EXHIBIT 10.7
                                 ------------

                                     LEASE

                                 by and between

                          AETNA LIFE INSURANCE COMPANY

                                      and

                       TELEPHONE BUSINESS MEETINGS, INC.

                           dba ACCESS CONFERENCE CALL

                                     RIDER
                                     -----

     The printed part of the Lease is hereby modified and supplemented as
follows.  Wherever there is a conflict between this Rider and the printed part
of the Lease the provisions of this Rider are paramount and the Lease shall be
construed accordingly.

1.  The following language is hereby added to the Lease:

    Renewal Option.
    -------------- 

    1.1 Tenant is granted the right and option (the "Renewal Option") to extend
the term of this Lease for one (1) additional period of five (5) years, and if
such renewal is effectively exercised, such renewal term (the "Renewal Term")
shall commence upon the expiration of the previous term of this Lease, provided
that:

        (a) Such option must be exercised, if at all, by notice from Tenant to
Landlord given at least one hundred eighty (180) days prior to the expiration of
the Lease Term; and

        (b) At the time of exercising such option, this Lease shall be in full
force and effect and there shall exist no default by Tenant which remains
uncured beyond any applicable period of grace.

    1.2 In the event the foregoing option is effectively exercised, all the
terms and conditions contained in this Lease shall continue to apply except
that:

        (a) There shall be no further right of renewal beyond the period
referred to above;

        (b) The Renewal Option shall apply to all (and not less than all) of the
Premises originally leased hereunder, plus any additional space leased by the
Tenant pursuant to any option contained herein or otherwise:

        (c) In the event Tenant shall have assigned this Lease or sublet in
excess of twenty-five percent (25%) of the Premises, except to an affiliate as
permitted in the Lease, this

 
Renewal Option shall automatically expire and be null and void with respect to
that portion of the Premises so assigned or sublet;

        (d) The rental rate applicable to the Premises during any Renewal Term,
plus any additional space then leased pursuant to Tenant shall enter into an
amendment to this Lease to set forth the amount of initial Rent during such
Renewal Term.

        (e) The Rent during each such Renewal Term shall be ninety-five percent
(95%) of the then current fair market rental rate for similar buildings in the
same geographic area including all applicable market concessions and rental
escalations.  If Landlord and Tenant are unable to reach agreement on the
current fair market rental rate for the Premises within ten (10) business days
after Tenant's written notice to Landlord of such renewal, then such
determination shall be made using the three broker method as follows: within ten
(10) business days after expiration of the ten (10) business day period for
Landlord and Tenant to reach mutual agreement as contemplated above, Landlord
and Tenant shall each select a commercial real estate broker who is licensed and
in good standing in the Commonwealth of Virginia, who has at least five (5)
years experience, and who is knowledgeable about the Reston area and commercial
leasing therein.  To determine the current fair market rental rate, the brokers
shall consider comparable office leases in the Reston area and shall compare all
relevant factors including (1) the age, quality, function, location and
condition of the Building; (2) the time period covered by the relevant Renewal
Term; (3) the amount of space being leased under the comparable leases as
compared to the amount of space within the Premises; and (4) market concession
such as, but not limited to, rental abatement and comparable tenant improvement
allowances for renewals and new leases (as the case may be).  Such brokers shall
also make appropriate adjustments in their calculation to account for any costs
or expenses (or savings) which relate to the inclusion or exclusion of specific
operating costs items (i.e., cost of electricity, etc.) and different base years
which may be applicable to such full service lease(s), or which are unique to
the particular comparable office leases in those Reston office buildings used in
arriving at their calculation of the current fair market rental rate for the
Premises as set forth above.  If Landlord's broker and tenant's broker are
unable to agree upon the current fair market rental rate for the Premises within
thirty (30) days of their selection, they shall mutually select a similarly
qualified third (3rd) broker, and the third (3rd) broker shall determine the
current fair market rental rate for the Premises.  If the determination of the
third broker falls between the determination of Landlord's broker and Tenant's
broker, the Rent during the Renewal Term shall be ninety-five percent (95%) of
the third broker's determination of the current fair market rental rate for the
Premises.  However, if the determination of the third broker does not fall
between the determinations of Landlord's broker and Tenant's broker, the Rent
during the Renewal Term shall be ninety-five percent (95%) of the average of the
two closest brokers' determinations.

    1.3 In the event Tenant fails to exercise the foregoing option in the manner
and within the time period set forth herein, the Lease shall automatically
terminate at the end of the then current term, the applicable Renewal Option
shall lapse and Tenant shall have no further right or option to extend the term
of this Lease.

2.  The following language is hereby added to the Lease:

                                       2

 
    2.1 Early Termination Option #1.  Tenant may terminate this Lease as of the
        ---------------------------                                            
seventy-second (72nd) month of the term by: (1) providing Landlord with not less
than 180 days written notice of its intent to terminate, and (2) providing a
payment of $15.07 per square foot of the Premises, fifty percent (50%) of which
shall be due upon Tenant's delivery of its notice of termination, and fifty
percent (50%) of which shall be due on the date of termination.  If the Lease is
terminated by Tenant as provided for under this paragraph, then the rights of
the parties with respect to said termination will be as provided for under the
Lease had the Lease Term expired on the Lease Expiration Date.

    2.2 Early Termination Option #2.  Tenant may terminate this Lease as of the
        ---------------------------                                            
ninety-sixth (96th) month of the term by: (1) providing Landlord with not less
than 180 days written notice of its intent to terminate, and (2) providing a
payment of $8.25 per square foot of the Premises, fifty percent (50%) of which
shall be due upon Tenant's delivery of its notice of termination, and fifty
percent (50%) of which shall be due on the date of termination.  If the Lease is
terminated by Tenant as provided for under this paragraph, then the rights of
the parties with respect to said termination will be as provided for under the
Lease had the Lease Term expired on the Lease Expiration Date.

3.  The following language is hereby added to the Lease Agreement.

    Right of First Refusal.  Subject to the rights, as of the date of the full
    ----------------------                                                    
execution of this Lease, of existing tenants, Landlord hereby grants to Tenant
an on-going right of first refusal ("Right of First Refusal") to lease any space
which becomes available for lease (the "Refusal Space") following the full
execution of this Lease (subject to the terms set forth below).  If Landlord
receives a bona fide offer to lease all or any part of the Refusal Space, then
Landlord shall deliver written notice of such offer to Tenant (the "Refusal
Notice") outlining the material terms of the offer and Tenant shall have the
right to exercise the Right of First Refusal upon all of the material terms and
conditions set forth in such Refusal Notice, by written notice to Landlord,
delivered no later than ten (10) business days after Landlord's delivery to
Tenant of the Refusal Notice.  Included with Tenant's written response to the
Refusal Notice (if positive) shall be current financial statements.  After
reviewing these statements, Landlord reserves right to request such credit
enhancements as Landlord deems reasonable given the rent for the space to be
leased (and with no such enhancements to be required unless Tenant's financial
condition has materially deteriorated since the execution of this Lease).  If
Tenant fails to exercise its Right of First Refusal, within such ten (10)
business day period (time being of the essence), Tenant shall be deemed to have
rejected the Refusal Space designated in the Refusal Notice and Landlord shall
have the right to lease the Refusal Space to the third party upon effectively
the same terms and conditions set forth in the Refusal Notice.  In the event
Tenant accepts Landlord's offer, Tenant shall execute a new lease for the
Refusal Space using the legal terms set forth in this Lease, but modifying the
business terms as necessary to conform to the business terms and conditions set
forth in the bona fide offer, as reflected in the Refusal Notice.

