*:                    $26.00 per rentable square foot
                                                                $1,090,881.96 per annum
                                                                $90,906.83 per month

                          [*subject to escalation as provided for in this Lease]

         e.       BASE YEAR:                                    2000

         f.       TENANT'S PRO RATA SHARE OF OPERATING
                  EXPENSES:                                     20.84%*

                  TENANT'S PRO RATA SHARE OF REAL ESTATE
                  TAXES:                                        20.84%*

                          [*subject to adjustments provided for in this Lease]

         g.       ADDRESS FOR NOTICES:

                  TO LANDLORD:                                  Herndon Lincoln I LLC
                                                                c/o Lincoln Property Company
                                                                1530 Wilson Boulevard, Suite 200
                                                                Arlington, Virginia  22209
                                                                Attention:  Ms. Bari Nichols

                  WITH A COPY TO:                               Holland & Knight LLP
                                                                2100 Pennsylvania Avenue, N.W., Suite 400
                                                                Washington, D.C. 20037
                                                                Attention:  David S. Kahn, Esquire

                  TO TENANT (BEFORE OCCUPANCY):                 Universal Access, Inc.
                                                                100 North Riverside Plaza
                                                                Suite 2200
                                                                Chicago, Illinois  60606
                                                                Attention:  Mr. Robert Pommer

                  TO TENANT (AFTER OCCUPANCY):                  At the Premises

         h.       SECURITY DEPOSIT:                             $1,800,000.00
</TABLE>

2.   PREMISES.

         a. PREMISES. In consideration of Tenant's agreement to pay Annual
Base Rent (hereinafter defined) and Additional Rent (hereinafter defined) and
subject to the covenants and conditions hereinafter set forth, Landlord hereby
leases to Tenant and Tenant hereby hires and leases from Landlord, upon the
terms and conditions set forth herein, those certain premises described in
Section 1a hereof and located in the Building (the "Premises"). The rentable
square footage of the Premises has been determined in accordance with the BOMA
Standard Method of Measurement (rev. June 1996). The lease of the Premises to
Tenant includes the right, together with other tenants of the Building and
members of the

<PAGE>

public, to use the common public areas of the Land (hereinafter
defined) and the Building, but includes no other rights not specifically set
forth herein.

         b.       IMPROVEMENTS.

                  (i) Landlord shall deliver the Premises to Tenant in their
"as-is" condition; provided, however, that Landlord shall construct in the
Premises: (A) at Landlord's sole cost and expense, the Landlord Improvements
(hereinafter defined); and (B) at Tenant's sole cost and expense, subject,
however, to application of the Improvement Allowance (hereinafter defined), the
Tenant Improvements (hereinafter defined), all in accordance with the terms of
the Work Agreement attached hereto as EXHIBIT B (the "Work Agreement"). In the
event that Landlord and Tenant have not finally agreed upon the scope and
details of the Tenant Improvements as of the Effective Date, Tenant's submission
to Landlord of plans and specifications detailing such work shall be subject to
Landlord's written approval. The Tenant Improvements shall be subject to
Landlord's prior written approval, which approval shall not be unreasonably
withheld, conditioned or delayed, except to the extent that any Tenant
Improvement proposed by Tenant involves changes to, or modifications of, the
base Building or any of the systems therein, in which event Landlord may approve
or reject such Tenant Improvement in its sole discretion. Tenant shall insure
that the Tenant Improvements, as designed by the Space Planner (hereinafter
defined), comply with all applicable building codes, laws and regulations
(including without limitation the Americans With Disabilities Act) and do not
include or require any changes to or modifications of any of the mechanical,
electrical, plumbing or other systems of the Building.

                  (ii) The cost of all design, architectural and engineering
work, demolition costs, construction costs, construction supervision (as set
forth in the Work Agreement), contractors' overhead and profit, licenses and
permits, and all other costs and expenses incurred in connection with the Tenant
Improvements shall be at Tenant's sole cost and expense, subject to the
application of the Improvement Allowance. Landlord shall pay the Improvement
Allowance as provided in the Work Agreement. All costs incurred in respect of
the Tenant Improvements in excess of the Improvement Allowance shall be paid by
Tenant.

         c.       ACCESS TO PREMISES PRIOR TO COMMENCEMENT DATE. Subject to the
terms and conditions set forth below, Tenant and its contractors shall be
permitted to enter the Building and the Premises during the thirty (30) day
period preceding the anticipated Commencement Date (hereinafter defined) of the
Lease (the "Pre-Occupancy Period") for the purpose of installing Tenant's
computer system, cabling, fixtures, furniture and telecommunications equipment
in the Premises, provided that such access does not interfere with, or delay the
completion of, the Landlord Improvements or the Tenant Improvements. Tenant
shall not be required to pay any Rent (hereinafter defined) during the
Pre-Occupancy Period. Tenant's contractors shall comply with the Construction
Rules and Regulations attached hereto as SCHEDULE B-6. Landlord shall determine
the days and hours of the day during which Tenant's contractors may undertake
work in the Premises during the Pre-Occupancy Period in order to coordinate such
schedules with those of the Contractor (hereinafter defined) and all
subcontractors performing portions of the Landlord Improvements and/or the
Tenant Improvements. Any delay in completing the Landlord Improvements or Tenant
Improvements resulting from Tenant's contractors' early access to the Building
or the Premises shall constitute Tenant Delay (hereinafter defined). In
addition, Tenant shall indemnify and hold harmless Landlord from any injury to
the Building or loss of life or injury to persons or property in or around the
Building resulting from such early occupancy by Tenant and its contractors.

         d. ACCEPTANCE. The taking of possession of the Premises by Tenant shall
constitute an acknowledgment by Tenant that the Premises are in good condition,
that Landlord has provided or constructed all improvements to be provided or
constructed by Landlord in accordance with the Work Agreement and that all
materials and labor provided by Landlord are satisfactory except as to (i) any
defects or incomplete work that are specified on the Punch List (as defined in
the Work Agreement), which Punch List shall be delivered to Landlord by Tenant
in accordance with the Work Agreement; and (ii) Latent Defects (hereinafter
defined). As used herein, the term "Latent Defects" means any defects in the
initial construction of the Landlord Improvements or the Tenant Improvements
which affect Tenant's use or occupancy of the Premises and which would not be
reasonably discoverable by a competent architect or engineer who undertakes an
inspection of the Premises on the Commencement Date. Landlord agrees to complete
promptly all (A) Punch List items which the Construction Supervisor (hereinafter
defined) confirms are defects or incomplete items; and (B) Latent Defects about
which Landlord is notified in writing by Tenant within six (6) months after the
Commencement Date.


3.   TERM AND COMMENCEMENT OF TERM.

         a.       TERM. This Lease shall be in full force and effect from the
Effective Date. The term of this Lease (the "Term") shall commence on the
Commencement Date (hereinafter defined) and shall expire on the last day of the
tenth (10th) Lease Year (hereinafter defined) (the "Lease Expiration Date"),
unless such Term is otherwise extended or terminated in accordance with the
terms hereof. As used herein, the "Commencement Date" shall be the earlier of:
(i) the date shown in Section 1c hereof, as such date may be extended pursuant
to Section 3b below, or (ii) the date on which Tenant, or anyone claiming
through or under Tenant, first commences use or occupancy of the Premises for
the conduct of Tenant's business. As used herein, the term "Lease Year" means
(a) each twelve (12)-month period commencing on the Commencement Date, except
that if the Commencement Date does not occur on the first day of a calendar
month, the first Lease Year shall commence on the Commencement Date and
terminate on the last day of the twelfth (12th) full calendar month after the
Commencement Date, and


                                       2
<PAGE>

(b) each successive period of twelve (12) calendar months thereafter during the
Term. Reference is made to the form of Declaration of Commencement Date (the
"Declaration") attached hereto as EXHIBIT C. After the Commencement Date
Landlord shall complete the Declaration and deliver the completed Declaration to
Tenant. Within five (5) business days after Tenant receives the completed
Declaration from Landlord, Tenant shall execute and return the Declaration to
Landlord (to the extent the Declaration is accurate) to confirm the Commencement
Date, the Term and the actual number of rentable square feet in the Premises.
Failure to execute the Declaration shall not affect the commencement or
expiration of the Term.

         b.       DELAYS. In the event that substantial completion (hereinafter
defined) of the Landlord Improvements or the Tenant Improvements is delayed for
any reason, this Lease shall remain in full force and effect and Tenant shall
have no claim against Landlord by reason of any such delay. If such delay in
substantial completion of the Landlord Improvements or the Tenant Improvements
results from a cause other than Tenant Delay (defined in the Work Agreement),
the date set forth in Section 1c, above, shall be extended to the date on which
Landlord substantially completes the Landlord Improvements and the Tenant
Improvements, provided, however that if such delay in substantial completion
results in whole or in part because of a Tenant Delay, the Commencement Date
shall be the date on which Landlord would have substantially completed the
Premises but for any such Tenant Delay. The terms "substantially complete" and
"substantial completion" shall mean the time when the construction of the
Landlord Improvements and the Tenant Improvements shall have progressed to the
point that all areas of the Premises have been materially completed (except for
Punch List items which do not interfere with the use of the Premises for its
intended purposes or have any material adverse affect on the appearance of the
Premises) substantially in accordance with the requirements of the final
Contract Documents (defined in the Work Agreement) and any Tenant-requested and
Landlord-approved change orders, such that Tenant can use and occupy the
Premises for the purposes and uses for which the Premises are intended
hereunder. Tenant's failure to meet its obligations with respect to the Tenant
Improvements (including all obligations of Tenant under the terms of the Work
Agreement) shall constitute a default under this Lease, entitling Landlord to
pursue all of its remedies as provided under Section 16 hereof. Notwithstanding
the foregoing, in the event that the Landlord Improvements and/or the Tenant
Improvements have not been substantially completed by November 30, 2000, as such
date is extended day-for-day by Tenant Delay and Force Majeure (hereinafter
defined), Tenant shall have the right to terminate this Lease upon thirty (30)
days' written notice to Landlord; provided, however, if Landlord effects
substantial completion of the Landlord Improvements and the Tenant Improvements
within thirty (30) days after Landlord's receipt of Tenant's termination notice,
the Lease shall not terminate and shall continue in full force and effect for
the entire Term. Should Landlord fail to effect substantial completion of the
Landlord Improvements and the Tenant Improvements within the foregoing thirty
(30) day period, the Lease shall terminate, whereupon neither party shall have
any further rights or obligations under the Lease.


4.  RENT. Beginning on the Commencement Date, Tenant covenants and agrees to pay
as Rent (hereinafter defined) for the Premises the following amounts set forth
in this Section 4 and as otherwise provided in this Lease. "Additional Rent"
shall mean such costs, expenses, charges and other payments to be made by (or on
behalf of) Tenant to Landlord (or to a third party if required under this
Lease), whether or not the same be designated as such. "Rent" or "rent" shall
mean all Annual Base Rent (hereinafter defined) and Additional Rent due
hereunder.

         a.       ANNUAL BASE RENT.

                  (i) During each Lease Year, Tenant shall pay the annual base
rent in the amounts set forth immediately below ("Annual Base Rent") which
Annual Base Rent shall be payable in equal monthly installments (the "Monthly
Base Rent"), in the amounts set forth immediately below:

<TABLE>
<CAPTION>

               --------------------- ------------------------- ------------------- -----------------------
                                          RENTAL RATE
                                         (PER RENTABLE             MONTHLY                ANNUAL
                   LEASE YEAR             SQUARE FOOT)            BASE RENT             BASE RENT
               --------------------- ------------------------- ------------------- -----------------------
               <S>                   <C>                       <C>                 <C>
                        1                    $ 26.00              $ 90,906.83          $ 1,090,882.00
               --------------------- ------------------------- ------------------- -----------------------
                        2                    $ 26.78              $ 93,634.04          $ 1,123,608.46
               --------------------- ------------------------- ------------------- -----------------------
                        3                    $ 27.58              $ 96,443.06          $ 1,157,316.71
               --------------------- ------------------------- ------------------- -----------------------
                        4                    $ 28.41              $ 99,336.35          $ 1,192,036.22
               --------------------- ------------------------- ------------------- -----------------------
                        5                    $ 29.26              $102,316.44          $ 1,227,797.30
               --------------------- ------------------------- ------------------- -----------------------
                        6                    $ 30.14              $105,385.94          $ 1,264,631.22
               --------------------- ------------------------- ------------------- -----------------------
                        7                    $ 31.05              $108,547.51          $ 1,302,570.16
               --------------------- ------------------------- ------------------- -----------------------
                        8                    $ 31.98              $111,803.94          $ 1,341,647.26
               --------------------- ------------------------- ------------------- -----------------------
                        9                    $ 32.94              $115,158.06          $ 1,381,896.68
               --------------------- ------------------------- ------------------- -----------------------
                        10                   $ 33.92              $118,612.80          $ 1,423,353.58
               --------------------- ------------------------- ------------------- -----------------------
</TABLE>

                  (ii) In addition to the payment of Annual Base Rent, Tenant
shall be responsible for the payment of Tenant's Pass-Through Costs (hereinafter
defined) pursuant to Section 4b hereof.

                  (iii) All installments of Monthly Base Rent shall be payable
in advance, with the first monthly installment due and payable upon execution of
this Lease. If the Commencement Date shall be a day other than the first day of
a calendar month, (1) the Annual Base Rent for the first Lease Year shall be an
amount equal to the sum of (x) the amount of Monthly Base Rent for the partial
month in which the Commencement Date occurs, plus (y) the amount of the Annual
Base Rent set forth in Section 1d, above, and (2) Monthly Base Rent for such
partial month shall be the prorated amount of the Monthly Base Rent


                                       3
<PAGE>

payable hereunder during the first Lease Year, which proration shall be based
upon the actual number of days of such partial month. The prorated Monthly Base
Rent for such partial month shall be payable on the first day of the calendar
month after the month in which the Commencement Date occurs.

         b.       TENANT'S PASS-THROUGH COSTS.

                  (i)      As used in this Lease:

                           (1) "OPERATING EXPENSES" shall mean any and all
expenses, costs and disbursements (but not specific costs billed to and paid by
specific tenants) of every kind and nature actually incurred by Landlord in
connection with the management, operation, maintenance, servicing and repair of
the Building and appurtenances thereto, including without limitation the common
areas thereof, and the land underlying the Building (the "Land"), including but
not limited to employees' wages, salaries, welfare and pension benefits and
other fringe benefits; payroll taxes; telephone service; painting of common
areas of the Building; exterminating service; detection and security services;
concierge services; sewer rents and charges; premiums for fire and casualty,
liability, rent, workmen's compensation, sprinkler, water damage and other
insurance; repairs and maintenance; building supplies; uniforms and dry
cleaning; snow removal; the cost of obtaining and providing electricity, water
and other public utilities to all areas of the Building; trash removal;
janitorial and cleaning supplies; and janitorial and cleaning services; window
cleaning; service contracts for the maintenance of elevators, boilers, HVAC and
other mechanical, plumbing and electrical equipment; fees for all licenses and
permits required for the ownership and operation of the Land and the Building;
business license fees and taxes, including those based on Landlord's rental
income from the Building; the rental value of the management office maintained
in the Building; all costs of operating, maintaining and replacing equipment in
the health and fitness facility located in the Building; sales, use and personal
property taxes payable in connection with tangible personal property and
services purchased for the management, operation, maintenance, repair, cleaning,
safety and administration of the Land and the Building; legal fees; accounting
fees relating to the determination of Operating Expenses and the tenants' share
thereof and the preparation of statements required by tenant's leases;
management fees, whether or not paid to any person having an interest in or
under common ownership with Landlord; purchase and installation of indoor plants
in the common areas of the Building; and landscaping maintenance and the
purchase and replacement of landscaping services, plants and shrubbery. If
Landlord makes a Permitted Capital Expenditure (hereinafter defined), and if,
under generally accepted accounting principles, such expenditure is not a
current expense, then the cost thereof shall be amortized over a period equal to
the useful life of such improvement, determined in accordance with generally
accepted accounting principles, and the amortized costs allocated to each
calendar year during the Term, together with an imputed interest amount
calculated on the unamortized portion thereof using an interest rate of ten
percent (10%) per annum, shall be treated as an Operating Expense. As used
herein, the term "Permitted Capital Expenditure" shall mean an expenditure for a
capital improvement to the Land and/or the Building by installing energy
conservation or labor-saving devices to reduce Operating Expenses, or to comply
with any law, ordinance or regulation pertaining to the Land and/or the
Building. The following costs shall specifically be excluded from the definition
of "Operating Expenses" under this Lease: (a) Real Estate Taxes (hereinafter
defined); (b) costs of initial improvements to any tenant's premises, or any
architectural, engineering or legal fees, relocation expense or any permit or
similar fees or charges associated with such improvements; (c) principal or
interest payments on loans, including loans secured by mortgages or trust deeds
on the Building and/or the Land and ground lease payments, if any; (d)
depreciation or amortization of any capital improvements (expressly excluding
Permitted Capital Expenditures, the cost of which shall be amortized and
included in Operating Expenses as set forth above); (e) costs of repairs,
alterations or replacements resulting from a casualty to the extent that
Landlord is reimbursed or compensated therefor through proceeds of insurance (or
with respect to which Landlord would have been compensated or reimbursed had
Landlord maintained the insurance required by this Lease); (f) costs of repairs,
alterations or replacements caused by the exercise of the power of eminent
domain; (g) costs and expenses incurred in connection with leasing space in the
Building, such as legal fees for the preparation of leases, tenant allowances,
space planner fees, real estate brokers' leasing commissions and advertising and
promotional expenses, expenses of any leasing office incurred with regard to
leasing the Building or portions thereof; (h) leasing commissions, attorneys'
fees, costs and disbursements and other expenses incurred in connection with
negotiations with tenants, occupants or prospective tenants or occupants of the
Building relating to the leasing of space in the Building; (i) costs incurred
due to the violation by Landlord of the terms of any lease for space in the
Building or any indemnity payments made by Landlord pursuant to any such lease
because of a violation by Landlord under such lease, but only to the extent that
any such cost would not have been incurred by Landlord absent the violation of
such lease by Landlord; (j) the portion, if any, of any payments made to
subsidiaries of Landlord or entities under common control with Landlord for
goods or services provided to, or in connection with the operation of, the
Building, to the extent that the cost of similar goods or services are
materially greater than the cost of such goods and services being provided by
unrelated third parties to landlords in the Herndon, Virginia area from time to
time; (k) any expense for goods or services for which any tenant of the Building
(including Tenant) directly reimburses Landlord (other than as a component of
Operating Expenses); (l) accounting fees (including those for the preparation of
Landlord's income taxes), other than reasonable accounting fees incurred in
connection with the operation and management of the Building; (m) any lender's
fees; (n) expenses for services provided to other tenants in the Building which
services are not being offered to Tenant; (o) costs to remediate Hazardous
Materials which are in, on or under the Land or the Building on the Commencement
Date (but expressly excluding Hazardous Materials brought on the Land or the
Building by Tenant); (p) management fees in excess of three percent (3%) of
gross rents for the Building; (q) wages, salaries and other compensation paid to
clerks or attendants in newsstands or other commercial concessions, if any,
operated by Landlord; (r) wages, salaries or other benefits or compensation paid
to any employee of Landlord or the property management company at the Building

                              4
<PAGE>

above the level of property manager; (s) costs relating to relocating
existing tenants in the Building; (t) expenses arising as a result of
Landlord's gross negligence of willful misconduct; (u) advertising and
promotional expenses of the Building; (v) the cost of installing, operating
and maintaining any athletic club or recreational facility, theater,
conference facility or art gallery unless Tenant is entitled to use such
facilities free of charge (or at a substantially reduced charge relative to
the general public); and (w) the cost of any Permitted Capital Expenditure
undertaken to cure a violation of law which existed on the Commencement Date.

                           (2)      "REAL ESTATE TAXES" shall mean all taxes,
assessments and charges levied upon or with respect to the Land, the
Building, and any improvements adjacent thereto (computed as payable in
installments as permitted by law regardless of whether so paid), including
without limitation vault rents, if any, franchise taxes, any tax, fee or
excise on rents, on the square footage of the Premises including the Fairfax
County Business License Tax, on the act of entering into this Lease, on the
occupancy of Tenant, on account of the rent hereunder or the business of
renting space now or hereafter levied or assessed against Landlord by the
United States of America or the state, county, city or town in which the
Building are located, or any political subdivision, public corporation,
district or other political or public entity; and shall also include any
other tax to the extent that such tax is imposed in lieu of or in addition to
such Real Estate Taxes. Reasonable legal fees, costs and disbursements
incurred by Landlord in connection with any proceedings for appeal or
reduction of any Real Estate Taxes shall also be considered Real Estate Taxes
for the year in question. Notwithstanding anything to the contrary in this
section, the following shall be excluded from the definition of "Real Estate
Taxes:" (a) all excess profit taxes, gift taxes, capital stock taxes,
inheritance and succession taxes, estate taxes, federal and state income
taxes, capital gain taxes and other similar taxes based on Landlord's net
income, (b) any item(s) included within "Operating Expenses", (c) any taxes
or other charges with respect to which Tenant is directly responsible for
paying to such taxing authority and (d) except as set forth immediately
below, interest and late charges payable as the result of the late payment of
Real Estate Taxes by Landlord. In the event that, at any time during the
Term, a special assessment is imposed on the Land and/or the Building by any
taxing authority having jurisdiction (the "Special Assessment"), and Landlord
is permitted to pay such Special Assessment over a period of time which spans
more than one calendar year, then in such event Landlord shall pay the
Special Assessment over the longest period of time permitted by such taxing
authority (without being in default); provided that any interest or late
charges imposed as a result of such late payment by Landlord shall be
included within the definition of Real Estate Taxes that are payable by
Tenant hereunder.

                           (3)      "TENANT'S PRO RATA SHARE OF OPERATING
EXPENSES," as of the date hereof, shall be as provided in Section 1f,
representing the ratio that the rentable area of the Premises bears to the
total rentable area of office space in the Building. If either the rentable
area of the Premises or the total rentable area of the Building shall be
increased or decreased, as reasonably determined by Landlord, Tenant's Pro
Rata Share of Operating Expenses shall be adjusted accordingly.

                           (4)      "TENANT'S PRO RATA SHARE OF REAL ESTATE
TAXES," as of the date hereof, shall be as provided in Section 1f,
representing the ratio that the area of the Premises bears to the total
rentable area of the Building. If either the rentable area of the Premises or
the total rentable area of the Building shall be increased or decreased, as
reasonably determined by Landlord, Tenant's Pro Rata Share of Real Estate
Taxes shall be adjusted accordingly.

                           (5)      "BASE YEAR" means calendar year 2000.

                  (ii)     If, in any calendar year during the Term, the total
amount of Operating Expenses for the Building exceeds the amount of Operating
Expenses in the Base Year, then Tenant shall pay to Landlord, as Additional
Rent, an amount which is the product of (1) the amount of such increase in
Operating Expenses, multiplied by (2) Tenant's Pro Rata Share of Operating
Expenses. Tenant's Pro Rata Share of Operating Expenses for any partial calendar
year during the Term shall be determined by multiplying the amount of Tenant's
Pro Rata Share of Operating Expenses for the full calendar year by a fraction,
the numerator of which is the number of days during such calendar year falling
within the Term and the denominator of which is three hundred sixty five (365).
If in any calendar year during the Term, the amount of Real Estate Taxes exceeds
the amount of Real Estate Taxes for the Base Year, then Tenant shall pay, as
Additional Rent, an amount which is the product of (x) the amount of such
increase in Real Estate Taxes, multiplied by (y) Tenant's Pro Rata Share of Real
Estate Taxes. Tenant's Pro Rata Share of Real Estate Taxes for any partial
calendar year during the Term shall be determined by multiplying the amount of
Tenant's Pro Rata Share of Real Estate Taxes for the full calendar year by a
fraction, the numerator of which is the number of days during such calendar year
falling within the Term and the denominator of which is three hundred sixty five
(365).