    Notwithstanding the foregoing, with respect to the remaining space on the
second floor, Tenant shall have, after full Lease execution, an additional two
(2) full Lease Year Right of First

                                      3

 
Refusal at the same terms and conditions of this Lease to include: (i) a Twenty
Dollar ($20.00) per square foot Tenant Improvement Allowance ("Improvement
Allowance") if Tenant leases the space in the first (1st) year of its term; (ii)
a Fifteen Dollar ($15.00) per square foot Improvement Allowance if Tenant leases
the space in the second year of its term; and (iii) a pro-rata share of the
rental abatement, provided for in Article 1.4 of the Lease (determined by
comparing the Lease Term for the Premises to the lease term for the Expansion
Space).

4.  The following language is hereby added to the Lease:

As security for its full and faithful performance of this Lease, Tenant shall
pay Landlord a total security deposit of One Hundred Thousand Dollars
($100,000.00) payable within thirty (30) days of the full execution of this
Lease.  Tenant shall have the right to provide the security deposit to Landlord
either in the form of immediately available funds (i.e., cash, certified check,
money order) or an irrevocable and transferable letter of credit running in
favor of Landlord, with such letter of credit securing Tenant's obligation
hereunder subject to the terms and conditions set forth hereinbelow.  The
security deposit shall not be considered an advance payment of rental or a
measure of Landlord's damages in case of default by Tenant.  The letter of
credit shall be issued by a bank acceptable to Landlord in Landlord's sole but
reasonable discretion and under the supervision of the banking commission of the
Commonwealth of Virginia, FDIC or FSLIC.  If the credit of the bank which
originally issues the letter of credit becomes unacceptable to Landlord in
Landlord's sole but reasonable discretion, Tenant shall substitute another
letter of credit from a bank which is acceptable to Landlord in Landlord's sole
reasonable discretion.  The letter of credit shall be irrevocable for the period
ending no less than one (1) year after the date of issuance.  Tenant shall renew
the letter of credit and maintain it for the period ending five (5) days after
the later of (i) the date of actual termination of this Lease or (ii) the date
Tenant shall have vacated and surrendered the entire Premises to Landlord in
accordance with the terms hereof and shall provide that it is automatically
renewable for said period hereby demised, unless released pursuant to the
provisions of this Section or unless the issuing bank delivers a notice of non-
renewal no later than thirty (30) days prior to expiration.  If Tenant fails to
renew the letter of credit within ten (10) business days of its expiration,
Landlord may draw upon the letter and maintain the funds as an interest-bearing
deposit to be returned to Tenant upon receipt by Landlord of a substitute letter
of credit from Tenant.

The form and terms of the letter of credit shall be reasonably acceptable to
Landlord and shall provide, among other things, in effect that:

    (a) Landlord ("Beneficiary") shall have the right to draw down an amount up
to the then current face amount of the letter of credit after a default by
Tenant under the Lease and expiration of the applicable notice and cure period
upon presentation to the issuing bank of Landlord's own declaration signed or
purportedly signed by or on its behalf reading as follows:

         i.  that the declarant is an officer (or general partner or sole
     proprietor in the case of a general partnership or sole proprietorship,
     respectively) of the Beneficiary on behalf of the Beneficiary;

                                       4

 
         ii.  that the declarant has authority to make the declaration on behalf
     of the Beneficiary;

         iii. that the declaration is made pursuant to the terms of the letter
     of credit number ____________;

         iv.  that Tenant is in default after expiration of the applicable
     notice and cure period under the terms of a lease made between Beneficiary
     and Telephone Business Meetings, Inc., dba Access Conference Call Service;

         v.   that the amount of the default is $_________; and

         vi.  [or in lieu of iv. and v.] that Tenant under the terms of a lease
     made between Beneficiary and Telephone Business Meetings, Inc., dba Access
     Conference Call Service has failed to provide a substitute letter of
     credit.

    (b) The letter of credit will be honored by the issuing bank without inquiry
as to the accuracy thereof and regardless of whether the Tenant disputes the
content of such statement;

    (c) In the event of a transfer of Landlord's interest in the Building,
Landlord shall have the right to transfer the letter of credit to the
transferee, and it is agreed that the provisions hereof shall apply to every
transfer or assignment of said letter of credit to a new Landlord.  In the event
of such a transfer, the provider of the letter of credit must be ratified by
Landlord by return of a transfer agreement.

    (d) If, as a result of any such application of all or any part of such
letter of credit, the amount secured by the letter of credit shall be less than
$100,000.00, Tenant shall forthwith provide Landlord with cash or other
immediately available funds, or an additional letter of credit which meets the
requirements of this Section, to cover the deficiency, or restore the amount
available to be drawn under the letter of credit to the amount required herein
upon written notice from Landlord to Tenant.

    (e) Tenant further covenants that it will not assign or encumber said letter
of credit or any part thereof and that neither Landlord nor its successors or
assigns will be bound by any such assignment, encumbrance, attempted assignment
or attempted encumbrance.

    (f) Without limiting the generality of the foregoing, if the letter of
credit expires earlier than as provided for herein, or the issuing bank notifies
Landlord that it shall not renew the letter of credit, Landlord will accept a
renewal thereof or substitute letter of credit (such renewal or substitute
letter of credit to be in effect not later than thirty (30) days prior to the
expiration thereof), which renewal or substitute letter of credit shall be
irrevocable and automatically renewable, and issued by a bank meeting the
requirements of this Section, for the entire period provided for in this
Section, upon substantially the same terms as the expiring letter of credit or
such other terms as may be acceptable to Landlord.  However, (i) if the letter
of credit is not timely renewed or a substitute letter of credit is not timely
received, or (ii) if Tenant fails to

                                       5

 
maintain the letter of credit in the amount and terms set forth in this Section,
then, at least thirty (30) days prior to the expiration of the letter of credit,
or immediately upon Tenant's failure to comply with each and every term of this
Section, Tenant shall deposit with Landlord cash security in the amounts
required by, and to be held subject to the terms of this Section, failing which
the Landlord may present such letter of credit to the bank, in accordance with
the terms of this Section, and the entire sum secured thereby shall be paid to
Landlord as a substitute security deposit, to be held by Landlord in the manner
provided for in this Section.