                 (iii)     If at any time during the Base Year, or during any
subsequent calendar year ("Subsequent Year"), less than ninety-five percent
(95%) of the total rentable square feet of office space in the Building is
occupied by tenants, the amount of Operating Expenses for the Base Year, or for
any such Subsequent Year, as the case may be, shall be deemed to be the amount
of Operating Expenses as reasonably estimated by Landlord that would have been
incurred if the percentage of occupancy of the Building during the Base Year or
any such Subsequent Year was ninety-five percent (95%). If at any time during
any calendar year, any part of the Building is leased to a tenant (hereinafter
referred to as a "Special Tenant") who, in accordance with the terms of its
lease, provides its own utilities, cleaning or janitorial services or other
services or is not otherwise required to pay a share of Operating Expenses in
accordance with the methodology set forth in this Section 4b, and Landlord does
not incur the cost of such services, Operating Expenses for such calendar year
shall be increased by the additional costs for cleaning and janitorial services
and such other applicable expenses as reasonably estimated by Landlord


                                     5
<PAGE>

that would have been incurred by Landlord if Landlord had furnished and paid
for cleaning and janitorial services and such other services for the space
occupied by the Special Tenant, or if Landlord had included such costs in
"operating expenses" as defined in the Special Tenant's lease.

                  (iv)     If, during the Base Year or during any Subsequent
Year thereafter, the amount of Real Estate Taxes payable by Landlord with
respect to the Land and the Building does not reflect an assessed value of
the Building equal to or greater than the then-current Fully Assessed Value
(hereinafter defined) of the Building, then in such event Landlord shall
increase the amount of Real Estate Taxes hereunder for the Base Year or any
Subsequent Year, as the case may be, to reflect such Fully Assessed Value for
the calendar year in question. As used herein, the term "Fully Assessed
Value" means the value of the Building, for the purpose of Real Estate Tax
assessment by the appropriate officials of Fairfax County, Virginia, using
the income method of valuation then being employed by Fairfax County,
Virginia, based upon the following assumptions for valuation purposes: (A)
the Building is substantially completed (including base Building improvements
and tenant improvements in 95% of the tenant space); (B) the Building is
ninety-five percent (95%) leased; and (C) the "average" rental rate for
valuation purposes shall be the applicable rental rate then being used by
Fairfax County for the Building and/or buildings comparable to the Building.

                   (v)     During the month of December, 2000, and thereafter
during the month of December of each Lease Year, Landlord shall use
reasonable efforts to furnish to Tenant a statement of Landlord's estimate of
Tenant's Pass-Through Costs for the next calendar year. "Tenant's
Pass-Through Costs" shall be an amount equal to the sum of (1) Tenant's Pro
Rata Share of Operating Expenses multiplied by the difference between
Operating Expenses incurred during any calendar year during the Term, and
Operating Expenses incurred in the Base Year; plus (2) Tenant's Pro Rata
Share of Real Estate Taxes multiplied by the difference between Real Estate
Taxes for any calendar year during the Term and Real Estate Taxes incurred
during the Base Year. Such statement shall show the amount of Tenant's
Pass-Through Costs, if any, payable by Tenant for such calendar year pursuant
to this Section 4b on the basis of Landlord's estimate. Commencing on January
1, 2001, and continuing on each monthly rent payment date thereafter until
further adjustment pursuant to this Section 4b(v), Tenant shall pay to
Landlord one-twelfth (1/12) of the amount of said estimated Tenant's
Pass-Through Costs. Within one hundred twenty (120) days after the expiration
of each calendar year during the Term, Landlord shall furnish to Tenant a
statement (the "Expense Statement") showing the actual Operating Expenses and
Real Estate Taxes for such calendar year. The Expense Statement shall be
conclusive and binding on Tenant, unless objected to in writing by Tenant
within six (6) months following Tenant's receipt thereof. In case of an
underpayment, Tenant shall, within thirty (30) days after the receipt of such
statement, pay to Landlord an amount equal to such underpayment. In case of
an overpayment, Landlord shall credit the next monthly rental payment by
Tenant with an amount equal to such overpayment. Additionally, if this Lease
shall have expired, Landlord shall apply such excess against any sums due
from Tenant to Landlord and shall refund any remainder to Tenant within
thirty (30) days after the expiration of the Term, or as soon thereafter as
possible.

                  (vi)     Within six (6) months of receipt of any Expense
Statement, Tenant shall be entitled to the following audit right with respect
to such Expense Statement. Such audit right shall be exercisable by Tenant
providing Landlord with a written notice of its exercise of such audit right.
If within sixty (60) days after Landlord's receipt of Tenant's written notice
and statement, Landlord and Tenant are unable to resolve Tenant's objections,
then not later than fifteen (15) days after the expiration of such sixty
(60)-day period Tenant shall deliver to Landlord written notice (the "Audit
Notice") that it wishes to employ on an hourly rate (and not a contingency
fee) basis an independent certified public accounting firm reasonably
acceptable to Landlord to inspect and audit Landlord's books and records
relating to the objections raised in Tenant's statement. If Tenant elects to
employ such accountant as set forth above, then Tenant shall deliver to
Landlord a confidentiality and nondisclosure agreement satisfactory to
Landlord executed by such accountant, and provide Landlord not less than
fifteen (15) days' notice of the date on which the accountant desires to
examine Landlord's books and records at the Building during regular business
hours; provided, however, that such date shall be between thirty (30) and
ninety (90) days after Tenant delivers to Landlord the Audit Notice. Such
audit shall be limited to a determination of whether Landlord calculated the
Expense Statement in accordance with the terms and conditions of this Lease,
and may include verification by Landlord of the costs and expenses on which
the Expense Statement in question is based. Except as otherwise expressly set
forth below, all costs and expenses of any such audit shall be paid by
Tenant. Any audit performed pursuant to the terms of this Section 4b(vi)
shall be conducted only by an independent certified public accounting firm
reasonably acceptable to Landlord. Notwithstanding anything contained herein
to the contrary, Tenant shall be entitled to exercise its right to audit
pursuant to this Section 4b(vi) only in strict accordance with the foregoing
procedures and each such audit shall relate only to the most recent calendar
year covered by the audited Expense Statement; provided, however, if (A) such
audit indicates that there was a demonstrated error in the calculation of a
component of Operating Expenses resulting in an overstatement of Operating
Expenses in the Expense Statement, and (B) such component is a recurring
Operating Expense and because of the nature of the component it is likely
that such component was similarly overstated in any prior calendar year
during the Term, then Tenant shall have the right to audit the books and
records relating solely to such component for each such prior year but such
audit shall be limited to determining whether or not the same component was
similarly in error in such prior calendar years. Such limited audit right
must be exercise only by Tenant delivering to Landlord written notice thereof
within thirty (30) days after the earlier of (1) the date Tenant receives the
audit report from the independent certified public accounting firm, or (2)
one hundred twenty (120) days after the date that Tenant delivers to Landlord
the Audit Notice in connection with the Expense Statement in which the error
was first discovered. The audit rights pursuant to this Section 4b(vi) shall
not transfer or apply to any subtenant or any other person or entity other
than the "tenant" hereunder. If on account of any demonstrated errors in the
Expense Statement under audit,


                                     6
<PAGE>

Tenant is entitled to a refund of the amount paid by Tenant for Tenant's Pro
Rata Share of Operating Expenses for the calendar year or years under audit
because such Expense Statement overstated the amounts to which Landlord was
entitled hereunder by more than five percent (5%) of the amount of Expenses
for the applicable calendar year, then Landlord shall promptly reimburse
Tenant for the reasonable costs and expenses incurred in such audit.

                 (vii)     All monies received from Tenant as Tenant's
Pass-Through Costs shall be received by Landlord to pay Operating Expenses
and Real Estate Taxes of the Building and the Land. Notwithstanding the
foregoing, Landlord shall have the right to commingle Tenant's Pass-Through
Costs with other funds collected by Landlord.

                (viii)     Tenant's obligation to pay, and Landlord's
obligation to refund, Tenant's Pass-Through Costs pursuant to the provisions
of this Section 4b, as applicable, shall survive the expiration or other
termination of this Lease with respect to any period during the Term hereof
and with respect to any holdover period of occupancy following the expiration
of the Term.

         c. PAYMENT OF RENT. All Rent shall be paid in lawful money of the
United States of America without deduction, diminution, set-off, counterclaim
or prior notice or demand, at the office of Landlord as provided in Section
1g hereof or at such other place as Landlord may hereafter designate in
writing, on the first day of every calendar month during the Term. All such
payments shall be made by good checks payable to Landlord or such other
person, firm or corporation as Landlord may hereafter designate in writing.
No payment by Tenant or receipt and acceptance by Landlord of a lesser amount
than the Monthly Base Rent or Additional Rent shall be deemed to be other
than partial payment of the full amount then due and payable; nor shall any
endorsement or statement on any check or any letter accompanying any check,
payment of Rent or other payment, be deemed an accord and satisfaction; and
the Landlord may accept, but is not obligated to accept, such partial payment
without prejudice to the Landlord's right to recover the balance due and
payable or to pursue any other remedy provided in this Lease or by law. If
Landlord shall at any time or times accept Rent after it becomes due and
payable, such acceptance shall not excuse a subsequent delay or constitute a
waiver of Landlord's rights hereunder. Any Rent owed by Tenant to Landlord,
including without limitation Annual Base Rent, Additional Rent, Tenant's
Pass-Through Costs and Late Charges, which is not paid within five (5) days
after the date such payment is due shall bear interest from the due date at a
rate equal to the prime rate on corporate loans quoted in the WALL STREET
JOURNAL (the "Prime Rate") plus two percent (2%). In addition, if any amount
of Rent required to be paid by Tenant to Landlord under the terms of this
Lease is not paid within five (5) days after the date such payment is due,
then in addition to paying the amount of Rent then due, Tenant shall pay to
Landlord a late charge (the "Late Charge") equal to five percent (5%) of the
amount of Rent then required to be paid. Payment of such Late Charge will not
excuse the untimely payment of Rent. In the event Tenant makes any payment of
Rent by check and said check is returned by the bank unpaid, Tenant shall pay
to Landlord the sum of One Hundred Dollars ($100.00) to cover the costs and
expenses of processing the returned check, in addition to the Rent payment
and any other charges provided for herein. Any interest, Late Charge and
other amounts charged hereunder shall constitute Additional Rent.

         d.     SEPARATE METERING AND RENT REDUCTION. Landlord may elect to
discontinue the distribution or furnishing of electricity and/or water to the
Premises if such services may feasibly be furnished directly to Tenant by the
utility company supplying same. In the event of any such election by
Landlord: (i) Landlord agrees to give reasonable advance notice of such
discontinuance to Tenant; (ii) Landlord agrees to permit Tenant to receive
electricity and/or water directly from the utilities supplying such service
to the Building and to permit the existing feeders, risers, wiring, pipes and
other facilities serving the Premises to be used by Tenant for such purpose
to the extent they are suitable and safely capable of carrying Tenant's
requirements; (iii) Landlord agrees to pay such charges and costs, if any, as
such public utility may impose in connection with the installation of
Tenant's meters; (iv) the amount of Additional Rent payable in respect to the
Operating Expenses shall be decreased appropriately to reflect such
discontinuance; and (v) such discontinuance shall not occur until direct
service has been obtained by Tenant (or, if Tenant fails timely to take steps
to obtain such direct service, by Landlord, on Tenant's behalf and at
Tenant's sole cost).

5.   SECURITY DEPOSIT.

         a.     Within seven (7) business days after the Effective Date (the
"Security Deposit Delivery Date"), time being of the essence, Tenant shall
tender to Landlord a security deposit in the amount set forth in Section 1h
hereof (the "Security Deposit") to be held by Landlord during the Term as
collateral security (and not prepaid rent), for the payment of Annual Base
Rent and Additional Rent and for the faithful performance by Tenant of all
other covenants, conditions and agreements of this Lease. Failure by Tenant
to deliver the Security Deposit to Landlord on or before the Security Deposit
Delivery Date shall constitute an Event of Default (hereinafter defined)
under this Lease. Landlord shall not be obligated to hold the Security
Deposit in a separate account. If the Security Deposit tendered by Tenant is
in the form of a Cash Security Deposit (hereinafter defined), the Security
Deposit shall earn simple interest at the rate of two and one half percent
(2 1/2%) per annum, which interest shall be included in the Cash Security
Deposit being held by Landlord hereunder. If any sum payable by Tenant to
Landlord shall be overdue and unpaid, or if Landlord makes any payments on
behalf of Tenant, or if Tenant fails to perform any of the terms of this
Lease, then Landlord, at its option and without prejudice to any other remedy
which Landlord may have, may apply such part of the Security Deposit
necessary to compensate Landlord for the payment of Annual Base Rent or
Additional Rent, or any loss or damage sustained by Landlord. Tenant shall
restore the Security Deposit to the original sum deposited upon demand.
Provided that Tenant shall have made all payments and performed all covenants
and agreements of this


                                     7
<PAGE>

Lease, Landlord shall return the Security Deposit to Tenant (except to the
extent of any portion of the Security Deposit which has been applied by
Landlord and not restored by Tenant) within thirty (30) days after the
expiration of this Lease or the vacation of the Premises by Tenant, whichever
is later or as soon thereafter as possible.

         b.     In substitution for the cash Security Deposit (the "Cash
Security Deposit") required under Section 5a above, Tenant shall have the
right to deliver to Landlord, on or before the Effective Date, an
unconditional and irrevocable letter of credit reasonably acceptable to
Landlord issued by the Bank (hereinafter defined) in the face amount of One
Million Eight Hundred Thousand Dollars ($1,800,000.00) (the "Letter of
Credit"), as a security deposit to be held by Landlord until disposed of in
accordance with the provisions of this Section 5. As used herein, the term
"Bank" shall mean American National Bank and Trust Company of Chicago or any
other federally-insured banking institution reasonably acceptable to Landlord
and having total assets of at least Three Billion Dollars ($3,000,000,000)
and a Standard & Poor's commercial paper rating of at least A-1. If the
Letter of Credit (or any replacement thereof) is issued for an effective
period of time less than the remaining Term of this Lease (or any renewal
thereof), Tenant shall from time to time, and not later than sixty (60) days
prior to the expiration of the Letter of Credit, replace each such expiring
Letter of Credit with a new Letter of Credit in the same amount and upon the
same terms. The Letter of Credit (and any replacement thereof) may be drawn
upon by Landlord under the terms and conditions as provided in this Section
5. Failure of Tenant to renew the Letter of Credit at least thirty (30) days
prior to its expiration shall constitute an Event of Default under this Lease
and shall entitle Landlord, in addition to the other remedies contained in
this Lease, to draw upon the Letter of Credit.

         c.     Landlord (or the beneficiary under the Letter of Credit, if
such beneficiary is not Landlord) shall have the right to draw upon the
Letter of Credit in any of the following circumstances (in addition to any
other right to draw on the Letter of Credit that is set forth in this Section
5): (i) if the total assets of the Bank are at anytime less than Three
Billion Dollars ($3,000,000,000), or the Bank has a Standard & Poor's
commercial paper rating of less than A-1 (provided if at anytime the current
Standard & Poor's commercial paper rating system is no longer in existence, a
comparable rating of a comparable commercial paper rating system from a
comparable company shall be selected by Landlord, in its reasonable
discretion, for purposes of this Section 5) and Tenant fails to deliver to
Landlord a replacement Letter of Credit complying with the terms of this
Lease within thirty (30) days of request therefor from Landlord, (ii) if the
credit rating of the Bank is downgraded from the credit rating of such issuer
at the time of the issuance of the Letter of Credit, the Bank shall enter
into any supervisory agreement with any governmental authority, or the Bank
shall fail to meet any capital requirements imposed by applicable law, and
Tenant fails to deliver to Landlord (or the beneficiary under the Letter of
Credit, if such beneficiary is not Landlord) a replacement Letter of Credit
complying with the terms of this Lease within thirty (30) days of request
from Landlord, (iii) if Tenant fails to provide Landlord with any renewal or
replacement Letter of Credit complying with the terms of this Lease at least
sixty (60) days prior to expiration of the then-current Letter of Credit
where the Bank has advised Landlord of its intention not to renew the Letter
of Credit, (iv) if Tenant fails to provide Landlord with any renewal or
replacement Letter of Credit complying with the terms of this Lease at least
sixty (60) days prior to the final expiration date (i.e., the date that, by
the terms of the Letter of Credit, the Letter of Credit expires and is either
not subject to any automatic renewal or extension or the conditions to such
automatic renewal or extension have not then been satisfied) of the
then-current Letter of Credit if such Letter of Credit expires prior to the
date that is thirty (30) days after the end of the Term, or (v) any voluntary
in involuntary proceedings are filed by or against Tenant under any
bankruptcy, insolvency or similar laws. In the event the Letter of Credit is
drawn upon due solely to the circumstances described in the foregoing clauses
(i), (ii), (iii), (iv) or (v), the amount drawn shall be held by Landlord as
a Cash Security Deposit in accordance with the terms of this Section 5, and
shall be otherwise retained, expended or disbursed by Landlord for any
amounts or sums due under this Lease to which the proceeds of the Letter of
Credit could have been applied pursuant to this Lease, and Tenant shall be
liable to Landlord for restoration, in cash or Letter of Credit complying
with the terms of this Lease, of any amount so expended to the same extent as
set forth in this Section 5.

         d.     In the event of the sale or transfer of Landlord's interest
in the Building, Landlord shall have the right to transfer the Cash Security
Deposit or the Letter of Credit to the purchaser or assignee, and upon
notification of Tenant of such transfer Tenant shall look only to the new
landlord for the return of the Cash Security Deposit, and Landlord shall
thereupon be released from all liability to Tenant for the return of the Cash
Security Deposit or Letter of Credit. Tenant hereby agrees not to look to the
mortgagee, as mortgagee, mortgagee in possession, or successor in title to
the property, for accountability for any Security Deposit required by the
Landlord hereunder, unless said sums have actually been received by said
mortgagee as security for Tenant's performance of this Lease. In the event of
any permitted assignment of Tenant's interest in this Lease, the Cash
Security Deposit or the Letter of Credit may, at Landlord's sole option, be
held by Landlord as a deposit made by the assignee, and Landlord shall have
no further liability to Tenant with respect to the return of the Cash
Security Deposit or the Letter of Credit.

         e.     Notwithstanding anything to the contrary set forth herein,
provided that (i) no default then exists under the Lease, and (ii) Tenant (or
a sublessee or assignee approved by Landlord or a Permitted Transferee
(hereinafter defined)) is then occupying 100% of the Premises, on the first
day of the third (3rd) Lease Year and on the first day of each Lease Year
thereafter during the Term (including the Extension Term (hereinafter
defined) if applicable), the Cash Security Deposit or the Letter of Credit,
as the case may be, shall be reduced by One Hundred Eighty Thousand Dollars
($180,000.00). The balance of the Cash Security Deposit or the Letter of
Credit, as applicable, which has not been reduced as aforesaid shall be
retained by Landlord throughout the Term.


                                     8
<PAGE>

6.   USE.

         a.     Tenant shall use and occupy the Premises only for general
office use and/or as a Call Center (hereinafter defined), and for no other
purposes. Tenant shall not use the Premises or allow the Premises to be used
for any other purpose without the prior written consent of the Landlord. As
used herein, the term "Call Center" shall mean Tenant's business operations
in the Premises in which Tenant's employees field telecommunication inquiries
from Tenant's customers, and perform customer service functions related to
the operations of Tenant's business; provided, however, that the Call Center
may not be operated by Tenant to provide telecommunication answering services
or customer service functions for or on behalf of businesses that are not
customers of, or owned by, Tenant. Notwithstanding anything to the contrary
set forth in this Lease, in no event shall Tenant permit more than two
hundred eighty (280) people (or one (1) person per one hundred fifty (150)
rentable square feet of space in the Premises) to use or occupy the Premises
at any time during the Term. Should Tenant violate the foregoing provision:
(i) Tenant shall be in default of this Lease; (ii) Tenant shall indemnify
Landlord and hold Landlord harmless from and against all costs, injury, loss
or damage (including reasonable attorneys' fees) incurred by Landlord as a
result of such violation; and (iii) Tenant shall reimburse Landlord, within
ten (10) days of demand, for all costs incurred by Landlord to repair, or
increase the capacity of, any base Building system to the extent Landlord
believes such action is required due to such violation by Landlord, such
actions by Landlord to include without limitation the installation of one or
more supplemental HVAC units to service the Premises. Tenant, at Tenant's
expense, shall comply with all laws, codes, rules, orders, ordinances,
directions, regulation, and requirements of federal, state, county, and
municipal authorities, now in force or which may hereafter be in force, which
shall impose any duty upon Landlord or Tenant with respect to the condition,
maintenance, use, occupation, operation or alteration of the Premises, or the
conduct of Tenant's business therein, including without limitation the
Americans With Disabilities Act and all applicable zoning, recycling and
environmental laws and regulations. Tenant hereby agrees to indemnify and
hold harmless Landlord and its agents, officers, directors and employees from
and against any cost, damage, claim, liability and expense (including
attorneys' fees) arising out of claims or suits brought by third parties
against Landlord, its agents, officers, directors and employees alleging or
relating to the failure of the Premises to comply with the terms of the
Americans With Disabilities Act or any other law or regulation applicable to
the Premises and/or its occupancy by Tenant. Tenant shall not use or permit
the Premises or any part thereof to be used in any manner that constitutes
waste, nuisance or unreasonable disturbances to other tenants of the Building
or for any disorderly, unlawful or hazardous purpose and will not store or
maintain therein any hazardous, toxic or highly combustible items other than
usual and customary office supplies intended for Tenant's use and in such
event, only in such amounts as permitted by applicable law. Tenant covenants
not to change Tenant's use of the Premises without the prior written approval
of Landlord.

         b.     Tenant shall not put the Premises to any use, the effect of
which use is reasonably likely to cause cancellation of any insurance
covering the Premises or the Building, or an increase in the premium rates
for such insurance. In the event that Tenant performs or commits any act, the
effect of which is to raise the premium rates for such insurance, Tenant
shall pay Landlord the amount of the additional premium, as Additional Rent
payable by Tenant upon demand therefor by Landlord. The Premises shall not be
used for any illegal purpose or in violation of any regulation of any
governmental body or the regulations or directives of Landlord's insurance
carriers, or in any manner which interferes with the quiet enjoyment of any
other tenant of the Building. Tenant will not install or operate in the
Premises any electrical or other equipment, other than such equipment as is
commonly used in modern offices (specifically excluding mainframe computers),
without first obtaining the prior written consent of Landlord, who may
condition such consent upon the payment by Tenant of Additional Rent in
compensation for excess consumption of water, electricity and/or other
utilities, excess wiring and other similar requirements, and any changes,
replacements or additions to any base building system, as may be occasioned
by the operation of said equipment or machinery.

         c.     Tenant agrees to maintain the Premises, and the Tenant
Improvements and other Alterations (hereinafter defined) therein, in good
order, repair and condition during the Term at Tenant's sole cost and
expense, and Tenant will, at the expiration or other termination of the Term,
surrender and deliver the same and all keys, locks and other fixtures
connected therewith (excepting only Tenant's personal property) in good
order, repair and condition, as the same shall be at the Commencement Date,
except as repaired, rebuilt, restored, altered or added to pursuant to this
Lease, and except for ordinary wear and tear and damage by fire or casualty
and/or condemnation. Landlord shall have no obligation to Tenant to make any
repairs in or to the Premises, the Tenant Improvements or any Alterations.
Any and all damage or injury to the Premises (including, but not limited to,
the Tenant Improvements), the Building or the Land caused by Tenant, or by
any employee, agent, contractor, assignee, subtenant, invitee or customer of
Tenant shall be promptly reported to Landlord and, except for injury or
damage to the Building which is covered by Landlord's insurance, repaired by
Tenant at Tenant's sole cost; provided, however, that Landlord shall have the
option of repairing any such damage, in which case Tenant shall reimburse
Landlord for all costs incurred by Landlord in respect thereof as Additional
Rent within fifteen (15) days after Tenant receives Landlord's notice of such
costs.

         d. Tenant shall not place a load upon the floor of the Premises
exceeding the designated floor load capacity of the Building (e.g. 100 pounds
per square foot: 80 pounds per square foot, live load, and 20 pounds per
square foot, dead load) without Landlord's prior written consent. Business
machines, mechanical equipment and materials belonging to Tenant which cause
vibration, noise, cold, heat or fumes that may be transmitted to the Building
or to any other leased space therein to such a degree as to be objectionable
to Landlord or to any other tenant in the Building shall be placed,
maintained, isolated, stored and/or vented by Tenant at its sole expense so
as to absorb and prevent such vibration, noise, cold, heat or fumes.

                                     9
<PAGE>

7.   ASSIGNMENT AND SUBLETTING.

         a.     Except with respect to transfers to Permitted Transferees,
Tenant shall not, without the prior written consent of Landlord (which
consent shall not be unreasonably withheld, conditioned or delayed, subject
to the conditions set forth below) in each instance: (i) assign or otherwise
transfer this Lease or any of Tenant's rights hereunder, (ii) sublet the
Premises or any part thereof, or permit the use of the Premises or any part
thereof by any persons other than Tenant or its employees, agent and
invitees, or (iii) permit the assignment or other transfer of this Lease or
any of Tenant's rights hereunder by operation of law. Landlord's consent to a
proposed assignment or sublease shall not be unreasonably withheld,
conditioned or delayed, provided Landlord determines that the proposed
assignee or subtenant (A) is of a type and quality consistent with the
first-class nature of the Building, (B) has the financial capacity and
creditworthiness to undertake and perform the obligations of this Lease or
the sublease, (C) is not a party by whom any suit or action could be defended
on the ground of sovereign immunity or diplomatic immunity and (D) will not
impose any additional material burden upon Landlord in the operation of the
Building (to an extent greater than the burden to which Landlord would have
been had Tenant continued to use such part of the Premises). In addition, the
following conditions must be satisfied at the time Tenant requests Landlord's
consent to an assignment or sublease:

                  (1)      no Event of Default (hereinafter defined) exists
and no event has occurred which, with notice and/or the passage of time,
would constitute an Event of Default if not cured within the time, including
any applicable grace period, specified herein;

                  (2)      Landlord receives at least thirty (30) days' prior
written notice of Tenant's intention to assign this Lease or sublet any
portion of the Premises;

                  (3)      the proposed use of the Premises (if other than
general office use) will not violate any agreement affecting the Premises or
the Building;

                  (4)      Tenant submits to Landlord at least thirty (30)
days prior to the proposed date of subletting or assignment such information
Landlord reasonably requests in order to permit Landlord to make a judgment
on the proposed subletting or assignment, including without limitation the
name, business experience, financial history, net worth and business
references of the proposed assignee or subtenant (and each of its
principals), an in-depth description of the transaction, and the
consideration delivered to Tenant for the assignment or sublease;

                  (5)      the proposed assignee or subtenant is not a tenant
of the Building;

                  (6)      Tenant is not then subletting more than thirty-five
percent (35%) of the rentable square feet of the Premises; and

                  (7)      Tenant has paid to Landlord an administrative fee
in the amount of Seven Hundred Fifty Dollars ($750.00) which shall be
retained by Landlord whether or not such consent is granted.

         b.     All proposed subleases and assignments shall be on Landlord's
approved form of sublease or assignment, whichever is applicable; and shall
contain, INTER ALIA, the following provisions: (i) any such assignment or
sublease shall include an assumption by the assignee or subtenant, from and
after the effective date of such assignment or sublease, of the performance
and observance of the covenants and conditions to be performed and observed
on the part of Tenant as contained in this Lease, and (ii) any such sublease
or assignment shall specify that this Lease or sublease shall not be further
assigned nor the Premises further sublet and shall specify that the term of
such sublease shall not extend beyond one (1) day prior to the expiration of
this Lease. The consent by Landlord to any assignment, transfer or subletting
to any person or entity shall not be construed as a waiver or release of
Tenant from any provision of this Lease, unless expressly agreed to in
writing by Landlord (it being understood that Tenant shall remain primarily
liable as a principal and not as a guarantor or surety), nor shall the
collection or acceptance of rent from any such assignee, transferee,
subtenant or occupant constitute a waiver or release of Tenant from any such
provision. No consent by Landlord to any such assignment, transfer or
subletting in any one instance shall constitute a waiver of the necessity for
such consent in a subsequent instance.

         c.     In the event that Tenant assigns this Lease or sublets all or
any portion of the Premises to a party other than a Permitted Transferee
(hereinafter defined), Tenant shall pay to Landlord as Additional Rent an
amount equal to fifty percent (50%) of the difference between (i) all sums
paid to Tenant or its agent (if and when received) by or on behalf of such
assignee or subtenant under the assignment or sublease, less the reasonable
out-of-pocket costs incurred by Tenant in connection with such sublease or
assignment, including brokerage commissions and tenant improvement costs, and
(ii) the Annual Base Rent and Additional Rent paid by Tenant under this Lease
and attributable to the portion of the Premises assigned or sublet. As used
herein, the term "Approved Tenant Affiliate" shall mean an entity related to
or affiliated with Tenant that controls (hereinafter defined), is controlled
by or is under common control with, Tenant. As used herein, the term
"control" means ownership of more than fifty percent (50%) of the voting
stock, partnership interests or other ownership interests in the entity in
question, along with the right to effect all significant management decisions
of the "controlled" entity.

         d.     For purposes of this Section, a transfer, conveyance, grant or
pledge, directly or indirectly, in one or more transactions, of an interest in
Tenant (whether stock, partnership interest or


                                     10
<PAGE>

other form of ownership or control, or the issuance of new interests) by
which an aggregate of more than twenty-five percent (25%) of the beneficial
interest in Tenant shall be vested in a party or parties who are not holders
of such interest(s) as of the date hereof) shall be deemed an assignment of
this Lease; provided, however, that this limitation shall not apply to (i)
any corporation which is listed on a national securities exchange as defined
in the Securities Exchange Act of 1934 (a "National Stock Exchange"); or (ii)
transfers to Permitted Transferees. The merger or consolidation of Tenant
into or with any other entity, the sale of all or substantially all of
Tenant's assets, or the dissolution of Tenant shall each be deemed to be an
assignment within the meaning of this Section, except or otherwise expressly
provided in Section 7j, below.

         e.      Any assignment or subletting not in conformance with the
terms of this Lease shall be void AB INITIO and shall, subject to the
provisions of Section 16, constitute a default under the Lease.

         f.      Upon receipt of the notice referred to in Section 7a(2),
above, except with respect to assignments, subleases or other transfers to
Permitted Transferees, Landlord may, at its option, in lieu of approving or
rejecting the proposed assignment or subletting, exercise all or any of the
following rights by written notice to Tenant of Landlord's intent to do so
within fifteen (15) business days of Landlord's receipt of Tenant's notice:

                  (i)    with respect to a proposed assignment of this Lease,
the right to terminate this Lease on the effective date of proposed
assignment as though it were the Lease Expiration Date;

                  (ii)   with respect to a proposed sublease of the entire
Premises, the right to terminate this Lease on the effective date of the
sublease as though it were the Lease Expiration Date;

                  (iii)  with respect to a proposed sublease of less than the
entire Premises, the right to terminate this Lease as to the portion of the
Premises affected by such sublease on the effective date of the sublease, as
though it were the Lease Expiration Date, in which case Tenant shall execute
and deliver to Landlord an appropriate modification of this Lease, in form
satisfactory to Landlord in all respects within ten (10) business days of
Landlord's notice of partial termination, which modification of this Lease
shall provide that the number of rentable square feet of the Premises shall
be decreased by, and the Monthly Base Rent and Additional Rent payable by
Tenant hereunder shall be adjusted in proportion to, the number of rentable
square feet of the Premises affected by such termination, as determined by
Landlord; or

                  (iv)   with respect to a proposed sublease for less than
the balance of the Term, the right to sublet the portion of the Premises from
Tenant upon the same terms and conditions (including Annual Base Rent and
Additional Rent) set forth in this Lease for the term of the proposed
sublease.

         g.      If Landlord exercises any of its options under Section 7f,
above, Landlord may then lease (or sublease) the Premises or any portion
thereof to Tenant's proposed assignee or subtenant, as the case may be,
without any liability whatsoever to Tenant.

         h.      Upon any assignment of this Lease or sublease of all or a
portion of the Premises (other than to a Permitted Transferee), any and all
option rights, rights of first refusal, rights of first negotiation, and
expansion rights shall terminate, it being understood that any and all such
rights are personal to Tenant (and not to any subtenant or, except for any
Permitted Transferee, assignee) and are not appurtenant to the Premises or
this Lease. Further, Tenant shall not have the right to exercise any such
rights unless Tenant (and not any assignee or subtenant of Tenant) shall be
in occupancy of all of the Premises at the time of the exercise of any such
right. In addition to the administrative fee described in Section 7a(7),
above, Tenant shall reimburse Landlord for its reasonable attorneys' fees and
other third party expenses incurred in reviewing any requested consent
whether or not such consent is granted. Tenant shall not collaterally assign,
mortgage, pledge, hypothecate or otherwise encumber this Lease or any of
Tenant's rights hereunder without the prior written consent of Landlord,
which consent Landlord may withhold in its sole discretion.

         i.      Notwithstanding any consent by Landlord to an assignment or
subletting, Tenant shall remain primarily liable for the performance of all
covenants and obligations contained in this Lease. Each approved assignee or
subtenant shall also automatically become liable for the obligations of
Tenant hereunder. Landlord shall be permitted to enforce the provisions of
this Lease directly against Tenant and/or against any assignee or sublessee
without proceeding in any way against any other person. Collection or
acceptance of Annual Base Rent or Additional Rent from any such assignee,
subtenant or occupant shall not constitute a waiver or release of Tenant from
the terms of any covenant or obligation contained in this Lease, nor shall
such collection or acceptance in any way be construed to relieve Tenant from
obtaining the prior written consent of Landlord to such assignment or
subletting or any subsequent assignment or subletting.

         j.      Notwithstanding anything contained in this Section 7 to the
contrary, Landlord's consent shall not be required in connection with a
sublease, assignment, transfer or change in ownership interest described
immediately below (nor shall Tenant be required to pay Landlord an
administrative fee in connection therewith):

                  (i)    a sublease of all or any portion of the Premises to
an Approved Tenant Affiliate;

                  (ii)   an assignment of the Lease to any Approved Tenant
Affiliate;


                                      11
<PAGE>

                  (iii)  a transfer of the ownership interests in, or change
in the ownership of, Tenant, but only so long as (A) the new owners of the
interests in Tenant continue to operate Tenant's business in the same manner
as it was operated before such transfer; (B) Tenant's net worth after such
change in ownership is substantially similar to or greater than Tenant's net
worth immediately prior to such change in ownership, and (C) such change in
ownership was effected for legitimate business purposes, and not merely as a
vehicle for transferring to the new owners the benefits and burdens of the
Lease;

                  (iv)   a transaction in which the stock or other ownership
interests in Tenant are listed for sale to the public on a National Stock
Exchange;

                  (v)    a merger or consolidation of Tenant into, or with,
an Approved Tenant Affiliate; and

                  (vi)   a merger or consolidation of Tenant into, or with,
an unrelated third party or an arm's length sale of all, or substantially
all, of the assets of Tenant to an unrelated third party, provided that, in
connection with such transaction, Tenant satisfies the requirements of
Section 7j(iii)(A)-(C), above. As used in this Section 7, the term "Permitted
Transferee" shall mean (i) the Approved Tenant Affiliate described in
Sections 7j(i) and 7j(ii), above; and (ii) the person(s) or entity (ies)
which is the transferee of the ownership interests in Tenant in any of the
transactions described in Sections 7j(iii), (iv), (v) or (vi), of this Lease.
Notwithstanding the fact that Landlord's consent is not required in
connection with any assignment, sublease or other transfer to a Permitted
Transferee, Tenant shall provide Landlord with written notice of any such
transaction, along with whatever information or documentation Landlord
reasonably requires in order to confirm that the proposed transaction
constitutes a transfer to a Permitted Transferee, promptly after the
consummation of any such assignment, sublease or other transfer to a
Permitted Transferee, provided, however, that no information or documentation
other than the notice shall be required for transactions described in Section
7j(iv), above; provided further, however, that the only information or
documentation to which Landlord shall be entitled with respect to
transactions described in Section 7j(v), above, shall be a certified
statement by an officer of Tenant that the entity into which, or with which,
Tenant is effecting such merger or consolidation satisfies the criteria for
an "Approved Affiliate" set forth in Section 7c, above.

8.   IMPROVEMENTS AND FIXTURES.

         a.      Tenant shall neither make nor allow any alterations,
decorations, replacements, changes, additions or improvements (collectively
referred to as "Alterations") to the Premises or any part thereof that will
or may affect the mechanical, electrical, plumbing, HVAC or other systems or
the exterior or structure of the Building, without the prior written consent
of Landlord, which may be withheld by Landlord in its sole discretion. Tenant
shall not make or allow any other kind of Alterations to the Premises or any
part thereof (except for Cosmetic Alterations (hereinafter defined)) without
the prior written consent of Landlord, which consent shall not be
unreasonably withheld, conditioned or delayed. As used herein, the term
"Cosmetic Alterations" shall mean any Alterations costing less than $25,000
in the aggregate and which do not require a building permit to undertake.
Tenant shall provide Landlord with at least ten (10) days prior written
notice (along with whatever documentation regarding same Landlord reasonably
requires) prior to undertaking any Cosmetic Alterations. All of such
Alterations, structural or otherwise, must conform to all rules and
regulations established from time to time by Landlord, must be performed in a
good and workmanlike manner, must comply with all applicable building codes,
laws and regulations (including without limitation the Americans With
Disabilities Act), shall not require any changes to or modifications of any
of the mechanical, electrical, plumbing, HVAC or other systems or the
exterior or structure of the Building, and shall otherwise be constructed in
strict accordance with the terms and conditions of this Section 8. Prior to
undertaking any Alterations in the Premises, Tenant shall furnish to Landlord
duplicate original policies or certificates thereof of worker's compensation
insurance (covering all persons to be employed by Tenant, and Tenant's
contractors and subcontractors in connection with such Alteration), builder's
all-risk insurance, and comprehensive public liability insurance (including
property damage coverage) in such form, with such companies, for such periods
and in such amounts as Landlord may reasonably require, naming Landlord and
its agents, and any mortgagee as additional insureds.

         b.      It is understood and agreed by Landlord and Tenant that any
Alterations undertaken in the Premises shall be constructed at Tenant's sole
expense. The costs of Alterations shall include without limitation the cost
of all architectural work, engineering studies, materials, supplies, plans,
permits and insurance. If requested by Landlord, Tenant shall provide to
Landlord satisfactory evidence of Tenant's ability to pay for such
Alterations (including, but not limited to, a payment or performance bond to
the extent that the cost of such work exceeds $100,000). No consent by
Landlord to any Alterations shall be deemed to be an agreement or consent by
Landlord to subject Landlord's interest in the Premises, the Building or the
Land to any mechanic's or materialman's liens which may be filed in respect
to such Alterations made by or on behalf of Tenant. If Landlord gives its
consent as specified in Section 8a above, Landlord may impose as a condition
to such consent such requirements as Landlord may deem necessary or
desirable, in its sole discretion exercised in good faith, including without
limitation the right to approve the plans and specifications for any work,
supervision of the work by Landlord or its agents or by Landlord's architect
or contractor and the payment to Landlord or its agents, architect or
contractor of a construction supervision fee (not to exceed 3% of the total
"hard" costs incurred) in connection therewith, the right to impose
requirements as to the manner in which or the time or times at which work may
be performed. Landlord shall also have the right to approve in its reasonable
discretion the contractor or contractors who shall perform any Alterations,
repairs in, to or about the Premises and to post notices of
non-responsibility and similar notices, as appropriate. In addition,
immediately after

                                      12
<PAGE>

completion of any Alterations, Tenant shall assign to Landlord any and all
warranties applicable to such Alterations and shall provide Landlord with
as-built plans of the Premises depicting such Alterations.

         c.      Tenant shall keep the Premises free from any liens arising
out of any work performed on, or materials furnished to, the Premises, or
arising from any other obligation incurred by Tenant. If any mechanic's or
materialmen's lien is filed against the Premises, the Building and/or the
Land for work claimed to have been done for or materials claimed to have been
furnished to Tenant, such lien shall be discharged by Tenant within fifteen
(15) business days thereafter, at Tenant's sole cost and expense, by the
payment thereof or by filing any bond required by law. If Tenant shall fail
to timely discharge any such mechanic's or materialman's lien, Landlord may,
at its option, discharge the same and treat the cost thereof as Additional
Rent payable with the installment of rent next becoming due; it being
expressly covenanted and agreed that such discharge by Landlord shall not be
deemed to waive or release the default of Tenant in not discharging the same.
Tenant shall indemnify and hold harmless Landlord, the Premises and the
Building from and against any and all expenses, liens, claims, actions or
damages to person or property in connection with any such lien or the
performance of such work or the furnishing of such materials. Tenant shall be
obligated to, and Landlord reserves the right to, post and maintain on the
Premises at any time such notices as shall in the reasonable judgment of
Landlord be necessary to protect Landlord against liability for all such
liens or actions.

         d.      Any Alterations of any kind to the Premises or any part
thereof, except Tenant's furniture and moveable trade fixtures, shall at once
become part of the realty and belong to Landlord and shall be surrendered
with the Premises, as a part thereof, at the end of the Term hereof;
provided, however, that Landlord may, by written notice to Tenant at least
thirty (30) days prior to the end of the Term, require Tenant to remove any
Alterations and to repair any damage to the Premises caused by such removal,
all at Tenant's sole expense. Landlord agrees that if Tenant, simultaneously
with Tenant's delivery to Landlord of a request for Landlord's approval of
any proposed Alterations, requests in writing that Landlord state whether or
not Landlord will require the removal of such Alterations upon termination or
expiration of this Lease, Landlord shall so state within ten (10) business
days after Landlord's receipt of Tenant's written request; provided that such
written request by Tenant shall specify, in bold letters that, "IF LANDLORD
FAILS TO SPECIFY TO TENANT, WITHIN TEN (10) BUSINESS DAYS AFTER LANDLORD'S
RECEIPT OF THIS NOTICE, THAT THE ALTERATIONS PROPOSED BY TENANT HEREIN MUST
BE REMOVED BY TENANT UPON THE TERMINATION OR EXPIRATION OF THE LEASE, SUCH
FAILURE SHALL BE DEEMED TO CONSTITUTE AN AGREEMENT BY LANDLORD THAT SUCH
ALTERATIONS (IF APPROVED BY LANDLORD) NEED NOT BE REMOVED BY TENANT." If
Landlord fails to respond to such a written request, Landlord shall be deemed
to have not required the removal of such Alterations upon the termination or
expiration of this Lease. Any article of personal property, including
business and trade fixtures, not attached to or built into the Premises,
which were installed or placed in the Premises by Tenant at its sole expense,
shall be and remain the property of Tenant and may be removed by Tenant at
any time during the Term, provided that Tenant repairs any damage to the
Premises or the Building caused by such removal.

9.   UTILITIES AND SERVICES.

         a.      Landlord shall furnish the following utilities and services
to the Premises: electric current (for lighting and operation of normal
desk-type office machines); water; lavatory supplies; heat and
air-conditioning during the appropriate seasons of the year as reasonably
required; elevator service; and trash removal, cleaning and char service
(after normal business hours Monday through Friday, excluding Holidays
(hereinafter defined)). Heating and air conditioning shall be provided to the
Premises only during normal business hours (I.E., Monday through Friday 8:00
a.m. to 6:00 p.m., and Saturday 8:00 a.m. to 1:00 p.m., excluding Holidays).
As used herein, the term "Holidays" shall mean New Year's Day, Martin Luther
King's Birthday, President's Day, Memorial Day, Independence Day, Labor Day,
Columbus Day, Thanksgiving Day and Christmas Day. At times other than the
normal business hours and days aforesaid, central air conditioning and
heating shall be provided to Tenant upon at least twenty-four (24) hours'
prior notice from Tenant, and upon payment by Tenant of the hourly charge
established by Landlord for each hour (or a portion thereof) of after-hours
usage. All light bulbs and tubes in the Premises shall be replaced at
Tenant's expense. In addition, Landlord may impose a reasonable additional
charge for any additional or unusual services required to be provided by
Landlord to Tenant because of the carelessness of Tenant, the nature of
Tenant's business or the removal of any refuse and rubbish from the Premises
except for discarded material placed in wastepaper baskets and left for
emptying as an incident to Tenant's normal cleaning of the Premises. In the
event that Landlord must temporarily suspend or curtail services because of
accident and repair, Landlord shall have no liability to Tenant for such
suspension or curtailment or due to any restrictions on use arising therefrom
or relating thereto, and Landlord shall proceed diligently to restore such
service. No interruption or malfunction of any such services shall constitute
an actual or constructive eviction or disturbance of Tenant's use and
possession of the Premises, the Building or the parking garage or parking
areas in or around the Building or constitute a breach by Landlord of any of
its obligations hereunder or render Landlord liable for damages or entitle
Tenant to be relieved from any of Tenant's obligations hereunder (including
the obligation to pay rent) or grant Tenant any right of setoff or claim
against Landlord or constitute a constructive or other eviction of Tenant.
Notwithstanding the foregoing, in the event such interruption or cessation of
services required to be furnished by Landlord hereunder: (i) is not caused by
Tenant, its employees, agents, contractors, or invitees; (ii) renders the
Premises untenantable for Tenant's business use therein; and (iii) exists for
more than seven (7) consecutive days, then, provided Tenant in fact ceases to
use the Premises during the entirety of such period of cessation or
interruption, Monthly Base Rent and Additional Rent hereunder shall abate
from the day after Tenant vacates the Premises until such time as the service
which was interrupted has been restored. The foregoing abatement of Monthly

                                      13
<PAGE>

Base Rent and Additional Rent shall be Tenant's sole and exclusive remedy
resulting from such cessation or interruption, and Landlord and Tenant agree
that Landlord's inability to furnish such services shall not be deemed to be
a constructive eviction of Tenant from the Premises. In the event of any such
interruption, Landlord shall use reasonable diligence to restore such
services.

         b.      Tenant will not, without the prior written consent of
Landlord (which consent shall not be unreasonably withheld, conditioned or
delayed, except to the extent that Landlord determines that the use of any
such apparatus or device may overburden or otherwise adversely affect any
base Building system herein, in which event Landlord may withhold its consent
in its sole discretion), use any apparatus or device in the Premises,
including without limitation electric data processing machines, punch card
machines and machines using current in excess of 110 volts which will in any
way increase the amount of the electricity or water which would otherwise be
furnished or supplied for the intended use of the Premises under this Section
9; and Tenant will not connect to electric current any apparatus or device
for the purpose of using electric current or water, except through existing
electrical outlets in the Premises or water pipes. If Tenant shall require
water or electricity in excess of that which would otherwise be furnished or
supplied for the intended use of the Premises, Tenant shall first secure the
written consent of Landlord for the use thereof, which consent shall not be
unreasonably withheld, conditioned or delayed; provided that Landlord may
condition its consent upon the requirement that a water meter or electric
current meter be installed in the Premises, so as to measure the amount of
water and electric current consumed for any such excess use. The cost of such
meters and installation, maintenance and repair thereof, the cost of any such
excess utility use as shown by said meter, the cost of any new or additional
utility installations, including without limitation wiring and plumbing,
resulting from such excess utility use, and the cost of any additional
expenses incurred in keeping count of such excess utility use shall be paid
by Tenant promptly upon demand by Landlord or, if Tenant is billed separately
therefor, promptly upon receipt of a bill for same. Whenever heat generating
machines or equipment are used in the Premises which affect the temperature
otherwise maintained by the air conditioning system, Landlord reserves the
right to install supplementary air conditioning units in the Premises and the
cost thereof, including the cost of installation, operation and maintenance
thereof, shall be paid by Tenant to Landlord upon demand by Landlord.

         c.      Tenant shall have the right to install and operate in the
Premises personal computers and other electrically-operated office equipment
normally used in modern offices. Tenant shall not install equipment of any
kind or nature whatsoever nor engage in any practice or use which will or may
necessitate any changes, replacements or additions to, or in the use of, the
water system, heating system, plumbing system, air conditioning system,
electrical system, floor load capacities, or other mechanical or structural
system of the Premises or the Building without first obtaining the prior
written consent of Landlord, which consent may be conditioned upon, but not
limited to, Tenant first securing at its expense additional capacity for any
said service in the Building; provided, however, Tenant shall be responsible
for paying for any excess utility consumption arising from any such change,
replacement, use or addition, such payments to be based on Landlord's
reasonable estimate or, at Landlord's option, a submeter or similar device to
measure such usage (said device to be installed at Tenant's expense).
Additionally, in the event that Landlord reasonably determines that Tenant's
electrical consumption exceeds standard office use, Tenant shall pay the
amount of such excess electrical consumption, as reasonably determined by
Landlord, within thirty (30) days after demand therefor. Machines, equipment
and materials belonging to Tenant which cause vibration, noise, cold, heat,
fumes or odors that may be transmitted outside of the Premises to such a
degree as to be objectionable to Landlord in Landlord's sole opinion or to
any other tenant in the Building shall be treated by Tenant at its sole
expense so as to eliminate such objectionable condition, and shall not be
allowed to operate until such time as the objectionable condition is remedied
to Landlord's satisfaction.

         d.      Tenant shall comply, at its sole cost and expense, with all
orders, requirements and conditions now or hereafter imposed by any
ordinances, laws, orders and/or regulations (hereinafter collectively called
"regulations") of any governmental body having jurisdiction over the Premises
or the Building, whether required of Landlord or otherwise, regarding the
collection, sorting, separation and recycling of waste products, garbage,
refuse and trash (hereinafter collectively called "waste products") including
but not limited to the separation of such waste products into receptacles
reasonably approved by Landlord and the removal of such receptacles in
accordance with any collection schedules prescribed by such regulations.
Landlord reserves the right (i) to refuse to accept from Tenant any waste
products that are not prepared for collection in accordance with any such
regulations, (ii) to require Tenant to arrange for waste product collection
at Tenant's sole cost and expense, utilizing a contractor reasonably
satisfactory to Landlord, and (iii) to require Tenant to 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 any such regulations.
Notwithstanding the foregoing, if Tenant is unable to comply with Landlord's
standard procedures regarding the internal collection, sorting, separation
and recycling of waste products, Landlord shall use reasonable efforts to
arrange for alternative procedures for Tenant, and Tenant shall pay Landlord
all additional costs incurred by Landlord with respect thereto.