    If Tenant provides the security deposit in the form of cash or other
immediately available funds, Landlord shall deposit such funds into an interest
bearing account chosen by Landlord in its reasonable discretion and, provided
Tenant is otherwise entitled to repayment of the security deposit hereunder,
Tenant shall be entitled to any and all interest accrued thereon.
Notwithstanding the foregoing, Tenant acknowledges and agrees that Landlord may
commingle the security deposit with other funds in Landlord's possession
provided Landlord otherwise complies with the terms hereof.  All direct out-of-
pocket expenses to set up and maintain such account shall be deducted from any
interest earned on the amount of such cash security deposit.  If Tenant defaults
with respect to any covenant or condition of this Lease, including but not
limited to the payment of Monthly Base Rent, additional rent or any other
payment due under this Lease, and the obligation of Tenant to maintain the
premises and deliver possession thereof back to Landlord at the expiration or
earlier termination of the Lease Term in the condition required herein, then
Landlord may (without any waiver of Tenant's default being deemed to have
occurred) apply all or any part of the security deposit to the payment of any
sum in default or any other sum which Landlord may be required or deem necessary
to spend or incur by reason of Tenant's default.  In such event, Tenant shall,
upon demand, deposit with Landlord the amount so applied to replenish the
security deposit.  If Tenant shall have fully complied with all of the covenants
and conditions of this Lease, but not otherwise, the amount of the security
deposit (including all interest accrued thereon if any) then held by Landlord
shall be repaid to Tenant within thirty (30) days after the expiration or sooner
termination of this Lease.  In the event of a sale or transfer of Landlord's
estate or interest in the Building, Landlord shall have the right to transfer
the security deposit to the purchaser or transferee, and Landlord shall be
considered released by Tenant from all liability for the return of the security
deposit, so long as the transferee acknowledges receipt of the security deposit
and Landlord's obligations under this Lease.

    Notwithstanding anything else herein to the contrary, and provided Tenant is
not then in default under the terms of this Lease and no event has occurred
which, with notice or the passage of time, or both, would constitute a default
under this Lease at the time the provisions of this paragraph are to take
effect, then after the end of the second (2nd) Lease Year, Tenant shall only be
required to maintain a security deposit of one month's Rent with Landlord.  All
terms of this Section relating to the security deposit shall be modified to
reflect such reduction in the security deposit, mutatis mutandis, but shall
                                                ----------------           
otherwise remain in full force and effect, and Landlord shall return the Letter
of Credit for substitution.

5.  The following language is hereby added to the Lease Agreement:

                                       6

 
    Landlord will work with Tenant's representatives and contractors to:

          i)  install secure conduit and riser capacity, minimum of 4 inch
     diameter, to connect new telephone room to existing one and from existing
     one in Tenant's suite.

         ii)  allow Bell Atlantic and/or MFS to place additional equipment in
     both current and new telephone rooms.

         iii)  install an electrical generator sufficient to power Tenant's
    equipment, in a mutually agreeable location in or near the Building, with
    electrical lines running to the Premises (with the intention of placing the
    generator in a location which minimizes Tenant's cost of installation and
    operation while giving due consideration to the Landlord's interest in
    maintaining an attractive building and site).

    All of the above to be at Tenant's cost.

6.  Landlord at Landlord's cost and expense shall provide conduit and sleeves to
Building and into Building for secondary fiber entrance as per Exhibit F
attached.

7.  The following language is hereby added to the Lease Agreement.

     Commencing on the Lease Commencement Date and continuing through the Lease
term, Landlord shall provide Tenant with two hundred fifty (250) square feet of
basement storage space in a mutually agreeable location at a rental rate of One
Hundred Twenty-Five Dollars ($125.00) per month.

8.  Contingency.     If Landlord does not deliver a fully executed original of
    -----------                                                               
this Lease to Tenant within ten (10) days following execution of this Lease by
Tenant and delivery to Landlord's representatives in Washington, D.C. (Trammell
Crow Company), this Lease shall be null and void.

                                       7

 
                                   EXHIBIT A

                          DESCRIPTION OF THE PROPERTY



                                   Suite 200

                                       8

 
                                   EXHIBIT B


                               TRUE COPY OF LEASE

                                       9

 
                                   EXHIBIT C

                        SCHEDULE OF LEASE MODIFICATIONS



NONE, EXCEPT THOSE, IF ANY, LISTED BELOW:

                                      10

 
                                     LEASE

                                 BY AND BETWEEN

                          AETNA LIFE INSURANCE COMPANY

                                  ("Landlord")

                                      AND

                       TELEPHONE BUSINESS MEETINGS, INC.
                       dba ACCESS CONFERENCE CALL SERVICE

                                   ("Tenant")



                           Multi-tenant Office Lease

                                      11

 
                               TABLE OF CONTENTS
                               -----------------



ARTICLE
- -------
 
1   TERMS
2   COMMENCEMENT AND EXPIRATION DATES
3   PAYMENT OF RENT
4   SECURITY DEPOSIT
5   USES
6   LATE CHARGES
7   REPAIRS AND MAINTENANCE
8   UTILITIES AND SERVICE
9   COST OF SERVICES AND UTILITIES
10  PROPERTY TAXES
11  LIABILITY AND CASUALTY INSURANCE
12  FIRE INSURANCE - FIXTURES AND EQUIPMENT
13  DAMAGE OR DESTRUCTION
14  ALTERATIONS AND ADDITIONS: REMOVAL OF FIXTURES
15  ACCEPTANCE OF PREMISES
16  TENANT IMPROVEMENTS
17  ACCESS
18  WAIVER OF SUBROGATION
19  INDEMNIFICATION
20  ASSIGNMENT AND SUBLETTING
21  ADVERTISING
22  LIENS
23  DEFAULT
24  SUBORDINATION AND ATTORNMENT
25  SURRENDER OF POSSESSION
26  NON-WAIVER
27  HOLDOVER
28  CONDEMNATION
29  NOTICES
30  MORTGAGEE PROTECTION
31  COSTS AND ATTORNEYS' FEES
32  BROKERS
33  LANDLORD'S LIABILITY
34  ESTOPPEL CERTIFICATES
35  FINANCIAL STATEMENTS
36  TRANSFER OF LANDLORD'S INTEREST
37  RIGHT TO PERFORM
38  SUBSTITUTED PREMISES
39  SALES AND AUCTIONS
40  ROOFTOP EQUIPMENT
41  SECURITY