10.  RIGHTS OF LANDLORD.

         a.      Landlord reserves the following rights:

                  (i)    to change the name or street address of the Building
without notice or liability to Tenant;


                                       14
<PAGE>

                  (ii)   to approve the design, location, number, size and
color of all signs or lettering on the Premises or visible from the exterior
of the Premises;

                  (iii)  to have pass keys and/or access cards to the
Premises;

                  (iv)   to grant to anyone the exclusive right to conduct
any particular business or undertaking in the Building, so long as Tenant is
not prohibited from conducting its business in the Premises;

                  (v)    to enter the Premises at any reasonable time upon
forty-eight (48) hours notice (or at any time without notice in the event of
any emergency) for inspection; to supply any service to be provided by
Landlord hereunder; to submit the Premises to prospective purchasers or
tenants; to post notices of non-responsibility; to affix and display "For
Rent" signs during the last twelve (12) months of the Term; and to make
repairs, alterations, additions or improvements to the Premises or the
Building; and

                  (vi)   to approve the design, location, number, size and
color of all signs located on the exterior of the Building.

         b.      Without limiting the generality of the provisions of Section
10a, above, at any time during the Term of this Lease, Landlord shall have
the right to remove, alter, improve, renovate or rebuild the common areas of
the Building (including but not limited to the lobby, hallways and corridors
thereof), and to install, repair, replace, alter, improve or rebuild in the
Premises, other tenants' premises and/or the common areas of the Building
(including the lobby, hallways and corridors thereof), any mechanical,
electrical, water, sprinkler, plumbing, heating, air conditioning and
ventilating systems, at any time during the Term of this Lease. In connection
with making any such installations, repairs, replacements, alterations,
additions and improvements under the terms of this Section 10, Landlord shall
have the right to access through the Premises as well as the right to take
into and upon and through the Premises or any other part of the Building, all
materials that may be required to make any such repairs, replacements,
alterations, additions or improvements, as well as the right in the course of
such work temporarily to close entrances, doors, corridors, elevators or
other facilities located in the Building or temporarily to cease the
operations of any services or facilities therein or to take portion(s) of the
Premises reasonably necessary in connection with such work, without being
deemed or held guilty of an eviction of Tenant; provided, however that
Landlord agrees to use all reasonable efforts not to interfere with or
interrupt Tenant's business operation in the Premises. Notwithstanding the
foregoing, in the event that, as a result of the exercise by Landlord of its
rights under this Section 10b, more than fifty percent (50%) of the rentable
area of the Premises is rendered untenantable for more than seven (7)
consecutive days, and Tenant ceases to use such untenantable portion of the
Premises during the entirety of such period, Annual Base Rent and Additional
Rent shall be equitably adjusted (based on the portion of the Premises which
is rendered untenantable) beginning on the eighth (8th) day of
untenantability until the Premises are no longer untenantable. Landlord shall
have the right to install, use and maintain pipes and conduits above the
ceilings, under the floors and behind the demising walls in the Premises,
including without limitation telephone and computer installations, provided
that such pipes and conduits do not permanently materially adversely affect
Tenant's access to or use of the Premises.

         c.      Except for injury, loss or damage resulting from Landlord's
negligence or willful misconduct, Landlord shall not be liable to Tenant for
any expense, injury, loss or damage resulting from Landlord's exercise of any
rights under this Section 10, all claims against Landlord for any and all
such liability being hereby expressly released by Tenant. Landlord shall not
be liable to Tenant for damages by reason of interference with the business
of Tenant or inconvenience or annoyance to Tenant or the customers of Tenant.
The Rent reserved herein shall not abate while the Landlord's rights under
this Section 10 are exercised, and Tenant shall not be entitled to any
set-off or counterclaims for damages of any kind against Landlord by reason
thereof, all such claims being hereby expressly released by Tenant.

         d.      Landlord shall have the right to use any and all means which
Landlord may deem proper to open all of the doors in, upon and about the
Premises, excluding Tenant's vaults and safes, in any emergency in order to
obtain entry to the Premises. Any entry to the Premises obtained by Landlord
by any of said means shall not be construed or deemed to be a forcible or
unlawful entry into, or a detainer of, the Premises, or an eviction of Tenant
from the Premises or any portion thereof.

11.  LIABILITY.

         a.      Landlord and its agents, officers, directors and employees
assume no liability or responsibility whatsoever with respect to the conduct
or operation of the business to be conducted in the Premises and shall have
no liability for any claim of loss of business or interruption of operations
(or any claim related thereto). Landlord and its agents, officers, directors
and employees shall not be liable for any accident to or injury to any person
or persons or property in or about the Premises which are caused by the
conduct and operation of said business or by virtue of equipment or property
of Tenant in said Premises. Tenant agrees to hold Landlord and its agents,
officers, directors and employees harmless against all such claims, except to
the extent resulting from Landlord's negligence or willful misconduct.
Landlord and its agents, officer, directors and employees shall not be liable
to Tenant, its employees, agents, business invitees, licensees, customers,
clients, family members or guests for any damage, compensation or claim
arising out of or related to managing the Premises or the Building, repairing
any portion of the Premises or the Building, the interruption in the use of
the Premises, accident or damage resulting from the use or operation (by
Landlord and its agents, officers, directors and employees, Tenant, or any
other person or persons whatsoever) or failure of elevators, or heating,
cooling, electrical or

                                      15
<PAGE>

plumbing equipment or apparatus, or the termination of this Lease by reason
of the destruction of the Premises, or from any fire, robbery, theft,
mysterious disappearance and/or any other casualty, or from any leakage in
any part of portion of the Premises or the Building, or from water, rain or
snow that may leak into or flow from any part of the Premises or the
Building, or from any other cause whatsoever, unless occasioned by the
willful misconduct or acts of negligence of Landlord. In no event shall
Landlord be liable for punitive or consequential damages, nor shall Landlord
be liable with respect to utilities furnished to the Premises, or the lack of
any utilities. Any goods, property or personal effects, stored or placed by
Tenant in or about the Premises or in the Building, shall be at the sole risk
of Tenant, and Landlord and its agents, officers, directors and employees
shall not in any manner be held responsible therefor, except if such injury
or damage results from Landlord's negligence or willful misconduct. The
agents and employees of Landlord are prohibited from receiving any packages
or other articles delivered to the Building for Tenant, and if any such agent
or employee receives any such package or articles, such agent or employee
shall be the agent of Tenant for such purposes and not of Landlord.

         b.      Tenant hereby agrees to indemnify and hold Landlord and its
agents, officers, directors and employees harmless from and against any cost,
damage, claim, liability or expense (including reasonable attorneys' fees)
incurred by or claimed against Landlord and its agents, officers, directors
and employees, directly or indirectly, as a result of or in any way arising
from (i) Tenant's use and occupancy of the Premises or in any other manner
which relates to the business of Tenant, including, but not limited to, any
cost, damage, claim, liability or expense arising from any violation of any
zoning, health, environmental or other law, ordinance, order, rule or
regulation of any governmental body or agency; (ii) the negligence or willful
misconduct of Tenant, its officers, directors, employees and agents; (iii)
any default, breach or violation of this Lease by Tenant; or (iv) injury or
death to individuals or damage to property sustained in or about the Premises.

         c.      Notwithstanding any other provision of this Lease to the
contrary, Landlord and Tenant agree that in the event that the Building, the
Premises or the contents thereof are damaged or destroyed by fire or other
casualty, each party hereto waives its rights, if any, against the other
party with respect to such damage or destruction to the extent such damage or
destruction is covered under the property insurance policy(ies) of the party
waiving such rights (or would have been covered had the party waiving such
rights carried the property insurance required hereunder to be carried by
such party); provided however, if any fire or other casualty caused by Tenant
shall have damaged or destroyed any part of the Building or the contents
thereof, Tenant shall be responsible for any deductible amount under
Landlord's property insurance policy(ies). All policies of fire and/or
extended coverage or other insurance covering the Premises or the contents
thereof obtained by Landlord or Tenant shall contain a clause or endorsement
providing in substance that (i) such insurance shall not be prejudiced if the
insureds thereunder have waived in whole or in part the right of recovery
from any person or persons prior to the date and time of loss or damage, if
any, and (ii) the insurer waives any rights of subrogation against Landlord
(in the case of Tenant's insurance policy) or Tenant (in the case of
Landlord's insurance policy), as the case may be.

12.  INSURANCE.

         a.      Tenant shall maintain at all times during the Term hereof
and at its sole cost and expense, broad-form commercial general liability
insurance for bodily injury and property damage naming Landlord as an
additional insured, in such amounts as are adequate to protect Landlord and
Landlord's managing agents against liability for injury to or death of any
person in connection with the use, operation or condition of the Premises.
Such insurance at all times shall be in an amount of not less than Three
Million Dollars ($3,000,000) combined single limit aggregate for bodily
injury or death or damage to property. If, in the reasonable opinion of the
insurance broker retained by Landlord, the amount of public liability and
property damage insurance coverage at any time during the Term is not
adequate, Tenant shall increase the insurance coverage as required by
Landlord's insurance broker. In no event shall the limits of such policy be
considered as limiting the liability of Tenant under this Lease.

         b.      Tenant shall at all times during the Term hereof maintain in
effect policies of insurance covering the Leasehold Improvements (including
any Alterations, additions or improvements as may be made by Tenant after the
Commencement Date), plate glass, trade fixtures, merchandise and all other
personal property from time to time in or on the Premises, in an amount not
less than one hundred percent (100%) of their actual replacement cost,
providing protection against all risks covered by standard form of "Fire and
Extended Coverage Insurance," together with insurance against vandalism and
malicious mischief. Tenant shall also maintain at its sole cost and expense
workman's compensation insurance in the maximum amount required by law.

         c.      All insurance required to be carried by Tenant shall be
issued by responsible insurance companies, qualified to do business in the
Commonwealth of Virginia and reasonably acceptable to Landlord. Each policy
shall name Landlord, Landlord's mortgagee and the property management company
retained by Landlord at the Building, as additional insureds, and shall
contain a provision that the same may not be cancelled or reduced without
providing Landlord not less than thirty (30) days' prior written notice.
Copies of all policies or, at Landlord's option, certificates of insurance
(ACORD 27 only) evidencing the existence and amounts of said insurance shall
be delivered to Landlord no later than five (5) days prior to the
Commencement Date, and renewals thereof shall be delivered to Landlord at
least ten (10) days prior to the expiration of any such policy. If Tenant
fails to adhere to the requirements of this Section 12, Landlord may order
such insurance and charge the cost thereof to Tenant, which amount shall be
deemed Additional Rent hereunder and shall be payable by Tenant upon demand.
Tenant's failure to provide and keep in force the aforementioned insurance
shall be regarded as a material default

                                      16
<PAGE>

hereunder, entitling Landlord to exercise any or all of the remedies provided
in this Lease. Any policy may be carried under so-called "blanket coverage"
form of insurance policies. Tenant shall obtain and furnish evidence to
Landlord of the waiver by Tenant's insurance carriers of any right of
subrogation against Landlord and Landlord's management company at the
Building.

         d.      Landlord agrees to maintain throughout the Term, property
damage insurance covering the Building in an amount equal to the then-full
replacement value of the Building. Such coverage may be provided by way of a
"blanket" policy of insurance maintained by Landlord.

         e.      Each party hereby waives any and every right or cause of
action for any and all loss of, or damage to, any of its property (whether or
not such loss or damage is caused by the fault or negligence of the other
party or anyone for whom said other party may be responsible), which loss or
damage is covered by valid and collectible fire, extended coverage, "All
Risk" or similar policies, maintained by such party or required to be
maintained by such party under this Lease, but only to the extent that such
loss or damage is recovered under said insurance policies (if such policy or
policies have been obtained) or would have been recovered if such party had
obtained the required insurance coverage hereunder. Written notice of the
terms of said mutual waivers shall be given to each insurance carrier and
said insurance policies shall be properly endorsed, if necessary, to prevent
the invalidation of said insurance coverages by reason of said waivers.

13. FIRE OR CASUALTY.

         a.      If the Premises or any part thereof shall be damaged by fire
or any other cause, Tenant shall give prompt notice thereof to Landlord. If,
in the reasonable judgment of Landlord's architect, restoration of the
Premises is feasible within a period of nine (9) months from the date of the
damage, Landlord shall restore the Premises to the extent of the Tenant
Improvements set forth in the Work Agreement, provided that adequate
insurance proceeds are made available to Landlord. Tenant agrees to make all
proceeds of Tenant's insurance policies available to Landlord in accordance
with Tenant's insurance obligations set forth in Section 12, above. In
addition, Tenant shall repair and restore, at Tenant's sole expense, all
furniture, fixtures and other property of Tenant located in the Premises
prior to such casualty. If the Premises are unusable, in whole or in part,
during such restoration, the Monthly Base Rent and Additional Rent hereunder
shall be abated to the extent and for the period that the Premises are
unusable; provided, however, that if such damage or destruction shall result
from the act or omission of Tenant, its employees, agents or invitees, Tenant
shall not be entitled to any abatement of Monthly Base Rent or Additional
Rent.

         b.      If restoration is not feasible in the reasonable judgment of
Landlord's architect within the aforesaid nine (9) month period, Landlord shall
so notify Tenant within thirty (30) days after the occurrence of such damage,
and Landlord and Tenant shall each have the right to terminate this Lease by
giving written notice thereof to the other party within sixty (60) days after
the occurrence of such damage, in which event this Lease and the tenancy
hereunder shall terminate as of the date of such damage or destruction and the
Monthly Base Rent and Additional Rent will be apportioned as of the date of such
damage or destruction. If neither party exercises its right of termination, the
Premises shall be restored as provided above.

         c.      In case the Building is so severely damaged by fire or other
casualty (although the Premises may not be affected) that Landlord shall decide
in its sole discretion not to rebuild or reconstruct such Building, then this
Lease and the tenancy hereunder shall terminate on the date specified by
Landlord in a notice given no later than sixty (60) days after the date of such
casualty.


14. EMINENT DOMAIN. If the Premises or any part thereof shall be taken by any
governmental or quasi-governmental authority pursuant to the power of eminent
domain, Tenant shall make no claim for compensation in such proceedings and
shall have no right to participate in any condemnation proceedings under any
statutes, laws or ordinances of the Commonwealth of Virginia. All sums awarded
or agreed upon between Landlord and the condemning authority for the taking of
the interest of Landlord or Tenant, whether as damages or as compensation, will
be the property of Landlord, provided, however, that Tenant may submit a claim
for its reasonable relocation costs incurred, if any. In the event of such
taking, Rent shall be paid to the date of vesting of title in the condemning
authority.

15. SUBORDINATION AND ESTOPPEL CERTIFICATES.

         a.      Subject to Tenant's receipt of an SNDA (hereinafter defined)
from the then-applicable mortgagee or ground lessor of the Building, this
Lease shall be subject and subordinate at all times to all ground or
underlying leases which now exist or may hereafter be executed affecting the
Building or any part thereof or the Land, and to the lien of any mortgages or
deeds of trust in any amount or amounts whatsoever now or hereafter placed on
or against the Building or any part thereof or the Land, or on or against
Landlord's interest or estate therein or on or against any ground or
underlying lease without the necessity of having further instruments on the
part of Tenant to effect such subordination. Upon request of Landlord, Tenant
will execute any further written instrument necessary to subordinate its
rights hereunder to any such underlying leases or liens. If, at any time, or
from time to time during the Term, any mortgagee shall request that this
Lease have priority over the lien of such mortgage, and if Landlord consents
thereto, this Lease shall have priority over the lien of such mortgage and
all renewals, modifications, replacements, consolidations and extensions
thereof and all advances made thereunder and interest thereon, and Tenant
shall, within fifteen (15) business days after receipt of a request therefor


                                     17
<PAGE>

from Landlord, execute, acknowledge and deliver any and all documents and
instruments confirming the priority of this Lease. In any event, however, if
this Lease shall have priority over the lien of a first mortgage, this Lease
shall not become subject or subordinate to the lien of any subordinate
mortgage, and Tenant shall not execute any subordination documents or
instruments for any subordinate mortgagee, without the written consent of the
first mortgagee. Landlord shall obtain for Tenant's benefit, from the current
mortgagee of the Building, a subordination, non-disturbance and attornment
agreement ("SNDA"), in recordable form, on such mortgagee's standard form of
SNDA. The SNDA shall provide that, upon a foreclosure under such mortgagee's
deed of trust (or a deed-in-lieu thereof), so long as Tenant is not then in
default hereunder, Tenant's rights under this Lease shall not be extinguished
and such mortgagee (or such other purchaser at a foreclosure sale) shall
recognize this Lease and Tenant's rights hereunder, subject to certain
limitations regarding the obligations of the successor Landlord hereunder as
may be set forth in the SNDA. Landlord shall use reasonable efforts to obtain
for Tenant's benefit from any future mortgagee an SNDA on such mortgagee's
standard form of SNDA.

         b.      In the event of (i) a transfer of Landlord's interest in the
Building, (ii) the termination of any ground or underlying lease of the
Building, or the Land, or both, or (iii) the purchase or other acquisition of
the Building, or Landlord's interest therein in a foreclosure sale or by deed in
lieu of foreclosure under any mortgage or deed of trust, or pursuant to a power
of sale contained in any mortgage or deed of trust, then in any of such events
Tenant shall, at the request of Landlord or Landlord's successor in interest,
attorn to and recognize the transferee or purchaser of Landlord's interest or
the interest of the lessor under the terminated ground or underlying lease, as
the case may be, as "Landlord" under this Lease for the balance then remaining
of the Term, and thereafter this Lease shall continue as a direct lease between
such person or entity, as "Landlord," and Tenant, as "Tenant," except that such
lessor, transferee or purchaser shall not be liable for any act or omission of
Landlord before such lease termination or before such person's succession to
title, nor be bound by any payment of Monthly Base Rent or Additional Rent
before such lease termination or before such person's succession to title for
more than one month in advance, nor, in the case of a transfer of the Landlord's
interest as a result of a foreclosure sale (or deed-in-lieu thereof), be subject
to any offset, defense or counterclaim accruing before such lease termination or
before such person's succession to title.

         c.      Tenant agrees, at any time, and from time to time, upon not
less than fifteen (15) days' prior notice by Landlord, to execute,
acknowledge and deliver to Landlord, a statement in writing certifying (to
the extent accurate as delivered or, it not, by modifying same to be
accurate) that (i) this Lease is unmodified and in full force and effect (or
if there have been modifications, that the same is in full force and effect
as modified and stating the modifications); (ii) the Term of the Lease has
commenced and the full rental is now accruing hereunder; (iii) Tenant has
accepted possession of the Premises and is presently occupying the same; (iv)
all improvements required by the terms of the Lease to be made by Landlord
have been completed and all tenant improvement allowances have been paid in
full; (v) there are no offsets, counterclaims, abatements or defenses against
or with respect to the payment of any rent or other charges due under the
Lease; (vi) no rent under the Lease has been paid more than thirty (30) days
in advance of its due date; (vii) to the best of the knowledge of the Tenant,
Landlord is not in default in the performance of any covenant, agreement,
provision or condition contained in the Lease or, if so, specifying each such
default of which Tenant may have knowledge; (viii) the address for notices to
be sent to Tenant; (ix) the only security deposit tendered by Tenant is as
set forth in the Lease, and such security deposit has been paid to Landlord;
and (x) any other information reasonably requested by Landlord or any
mortgagee or ground lessor of the Building and/or the Land it being intended
that any such statement delivered pursuant hereto may be relied upon by any
prospective purchaser or lessee of the Building or any part thereof, any
mortgagee or prospective mortgagee thereof, any prospective assignee of any
mortgage thereof, any ground lessor or prospective ground lessor of the Land
and/or the Building, or any prospective assignee of any such ground lease.
Tenant also agrees to execute and deliver from time to time such reasonable
estoppel certificates as an institutional lender may require with respect to
this Lease.

16. DEFAULT AND REMEDIES.

         a.      If Tenant shall (i) fail to pay any installment of Monthly
Base Rent, although no legal or formal demand has been made therefor, within
five (5) business days after written notice by Landlord (provided that no
such notice shall be required with respect to the second (2nd) and each
successive late payment of Monthly Base Rent during any twelve (12) month
period hereunder, with respect to which an Event of Default shall occur
hereunder upon Tenant's failure to tender any such installment of Monthly
Base Rent to Landlord with five (5) business days after its due date), or
(ii) fail to make any payment of Additional Rent or any other payment
required by the terms and provisions hereof, within five (5) days after
notice or demand therefor; or (iii) convey, assign, mortgage or sublet this
Lease, the Premises or any part thereof, or Tenant's interest therein, or
attempt any of the foregoing, without the prior written consent of Landlord;
or (iv) commit or suffer to exist an Event of Bankruptcy (hereinafter
defined), or (v) fail to maintain the insurance coverage required by Section
12, above, or (vi) violate or fail to perform any of the other terms,
conditions, covenants, or agreements herein made by Tenant and fails to cure
such default within thirty (30) calendar days after notice, provided,
however, that if the nature of Tenant's failure is such that more than thirty
(30) days are reasonably required for its cure, then Tenant shall not be in
default if it begins such cure within the thirty (30) day period described
above and thereafter diligently prosecutes such cure to completion within an
additional thirty (30) days; then there shall be deemed to have been
committed an "Event of Default".


                                     18
<PAGE>

         b.      In the event of any Event of Default by Tenant as defined in
Section 16a, Landlord may at any time thereafter, without notice and demand
and without limiting Landlord in the exercise of any other right or remedy
which Landlord may have by reason of such default or breach do any of the
following:

                 (i)      Landlord may terminate this Lease, by giving written
notice of such termination to Tenant, whereupon this Lease shall automatically
cease and terminate and Tenant shall be immediately obligated to quit the
Premises. Any other notice to quit or notice of Landlord's intention to re-enter
the Premises is hereby expressly waived. If Landlord elects to terminate this
Lease, everything contained in this Lease on the part of Landlord to be done and
performed shall cease without prejudice, subject, however, to the right of
Landlord to recover from Tenant all rent and any other sums accrued up to the
time of termination or recovery of possession by Landlord, whichever is later.

                (ii)      With or without the termination of this Lease,
Landlord may proceed to recover possession of the Premises under and by
virtue of the provisions of the laws of the jurisdiction in which the
Building is located, or by such other proceedings, including re-entry and
possession, as may be applicable. If this Lease is terminated or Landlord
recovers possession of the Premises before the expiration of the Term by
reason of Tenant's default as hereinabove provided, Landlord shall take
reasonable steps to attempt to relet the Premises for such rent and upon such
terms as are not unreasonable under the circumstances and, if the full rental
reserved under this Lease (and any of the costs, expenses or damages
indicated below) shall not be realized by Landlord, Tenant shall be liable
for all damages sustained by Landlord, including without limitation
deficiency in rent during any period of vacancy or otherwise; the costs of
removing and storing the property of Tenant or of any other occupant; the
then-remaining unamortized portion of the Improvement Allowance described in
the Work Agreement; all reasonable expenses incurred by Landlord in enforcing
Landlord's remedies, including without limitation reasonable attorneys' fees
and Late Charges as provided herein, and advertising, brokerage fees and
expenses of placing the Premises in first class rentable condition. Landlord,
in putting the Premises in good order or preparing the same for rerental may,
at Landlord's option, make such alterations, repairs, or replacements in the
Premises as Landlord, in its sole judgment, considers advisable and necessary
for the purpose of reletting the Premises, and the making of such
alterations, repairs, or replacements shall not operate or be construed to
release Tenant from liability hereunder as aforesaid.

               (iii)      Any damage or loss of rent sustained by Landlord
may be recovered by Landlord, at Landlord's option, at the time of
termination of this Lease, the time of the reletting, or in separate actions,
from time to time, as said damage shall have been made more easily
ascertainable by successive relettings, or at Landlord's option in a single
proceeding deferred until the expiration of the Term (in which event Tenant
hereby agrees that the cause of action shall not be deemed to have accrued
until the date of expiration of said Term) or in a single proceeding prior to
either the time of reletting or the expiration of the Term. If the Landlord
elects to repossess the Premises without terminating this Lease, then Tenant
shall be liable for and shall pay to Landlord all Rent and other indebtedness
accrued to the date of such repossession, plus Rent required to be paid by
Tenant to Landlord during the remainder of this Lease until the date of
expiration of the Term, diminished by any net sums thereafter received by
Landlord through reletting the Premises during such period (after deducting
expenses incurred by Landlord as provided in Section 16b(ii), above). In no
event shall Tenant be entitled to any excess of any Rent obtained by
reletting over and above the Rent herein reserved. Actions to collect amounts
due from Tenant as provided in this Section 16(a)(iii) may be brought from
time to time, on one or more occasions, without the necessity of Landlord's
waiting until expiration of this Lease term. Upon termination of this Lease
or repossession of the Premises following a default hereunder, Landlord shall
attempt to relet the Premises or any portion thereof; provided that, if
Landlord is successful in reletting, it shall not be responsible for the
payment of Rent by such new tenant. In the event of reletting Landlord may
relet the whole or any portion of the Premises for any period, to any tenant,
and for any use and purpose on such terms and at such rentals as Landlord in
its exclusive judgment may determine.

         c.      Notwithstanding the foregoing, if Landlord terminates this
Lease pursuant to Section 16b(i), above, Landlord shall be entitled to
recover from Tenant, and Tenant shall pay to Landlord on demand, as and for
liquidated and agreed final damages for Tenant's default, an amount equal to
the difference between (i) all Monthly Base Rent, Additional Rent and other
sums which would be payable under this Lease from the date of such demand
(or, if it is earlier, the date to which Tenant shall have satisfied in full
its obligations under Section 16b(ii), above) for what would be the then
unexpired Term in the absence of such termination, and (ii) the fair market
rental value of the Premises over the same period (net of all expenses and
all vacancy periods reasonably projected by Landlord to be incurred in
connection with the reletting of the Premises), with such differential
discounted at the rate of seven percent (7%) per annum. Nothing herein shall
be construed to affect or prejudice Landlord's right to prove, and claim in
full, unpaid Rent or any other amounts accrued prior to termination of this
Lease.

         d.      Notwithstanding anything herein to the contrary, upon the
occurrence of an Event of Default hereunder, Landlord, with or without
terminating the Lease, may immediately reenter and take possession of the
Premises and evict Tenant therefrom, without legal process of any kind, using
such force as may be necessary, without being liable for or guilty of
trespass, forcible entry or any other tort. Landlord's right to exercise such
"self-help" remedy shall be in addition to, and not in limitation of,
Landlord's other rights and remedies hereunder for a breach by Tenant of its
obligations under the Lease.

         e.      Tenant hereby expressly waives any and all rights of
redemption granted by or under any present of future laws in the event Tenant
is evicted or dispossessed for any cause, or in the event Landlord obtains
possession of the Premises, by reason of the violation by Tenant of any of
the covenants and conditions of this Lease or otherwise. In addition, Tenant
hereby expressly waives any


                                     19
<PAGE>

and all rights to bring any action whatsoever against any tenant taking
possession after Tenant has been dispossessed or evicted hereunder, or to
make any such tenant or party to any action brought by Tenant against
Landlord.

         f.      Landlord and Tenant shall and each does hereby waive trial
by jury in any action, proceeding or counterclaim brought by either of the
parties hereto against the other on any matters whatsoever arising out of or
in any way connected with this Lease or its termination, the relationship of
Landlord and Tenant, Tenant's use or occupancy of the Premises or any claim
of injury or damage and any emergency statutory or any other statutory
remedy. In the event Landlord commences any summary proceeding for nonpayment
of Rent or Additional Rent, or commences any other action or proceeding
against Tenant in connection with this Lease, Tenant will interpose no
counterclaim of whatever nature or description in any such proceeding.

         g.      Nothing contained herein shall prevent the enforcement of
any claim Landlord may have against Tenant for anticipatory breach of the
unexpired Term. In the event of a breach or anticipatory breach by Tenant of
any of the covenants or provisions hereof, Landlord shall have the right of
injunction and the right to invoke any remedy allowed at law or in equity as
if reentry, summary proceedings and other remedies were not provided for
herein.

         h.      Prior to exercising any rights or remedies upon a default by
Landlord, Tenant will give Landlord notice specifying such default, and
Landlord shall have thirty (30) days after receipt of such notice in which to
cure any such default; provided, however, that if such default cannot, by its
nature, be cured within such period, Landlord shall not be deemed in default
if Landlord shall within such period commence to cure such default and shall
diligently prosecute the same to completion. Unless and until Landlord fails
so to cure any default after notice, Tenant shall have no remedy or cause of
action by reason thereof. All obligations of Landlord hereunder will be
construed as covenants, not conditions; all such obligations will be binding
upon Landlord only during the period of its ownership of the Building and not
thereafter; and no default or alleged default by Landlord shall relieve or
delay performance by Tenant of its obligations to continue to pay Annual Base
Rent and Additional Rent hereunder as and when the same shall be due, except
as expressly provided in Section 9a, above.

17. BANKRUPTCY.

         a.      For purposes of this Lease, the following shall be deemed
"Events of Bankruptcy": (i) if a receiver or custodian is appointed for any
or all of Tenant's property or assets, or if there is instituted a
foreclosure action on any of Tenant's property and such action is not
dismissed within thirty (30) days thereafter; or (ii) if Tenant files a
voluntary petition under 11 U.S.C. Article 101, ET SEQ., as amended (the
"Bankruptcy Code"), or under the insolvency laws of any jurisdiction (the
"Insolvency Laws"); or (iii) if there is filed an involuntary petition
against Tenant as the subject debtor under the Bankruptcy Code or Insolvency
Laws, which is not dismissed within sixty (60) days of filing; or (iv) if
Tenant makes or consents to an assignment of its assets, in whole or in part,
for the benefit of creditors, or a common law composition of creditors; or
(v) if Tenant generally is not paying its debts as its debts become due.

         b.      Upon the occurrence of an Event of Bankruptcy, Landlord, at
its option and sole discretion, may terminate this Lease by written notice to
Tenant (subject, however, to applicable provisions of the Bankruptcy Code or
Insolvency Laws during the pendency of any action thereunder). If this Lease
is terminated under this Section 17, Tenant shall immediately surrender and
vacate the Premises, waives all statutory or other notice to quit, and agrees
that Landlord shall have all rights and remedies against Tenant provided in
Section 16 in case of an Event of Default by Tenant.

         c.      If Tenant becomes the subject debtor in a case pending under
the Bankruptcy Code (the "Bankruptcy Case"), Landlord's right to terminate
this Lease under this Section 17 shall be subject to the applicable rights
(if any) of the debtor-in-possession or the debtor's trustee in bankruptcy
(collectively, the "Trustee") to assume or assign this Lease as then provided
for in the Bankruptcy Code, however, the Trustee must give to Landlord, and
Landlord must receive, proper written notice of the Trustee's assumption or
rejection of this Lease, within sixty (60) days (or such other applicable
period as is provided pursuant to the Bankruptcy Code, it being agreed that
sixty (60) days is a reasonable period of time for election of an assumption
or rejection of this Lease) after the commencement of the Bankruptcy Case; it
being agreed that failure of the Trustee to give notice of such assumption
hereof within said period shall conclusively and irrevocably constitute the
Trustee's rejection of this Lease and waiver of any right of the Trustee to
assume or assign this Lease. The Trustee shall not have the right to assume
or assign this Lease unless said Trustee (i) promptly and fully cures all
defaults under this Lease, (ii) promptly and fully compensates Landlord and
any third party (including other tenants) for all monetary damages incurred
as a result of such default, and (iii) provides to Landlord "adequate
assurance of future performance." Landlord and Tenant (which term may include
the debtor or any permitted assignee of debtor) hereby agree in advance that
"adequate assurance of performance" as used in this paragraph, shall mean
that all of the following minimum criteria must be met: (1) the source of
Monthly Base Rent, Additional Rent, and other consideration due under this
Lease, and the financial condition and operating performance of Tenant, and
its guarantor, if any, shall be similar to the financial condition and
operating performance of Tenant as of the Lease Commencement Date; (2)
Trustee or Tenant must pay to Landlord all Monthly Base Rent and Additional
Rent payable by Tenant hereunder in advance, (3) Trustee or Tenant must agree
(by writing delivered to Landlord) that the use of the Premises shall be used
only for the permitted use as stated in this Lease, and that any assumption
or assignment of this Lease is subject to all of the provisions thereof and
will not violate or affect the rights or agreements of any other tenants or
occupants in the Building or of Landlord (including any mortgage or other
financing


                                     20
<PAGE>

agreement for the Building, (4) Trustee or Tenant must pay to Landlord at the
time the next Monthly Base Rent is due under this Lease, in addition to such
installment of Monthly Base Rent, an amount equal to the installments of
Monthly Base Rent and Additional Rent due under this Lease for the next six
(6) months of this Lease, said amount to be held by Landlord in escrow until
either Trustee or Tenant defaults in its payment of Monthly Base Rent and
Additional Rent or other obligations under this Lease (whereupon Landlord
shall have the right to draw on such escrowed funds) or until the expiration
of this Lease (whereupon the funds shall be returned to Trustee or Tenant
except to the extent the funds have been drawn and not replaced); and (5)
Trustee or Tenant must agree to pay to Landlord at any time Landlord is
authorized to and does draw on the escrow account the amount necessary to
restore such escrow account to the original level required by clause (4),
above. The criteria stated above are not intended to be exhaustive or
all-inclusive and Landlord may determine that the circumstances of Tenant or
of this Lease require other or further assurances of future performance. In
the event Tenant is unable to: (a) cure its defaults, (b) reimburse Landlord
for its monetary damages, (c) pay the Monthly Base Rent and Additional Rent
due under this Lease on time, or (d) meet that criteria and obligations
imposed by (1) through (5), above, then Tenant hereby agrees in advance that
it has not met its burden to provide adequate assurance of future
performance, and this Lease may be terminated by Landlord in accordance with
Section 17b, above.

18. PAYMENT OF TENANT'S OBLIGATIONS BY LANDLORD AND UNPAID RENT. All covenants
and agreements to be performed by Tenant under any of the terms of this Lease
shall be performed by Tenant at Tenant's sole cost and expense. If Tenant shall
fail to pay any sum of money, other than Rent, required to be paid by it
hereunder or shall fail to perform any other act on its part to be performed
hereunder, and such failure shall continue beyond any applicable grace period
set forth in this Lease, Landlord may, without waiving or releasing Tenant from
any of its obligations hereunder, make any such payment or perform any such
other required act on Tenant's part. All sums so paid by Landlord, and all
necessary incidental costs, together with interest thereon at two percentage
points (2%) over the Prime Rate then in effect, from the date of such payment by
Landlord, shall be payable by Tenant to Landlord as Additional Rent hereunder,
on demand, and Tenant covenants and agrees to pay any such sums. Landlord shall
have (in addition to any other right or remedy of Landlord hereunder or at law)
the same rights and remedies in the event of the nonpayment thereof by Tenant as
in the case of default by Tenant in the payment of Additional Rent. In addition,
any Rent, including without limitation Annual Base Rent, Additional Rent,
Tenant's Pass-Through Costs and/or Late Charges, which is not paid timely will
accrue interest per annum at two percentage points (2%) over the Prime Rate from
the date such payment is due until the date paid in full (including all accrued
interest).

19. VOLUNTARY SURRENDER. The voluntary or other surrender of this Lease by
Tenant, or a mutual cancellation thereof, shall not work a merger, and shall, at
the sole option of Landlord, terminate all or any existing subleases or
subtenancies, or may, at the sole option of Landlord, operate as an assignment
to Landlord of any or all such subleases or subtenancies; provided however, that
if Landlord elects to treat such termination as an assignment of any such
sublease, Landlord shall have no obligation or liability to the subtenant
thereunder for any claim, damage or injury which accrued prior to the date of
surrender or mutual cancellation hereunder.

20. ABANDONMENT OF PERSONAL PROPERTY. Upon the expiration of the Term or earlier
termination of this Lease, Tenant shall forthwith remove Tenant's goods and
effects and those of any other persons claiming through or under Tenant, or
subtenancies assigned to it, and quit and deliver the Premises to the Landlord
peaceably and quietly. Goods and effects not removed by Tenant after termination
of this Lease (or within three (3) business days after a termination by reason
of Tenant's default) shall be considered abandoned. Landlord shall give Tenant
notice of right to reclaim abandoned property pursuant to applicable local law
and may thereafter dispose of the same as Landlord deems expedient, including
public or private sale and/or storage in a public warehouse or elsewhere at the
sole cost, and for the account, of Tenant, and Tenant shall promptly upon demand
reimburse Landlord for any expenses incurred by Landlord in connection
therewith, including reasonable attorneys' fees.

21. HOLD-OVER. If Tenant shall not immediately surrender the Premises at the
expiration of the Term then Tenant shall, by virtue of the provisions of this
Section 21, become a tenant by the month. In such event Tenant shall be
required to pay one hundred fifty percent (150%) of the amount of the Monthly
Base Rent then in effect and as subsequently escalated in accordance with the
provisions hereof, together with all Additional Rent in effect during the
last month of the Term commencing said monthly tenancy with the first day
next after the end of the Term; and said Tenant, as a month-to-month tenant,
shall be subject to all of the conditions and covenants of this Lease as
though the same had originally been a monthly tenancy, except as otherwise
provided above with respect to the payment of Rent. Each party hereto shall
give to the other at least thirty (30) days' written notice to quit the
Premises, except in the event of non-payment of Rent provided for herein when
due, or of the breach of any other covenant by the said Tenant, in which
event, Tenant shall not be entitled to any notice to quit, the usual thirty
(30) days' notice to quit being expressly waived; provided, however, that in
the event that Tenant shall hold over after expiration of the Term, and if
Landlord shall desire to regain possession of said Premises promptly at the
expiration of the Term, then at any time prior to the acceptance of the Rent
by Landlord from Tenant, as a monthly tenant hereunder, Landlord, at its
election or option, may reenter and take possession of the Premises
forthwith, without process, or by any legal action or process in the
Commonwealth of Virginia.


                                     21
<PAGE>

22.  OPTION TO EXTEND TERM.

         a.      Tenant shall have and is hereby granted the option to extend
the Term hereof for one (1) additional period of five (5) years (the
"Extension Period"), provided (i) Tenant gives written notice to Landlord of
Tenant's election to exercise such extension option no earlier than fifteen
(15), and no later than twelve (12), months prior to the expiration of the
last Lease Year of the Term; (ii) no Event of Default has occurred during the
Term, and no event exists at the time of the exercise of such option or
arises subsequent thereto, which event by notice and/or the passage of time
would constitute an Event of Default if not cured within the applicable cure
period; and (iii) Tenant has not assigned its interest in this Lease or
sublet more than twenty percent (20%) of the Premises to a person or entity
other than a Permitted Transferee.

         b.      All terms and conditions of this Lease, including without
limitation all provisions governing the payment of Additional Rent and annual
increases in the Annual Base Rent, shall remain in full force and effect
during the Extension Period, except that Annual Base Rent payable during the
first Lease Year of the Extension Period shall be the then-current Fair
Market Rental Rate (hereinafter defined) with respect to comparable office
space at the time of the commencement of the Extension Period (using a Base
Year of the calendar year in which the Extension Period commences for
purposes of determining Tenant's Pass-Through Costs); provided, however, in
no event shall the Annual Base Rent for the first Lease Year of the Extension
Period be less (on a per square foot basis) than the Annual Base Rent in
effect for the last Lease Year of the initial Term. Landlord shall not be
obligated to make, or pay for, any improvements or alterations in or to the
Premises. There shall be no rental abatement during the Extension Period. As
used in this Lease, the term "Fair Market Rental Rate" shall mean the fair
market rental rate per square foot of rentable area that would be agreed upon
between a landlord and a tenant entering into a new lease for comparable
space as to location, configuration, view and elevator exposure, size and
use, in a comparable building as to location, quality, reputation and age,
with a comparable build-out, a comparable term and a comparable base year for
operating expense and real estate tax pass-throughs assuming the following:
(1) the landlord and tenant are informed and well-advised and each is acting
in what it considers its own best interests; (2) a tenant improvement
allowance, free rent periods or any other special concessions (for example,
design fees, moving allowances, refurbishing allowances, etc.) will not be
provided to Tenant except to the extent that such allowances or concessions
are reflected in the fair market rental rates being obtained (in which event
the Fair Market Rental Rate shall be reduced by the economic equivalent of
the allowances or concessions not offered to Tenant); and (3) the tenant will
continue to pay its share of Operating Expenses and Real Estate Taxes over a
new base year (which, for Tenant, is the calendar year in which occurs the
first day of the Extension Period).

         c.      Landlord and Tenant shall negotiate in good faith to
determine the Annual Base Rent for the first Lease Year of the Extension
Period, for a period of thirty (30) days after the date on which Landlord
receives Tenant's written notice of Tenant's election to exercise the
extension option provided for under this Section 22. In the event Landlord
and Tenant are unable to agree upon the Annual Base Rent for the first Lease
Year of the Extension Period within said thirty (30)-day period, the Fair
Market Rental Rate for the Premises shall be determined by a board of three
(3) licensed commercial real estate brokers, one of whom shall be named by
the Landlord, one of whom shall be named by Tenant, and the two so appointed
shall select a third. Each real estate broker so selected shall be licensed
in the jurisdiction in which the Building is located as a real estate broker
specializing in the field of commercial office leasing in the Herndon area of
Fairfax County, Virginia, having no less than ten (10) years' experience in
such field, and recognized as ethical and reputable within the field.
Landlord and Tenant agree to make their appointments promptly within ten (10)
days after the expiration of the thirty (30)-day period, or sooner if
mutually agreed upon. The two (2) brokers selected by Landlord and Tenant
shall promptly select a third broker within ten (10) days after they both
have been appointed, and each broker, within fifteen (15) days after the
third broker is selected, shall submit his or her determination of the Fair
Market Rental Rate. The Fair Market Rental Rate shall be the mean of the two
closest rental rate determinations; provided, however, in no event shall the
Annual Base Rent for the first Lease Year of the Extension Period be less (on
a per square foot basis) than the Annual Base Rent in effect for the last
Lease Year of the initial Term. Landlord and Tenant shall each pay the fee of
the broker selected by it, and they shall equally share the payment of the
fee of the third broker.

         d.      Should the Term of the Lease be extended hereunder, Tenant
agrees to execute an amendment modifying this Lease within fifteen (15)
business days after Landlord presents same to Tenant, which agreement shall
set forth the Annual Base Rent and the Monthly Base Rent for first Lease Year
of the Extension Period. Should Tenant fail to execute the amendment (which
amendment accurately sets forth the economic terms of the demise of the
Premises during the Extension Period) within fifteen (15) business days after
presentation of same by Landlord, time being of the essence, Tenant's right
to extend the Term shall, at Landlord's sole option, terminate, and Landlord
shall be permitted to lease the Premises to any other person or entity upon
whatever terms and conditions are acceptable to Landlord in its sole
discretion.

23. PARKING.

         a.      Tenant shall be provided, without charge, one hundred
sixty-eight (168) parking spaces (or 4 spaces per 1,000 r.s.f. of the
Premises then being leased by Tenant) located on the surface lot adjacent to
the Building, for use by Tenant's employees, agents and guests. Of the one
hundred sixty-eight (168) spaces being provided by Landlord, one hundred
sixty-three (163) shall be unreserved spaces and five (5) shall be reserved
spaces. The reserved spaces shall be in the location shown on the attached
EXHIBIT D. A "Reserved Parking" sign bearing Tenant's name (the "Parking
Sign") shall be


                                     22
<PAGE>

installed adjacent to each reserved parking space provided to Tenant.
Landlord, at Tenant's sole cost, shall design, fabricate and install the
Parking Signs.

         b.      Tenant agrees that it and its employees shall observe
reasonable safety precautions in the use of the surface parking lot, and
shall at all times abide by all rules and regulations promulgated by Landlord
or the parking operator governing the use of the surface parking lot. Tenant
understands and agrees that Landlord does not assume any responsibility for
any damage or loss to any automobiles parked on the surface parking lot, or
to any personal property located therein or thereon, or for any injury
sustained by any person in or about the surface parking lot. Landlord shall
not be responsible for "policing" Tenant's reserved parking spaces to insure
that such spaces are occupied only by automobiles belonging to Tenant, its
employees and guests.

24. NOTICES.     Any and all notices or demands required or permitted herein
shall be in writing and served (a) personally, (b) by certified mail, return
receipt requested, or (c) by guaranteed overnight courier, at the addresses
provided in Section 1g above. If served personally, service shall be
conclusively deemed made at the time of such delivery. If served by certified
mail, service shall be conclusively deemed made forty-eight (48) hours after
the deposit thereof in the United States mail, postage prepaid, pursuant to
this Section 24. If served by overnight courier, service shall be
conclusively deemed made one (1) business day after deposit with such
courier. Either party may specify a different address according to the terms
of this Section 24.