                                      12

 


  
42   AUTHORITY OF TENANT
43   NO ACCORD OR SATISFACTION
44   MODIFICATIONS FOR LENDER
45   PARKING
46   GENERAL PROVISIONS
47   RULES AND REGULATIONS
48   NO WARRANTIES OR REPRESENTATIONS BY LANDLORD
49   LANDLORD'S CONSENT OR APPROVAL
50   WAIVER OF TRIAL BY JURY


             
EXHIBIT  A  -  LOCATION AND DIMENSIONS OF PREMISES
EXHIBIT  B  -  RENT INCREASES
EXHIBIT  C  -  TENANT WORK FUNDINGS
EXHIBIT  D  -  HVAC SPECIFICATIONS
EXHIBIT  E  -  CLEANING SPECIFICATIONS
EXHIBIT  F  -  SECONDARY FIBER CONDUIT
RIDER

                                      13

 
                                     LEASE
                                     -----
                                        
    THIS LEASE (the "Lease") is made this 6th day of December, 1994, by and
between Aetna Life Insurance Company, a Connecticut corporation ("Landlord"),
c/o Trammell Crow Company, 1115 30th St., N.W., Washington, D.C. 20007, and
Telephone Business Meetings, Inc., dba Access Conference Call Service, a
Delaware corporation ("Tenant"), having an address of 1801 K Street, N.W., Suite
201, Washington, D.C. 20006 prior to the Lease Commencement Date (and the
Premises thereafter).

    Landlord, for and in consideration of the rents and all other charges and
payments hereunder and of the covenants, agreements, terms, provisions and
conditions to be kept and performed hereunder by Tenant, demises and leases to
Tenant, and Tenant hereby hires and takes from Landlord, the premises described
below ("Premises") , subject to all matters hereinafter set forth and upon and
subject to the covenants, agreements, terms, provisions and conditions of this
Lease for the term hereinafter stated.

    1.  TERMS.
        ----- 

        1.1. PREMISES.  The Premises demised by this Lease are approximately 
             --------                                                        
Nineteen Thousand Seven Hundred Sixty-five (19,765) square feet located on the
second (2nd) floor in 1861 Wiehle Avenue ("Building"), Reston, Va., 22090,
together with a nonexclusive right to use parking and other common areas. The
location and dimensions of the Premises are shown on EXHIBIT A, attached hereto
                                                     ----------
and incorporated herein by reference. No easement for light or air is included
in this Lease. Landlord shall not intentionally block Tenant's view from the
Premises.

        1.2. BUILDING.  Landlord represents that the total rentable area of the 
             --------  
Building is approximately 73,685 sq. ft. and Tenant's percentage of the Building
is 26.82%.

        1.3. LEASE TERM.  The parties agree that the Lease Commencement Date 
             ----------                                                  
and the Lease Expiration Date are as follows:



                                         
          Installation Commencement Date:   April 1, 1995
          Operational Commencement Date:    May 1, 1995
          Lease Commencement Date:          June 1, 1995
          Lease Expiration Date:            May 31, 2005


        1.4.  BASE RENT.  The basic rent ("Base Rent") is $23,306.23 per month,
              ---------                                                        
commencing on the Lease Commencement Date, and thereafter shall increase as set
forth in EXHIBIT B attached hereto and incorporated herein by reference.  In
         ---------                                                          
addition to the Base Rent, Tenant shall pay all amounts designated as Additional
Rent ("Additional Rent") under this Lease, including but not limited to charges
for additional services under Section 8.2, increases in costs of services and
utilities under Article 9, and increases in Property Taxes under Article 10, all
of which shall be deemed rent ("Rent") due under this Lease.

                                      14

 
          Notwithstanding the foregoing, Landlord hereby agrees to abate and
forgive the payment of fifty percent (50%) of the Base Rent during the first
five (5) full calendar months of the Lease term, for a total abatement of Fifty-
Eight Thousand Two Hundred Sixty-five and 57/100 Dollars ($58,265.57).

        1.5.  INITIAL PAYMENT.  See Rider, Paragraph #4.
              ---------------                           

    2.  DELIVERY OF POSSESSION.  Landlord shall deliver possession of the 
        ----------------------                                           
computer room of the Premises to Tenant, with Landlord's Work (as hereinafter
defined) therein substantially complete ("Ready for Installation") , on or
before the Installation Commencement Date. Landlord shall deliver possession of
the operations/conference center and customer service area of the Premises to
Tenant, with Landlord's Work therein substantially complete ("Ready for Phase-
In"), on or before the Operational Commencement Date. Landlord shall deliver
possession of the entire Premises to Tenant, with Landlord's Work substantially
complete ("Ready for Occupancy"), on or before the Lease Commencement Date.
During the period from the Installation Commencement Date to the Operational
Commencement Date (the "Installation Period"), Tenant shall have the right to
install equipment in the computer room of the Premises and connect such
equipment to its cabling. During the period from the Operational Commencement
Date to the Lease Commencement Date (the "Phase-In Period"), Tenant shall have
the right to install, test, operate its equipment and phase-in its business
operations in the Premises. During the Installation Period and the Phase-In
Period, all provisions of this Lease, other than the payment of Rent, shall be
fully effective. If Landlord does not deliver possession of the Premises to
Tenant on the Lease Commencement Date this Lease shall not be void or voidable
(except as expressly set forth below) , nor shall Landlord be liable to Tenant
for any loss or damage resulting therefrom, nor shall the expiration date of the
term be extended, but in such event Tenant shall not be liable for any Rent or
other charges due under this Lease until such time as Landlord tenders delivery
of possession of the Premises to Tenant with Landlord's Work (as hereinafter
defined) substantially complete. Tenant's contractor (cabling) shall have access
to the Premises during the Landlord's construction, prior to closing walls,
ceilings and raised floorings (if any) to install cabling prior to April 1,
1995. Landlord and Tenant's contractors will work in harmony during this period.

          Notwithstanding the foregoing, if Landlord fails to deliver the
Premises Ready for Occupancy on or before the Lease Commencement Date, then
Tenant shall have the right to offset against Rent the amount of Ten Thousand
Seven Hundred Ninety-five and 77/100 Dollars ($10,795.77) for each month or
partial month of such delay plus a daily penalty of $833.00 for each day of such
delay, up to a maximum daily penalty per month of Twelve Thousand One Hundred
Ninety-seven and 98/100 ($12,197.98) (i.e., the combined monthly and daily
penalties cannot exceed more than Twenty-two Thousand Nine Hundred Ninety-three
and 75/100 ($22,993.75) or one month's Base Rent).  If Landlord fails to deliver
the Premises Ready for Occupancy on or before August 1, 1995, then, in addition
to the offset rights set forth above in this paragraph, Tenant shall have the
right to complete Landlord's Work and offset the reasonable cost of such
completion against Rent.  Landlord further agrees to include in the bid package
prepared by the construction manager (as set forth in Exhibit C) a requirement
for the general contractors to include in their bid a penalty equal to Ten
Thousand Seven Hundred Ninety-five

                                      15

 
Dollars and 77/100 ($10,795.77) for each month or partial month of delay plus a
daily penalty equal to $833.00 for each day of delay if the general contractor
fails to (i) deliver the computer room of the Premises substantially complete on
or before the Installation Commencement Date or (ii) deliver the
operations/conference center and customer service area of the Premises Ready for
Phase-In on or before the Operational Commencement Date.  Notwithstanding the
foregoing, each of the deadlines specified above shall be extended one (1) day
for each day of delay attributable to "Tenant Delays", "Governmental Delays" and
"Force Majeure" as hereafter defined.  "Tenant Delays" shall mean any delay in
Landlord's completion of the Tenant Improvements caused by (i) Tenant's failure
or refusal to meet its obligation to prepare the Tenant Plans and Working
Drawings within the time periods specified in Exhibit C, (ii) any change orders,
(iii) Tenant's selection of carpet and other finish items not in stock (so long
as Landlord has notified Tenant as soon as possible after Landlord learns of the
non-availability) , or (iv) any delay caused by Tenant's failure (upon request
by Landlord) to cooperate with Landlord to expedite permit submissions or the
County's approval process.  "Governmental Delays" shall mean any delay in
Landlord's completion of the Tenant Improvements caused by (i) processing delays
by the applicable governmental entity in the issuance of a building permit or
demolition permit, (ii) delays by the applicable governmental entity in
scheduling or performing required inspections of the Tenant Finish Work not
caused by Landlord's fault, and (iii) the action or inaction of applicable
governmental authorities (provided Landlord diligently pursues all required
governmental actions) not attributable to Landlord's fault.  "Force Majeure"
shall mean delays beyond the reasonable control of a party and without its fault
or neglect, such as due to war, riot, civil unrest, shortages of labor or
materials despite due diligence, strikes and labor disputes, unusually inclement
weather and acts of God.

    3.  PAYMENT OF RENT.  Except as otherwise provided in this Lease, Tenant 
        ---------------                                                   
shall pay Landlord the Rent and any other payments due under this Lease without
demand, deduction or offset, in lawful money of the United States in advance on
or before the first day of each month, except that the first month's Base Rent
shall be paid upon the execution hereof, at the address noted in Section 29, or
to such other party or at such other place as Landlord may hereafter from time
to time designate in writing.  Rent and other amounts due under this Lease for
any partial month at the beginning or end of the Lease term shall be prorated,
on a per diem basis.

    4.  SECURITY DEPOSIT.  See Rider, Paragraph #4.
        ----------------                           

    5.  USES.
        ---- 

        5.1.  PERMITTED USES.  The Premises are to be used only for general 
              --------------                                               
office purposes including without limitation the operation of a
telecommunications service business which includes audio, video, graphic and
data telecommunications ("Permitted Uses") and for no other business or purpose
without the prior written consent of Landlord. Tenant is a group communications
company serving the trade association, corporate, legal and government agency
market. Initially during the Lease term Tenant's sophisticated computer-based
switches will be connected to the public telephone network via fiber optic
cable. Approximately 1,000 telephone lines are currently in use, with
expectations that line capacity will double and re-double in the

                                      16

 
near term.  No act shall be done in or about the Premises that is unlawful or
that will increase the existing rate of insurance on the Building.  Landlord
represents that, to Landlord's knowledge, Tenant's permitted uses shall not
increase the existing rate of insurance in the Building.  In the event of a
breach of this covenant, Tenant shall immediately cease the performance of such
unlawful act or such act that is increasing or has increased the existing rate
of insurance and shall pay to Landlord any and all increases in insurance
premiums resulting from such breach.  Tenant shall not commit or allow to be
committed any waste upon the Premises, or any public or private nuisance or
other act or thing which produces noise or disturbance to the quiet enjoyment of
any other tenant in the Building.  If any of the Tenant's office machines or
equipment produces noise or disturbance within the premises of any other tenant
in the Building, then Tenant shall provide adequate insulation, or take such
other action as may be necessary to eliminate the noise or disturbance at its
sole cost and expense.  Subject to the provisions set forth in Section 14,
Tenant shall obtain and maintain any required permit for equipment, machine,
device, tank or vessel which is subject to any federal, state or local
permitting requirement.  Tenant, at its expense, shall comply with all laws,
statutes, ordinances and governmental rules, regulations or requirements
governing the installation, operation and removal of any such equipment,
machine, device, tank or vessel.  Tenant, at its expense, shall comply with all
laws, statutes, ordinances, governmental rules, regulations or requirements, and
the provisions of any recorded documents now existing or hereafter in effect
relating to its use, operation or occupancy of the Premises and shall observe
such reasonable rules and regulations as may be adopted and made available to
Tenant by Landlord from time to time for the safety, care and cleanliness of the
Premises or the Building and for the preservation of good order therein,
provided, however, that in no event shall Tenant be required to perform
Alterations (as hereinafter defined) outside of the Premises or with respect to
the structural elements of the Building within the Premises.  Landlord
represents that the provisions of any recorded documents now existing or
hereafter in effect relating to Tenant's use, operation or occupancy of the
Premises shall not limit Tenant's use of the Premises for the permitted uses
described in this Section 5.1.  Landlord, at its sole cost and expense, shall be
responsible for ensuring all Building Life/Safety Systems meet the applicable
federal, state and local codes and regulations.  Landlord shall be solely
responsible for compliance with the ADA (Americans with Disabilities Act),
legislation concerning CFC's and all other legal requirements not relating
exclusively to tenant's use and occupancy of the Premises.  Landlord shall not
lease space in the Building to another tenant who will, within the Building,
operate a telecommunication conferencing business.

        5.2.  HAZARDOUS MATERIALS.
              ------------------- 

              5.2.1.  As used herein, the term "Hazardous Material" shall mean 
any substance or material which has been determined by any state, federal or
local governmental authority to be capable of posing a risk of injury to health,
safety or property, including all of those materials and substances designated
as hazardous or toxic by the city in which the Premises are located, the U.S.
Environmental Protection Agency (the "EPA"), or any federal agencies that have
overlapping jurisdiction with such state agencies, or any other governmental
agency now or hereafter authorized to regulate materials and substances in the
environment.