25. BROKERS.     Landlord and Tenant recognize Dean Topping & Company,
Charles E. Smith Commercial Realty and LPC Commercial Services, Inc.
(collectively, the "Brokers") as the sole brokers with respect to this Lease
and Landlord agrees to be responsible for the payment of any leasing
commissions owed to the aforesaid Brokers in accordance with the terms of
separate commission agreements entered into between Landlord and each of said
Brokers. Landlord and Tenant each represents and warrants to the other that,
except for the Brokers, no other broker has been employed in carrying on any
negotiations relating to this Lease and shall each indemnify and hold
harmless the other from any claim for brokerage or other commission arising
from or out of any breach of the foregoing representation and warranty.

26. ENVIRONMENTAL CONCERNS.

         a.      Tenant, its agents, employees, contractors or invitees shall
not (i) cause or permit any Hazardous Materials (hereinafter defined) to be
brought upon, stored, used or disposed on, in or about the Premises and/or
the Building, or (ii) knowingly permit the release, discharge, spill or
emission of any Hazardous Material in or from the Premises.

         b.      Tenant hereby agrees that it is and shall be fully
responsible for all costs, expenses, damages or liabilities (including, but
not limited to those incurred by Landlord and/or its mortgagee) which may
occur from the use, storage, disposal, release, spill, discharge or emissions
of Hazardous Materials by Tenant whether or not the same may be permitted by
this Lease. Tenant shall defend, indemnify and hold harmless Landlord, its
mortgagee and its agents from and against any claims, demands, administrative
orders, judicial orders, penalties, fines, liabilities, settlements, damages,
costs or expenses (including, without limitation, reasonable attorney and
consultant fees, court costs and litigation expenses) of whatever kind or
nature, known or unknown, contingent or otherwise, arising out of or in any
way related to the use, storage, disposal, release, discharge, spill or
emission of any Hazardous Material, or the violation of any Environmental
Laws, by Tenant, its agents, employees, contractors or invitees. The
provisions of this Section 26 shall be in addition to any other obligations
and liabilities Tenant may have to Landlord at law or in equity and shall
survive the transactions contemplated herein or any termination of this Lease.

         c.      As used in this Lease, the term "Hazardous Materials" shall
include, without limitation:

                  (i)      those substances included within the definitions of
         "hazardous substances", "hazardous materials," toxic substances," or
         "solid waste" in the Comprehensive Environmental Response Compensation
         and Liability Act of 1980 (42 U.S.C. Section 9601 ET SEQ.) ("CERCLA"),
         as amended by Superfund Amendments and Reauthorization Act of 1986
         ("SARA"), the Resource Conservation and Recovery Act of 1976 ("RCRA"),
         and the Hazardous Materials Transportation Act, and in the regulations
         promulgated pursuant to said laws, all as amended;

                 (ii)      those substances listed in the United States
         Department of Transportation Table (49 CFR 172.101 and amendments
         thereto) or by the Environmental Protection Agency (of any successor
         agency) as hazardous substances (40 CFR Part 302 and amendments
         thereto); and

                (iii)      any material, waste or substance which is (A)
         petroleum, (B) asbestos, (C) polychlorinated biphenyl, (D) designated
         as a "hazardous substance" pursuant to Section 311 of the Clean Water
         Act, 33 U.S.C. Section 1251 ET SEQ. (33 U.S.C. Section 1321) or
         listed pursuant to Section of the Clean Water Act (33 U.S.C. Section
         1317); (E) flammables or explosives; or (F) radioactive materials.

         d.      All federal, state or local laws, statutes, regulations,
rules, ordinances, codes, standards, orders, licenses and permits of any
governmental authority or issued or promulgated thereunder shall be referred
to as the "Environmental Laws".

                                     23
<PAGE>

27. LANDLORD'S LIEN. To secure the payment of all Annual Base Rent and
Additional Rent due and to become due hereunder and to assure the faithful
performance of all of the other covenants of this Lease required to be
performed by Tenant, Landlord shall continue to possess its statutory and
common law liens provided under Virginia law. Notwithstanding the foregoing,
Landlord agrees to subordinate its statutory and common law liens to the lien
of any purchase money mortgage or deed of trust securing a loan made by a
bank or other institutional lender to Tenant, the proceeds of which are used
by Tenant to purchase equipment and personalty used by Tenant in the
operation of its business in the Premises. No equipment which is leased
(rather than owned) by Tenant shall be subject to the Landlord's lien
described in this Section 27.

28. ROOFTOP COMMUNICATIONS EQUIPMENT.

         a.      Tenant shall have the non-exclusive right to use a portion
of the roof of the Building designated by Landlord in Landlord's sole
discretion for the installation of one (1) of the following types of
equipment: satellite dish, antenna and/or telecommunications and fiber optic
equipment (collectively, the "Communications Equipment"), provided that (i)
the Communications Equipment sought to be installed by Tenant is permitted
under, and conforms to the requirements of, the laws, rules and regulations
of the Town of Herndon, Virginia, Fairfax County, the Commonwealth of
Virginia and any other governmental or quasi-governmental authorities having
appropriate jurisdiction over the Building; (ii) Tenant obtains and maintains
all permits, licenses, variances, authorizations and approvals that may be
required in order to install such Communications Equipment; (iii) Tenant
shall obtain insurance coverages reasonably required by Landlord relating to
the installation and operation of such Communications Equipment; (iv) Tenant
shall install any screen or other covering for the Communications Equipment
that Landlord may require in order to camouflage or conceal the
Communications Equipment; (v) Landlord shall have approved in its sole
discretion the dimensions and specifications for the Communications
Equipment, and the proposed method of attaching the Communications Equipment
to the roof of the Building; (vi) the diameter of any Communications
Equipment installed by Tenant shall not exceed twenty-four (24) inches; (vii)
Landlord's engineer determines in its reasonable discretion that the portion
of the roof on which Tenant desires to install the Communications Equipment
is capable of bearing the weight of the Communications Equipment; and (viii)
Landlord's engineer determines in its reasonable discretion that there is
space available on the roof of the Building to accommodate Tenant's
Communication Equipment. Tenant shall pay to Landlord monthly rent for the
roof rights provided to Tenant in this Section 28 ("Communications Rent") in
an amount equal to Two Hundred Fifty Dollars ($250.00). Communications Rent
hereunder shall be increased as of the first day of the second (2nd) Lease
Year and each Lease Year thereafter during the Term by an amount equal to
three percent (3%) of the Communications Rent in effect during the last
calendar month of the previous Lease Year. Communications Rent shall be paid
by Tenant, in advance, beginning on the date on which Tenant installs the
Communications Equipment, and thereafter on the first day of each and every
calendar month of the Term during which such Communications Equipment is
located on the roof of the Building.

         b.      Prior to or contemporaneous with requesting Landlord's
approval of the installation of any Communications Equipment, Tenant shall
provide to Landlord: (i) plans and specifications for the Communications
Equipment; (ii) copies of all required governmental and quasi-governmental
permits, licensees, special zoning variances, and authorizations, all of
which Tenant shall obtain at its own cost and expense; and (iii) a policy or
certificate of insurance evidencing such insurance coverage as may reasonably
be required by Landlord for the installation, operation and maintenance of
the Communications Equipment and sufficient to cover, INTER ALIA, the
indemnities from Tenant to Landlord provided in the Lease relating to the
installation, maintenance, operation and removal of the Communications
Equipment. Landlord may withhold its approval of the installation of the
Communications Equipment if Landlord reasonably believes that the
installation, operation or removal of the Communications Equipment may (A)
damage the structural integrity of the Building or void any warranty or
guaranty applicable to the roof or Building; (B) cause the violation of any
zoning ordinance or other governmental or quasi-governmental law, rule or
regulation applicable to the Building; or (C) interfere with the use or
operation of any antenna or other communications device of any other tenant
in the Building, which has been installed or previously approved for
installation by Landlord. Landlord may require as a precondition to its
approval of the installation of the Communications Equipment that Tenant (or,
at Landlord's option, Landlord), at Tenant's sole cost and expense, install
additional structural support (in a manner determined by Landlord's engineer
in its sole discretion) to the portion of the roof on which Tenant desires to
install the Communications Equipment. Tenant shall not be entitled to rely on
any such approval as being a representation by Landlord that such
installation and operation is permitted by or in accordance with any zoning
ordinance or other governmental or quasi-governmental law, rule or regulation
applicable to the Building.

         c.      Landlord shall be provided with access to the roof of the
Building, including the portion of the roof on which the Communications
Equipment is located, in order to inspect the Communications Equipment and
roof to determine, INTER ALIA, if the Communications Equipment is causing
damage to the roof or any other part of the Building and/or to repair the
roof or remove or relocate the Communications Equipment. Landlord, at its
sole option and discretion, may require Tenant, at any time prior to the
expiration of the Lease, to terminate the operation of the Communications
Equipment if it is causing physical damage to the structural integrity of the
Building or voids any warranty or guaranty applicable to the roof or the
Building, or interfering with any satellite dish, antennae or other
telecommunications device being operated (or approved by Landlord for
operation) as of the Commencement Date, on the roof or elsewhere in the
Building by any tenant in the Building or other licensee authorized by
Landlord, or causing the violation of any condition or provision of the Lease
or any governmental or quasi-governmental law, rule or regulation (now or
hereafter in effect) applicable to the Building. If, however,


                                     24
<PAGE>

Tenant can correct the damage or cure such violation to Landlord's reasonable
satisfaction within sixty (60) days after receipt of written notice from
Landlord, Tenant may restore its operation so long as Tenant promptly
commences to cure such damage and/or cure such violation and diligently
pursues such cure to completion.

         d.      Tenant acknowledges that the rights contained in this
Section 28 are non-exclusive, and that Landlord may grant such rights to any
other tenant in the Building or any other licensee of Landlord's choice
(whether or not such licensee is a tenant of the Building). Tenant expressly
acknowledges that it may not (i) license or otherwise permit third parties to
install on the roof of the Building or anywhere else in the Premises, any
Communications Equipment; or (ii) permit any third party to use any portion
of the roof for any purpose whatsoever. The breach of this provision shall
constitute a default under this Lease.

         e.      At the expiration or earlier termination of the Lease,
Tenant, at Tenant's sole cost, shall remove the Communications Equipment and
all cabling and other equipment relating thereto from the Building, and
Tenant shall restore the area where the Communications Equipment was located
to its condition existing prior to such installation in a manner and with
materials determined by Landlord. In the event Tenant fails to promptly do
so, Tenant hereby authorizes Landlord to remove the Communications Equipment
and restore the area of the roof and the other portions of the Building
affected thereby, and charge Tenant for all reasonable costs and expenses
incurred in connection therewith. Tenant's obligation to perform and observe
this covenant shall survive the expiration or earlier termination of the Term
of the Lease.

         f.      Tenant covenants and agrees that the installation, operation
and removal of the Communications Equipment will be at its sole cost and
risk. Tenant covenants and agrees absolutely and unconditionally to
indemnify, defend and hold Landlord harmless from and against all claims,
actions, damages, liability, judgments, settlements, costs and expenses
(including reasonable attorneys' fees and expenses) suffered or sustained by
Landlord arising out of the installation, operation, maintenance or removal
of the Communications Equipment, including without limitation any loss or
injury resulting from transmissions from the Communications Equipment, unless
resulting directly from the gross negligence or intentionally wrongful acts
or omissions of Landlord or any agent or employee of Landlord.

         g.      The rights contained in this Section 28 are personal to
Universal Access, Inc. and may not be exercised by any subtenant, licensee
or, except for a Permitted Transferee, assignee of Tenant.

29. EXTERIOR SIGNAGE. Tenant shall have the non-exclusive right to install, at
Tenant's sole cost and expense, a sign bearing Tenant's name (the "Exterior
Sign") on the exterior of the Building, in the location shown on the attached
EXHIBIT E. All attributes of the Exterior Sign, including without limitation
size, materials and color, shall be subject to Landlord's prior approval, which
shall not be unreasonably withheld, conditioned or delayed; provided, however,
in no event shall any aspect of the Exterior Sign, including without limitation
the size of Tenant's name or logo thereon, be larger than the dimensions shown
on the attached EXHIBIT E-1. Prior to installing the Exterior Sign, Tenant shall
submit to Landlord for its approval a drawing of the Exterior Sign, which
drawing shall specify the size, materials, color and other attributes of the
Exterior Sign which Tenant desires to install. Tenant's right to install the
Exterior Sign shall be subject to Tenant's receipt of all necessary permits and
governmental approvals for such installation; provided that the failure to
obtain such permits or approvals shall not affect the Lease (or Tenant's
obligations hereunder) in any way. The exact placement of the Exterior Sign on
the Building shall be subject to Landlord's approval regarding structural
support issues. Tenant shall be solely responsible for obtaining and maintaining
all permits and governmental approvals necessary for the installation and
operation of the Exterior Sign. Tenant shall be responsible for repairing and
maintaining the Exterior Sign installed by Tenant in a first-class condition
throughout the Term. The Exterior Sign shall be installed by a licensed
contractor reasonably acceptable to Landlord using a mounting procedure approved
by Landlord in its reasonable discretion exercised in good faith. Tenant shall
cause its insurance carrier to include the Exterior Sign in the coverage
required to be obtained by Tenant pursuant to Section 12, above. The right to
install the Exterior Sign shall be personal to Universal Access, Inc.; provided
that, upon the assignment of the Lease to a Permitted Transferee and the removal
of the then-existing Exterior Sign by Tenant, such Permitted Transferee shall be
permitted to install an Exterior Sign, such installation to be undertaken
subject to, and in accordance with, the provisions of this Section 29. Tenant
agrees to indemnify Landlord and hold it harmless from and against all claims,
damage or liability (including reasonable attorneys' fees) sustained or suffered
by Landlord arising out of or related to the installation, maintenance or
removal of the Exterior Sign, except to the extent such claims or liability
results from the negligence or willful misconduct of Landlord, its employees or
agents. Tenant shall remove the Exterior Sign at the end of the Term and shall
restore the portions of the Building affected by such removal to their condition
immediately prior to the installation of such signs, reasonable wear and tear
and casualty excepted.

30. RULES AND REGULATIONS. Tenant shall at all times comply with the rules and
regulations set forth in EXHIBIT F attached hereto and with any reasonable
additions thereto and modifications thereof adopted from time to time by
Landlord for all tenants of the Building; and Tenant shall be given five (5)
days' written notice of any such additions and modifications. Each such rule or
regulation shall be deemed to be a covenant of this Lease to be performed and
observed by Tenant. The rules and regulations shall be uniformly applied by
Landlord as against all tenants in the Building.


                                     25
<PAGE>

31. QUIET ENJOYMENT. Landlord covenants that, if Tenant is not in default
hereunder, Tenant shall at all times during the Term peaceably and quietly
have, hold and enjoy the Premises without disturbance from Landlord or any
party claiming by or through Landlord, subject to the terms of this Lease.

32. MISCELLANEOUS PROVISIONS.

         a.      Time is of the essence with respect to all of Tenant's
obligations under this Lease.

         b.      The waiver by Landlord or Tenant of any term, covenant or
condition herein contained shall not be deemed to be a waiver of such term,
covenant or condition of any prior or subsequent breach of the same or any
other term, covenant or condition herein contained. The subsequent acceptance
of rent hereunder by Landlord shall not be deemed to be a waiver of any prior
breach by Tenant of any term, covenant or condition of this Lease, other than
the failure of Tenant to pay the particular rental so accepted, regardless of
Landlord's knowledge of such prior breach at the time of acceptance of such
rent.

         c.      In the event of any action or proceeding brought by either
party against the other under this Lease, the prevailing party shall be
entitled to recover from the other party the fees of its attorneys in such
action or proceeding in such amount as the court may judge to be reasonable
for such attorneys' fees.

         d.      Except as expressly otherwise provided in this Lease, all of
the provisions of this Lease shall bind and inure to the benefit of the
parties hereto and to their heirs, successors, representatives, executors,
administrators, transferees and assigns. The term "Landlord," as used herein,
shall mean only the owner of the Building and the Land or of a lease of the
Building and the Land, at the time in question, so that in the event of any
transfer or transfers of title to the Building and the Land, or of Landlord's
interest in a lease of the Building and the Land, the transferor shall be and
hereby is relieved and freed of all obligations of Landlord under this Lease
accruing subsequent to such transfer, and it shall be deemed, without further
agreement, that such transferee has assumed and agreed to perform and observe
all obligations of Landlord herein during the period it is the holder of
Landlord's interest under this Lease.

         e.      At Landlord's request, Tenant will execute a memorandum of
this Lease in recordable form setting forth such provisions hereof as
Landlord deems desirable. Further, at Landlord's request, Tenant shall
acknowledge before a notary public its execution of this Lease, so that this
Lease shall be in form for recording. The cost of recording this Lease or
memorandum thereof shall be borne by Landlord.

         f.      Notwithstanding any provision to the contrary herein, Tenant
shall look solely to the estate and property of Landlord in and to the Land
and the Building in the event of any claim against Landlord arising out of or
in connection with this Lease, the relationship of Landlord and Tenant, or
Tenant's use of the Premises, and Tenant agrees that the liability of
Landlord arising out of or in connection with this Lease, the relationship of
Landlord and Tenant, or Tenant's use of the Premises, shall be limited to
such estate and property of Landlord in and to the Land and the Building. No
properties or assets of Landlord other than the estate and property of
Landlord in and to the Building and no property owned by any partner of
Landlord shall be subject to levy, execution or other enforcement procedures
for the satisfaction of any judgment (or other judicial process) or for the
satisfaction of any other remedy of Tenant arising out of or in connection
with this Lease, the relationship of Landlord and Tenant or Tenant's use of
the Premises.

         g.      Landlord and Landlord's agents have made no representations
or promises with respect to the Building, the Land or the Premises except as
herein expressly set forth.

         h.      Landlord and Tenant shall be excused from performing an
obligation or undertaking provided for in this Lease so long as such
performance is prevented or delayed, retarded or hindered by an Act of God,
force majeure, fire, earthquake, flood, explosion, action of the elements,
war, invasion, insurrection, riot, mob violence, sabotage, inability to
procure or a general shortage of labor, equipment, facilities, materials or
supplies in the open market, failure of transportation, strike, lockout,
action of labor unions, a taking by eminent domain, requisition, laws orders
of government, or of civil, military or naval authorities, or any other cause
whether similar or dissimilar to the foregoing, not within the reasonable
control of Landlord or Tenant, as applicable, including reasonable delays for
adjustments of insurance (collectively, "Force Majeure"); provided, however,
that no such event or cause shall relieve Tenant of its obligations hereunder
to make full and timely payments of Rent as provided herein.

         i.      Tenant hereby elects domicile at the Premises for the
purpose of service of all notices, writs of summons or other legal documents
or process in any suit, action or proceeding which Landlord or any mortgagee
may undertake under this Lease.

         j.      Landlord shall not be liable to Tenant for any damage caused
by other tenants or persons in the Building or caused by operations of others
in the construction of any private, public or quasi-public work.

         k.      If in this Lease it is provided that Landlord's consent or
approval as to any matter will not be unreasonably withheld, and it is
established by a court or body having final jurisdiction thereover that
Landlord has been unreasonable, the sole effect of such finding shall be that
Landlord shall be deemed to have given its consent or approval, but Landlord
shall not be liable to Tenant in any respect for money damages or expenses
incurred by Tenant by reason of Landlord having withheld its consent. Nothing


                                     26
<PAGE>

contained in this paragraph shall be deemed to limit Landlord's right to give
or withhold consent unless such limitation is expressly contained in the
paragraph to which such consent pertains.

         L.      If any governmental entity or authority hereafter imposes a
tax or assessment upon or against any of the rent or other charges payable by
Tenant to Landlord hereunder (whether such tax takes the form of a lease tax,
sales tax or other tax), Tenant shall be responsible for the timely payment
thereof. Unless Landlord and Tenant otherwise agree in writing with respect
to the payment thereof, Tenant shall pay the applicable tax to Landlord in
monthly installments on the date upon which Tenant pays to Landlord the
installments of Monthly Base Rent due under this Lease.

         M.      This Lease and the Exhibits hereto constitute the entire
agreement between the parties, and supersedes any prior agreements or
understandings between them. This Lease is not effective until executed and
delivered by Landlord and Tenant and approved by any current mortgagee of the
Building and/or the Land. The provisions of this Lease may not be modified in
any way except by written agreement signed by both parties.

         N.      This Lease shall be subject to and construed in accordance
with the laws of the Commonwealth of Virginia.

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


                                    LANDLORD:

                                    HERNDON LINCOLN I LLC, a Delaware limited
                                    liability company

                                    By: Lincoln-Herndon LLC, a Delaware limited
                                        liability company, its Managing Member

                                        By: Lincoln Investors Group 2, Inc., a
                                            Texas corporation, its Managing
                                            Member

WITNESS:

/s/ Barbara Murphy                      By: /s/ William Hickey Jr.
------------------------------          Name: William Hickey Jr.
                                        Title: Vice President


                                    TENANT:
WITNESS:
                                    UNIVERSAL ACCESS, INC., a Delaware
                                    corporation


                                     By: /s/ Patrick Shutt
/s/ Robert Brown                     Name: Patrick Shutt
-----------------------              Title: CEO



                                             LIST OF EXHIBITS

                           EXHIBIT A:        Floor Plan of Premises
                           EXHIBIT B:        Work Agreement
                           EXHIBIT C:        Declaration of Commencement Date
                           EXHIBIT D:        Location of Reserved Parking Spaces
                           EXHIBIT E:        Location of Exterior Sign
                           EXHIBIT E-1:      Dimensions of Exterior Sign
                           EXHIBIT F:        Rules and Regulations


                                     27
<PAGE>

                                    EXHIBIT A

                             FLOOR PLAN OF PREMISES


                                    [Attach]


<PAGE>

                                    EXHIBIT B

                                 WORK AGREEMENT


         This Work Agreement (the "Work Agreement") is attached to and made a
part of that certain Deed of Lease (the "Lease") dated April ___, 2000, by and
between HERNDON LINCOLN I LLC, as landlord ("Landlord") and UNIVERSAL ACCESS,
INC., as tenant ("Tenant") for the premises (the "Premises") described therein
in the building known as 13900 Lincoln Park Drive, Herndon, Virginia (the
"Building"). It is the intent of this Work Agreement that Tenant shall be
permitted freedom in the design and layout of the Premises, consistent with
applicable building codes and requirements of law, including without limitation
the Americans With Disabilities Act, and with sound architectural and
construction practice in first-class office buildings, provided that neither the
design nor the implementation of the Tenant Improvements (hereinafter defined)
shall cause any interference to the operation of the Building's HVAC,
mechanical, plumbing, life safety, electrical or other systems or to other
Building operations or functions, nor shall they increase maintenance or utility
charges for operating the Building. Capitalized terms not otherwise defined in
this Work Agreement shall have the meanings set forth in the Lease. In the event
of any conflict between the terms hereof and the terms of the Lease, the terms
hereof shall prevail for the purposes of design and construction of the Tenant
Improvements.

         A.       BASE BUILDING AND LEASEHOLD IMPROVEMENTS.

                  1.      BASE BUILDING. Landlord, at Landlord's sole cost
and expense, shall construct on the Land, the base Building improvements (the
"Base Building Improvements") described in the plans and specifications
listed on SCHEDULE B-1 attached hereto and incorporated herein by reference
(the "Base Building Plans"). Landlord reserves the right to make changes to
the Base Building Plans, provided however, that the quality and finish of the
Base Building, as constructed, shall be consistent with the level of quality
and finish set forth in the Base Building Plans. The Base Building shall be
constructed in a workmanlike manner by a general contractor and
subcontractors selected by Landlord in its sole discretion.

                  2.      LANDLORD IMPROVEMENTS. Landlord, at Landlord's
sole cost and expense, shall construct and install the components of the
Building located within the Premises, or provided for the benefit of the
Premises, as are shown on SCHEDULE B-2 (the "Landlord Improvements"). The
Landlord Improvements shall be constructed in a workmanlike manner by a
general contractor and subcontractors selected by Landlord in its sole
discretion.