                                      17

 
              5.2.2.  Landlord represents to Tenant that, to Landlord's 
knowledge, the Premises and the Building are free from hazardous substances as
of the date of execution of this Lease. In addition, Landlord agrees that should
any hazardous substances be found within the Premises or the Building which were
placed therein by Landlord, its agents, employees or contractors or which were
within the Premises prior to the Lease Commencement Date and were not introduced
by Tenant, its agents, employees and invitees, Landlord shall be responsible for
all costs associated with removing said hazardous substances from the Premises
and the Building and otherwise complying with the applicable federal, state or
local laws with regard thereto. During the term of this Lease, Landlord agrees
that it shall not introduce, dispose of, or store hazardous substances within
the Premises or the Building in violation of applicable law, and shall comply
with all valid orders issued by federal, state and local authorities relating
thereto.

              5.2.3.  Tenant hereby covenants not to cause or permit any 
Hazardous Material to be placed, held, located or disposed of in, on or at the
Premises or any part thereof and hereby covenants that neither the Premises nor
any part thereof shall ever be used as a dump site or storage site (whether
permanent or temporary) for any Hazardous Material during the term of this Lease
(other than incidental office use in compliance with the law). Tenant hereby
agrees to indemnify Landlord and hold Landlord harmless from and against any and
all losses, liabilities, including strict liability, damages, injuries,
expenses, including reasonable attorneys' fees, costs of any settlement or
judgment and claims of any and every kind whatsoever paid, incurred or suffered
by, or asserted against, Landlord by any person or entity or governmental agency
for, with respect to, or as a direct or indirect result of, the presence on, or
the escape, seepage, leakage, spillage, discharge, emission, discharging or
release from, the Premises of any Hazardous Material (including, without
limitation, any losses, liabilities, including strict liability, damages,
injuries, expenses, including reasonable attorneys fees, costs of any settlement
or judgment or claims asserted or arising under the Comprehensive Environmental
Response, Compensation and Liability Act, any so-called federal, state or local
"Superfund" or "Superlien" laws, statute, law, ordinance, code, rule,
regulation, order or decree regulating, relating to or imposing liability,
including strict liability, substances or standards of conduct concerning any
Hazardous Material), provided, however, that the foregoing indemnity is limited
to matters arising solely from Tenant's violation of the covenant contained in
the first sentence of this Section 5.2.3. Tenant hereby agrees fully to
cooperate with Landlord and provide such documents, affidavits and information
as may be reasonably requested by Landlord (i) to comply with any environmental
law, (ii) to comply with the reasonable request of any lender, purchaser or
tenant, and/or (iii) for any other reason deemed necessary by Landlord in its
sole but reasonable discretion. Landlord shall have the right but not the
obligation, and without limitation of Landlord's rights under this Lease, to
enter onto the Premises or to take such other actions as it deems necessary or
advisable to cleanup, remove, resolve or minimize the impact of, or otherwise
deal with, any Hazardous Material following receipt of any notice from any
person or entity (including without limitation the EPA) asserting the existence
of any Hazardous Material in, on or at the Premises or any part thereof which,
if true, could result in an order, suit or other action against Tenant or
Landlord or both. All reasonable costs and expenses incurred by Landlord in the
exercise of any such rights, which costs and expenses result from Tenant's
violation of the covenant contained in the first sentence of this Section 5.2.3,
shall be deemed Additional Rent under this Lease and shall be payable by Tenant
upon Landlord's demand
                                      18

 
therefor.  The provisions of this Section 5.2 shall survive the cancellation,
termination or expiration of this Lease.

    6.  LATE CHARGES.  Tenant hereby acknowledges that late payment to 
        ------------   
Landlord of Rent or other sums due hereunder will cause Landlord to incur costs
not contemplated by this Lease, the exact amount of which will be extremely
difficult to ascertain. If any Rent or other sum due from Tenant is not received
within five (5) business days of its due date , then Tenant shall pay to
Landlord immediately upon Landlord's demand therefor a late charge in an amount
equal to two percent (2%) of such overdue amount, plus any attorneys' fees and
costs incurred by Landlord by reason of Tenant's failure to pay Rent and other
charges when due hereunder. Notwithstanding the foregoing, once per calendar
year, Landlord shall agree to forego the late charge specified above provided
Tenant pay such Rent or other sums due hereunder within five (5) days of
Tenant's receipt of written notice from Landlord that such payment is due.

    7.  REPAIRS AND MAINTENANCE.  Landlord shall maintain, or cause to be 
        -----------------------                                              
maintained in first class working condition, the common areas of the Building
and the land upon which it is situated, including without limitation the
lobbies, elevators, stairs, and corridors, the roof, foundations, structural
elements, building systems, parking areas and exterior walls of the Building,
and the underground utility and sewer pipes outside the exterior walls of the
Building, if any, except any of such repairs rendered necessary by the
negligence or misconduct of Tenant, its agents, customers, employees,
independent contractors, guests or invitees (to the extent not released by
Landlord pursuant to Section 18.2), the repair of which shall be paid for by
Tenant within thirty (30) days of Landlord's written demand with backup
invoices. Landlord shall not alter the existing windows of the Premises (whether
by addition of film or otherwise). Subject to Landlord's right of access
pursuant to Article 17, Tenant shall be exclusively responsible for the interior
of the Premises (other than structural elements of the Building and portions of
the Building systems within the Premises), which shall be maintained by Tenant
in good order and repair, and Landlord shall be under no obligation to inspect
the Premises or, except as otherwise expressly provided in this Lease, repair
the Premises. Tenant shall promptly report in writing to Landlord any defective
condition known to it which Landlord is required to repair, and failure to so
report such defects shall make Tenant responsible to Landlord for any liability
incurred by Landlord by reason of such conditions. Tenant hereby waives the
right to make repairs at Landlord's expense under any law, statute or ordinance
now or hereafter in effect.

    8.  UTILITIES AND SERVICES.
        ---------------------- 

        8.1.  SERVICE.  From 8:00 a.m. to 6:00 p.m. on weekdays ("Normal 
              -------  
Business Hours") and from 9:00 a.m. to 12:00 p.m. on Saturday ("Saturday
Mornings") (except for legal holidays), Landlord shall furnish to the Premises
electricity for lighting and operation of low-power usage office machines in an
amount no less than 6.0 watts per square foot, water, heat and air conditioning
in accordance with the HVAC specifications attached hereto as EXHIBIT D, and
                                                              ---------
elevator service. During all other hours, Landlord shall furnish such service
except for heat and air conditioning. Elevator service shall be provided to the
Premises, twenty-four (24) hours per day, seven (7) days per week. Landlord
shall be responsible for maintaining the offsite monitoring fire suppression
system for the Building.
                                      19

 
        8.2.  ADDITIONAL SERVICES.  If requested by Tenant, Landlord shall 
              -------------------                                            
furnish heat and air conditioning at times other than Normal Business Hours and
Saturday Mornings and the cost of such services shall be Landlord's actual cost
(which as of the date of this Lease is $25.00 per hour) and shall be paid by
Tenant as Additional Rent, payable within thirty (30) days after receipt of
Landlord's Invoice. Landlord shall also provide toilet room supplies, window
washing at reasonable intervals, and customary Building janitorial service in
accordance with the cleaning specifications attached hereto as Exhibit E other
                                                               ---------
types of services provided or caused to be provided by Landlord to Tenant which
are in addition to the services ordinarily provided Building tenants shall be
payable as provided in Section 9.1.1.2 of this Lease. Landlord shall not be
liable for any loss, injury or damage to property caused by or resulting from
any variation, interruption, or failure of such services due to any cause
whatsoever, or from failure to make any repairs or perform any maintenance. In
no event shall Landlord be liable to Tenant for any damage to the Premises or
for any loss, damage or injury to any property therein or thereon occasioned by
bursting, rupture, leakage or overflow of any plumbing or other pipes or other
similar cause in, above, upon or about the Premises or the Building. If
restoration of any service is within Landlord's control, Landlord shall use
diligent efforts to restore such service. If HVAC or electrical services to the
Premises are interrupted for more than three (3) business days and Tenant cannot
reasonably conduct its business, then until such service is restored, the Rent
and the Additional Rent shall be abated in the same proportion as the
untenantable portion of the Premises bears to the whole thereof, and this Lease
shall continue in full force and effect, subject however to Tenant's rights at
law or in equity to make a claim for constructive eviction or otherwise.

    9.  COST OF SERVICES AND UTILITIES.
        ------------------------------ 

        9.1.  DEFINITIONS.  In addition to the Base Rent and other Additional 
              -----------  
Rent as set forth in this Lease, Tenant shall pay to Landlord as Additional Rent
increases under this Article 9. Said increases shall be made as provided herein,
using the following definitions:

              9.1.1.  "Operating Costs" shall include Costs of Utilities and 
                       ---------------                                     
Other Operating Costs.

                       9.1.1.1.  "Costs of Utilities" shall mean all expenses 
                                  ------------------
paid and incurred by Landlord for electricity, water, gas, sewers, oil and
utility services for the Building, land and parking and other common areas.

                       9.1.1.2.  "Other Operating Costs" shall mean all other 
                                  ---------------------  
expenses paid and incurred by Landlord for maintaining, operating, replacing,
repairing, and managing (i) the Building, (ii) the personal property used in
conjunction therewith, (iii) the Building roof, or (iv) the land upon which the
Building is situated, including all curbs and sidewalks adjacent to the same.
Such costs shall include, without limitation, supplies, cleaning services,
garbage and trash collection, personal property taxes, replacement lighting,
maintenance and service contracts, wall and window washing, towel service,
machinery, equipment, a commercially reasonable management fee consistent with
market rates, window glass replacement and repair,

                                      20

 
landscaping services of independent contractors (including, without limitation,
ice and snow removal), compensation (including employment taxes and fringe
benefits) of all persons who perform regular and recurring duties in connection
with the management excluding: (a) Costs of any special services rendered to
individual tenants (including Tenant), for which a special, separate charge
shall be made; (b) Property Taxes (as defined in Section 10.1.1); (c)
depreciation or amortization of costs required to be capitalized in accordance
with generally accepted accounting practices (except for proper depreciation of
the costs of energy savings devices to the extent in any year of the documented
annual energy savings realized therefrom); (d) the costs of all repairs and
replacements of the Premises and the remainder of the Building or portions
thereof or fixtures, equipment and facilities comprising or serving the Premises
and building made necessary as a result of defects in workmanship or materials
of initial construction of the Building; (e) the cost to prepare space for
occupancy by any tenants of the Building and for renovating, painting,
repainting, decorating, redecorating, planning and designing space for any
tenants (including the Tenant); (f) the cost of overtime or other expenses to
the Landlord in curing its default or performing work expressly provided for in
this Lease to be borne at the Landlord's expense (including such work for other
tenants in the Building); (g) other expenses incurred in leasing or for
procuring tenants; (h) debt service payments on any mortgage or on any
amortization of debts, points, commissions and legal fees associated with
financing; (i) the cost of materials, work or utilities separately charged to
individual tenants of the Building; (j) legal fees paid or incurred in
connection with litigation with tenants for any defaults under their leases and
any legal fees incurred in leasing space to tenants; (k) income, net profits,
estate, inheritance, gift, franchise, business, professional, occupational or
succession taxes and any similar tax or assessment imposed upon or measured by
the Landlord's income from the Building; (1) credits, allowances, permits,
licenses, inspections, or other payments or rent waivers or concessions granted
to any tenant (including Tenant) or incurred in completing, fixturing,
renovating or otherwise improving, decorating or redecorating tenant space in
the Building; (m) any costs paid to induce tenants to move into or maintain
their tenancy at the Building, such as moving expenses or rental or other
concessions to tenants (including specified cleaning or other services not
provided to other tenants of the Building on a regular basis), including any
such costs incurred with respect to the Tenant; (n) all costs incurred in
connection with parking operations of the Building (if any); (o) the costs of
any capital improvement or the cost of leasing any equipment, fixtures, or trade
fixtures where purchase would be considered a capital cost under generally
accepted accounting principles, but including any capital improvements expressly
permitted to be included in Operating Costs pursuant to the terms of this
Section, (p) compensation paid to officers of Landlord or officers of the
management agent; (q) costs directly resulting from the gross negligence or
willful misconduct of Landlord, its employees, agents, contractors or employees;
(r) costs for which Landlord is reimbursed by any insurance required to be
carried hereunder or actually carried by Landlord or the cost for which Landlord
would have been reimbursed by insurance required to be carried hereunder in the
event Landlord fails to diligently pursue the insurance proceeds; (s) costs for
any structural maintenance, replacement or redesign; (t) costs or expense
associated with the enforcement of any leases by Landlord; (u) costs or fees
relating to the defense of Landlord's title or interest in the real estate
containing the Building, or any part thereof; (v) any costs or expenses relating
to Landlord's obligations under any workletter to construct tenant improvements;
(w) expenses in connection with services or other benefits of a type which are
not made available to Tenant but which are provided to another