                  3.      TENANT IMPROVEMENTS. Landlord shall furnish and
install in the Premises in accordance with the terms of this Work Agreement,
the improvements set forth in the Tenant's Plans (hereinafter defined) which
have been approved by Landlord in accordance with Paragraph B-2, below (the
"Tenant Improvements"). The parties agree that (a) no furniture (including
systems furniture) or equipment shall be included in the Tenant Improvements;
and (b) no delay by Landlord or Tenant in installing Tenant's furniture
(including systems furniture) or equipment in the Premises shall delay or
otherwise affect the Commencement Date under the Lease. The costs of all
design, space planning, and architectural and engineering work for or in
connection with the Tenant Improvements, including without limitation all
drawings, plans, specifications, permits or other approvals relating thereto,
and all insurance, bonds and other requirements and conditions hereunder, and
all costs of demolition and construction, including supervision thereof,
shall be at Tenant's sole cost and expense, subject to the application of the
Improvement Allowance in accordance with the terms of this Work Agreement.

         B.       PLANS AND SPECIFICATIONS

                  1.      SPACE PLANNER. Tenant has retained the services of
The Architects Partnership, Ltd. (the "Space Planner"), who will design the
Premises and prepare the Contract Documents (hereinafter defined). The Space
Planner shall meet with the Construction Supervisor (hereinafter defined)
from time to time to obtain information about the Building and to insure that
the improvements envisioned in the Contract Documents do not interfere with
and/or adversely affect the Building or any systems therein. The Space
Planner and the Engineers (hereinafter defined), shall prepare all plans and
specifications described in Paragraph B.2, below, in conformity with the base
Building plans and systems, and the Space Planner shall coordinate its plans
and specifications with the Engineers and the Construction Supervisor. All
fees of the Space Planner and the Engineers shall be borne solely by Tenant,
subject to application of the Improvement Allowance as hereinafter provided.

                  2.      ENGINEERS. Tenant shall retain the services of
mechanical, electrical, plumbing and structural engineers approved by
Landlord in its reasonable discretion (the "Engineers") to: (i) design the
type, number and location of all mechanical systems in the Premises,
including without limitation the heating, ventilating and air conditioning
system therein, and to prepare all of the mechanical plans; (ii) assist
Tenant and the Space Planner in connection with the electrical design of the
Premises, including the location and capacity of light fixtures, electrical
receptacles and other electrical elements, and to prepare all of the
electrical plans; (iii) assist Tenant and the Space Planner in connection
with plumbing-related issues involved in designing the Premises and to
prepare all of the plumbing plans; (iv) assist Tenant and the Space Planner
in connection with the structural elements of the Space Planner's design of
the Premises and to prepare all the structural plans. All fees of the
Engineers shall be borne solely by Tenant, subject to application of the
Improvement Allowance as hereinafter provided.

<PAGE>

                  3.       TIME SCHEDULE.

                           a.       On or before April 4, 2000, Tenant shall
have furnished to Landlord for its review and approval a proposed detailed
space plan for the Tenant Improvements (the "Final Space Plan") prepared by
the Space Planner, in consultation with the Construction Supervisor and the
Engineers. The Final Space Plan shall contain the information and otherwise
comply with the requirements therefor described in SCHEDULE B-3 attached
hereto. Landlord shall advise Tenant of Landlord's approval or disapproval of
the Final Space Plan tendered by Tenant within seven (7) days after Tenant
submits the Final Space Plan to Landlord. In the event Landlord disapproves
the Final Space Plan, Landlord shall specify its reasons for such
disapproval. Tenant shall revise the proposed Final Space Plan to the extent
reasonably necessary meet Landlord's objections, if any, and resubmit the
Final Space Plan to Landlord for its review and approval within five (5) days
after Landlord notifies Tenant of Landlord's objections, if any.

                           b.       On or before April 30, 2000, Tenant shall
furnish to Landlord for its review and approval, all architectural plans,
working drawings and specifications (the "Contract Documents") necessary and
sufficient (i) for the construction of the Tenant Improvements in accordance
with the Final Space Plan; and (ii) to enable the Contractor (hereinafter
defined) to obtain a building permit for the construction of the Tenant
Improvements. The Contract Documents shall (A) contain the information and
otherwise comply with the requirements therefore described in SCHEDULE B-4
attached hereto; and (B) incorporate into the Tenant Improvements the
Building standard materials set forth on SCHEDULE B-5 attached hereto (the
"Building Standard Materials"). Landlord shall advise Tenant of Landlord's
approval or disapproval of the Contract Documents, or any of them, within ten
(10) days after Tenant submits the Contract Documents to Landlord, and in the
event Landlord disapproves same, Landlord shall specify its reasons for such
disapproval. Tenant shall revise the Contract Documents to the extent
reasonably necessary meet Landlord's objections, if any, and resubmit the
Contract Documents to Landlord for its review and approval within five (5)
business days after Landlord notifies Tenant of Landlord's objections, if
any. Notwithstanding anything herein to the contrary, approval by Landlord of
the Contract Documents shall not constitute an assurance by Landlord that the
Contract Documents: (A) satisfy applicable code requirements, (B) are
sufficient to enable the Contractor to obtain a building permit for the
undertaking of the Tenant Improvements in the Premises, or (C) will not
interfere with, and/or otherwise adversely affect, base Building systems;
provided, however, that if the Contract Documents must be revised for such
reasons, or otherwise, such revisions shall be at Tenant's cost and any delay
arising in connection therewith shall constitute a "Tenant Delay"
(hereinafter defined).

                           c.       In the event that: (i) Landlord fails to
approve or reject the Final Space Plan within seven (7) days of Tenant's
submission of same to Landlord (pursuant to Section 3.a, above), or (ii)
Landlord fails to approve or reject the Contract Documents within ten (10)
days after Tenant's submission of same to Landlord (pursuant to Section 3.b,
above), Tenant shall have the right to deliver to Landlord (at the address
set forth in Section 1.g, above, provided that such notice shall also name
"Neil Alt" as an addressee thereof), a written notice (the "Plans Approval
Notice") advising Landlord that Landlord has failed to timely approve the
Final Space Plan or the Contract Documents, as the case may be in accordance
with Paragraphs B.3 of the Work Agreement. The Plans Approval Notice shall
state, in bold letters, the following:

                  "FAILURE BY LANDLORD TO APPROVE OR REJECT THE FINAL SPACE
                   PLAN OR THE CONTRACT DOCUMENTS (AS APPLICABLE) WHICH WAS
                   PREVIOUSLY TENDERED BY UNIVERSAL ACCESS, INC. ("TENANT"),
                   WITHIN FIVE (5)BUSINESS DAYS AFTER LANDLORD'S RECEIPT
                   HEREOF MAY RESULT IN LANDLORD'S HAVING TO ABATE RENT
                   PURSUANT TO SECTION 3.C OF TENANT'S LEASE OF PREMISES AT
                   13900 LINCOLN PARK DRIVE, HERNDON, VIRGINIA."

In the event that Landlord fails to approve or reject the Final Space Plan or
Contract Documents described in the Plans Approval Notice, by the date (the
"Final Approval/Rejection Date") which is five (5) business days after
Landlord's receipt of the Plans Approval Notice (which notice contains the
language set forth above), and as a result of such delay by Landlord, the
Tenant Improvements are not substantively completed by October 1, 2000
(extended day-for-day by Tenant Delay or Force Majeure), then in such event,
for each day after the Final Approval/Rejection Date that Landlord fails to
approve or reject the Final Plan or the Contract Documents, as applicable,
Tenant shall be entitled to receive, after the Commencement Date, an
abatement of one day of Annual Base Rent under the Lease.

                           d.       Within two (2) business days after
Landlord approves the Contract Documents, the Space Planner shall deliver to
Landlord (i) a reasonable number of "permit sets" of the Contract Documents;
and (ii) a reasonable number of sets of the Contract Documents for delivery
to the Approved Bidders (hereinafter defined) for review and pricing.

                           e.       The Final Space Plan and the Contract
Documents are referred to collectively herein as the "Tenant's Plans." All
approvals by Landlord hereunder shall be in Landlord's reasonable discretion,
except to the extent that any proposed Tenant Improvement affects or alters
the base Building or any base Building system, in which event Landlord's
approval or rejection of such Tenant Improvement shall be made by Landlord in
its sole discretion.

                           f.       The Tenant's Plans shall be prepared in
accordance with a Data Cadd or convertible DXF format for working drawings in
conformity with the base Building plans and systems and


                              EXHIBIT B, PAGE 2
<PAGE>

with information furnished by and in coordination with the Construction
Supervisor and Engineers. Tenant's Plan shall comply with all applicable
building codes, laws and regulations (including without limitation the
Americans With Disabilities Act), shall not interfere with or require any
changes to or modifications of the base Building's HVAC, mechanical,
electrical, plumbing, life safety or other systems or to other Building
operations or functions, and shall not increase maintenance or utility
charges for operating the Building in excess of the standard requirements for
normal first-class office buildings in the Herndon, Virginia area.

                  4.       BASE BUILDING CHANGES. If Tenant requests work to
be done in the Premises or for the benefit of the Premises that necessitates
revisions or changes in the design or construction of the base Building or
Building systems, any such changes shall be subject to prior written approval
of Landlord, in its sole discretion, and Tenant shall be responsible for all
costs and delays resulting from such design revisions or construction
changes, including architectural and engineering charges, and any special
permits or fees attributed thereto. Before any such design and/or
construction changes are made, Tenant shall pay to Landlord the full costs
incurred by Landlord in connection with such changes including without
limitation the Construction Supervision Fee (hereinafter defined)
attributable thereto.

                  5.       CHANGES.

                           a.       In the event that Tenant requests any
changes to the Final Space Plan or the Contract Documents after Landlord has
approved same, or if it is determined that the Contract Documents prepared in
accordance with the Final Space Plan deviate from the requirements of
applicable law, do not utilize the Building Standard Materials, or interfere
with, and/or otherwise adversely affect, base Building systems, Tenant shall
be responsible for all costs and expenses and for all delay resulting
therefrom, including without limitation costs or expenses relating to (i) any
additional architectural or engineering services and related design expenses,
(ii) any changes to materials in process of fabrication, (iii) cancellation
or modification of supply or fabricating contracts, or (iv) removal or
alteration of work or plans completed or in process. In addition, Tenant
shall pay Landlord or, at Landlord's direction, the Construction Supervisor
(hereinafter defined), a change order fee equal to three percent (3%) of any
costs or expenses charged in connection with a change or modification of the
Contract Documents. In those instances in which such proposed revision
results from a change voluntarily requested by Tenant, upon the completion of
such revised working drawings and specifications, Landlord shall notify
Tenant in writing of the cost which will be chargeable to Tenant by reason of
such change, addition or deletion. Tenant shall within three (3) business
days after receipt of Landlord's notice of cost increase notify Landlord in
writing whether Tenant desires to proceed with such change, addition or
deletion. In the absence of (A) such written authorization and payment in
full of the total costs of such change, addition or deletion or (B) written
notice by Tenant that it has elected not to proceed with proposed the
change(s), Landlord shall not be obligated to continue work on construction
of the Tenant Improvements and may suspend work and Tenant shall be
chargeable with any and all delays in the completion of the Premises
resulting therefrom. Landlord shall notify Tenant in writing of any changes
to the Final Space Plan or the Contract Documents required by Landlord after
such plan and/or documents have been approved by Landlord which it determines
are necessitated by the deviation of such plan and/or documents from
applicable code requirements, and Landlord shall notify Tenant of the
additional cost to Tenant resulting from any such required change(s).

                           b.       No changes shall be made to the Contract
Documents without the prior written approval of Landlord, which approval
shall not be unreasonably withheld, conditioned or delayed except to the
extent such change affects the base Building or Building systems; provided,
however, that Landlord shall not be obligated to approve any such change or
modification which, in Landlord's reasonable opinion, will cause an
unreasonable delay in the completion of the Tenant Improvements or any cost
or expense to Landlord in the performance of the Tenant Improvements.
Landlord shall not be responsible for delay in occupancy by Tenant, nor shall
the Commencement Date be delayed, because of any changes to the Final Space
Plan or the Contract Documents after approval by Landlord, or because of
delay caused by or attributable to any deviation from applicable code
requirements contained in the Contract Documents. Tenant shall be required to
pay the costs incurred in connection with any changes to the Contract
Documents or Final Space Plan to Landlord, in full, within ten (10) days
after invoice.

                  6.       DEADLINES. Tenant acknowledges that it is vital
that it meet all of the schedule deadlines set forth herein in order to allow
Landlord sufficient time to review the Tenant's Plans, estimate costs, and to
substantially complete the work within the contemplated time frame. The
foregoing deadlines are required to be met even if certain deadlines occur
prior to the date the Lease is executed.

         C.       COST OF TENANT IMPROVEMENTS

                  1.       CONSTRUCTION COSTS. All costs of design and
construction of the Tenant Improvements, including without limitation the
costs of all space planning, architectural and engineering work related
thereto; all governmental and quasi-governmental approvals and permits
required therefor; all demolition costs; all direct and indirect construction
costs (the "Hard Costs"); insurance, bonds and other requirements; and any
changes and the Construction Supervision Fee (collectively, "Construction
Costs"), shall be paid by Tenant, subject, however, to the application of the
Improvement Allowance described in Paragraph C.2 below, not previously
disbursed pursuant to this Work Agreement (the "Available Allowance").

                  2.       IMPROVEMENT ALLOWANCE. Provided that Tenant has
fully performed all of its obligations under this Work Agreement and the
Lease, Landlord agrees to provide to Tenant an allowance (the "Improvement
Allowance") in the amount of One Million One Hundred Seventy-Four


                              EXHIBIT B, PAGE 3
<PAGE>

Thousand Seven Hundred Fifty-Six Dollars ($1,174,756.00) (or Twenty-Eight
Dollars ($28.00) per rentable square foot of the Premises), to be applied
solely to the Construction Costs. Notwithstanding the foregoing, up to Two
Hundred Fifty-One Thousand Seven Hundred Forty-Two Dollars ($251,742.00) (or
$6.00 per rentable square foot of the Premises) of the Improvement Allowance
may be used by Tenant to pay for space planning, architectural and
engineering services, cabling, wiring, telephone equipment, and, the
Construction Management Fee (hereinafter defined). Subject to the provisions
of Paragraph C.3, below, the Construction Costs shall be paid by Landlord to
the extent of, and shall be deducted by Landlord from, the Available
Allowance, as invoices therefor are rendered to Landlord as and when
Construction Costs are actually incurred by Tenant; provided, however, that
Landlord shall have received partial lien waivers and such other
documentation as Landlord may require from the party requesting such payment.

                  3.       COSTS EXCEEDING AVAILABLE ALLOWANCE. All
Construction Costs outstanding upon exhaustion of the Improvement Allowance
shall be borne exclusively by Tenant, and Tenant agrees to indemnify Landlord
from and against any such costs. All amounts payable by Tenant pursuant to
this Work Agreement shall be deemed to be Additional Rent for purposes of the
Lease. If required by Landlord, Tenant shall provide evidence reasonably
satisfactory to Landlord that Tenant has sufficient funds available to pay
all Construction Costs in excess of the Improvement Allowance.

         D.       CONSTRUCTION

                  1.       SELECTION OF GENERAL CONTRACTOR. Once Landlord has
approved the Contract Documents, Landlord shall prepare a bid package
containing such requirements as Landlord, in its reasonable discretion, shall
determine and shall submit the Contract Documents to at least three (3)
general contractors selected by Landlord and approved by Tenant, such
approval not to be unreasonably withheld (the "Approved Bidders"), in order
to obtain from such Approved Bidders market rate, fixed price bids (the "Bid
Price") for the contract for construction of the Tenant Improvements. Within
three (3) business days after Landlord receives bids from those Approved
Bidders which timely submit conforming bids, Tenant shall (a) discuss with
the Approved Bidders the bids they submitted; (b) select the contractor
("Contractor") which will undertake construction of the Tenant Improvements
from among the Approved Bidders submitting conforming bids; and (c) instruct
Landlord to enter into the Construction Contract (hereinafter defined) and
begin construction of the Tenant Improvements.

                  2.       CONSTRUCTION SUPERVISION. All Tenant Improvements
shall be performed by the Contractor selected in accordance with this Work
Agreement. Landlord shall retain LPC Commercial Services, Inc. ("Construction
Supervisor") as Landlord's construction supervisor in connection with the
construction of the Tenant Improvements, and Tenant shall pay the
Construction Supervisor a construction supervision fee ("Construction
Supervision Fee") equal to (a) three percent (3%) of the first $1,174,796.00
of Hard Costs incurred in connection with the Tenant Improvements, and (b)
one and one-half percent (1 1/2%) of Hard Costs incurred in connection with
the Tenant Improvements in excess of $1,174,796.00, to cover the costs of
coordination and supervision of the Tenant Improvements work. The
Construction Supervision Fee shall be deducted from the Improvement Allowance.

                  3.       TENANT INSPECTION. Tenant is authorized by
Landlord to make periodic inspections of the Premises during construction
during reasonable business hours, provided Tenant is accompanied by a
representative of Landlord or the Contractor.

                  4.       DELAYS.

                           a.       If Landlord shall be delayed in
substantially completing the Landlord Improvements or the Tenant Improvements
or in delivering the Premises to Tenant, as a result of any act, neglect,
failure or omission of Tenant, its employees or agents (including without
limitation the Space Planner and any contractor or subcontractor employed by
Tenant performing work at the Premises), including any of the following, such
delay shall be deemed a "Tenant Delay": (1) Tenant's failure to timely
furnish to Landlord the Final Space Plan or the Contract Documents; (2)
Tenant's failure to timely furnish to Landlord a revised Final Space Plan or
Contract Documents after objection by Landlord; (3) Tenant's delay in
submitting or approving any other drawings, plans or specifications; (4)
Tenant's failure, within three (3) business days after request therefor, to
provide Landlord with any other information requested by Landlord for the
purpose of completing the Tenant's Plans or the ordering of materials or the
letting of bids for the Tenant Improvements; (5) any change by Tenant (to the
extent such change is permitted by this Work Agreement) in the Contract
Documents after Landlord has approved same; furnished by Tenant; (6)
installation of Tenant's telephone and/or other communications systems; (7)
any Change Orders (hereinafter defined) or direction by Tenant that Landlord
hold up proceeding or continuing with a segment of the Tenant Improvements
preliminary to a possible Change Order or for any other reason; (8) Long Lead
Items (hereinafter defined); or (9) any delay in completing the Tenant
Improvements resulting from the Contract Documents: (a) being incomplete,
inaccurate or otherwise deficient, or (b) deviating from the Final Space
Plan, applicable code requirements and/or any Legal Requirements (hereinafter
defined). In any such event, such delay or delays shall not postpone or defer
the Commencement Date, or Tenant's obligation to pay Rent as of the
Commencement Date, but the Commencement Date shall occur on the day when it
would otherwise have occurred if such delay or delays had not occurred, and
the period of time for the substantial completion of the Premises shall be
extended for a period of time equal to the number of days of such delay or
delays. In addition, Tenant shall pay to Landlord all additional costs
incurred by Landlord resulting from any Tenant Delay, including without
limitation delay damages to the Contractor under the contract for the
construction of the Tenant Improvements (the "Construction Contract"). Any
such sums shall be paid to Landlord within ten (10) days after demand
therefor by Landlord. Any costs payable by Tenant to Landlord hereunder may
be


                              EXHIBIT B, PAGE 4
<PAGE>

satisfied from the Improvement Allowance and shall be deemed to be Additional
Rent under the Lease, and in the event of any default by Tenant in any
payment thereof, Landlord shall (in addition to all other rights and
remedies) have the same rights and remedies arising under the Lease in the
event of an Event of Default regarding the payment of Rent. As used herein,
the term "Change Order" shall mean any change in the Tenant's Plans and/or
the work included within the Tenant Improvements which results in an
amendment to or modification of the Construction Contract, including without
limitation Change Orders which: (i) arise out of a request by Tenant to
modify the Tenant's Plans or to otherwise change the scope of the work
included within the Tenant Improvements; (ii) are required because the
Contract Documents are incomplete, inaccurate or otherwise deficient, or
deviate from the Preliminary Plan or the Final Space Plan approved by
Landlord or from applicable code requirements and/or any Legal Requirements;
and/or (iii) are required because certain work performed or to be performed
in the Premises (and shown in the Tenant's Plans) deviates from any
applicable Legal Requirements. All Change Orders must be submitted to
Landlord for its approval in its reasonable discretion; provided however, if
Change Orders involve construction which involves structural changes to the
Building or the modification of any base Building systems, such approval by
Landlord shall be in its sole discretion. As used herein, the term "Long Lead
Item" shall mean any component of the Tenant Improvements which is not
readily available in reasonable quantities in the metropolitan Washington,
D.C. area or which requires a long term lead time for procurement or
installation. As used herein, the term "Legal Requirements" shall mean any
laws, ordinances, regulations and orders of the United States of America, the
County of Fairfax, the Commonwealth of Virginia and any other governmental
authority with jurisdiction over the Building or the construction of the
Tenant Improvements.

                           b.       If Landlord has substantially completed
all of the Tenant Improvements, as certified by Landlord's architect or the
Construction Supervisor, except for Tenant Improvements constituting Long
Lead Items, then the Tenant Improvements shall be deemed to be substantially
completed and the Commencement Date shall not be delayed. After delivery of
such materials for the items of Tenant Improvements, Landlord shall proceed
with due diligence to install such materials and to complete all other
portions of the Tenant Improvements that could not be completed until after
the installation of such items of Tenant Improvements.

         E.       ACCEPTANCE OF PREMISES. Approximately three (3) days prior
to the delivery of possession of the Premises to Tenant, Landlord, Tenant and
the Contractor shall make an inspection of the Premises to determine that (1)
the Landlord Improvements have been substantially completed by Landlord; and
(2) the construction and installation of the Tenant Improvements has been
completed in accordance with the Tenant's Plans and to prepare a "Punch List"
of work requiring correction or completion by Landlord. Subject to
Unavoidable Delays, Landlord shall correct or complete all Punch List items
within forty-five (45) days after the Commencement Date.

         F.       CONTRACTOR'S RULES AND REGULATIONS. Tenant's contractors,
subcontractors and vendors may not enter the Building to perform any work or
installations prior to the Commencement Date without Landlord's prior written
consent in accordance with the provisions of Section 2c of the Lease. If
Landlord consents to such entry, each contractor, subcontractor or vendor
shall observe all rules and regulations (the "Construction Rules and
Regulations") promulgated by Landlord in connection with the performance of
work in the Building, attached hereto as SCHEDULE B-6.

         G.       TENANT'S AGENT. Tenant hereby designates Robert M. Brown,
whose address is c/o Universal Access, Inc., 100 North Riverside Plaza, Suite
2200, Chicago, Illinois 60609 and whose telephone number is (312) 660-5059,
to act as Tenant's agent for purposes of authorizing and executing any and
all documents, workletters or other writings and changes thereto needed to
effect this Work Agreement, and any and all changes, additions or deletions
to the work contemplated herein, and Landlord shall have the right to rely on
any documents executed by such authorized party.

                                LIST OF SCHEDULES

                      SCHEDULE B-1   BASE BUILDING PLANS AND SPECIFICATIONS
                      SCHEDULE B-2   LANDLORD WORK
                      SCHEDULE B-3   REQUIREMENTS FOR FINAL SPACE PLAN
                      SCHEDULE B-4   REQUIREMENTS FOR CONTRACT DOCUMENTS
                      SCHEDULE B-5   LIST OF BUILDING STANDARD MATERIALS
                      SCHEDULE B-6   CONSTRUCTION RULES AND REGULATIONS

                              EXHIBIT B, PAGE 5
<PAGE>

                                  SCHEDULE B-1

                     BASE BUILDING PLANS AND SPECIFICATIONS


<PAGE>



                              SCHEDULE B-1, PAGE 2

<PAGE>

                                  SCHEDULE B-2

                                  LANDLORD WORK


LOBBIES AND COMMON AREAS: Ground floor and second (2nd) floor fully finished.
Floors three (3) through five (5) will be fully finished with the exception of
the floor covering.

RESTROOMS: Two (2) sets of Men's and Women's bathrooms will be fully finished on
each floor (one set on each wing).

EXTERIOR WALLS: Exterior walls will include drywall and insulation. The drywall
will be ready to bed, tape and finish.

MECHANICAL SYSTEM: Cooling will be provided by self-contained variable air
volume package units (two (2) per floor) serving a medium pressure sheet metal
duct system. Outside air will be ducted from the roof through a vertical chase
to each packaged unit on each floor. The main ductwork trunk lines will be
provided.

Twenty-one (21) Power Induction Boxes ("PIB's") and five (5) Variable Air Volume
Units ("VAV's") shall be furnished and installed in the Premises, in accordance
with the Base Building Plans and Specifications. An additional fifteen (15)
VAV's shall be supplied, but not installed by Landlord in the Premises.

ELECTRICAL SYSTEM: Two (2) watts of lighting load and six (6) watts of power
load diversified for normal office usage to a total lighting and power load of
eight (8) watts per square foot.

Switches shall serve feeders from the main switchboard to two (2) 2500 amp
vertical bus ducts located in each electrical room (two (2) rooms per floor).
Room for additional switches will be provided for future requirements. Within
each electrical room, a bus tap will feed a 42 circuit, 400 amp 277-480 volt
high voltage panel and the self-contained package unit, lighting loads, and a
112.5 Kva transformer serving a 42 circuit 400 amp, 120-208 volt panel for low
voltage power loads.

LIFE SAFETY: Fire standpipe and base building fire alarm system are installed
per building code. The system shall be a complete multi-plexed intelligent,
addressable system with a remote enunciator panel located in the building lobby.
The fire alarm system will monitor and enunciate manual pull stations, smoke
detectors, fire protection systems, flow and tamper switches, etc. An automatic
dialer shall notify the fire department or local monitoring service in case of
trouble alarm.

SPRINKLER SYSTEM: Upturned sprinkler heads will be provided in accordance with
NFPA 13 at a spacing of one head per 225 square feet.

WET STACKS: Two (2) wet stacks will be provided per floor, one (1) per wing.
These stacks shall include sanitary waste connections, vent connections and
domestic water connections.

WINDOW COVERINGS:  Horizontal 1 inch slat venetian blinds will be provided.


<PAGE>

                                  SCHEDULE B-3

                        REQUIREMENTS FOR FINAL SPACE PLAN


         Floor plans, together with related information for mechanical,
electrical and plumbing design work, showing partition arrangement and reflected
ceiling plans (three (3) sets), including without limitation the following
information:

         a.      identify the location of conference rooms and density of
                 occupancy;

         b.      indicate the density of occupancy for all rooms;

         c.      identify the location of any food service areas or vending
                 equipment rooms;

         d.      identify areas, if any, requiring twenty-four (24) hour air
                 conditioning;

         e.      indicate those partitions that are to extend from floor to
                 underside of structural slab above or require special
                 acoustical treatment;

         f.      identify the location of rooms for, and layout of, telephone
                 equipment other than building core telephone closet;

         g.      identify the locations and types of plumbing required for
                 toilets (other than core facilities), sinks, drinking
                 fountains, etc.;

         h.      indicate light switches in offices, conference rooms and all
                 other rooms in the Premises;

         i.      indicate the layouts for specially installed equipment,
                 including computer and duplicating equipment, the size and
                 capacity of mechanical and electrical services required and
                 heat rejection of the equipment;

         j.      indicate the dimensioned location of: (A) electrical
                 receptacles (one hundred twenty (120) volts), including
                 receptacles for wall clocks, and telephone outlets and their
                 respective locations (wall or floor), (B) electrical
                 receptacles for use in the operation of Tenant's business
                 equipment which requires two hundred eight (208) volts or
                 separate electrical circuits, (C) electronic calculating and
                 CRT systems, etc., and (D) special audio-visual requirements;

         k.      indicate proposed layout of sprinkler and other life safety
                 and fire protection equipment, including any special equipment
                 and raised flooring;

         l.      indicate the swing of each door;

         m.      indicate a schedule for doors and frames, complete with
                 hardware, if applicable; and

         n.      indicate any special file systems to be installed.


<PAGE>

                                  SCHEDULE B-4

                       REQUIREMENTS FOR CONTRACT DOCUMENTS


         Final architectural detail and working drawings, finish schedules and
related plans (three (3) reproducible sets) including without limitation the
following information and/or meeting the following conditions:

         a.      materials, colors and designs of wallcoverings, floor
                 coverings and window coverings and finishes;

         b.      paintings and decorative treatment required to complete all
                 construction;

         c.      complete, finished, detailed mechanical, electrical, plumbing
                 and structural plans and specifications for the Tenant
                 Improvements, including but not limited to the fire and life
                 safety systems and all work necessary to connect any special
                 or non-standard facilities to the Building's base mechanical
                 systems;

         d.      all final drawings and blueprints must be drawn to a scale of
                 one-eighth (1/8) inch to one (1) foot. Any architect or
                 designer acting for or on behalf of Tenant shall be deemed to
                 be Tenant's agent and authorized to bind Tenant in all
                 respects with respect to the design and construction of the
                 Premises;

         e.      for all new construction, Tenant shall purchase from Landlord
                 (or its suppliers) and install in the Premises the following
                 building standard equipment and materials: (1) ceiling tiles
                 and suspension system, (2) diffusers, (3) doors (interior and
                 exterior) and (4) door frames and hinges; and

         f.      notwithstanding anything to the contrary set forth herein, in
                 the Work Agreement or in the Lease, Tenant shall not request
                 any work which would: (1) require changes to structural
                 components of the Building or the exterior design of the
                 Building; (2) require any material modification to the
                 Building's mechanical installations or installations outside
                 the Premises; (3) not comply with all applicable laws, rules,
                 regulations and requirements of any governmental department
                 having jurisdiction over the construction of the Building
                 and/or the Premises, including specifically, but without
                 limitation, the Americans With Disabilities Act; (4) be
                 incompatible with the building plans filed with the
                 appropriate governmental agency from which a building permit
                 is obtained for the construction of the Tenant Improvements or
                 with the occupancy of the Building as a first-class office
                 building; or (5) delay the completion of the Premises or any
                 part thereof. Tenant shall not oppose or delay changes
                 required by any governmental agency affecting the construction
                 of the Building and/or the Tenant Improvements in the
                 Premises.


<PAGE>

                                  SCHEDULE B-5

                       LIST OF BUILDING STANDARD MATERIALS


Partitions:                      Partitions within the tenant suite shall
                                 be constructed using 2 1/2" steel studs
                                 and 1/2" gypsum wallboard, floor to
                                 ceiling.

                                 Demising partitions between suites will be
                                 slab-to-slab using 2 1/2" steel studs with
                                 1/2" gypsum wallboard with sound batt
                                 insulation. Walls shall be one (1) hour
                                 rated as required by local building codes.

Door Frames:                     Door frames will be 3'-0" x 9'-2" factory
                                 finished aluminum frames with 1 1/2" trim.
                                 Color to be building standard painted
                                 finish.

Suite Entry Doors:               3'-0" x 9'-0" prefinished solid core wood
                                 with hardwood edge bands to match face
                                 veneers. Veneers to be plain sliced Red
                                 Oak stained to match existing core doors
                                 with a catalyzed lacquer satin sheen top
                                 coat. Doors to be prepped to receive
                                 concealed closers, mortise locksets and
                                 four hinges.

Tenant Doors:                    3'-0" x 9'-0" prefinished solid core wood
                                 with hardwood edge bands to match face
                                 veneers. Veneers to be plain sliced Red
                                 Oak stained in a manner to be selected by
                                 Tenant from the choices offered by
                                 Landlord.

Hardware:                        Suite entry doors shall Schlage Mortise
                                 Lever Locksets. Interior tenant doors
                                 shall have Schlage Heavy Duty Cylindrical
                                 Lever Locksets. The finish for all
                                 hardware is 32D (Stainless Steel). Suite
                                 entry doors shall have overhead fully
                                 concealed closers.

Suite Entry Glass Doors:         Glass doors at suite entries are subject
                                 to the owner's review and approval of all
                                 details.

Ceiling Grid:                    Armstrong Silhouette XL 9/16" Bolt-Slot
                                 white grid with 1/4" reveal. Typical
                                 ceiling height to be 9'-6" AFF.

Ceiling Tile:                    Armstrong Cortega 24" x 24" white tile,
                                 item #2195.

Vinyl Composite Tile:            12"x12"x 1/8" standard commercial grade
                                 vinyl composite tile in standard colors as
                                 selected by tenant.

Vinyl Wall Base:                 4" high vinyl straight base for carpet. 4"
                                 high vinyl cove base for VCT flooring.
                                 Standard colors as selected by tenant.

Carpet:                          Commercial grade, 30 oz. (or greater),
                                 with a ten year warranty. Installation is
                                 direct glue. Colors and patterns as
                                 selected by tenant.

Paint:                           Two (2) coats as selected by Tenant
                                 (includes prime coat and one coat of
                                 latex, eggshell finish) with a limit of
                                 one (1) color per room and two (2) colors
                                 per suite. All wood and metal surfaces
                                 will receive a primer coat and
                                 two (2) coats of semi-gloss paint.

Window Blinds:                   Levelor Monaco (Contract) 1" horizontal
                                 aluminum blinds; Color #201 - Ivory or
                                 equal.

Tenant Suite Signage:            Building standard tenant suite
                                 identification signage will be provided by
                                 the Landlord and paid for by the tenant.

Sprinkler Piping:                Black steel piping manufactured to satisfy
                                 ASTM Standards A53 or A135. For ASTM
                                 Standard A53, use schedule 40 piping for
                                 sizes up to 8" and schedule 30 for sizes
                                 8" and greater. For ASTM Standard A135,
                                 use schedule 10 piping for sizes through
                                 5". For 6" through 10" sizes, use NFPA
                                 specified wall thickness. Fittings to be
                                 class 250 threaded cast iron or
                                 grooved-end type iron fittings, style 77,
                                 as manufactured by Victaulic Corporation
                                 or accepted equal.

Sprinkler Heads:                 Fully-recessed heads rated at 165(Deg.)
                                 F with painted off white escutcheon
                                 plates. All sprinkler heads to be center
                                 of tile in acoustical tile ceilings;
                                 provided, however, in no event shall any
                                 sprinkler head(s) be closer than 3"
                                 from the edge of any ceiling tile.

Fire Dampers:                    Ruskin Type 1BD2, with a 165(Deg.) F
                                 fusible link; UL approved. Style A
                                 directly behind registers, Style B for
                                 rectangular duct, and Style LR for
                                 round duct or equal.


<PAGE>

Registers/Grilles/Diffusers:     Perimeter diffusers to be plenum slot
                                 diffusers.
                                 24" x 24" supply air diffusers to, 3/4"
                                 slots, with integral building standard
                                 ceiling tile.
                                 24" x 24" return air diffusers to 3/4" slots,
                                 with integral building standard ceiling tile.

VAV Boxes:                       Fan Powered VAV Boxes with electric heat
                                 to be Trane Model VPEE2415 or equal.
                                 10" outlet standard VAV boxes to be Trane
                                 Model VCCE17 or equal; 1700 CFM rated, 270
                                 CFM minimum, 1500 CFM maximum.
                                 8" outlet standard VAV boxes to be Trane
                                 Model VCCE11 or equal; 1100 CFM rated, 170
                                 CFM minimum, 615 CFM maximum.
                                 Bottom of thermostats to be 60" AFF typical.

Fire Alarm System:               Fire Alarm System to be fully addressable.
                                 All connections to base building fire
                                 alarm panels must be performed by the
                                 Landlord's fire alarm contractor.

Light Fixtures:                  2'x4' Fluorescent 277V fixtures with
                                 chrome 18 cell parabolic lenses, high
                                 efficiency electronic ballasts and cool
                                 white F32/T8 lamps.

                                 Public Corridor light fixtures shall be
                                 2'x 4' Fluorescent 277V fixtures with
                                 chrome 9 cell parabolic lenses, high
                                 efficiency electronic ballasts and cool
                                 white F32/T8 lamps

Exit Lights:                     LED exit lights with a white steel housing
                                 and red letters.

Electrical Meters:               Provided for tenant supplemental HVAC
                                 systems within the tenant suite. National
                                 Meters Industries, Series 3000, Model
                                 K3240, 240V 1 phase 2W 60 Hz or equal. A
                                 4000 Series model or equal may be required
                                 for large HVAC units.

Electrical Panels:               All panels to be GE to match building
                                 standard.


                           Schedule B-5, page 2
<PAGE>

                                  SCHEDULE B-6

                       CONSTRUCTION RULES AND REGULATIONS


1.      Tenant and/or the general contractor will supply Landlord with a copy
        of all permits prior to the start of any work.

2.      Tenant and/or the general contractor will post applicable permits on a
        wall of the construction site while work is being performed.

3.      Public area corridor, and carpet, is to be protected by plastic runners
        or a series of walk-off mats from the elevator to the suite under
        reconstruction.

4.      Walk-off mats are to be provided at entrance doors.

5.      Contractors will remove their trash and debris daily, or as often as
        necessary to maintain cleanliness in the building. Building trash
        containers are not to be used for construction debris. Landlord
        reserves the right to bill Tenant for any cost incurred to clean up
        debris left by the general contractor or any subcontractor. Further,
        the building staff is instructed to hold the driver's license of any
        employee of the contractor while using the freight elevator to ensure
        that all debris is removed from the elevator.

6.      No utilities (electricity, water, gas, plumbing) or services to the
        tenants are to be cut off or interrupted without first having
        requested, in writing, and secured, in writing, the permission of the
        Landlord.

7.      No electrical services are to be put on the emergency circuit, without
        specific written approval from the Landlord.

8.      When utility meters are installed, the general contractor must provide
        the property manager with a copy of the operating instructions for that
        particular meter.

9.      The Landlord will be notified of all work schedules of all workmen on
        the job and will be notified, in writing, of names of those who may be
        working in the building after "normal" business hours.

10.     Passenger elevators shall not be used for moving building materials and
        shall not be used for construction personnel except in the event of an
        emergency. The designated freight elevator is the only elevator to be
        used for moving materials and construction personnel. This elevator may
        be used only when it is completely protected as determined by
        Landlord's building engineer.

11.     Contractors or personnel will use loading dock area for all deliveries
        and will not use loading dock for vehicle parking.

12.     Contractors will be responsible for daily removal of waste foods, milk
        and soft drink containers, etc. to trash room and will not use any
        building trash receptacles but trash receptacles supplied by them.

13.     No building materials are to enter the building by way of main lobby,
        and no materials are to be stored in any lobbies at any time.

14.     Construction personnel are not to eat in the lobby or in front of
        building nor are they to congregate in the lobby or in front of
        building.

15.     The Landlord is to be contacted by Tenant when work is completed for
        inspection. All damage to building will be determined at that time.

16.     All key access, fire alarm work, or interruption of security hours must
        be arranged with the Landlord's building engineer.

17.     There will be no radios allowed on job site.

18.     All workers are required to wear a shirt, shoes, and full length
        trousers.

19.     Protection of hallway carpets, wall coverings, and elevators from
        damage with masonite board, carpet, cardboard, or pads is required.

20.     Public spaces -- corridors, elevators, bathrooms, lobby, etc. -- must
        be cleaned immediately after use. Construction debris or materials
        found in public areas will be removed at Tenant's cost.

21.     There will be no smoking, eating, or open food containers in the
        elevators, carpeted areas or public lobbies.

22.     There will be no yelling or boisterous activities.

<PAGE>

23.      All construction materials or debris must be stored within the project
         confines or in an approved lock-up.

24.      There will be no alcohol or controlled substances allowed or tolerated.

25.      The general contractor and Tenant shall be responsible for all loss of
         their materials and tools and shall hold Landlord harmless for such
         loss and from any damages or claims resulting from the work.





                               Schedule B-6, page  2       HOLLAND & KNIGHT LLP
<PAGE>

                                    EXHIBIT C

                        DECLARATION OF COMMENCEMENT DATE


         This Declaration of Commencement Date is made as of__________________,
2000, by HERNDON LINCOLN I LLC ("Landlord"), and UNIVERSAL ACCESS, INC.
("Tenant"), who agree as follows:

         1.      Landlord and Tenant entered into a Deed of Lease dated April
___, 2000, in which Landlord leased to Tenant and Tenant leased from Landlord
certain Premises described therein in the office building located at 13900
Lincoln Park Drive, Herndon, Virginia (the "Building"). All capitalized terms
herein are as defined in the Lease.

         2.      Pursuant to the Lease, Landlord and Tenant agreed to and do
hereby confirm the following matters as of the Commencement Date of the Term:

                 a.      the Commencement Date of the Lease is _____________,
                         2000;

                 b.      the Lease Expiration Date of the Lease is
                         _____________, 2010;

                 c.      the number of rentable square feet of the Premises is
                         _____________;

                 d.      Tenant's Pro Rata Share of Operating Expenses is
                         _____________%; and

                 e.      Tenant's Pro Rata Share of Real Estate Taxes is
                         _____________%.

         3.      Tenant confirms that:

                 a.      it has accepted possession of the Premises as
                         provided in the Lease;

                 b.      any work  required to be performed  or  furnished  by
                         Landlord  under the Lease has been completed and/or
                         furnished;

                 c.      Landlord has fulfilled all of its obligations under
                         the Lease as of the date hereof;

                 d.      the Lease is in full force and effect and has not
                         been  modified,  altered,  or amended, except as
                         follows:  __________________________________; and

                 e.      there are no set-offs or credits  against Rent, and
                         no Security  Deposit or prepaid Rent has been paid
                         except as provided by the Lease.

         4.      The provisions of this Declaration of Commencement Date
shall inure to the benefit of, or bind, as the case may require, the parties
and their respective successors and assigns, and to all mortgagees of the
Building, subject to the restrictions on assignment and subleasing contained
in the Lease, and are hereby attached to and made a part of this Lease.

                                    LANDLORD:

                                    HERNDON LINCOLN I LLC, a Delaware limited
                                    liability company

                                    By:  Lincoln-Herndon LLC, a Delaware
                                         limited liability company, its
                                         Managing Member
WITNESS:
                                          By:  Lincoln Investors Group 2, Inc.,
                                               a Texas corporation, its
                                               Managing Member


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

                                    TENANT:

WITNESS:                            UNIVERSAL ACCESS, INC., a Delaware
                                    corporation


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


<PAGE>

                                    EXHIBIT D

                       LOCATION OF RESERVED PARKING SPACES


                                    [Attach]


<PAGE>

                                    EXHIBIT E

                            LOCATION OF EXTERIOR SIGN


                                    [Attach]


<PAGE>

                                   EXHIBIT E-1

                           DIMENSIONS OF EXTERIOR SIGN


                                    [Attach]


<PAGE>

                                    EXHIBIT F

                               RULES & REGULATIONS


1.      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 (including without
        limitation coffee grounds) shall be thrown therein. All damages
        resulting from misuse of the fixtures shall be borne by Tenant if
        Tenant or its servants, employees, agents, visitors or licensees shall
        have caused the same.

2.      No cooking (except for hot-plate and microwave cooking by Tenants'
        employees for their own consumption, the location and equipment of
        which is first approved by Landlord), sleeping or lodging shall be
        permitted by any tenant on the Premises. No tenant shall cause or
        permit any unusual or objectionable odors to be produced upon or
        permeate from the Premises.

3.      No inflammable, combustible, or explosive fluid, material, chemical or
        substance shall be brought or kept upon, in or about the Premises. Fire
        protection devices, in and about the Building, shall not be obstructed
        or encumbered in any way.

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

5.      There shall not be used in any space, or in the public halls of the
        Building, either by any tenant or by its agents, contractors, jobbers
        or others, in the delivery or receipt of merchandise, freight, or other
        matters, any hand trucks or other means of conveyance except those
        equipped with rubber tires, rubber side guards, and such other
        safeguards as Landlord may require, and Tenant shall be responsible to
        Landlord for any loss or damage resulting from any deliveries to Tenant
        in the Building. Deliveries of mail, freight or bulky packages shall be
        made through the freight entrance or through doors specified by
        Landlord for such purpose.

6.      Mats, trash or other objects shall not be placed in the public
        corridors. The sidewalks, entries, passages, elevators, public
        corridors and staircases and other parts of the Building which are not
        occupied by Tenant shall not be obstructed or used for any other
        purpose than ingress or egress.

7.      Tenant shall not install or permit the installation of any awnings,
        shades, draperies and/or other similar window coverings, treatments or
        like items visible from the exterior of the Premises other than those
        approved by the Landlord in writing.

8.      Tenant shall not construct, maintain, use or operate within said
        Premises or elsewhere in the Building or on the outside of the
        Building, any equipment or machinery which produces music, sound or
        noise which is audible beyond the Premises.

9.      Bicycles, motor scooters or any other type of vehicle shall not be
        brought into the lobby or elevators of the Building or into the
        Premises except for those vehicles which are used by a physically
        disabled person in the Premises.

10.     All blinds for exterior windows shall be building standard and shall be
        maintained by Tenant.

11.     No additional locks shall be placed upon doors to or within the
        Premises except as shall be necessary adequately to safeguard United
        States Government security classified documents stored with the
        Premises. The doors leading to the corridors or main hall shall be kept
        closed during business hours, except as the same may be used for
        ingress or egress.

12.     Tenant shall maintain and clean all areas or rooms within the Premises
        in which security classified work is being conducted or in which such
        work is stored; Landlord shall not provide standard janitorial service
        to such areas, the provisions of Section 9 of this Lease
        notwithstanding.

13.     Landlord reserves the right to shut down the air conditioning,
        electrical systems, heating, plumbing and/or elevators when necessary
        by reason of accident or emergency, or for repair, alterations,
        replacements or improvement.

14.     No carpet, rug or other article shall be hung or shaken out of any
        window of the Building; and Tenant shall not sweep or throw or permit
        to be swept or thrown from the Premises any dirt or other substances
        into any of the corridors or halls, elevator, or out of the doors or
        windows or stairways of the Building. Tenant shall not use, keep or
        permit to be used or kept any foul or noxious gas or substance in the
        Premises, or permit or suffer the Premises to be occupied or used in a
        manner offensive or objectionable to Landlord or other occupants of the
        Building by reason of noise, odors and/or vibrations, or interfere in
        any way with other tenants or those having business therein, nor shall
        any animals or birds be kept in or about the Building. Smoking or
        carrying lighted cigars or cigarettes in the elevators of the Building
        is prohibited.

15.     Landlord reserves the right to exclude from the Building on weekdays
        between the hours of 6:00 p.m. and 8:00 a.m. and at all hours on
        weekends and legal holidays, all persons who do not present a pass to
        the Building signed by Landlord; provided, however, that reasonable
        access for


<PAGE>

        Tenant's employees and customers shall be accorded. Landlord
        will furnish passes to persons for whom Tenant requires same in
        writing. Tenant shall be responsible for all persons for whom it
        requests such passes and shall be liable to Landlord for all acts of
        such persons.

16.     Tenant agrees to keep all windows closed at all times and to abide by
        all rules and regulations issued by Landlord with respect to the
        Building's air conditioning and ventilation systems.

17.     Tenant will replace all broken or cracked interior windows and glass
        doors within the Premises at its own expense, with glass of like kind
        and quality, provided that such windows and doors are not broken or
        cracked by Landlord, its employees, agents or contractors.

18.     In the event it becomes necessary for the Landlord to gain access to
        the underfloor electric and telephone distribution system for purposes
        of adding or removing wiring, then upon request by Landlord, Tenant
        agrees to temporarily remove the carpet over the access covers to the
        underfloor ducts for such period of time until work to be performed has
        been completed. The cost of such work shall be borne by Landlord except
        to the extent such work was requested by or is intended to benefit
        Tenant or the Premises, in which case the cost shall be borne by
        Tenant.

19.     Violation of these rules, or any amendments thereof or additions
        thereto, may be considered a default of Tenant's lease after written
        notice of such violation and the failure by Tenant to cure such
        violation within thirty (30) days thereafter, and shall be sufficient
        cause for termination of this Lease at the option of Landlord.


                                Exhibit F, page 2