                                      21

 
tenant or occupant; (x) renovation of the Building made necessary by the
exercise of eminent domain; (y) any cost attributable to income received by
Landlord or an affiliate of Landlord for the provision of any goods or services,
to the extent such cost exceeds the cost for such goods and services in the
prevailing market place; (z) ground rent; (aa) legal fees which are not related
to the operation, maintenance and management of the Property or other
professional or consulting fees which are not directly related to the
maintenance, operation and management of the Building, except for any legal fees
incurred by Landlord which are attributed solely to Tenant in accordance with
the terms of this Lease; intentionally deleted; (cc) increased insurance
premiums caused by Landlord's or any tenants' hazardous acts only to the extent
of such increase, except for an increase attributed solely to Tenant's hazardous
acts; (dd) costs arising from the presence of hazardous materials or substances
in or about or below the Building or the land upon which it is situated,
including without limitation, hazardous substances in the groundwater or soil,
except to the extent Tenant is responsible for the presence of such hazardous
materials; (ee) costs incurred for any items to the extent of Landlord's
recovery under a manufacturer's, materialmen's vendors or contractor's warranty;
(ff) wages, salaries or other compensation or benefits for off site employees
applicable to the time spent working at other buildings, other than the Building
manager (provided that with respect to each employee that services the Building
and other buildings, a pro rata portion of such employee's salary shall be
included in operating expenses, as applicable); (gg) excessive and unreasonable
costs of acquisition of sculpture, paintings, or other objects of art; (hh) the
rent or expenses in lieu of rent for any on-site leasing office of Landlord in
the Building, or of any other space (except the management office serving the
Building) in the Building set aside for storage or other facilities for the
benefit of Landlord; (ii) management fees in excess of management fees
specifically allowed above; and (jj) any special assessments caused by other
tenants of the Building.  In the event that Landlord receives proceeds from
insurance that reimburse Landlord for items previously included in Landlord's
Operating Costs (even if for a prior year) , the Actual Costs for the year in
which such charge was made shall be recalculated to reflect the receipt of the
insurance proceeds (less any reasonable expense incurred by Landlord to obtain
such proceeds) and Tenant's proportionate share of any overpayment made for
Operating Costs for such year, as recalculated, shall be refunded to Tenant in
thirty (30) days.

              9.1.2.  "Lease Year" shall mean the twelve-month period 
                       ----------                                             
commencing January 1 and ending December 31.

              9.1.3.  "Base Services Year" shall mean calendar year 1995.
                       ------------------                                

              9.1.4.  Intentionally Deleted.

              9.1.5.  "Actual Costs" shall mean the actual expenses paid and 
                       ------------    
incurred by Landlord for Operating Costs during any Lease Year of the term 
hereof.

              9.1.6.  "Actual Costs Allocable to the Premises" shall mean the 
                       --------------------------------------                
Tenant's share of the Actual Costs determined by multiplying Tenant's 
percentage of the Building described in Section 1.2 by the Actual Costs.

                                      22

 
              9.1.7.  "Estimated Costs Allocable to the Premises" shall mean 
                       -----------------------------------------
Landlord's reasonable estimate of Actual Costs Allocable to the Premises for the
following Lease Year to be given by Landlord to Tenant pursuant to Section 9.3.

        9.2.  BASE AMOUNT.  Operating Costs allocable to the Premises for the 
              -----------                                                  
Base Services Year shall be deemed the "Base Amount".

        9.3.  ADDITIONAL RENT.  Prior to the commencement of each Lease Year 
              ---------------                                             
(except the Base Services Year) during the term hereof, Landlord shall furnish
Tenant a written statement of the Estimated Costs Allocable to the Premises for
such Lease Year and a calculation of the portion of Estimated Costs Allocable to
the Premises payable by Tenant as Additional Rent in accordance with this
Section. In advance of or before the first day of each month during the term
hereof commencing on the first day of the first Lease Year following the Base
Services Year, Tenant shall pay as Additional Rent for each month during each
such Lease Year: one-twelfth (1/12th) of the amount, if any, by which the
Estimated Costs Allocable to the Premises exceed the Base Amount. If at any time
or times during any such Lease Year, it appears to Landlord that the Estimated
Costs Allocable to the Premises will vary from Landlord's estimate by more than
five percent (5%) on an annualized basis, Landlord may, by written notice to
Tenant, reasonably revise its estimate for such Lease Year and the portion of
the Estimated Costs Allocable to the Premises payable by Tenant as Additional
Rent as provided herein for such Lease Year shall be accordingly adjusted based
on such revised estimate. Notwithstanding the foregoing, Landlord hereby abates
and forgives the payment of Additional Rent pursuant to this ARTICLE 9 during
the first twelve (12) months of the Lease Term.

        9.4.  ACTUAL COSTS.  Within ninety (90) days after the close of each 
              ------------                                                   
Lease Year during the term hereof, Landlord shall deliver to Tenant a written
statement of the Actual Costs, with a line item breakdown, and the Actual Costs
Allocable to the Premises, during the preceding Lease Year. The first such
statement shall be for the Base Services Year, although no Rent shall be due
from Tenant on account thereof. If such costs for any Lease Year less the Base
Amount exceed the amounts paid by Tenant to Landlord pursuant to Section 9.3,
Tenant shall pay the amount of such excess to Landlord as Additional Rent within
thirty (30) days after receipt of such statement by Tenant. If such statement
shows such costs to be less than the amount paid by Tenant to Landlord pursuant
to Section 9.3, then the amount of such overpayment by Tenant shall be credited
by Landlord to the next Rent payable by Tenant. In the event such overpayment
cannot be fully credited by Landlord to the next Rent payable by Tenant due to
the expiration of the term of this Lease, any remaining overpayment shall be
credited by Landlord to any other charges due under this Lease and, to the
extent no such charges are due, shall be refunded to Tenant by Landlord within
thirty (30) days of the Lease Expiration Date.

        9.5.  END OF TERM.  If this Lease terminates on a day other than the 
              -----------                                                 
last day of a Lease Year, the amount of any adjustment to Estimated Costs
Allocable to the Premises with respect to the Lease Year in which such
termination occurs shall be prorated on the basis which the number of days from
the commencement of such Lease Year to and including such termination date bears
to 365; and any amount payable by Landlord to Tenant or Tenant to Landlord with
respect to such adjustment shall be payable within thirty (30) days after
delivery

                                      23

 
by Landlord to Tenant of the statement of Actual Costs Allocable to the Premises
with respect to such Lease Year.

        9.6.  FURTHER ADJUSTMENT.  In the event the average occupancy level of 
              ------------------                                          
the Building for the Base Services Year and/or any subsequent Lease Year was not
ninety-five percent (95%) or more of full occupancy, then the Actual Costs for
such year shall be adjusted and apportioned among the tenants by the Landlord to
reflect those costs which would have occurred had the Building been ninety-five
percent (95%) occupied during such year.

        9.7.  TENANT'S AUDIT RIGHTS.  Tenant shall have the right, with fifteen 
              ---------------------                                       
(15)days' written notice to Landlord and at Tenant's sole cost and expense, to
audit Landlord's books and records pertaining to the Actual Costs for the
preceding year and for the Base Services Year one time per year within one
hundred eighty (180) days of Tenant's receipt of Landlord's reconciliation at
Landlord's or Landlord's property manager's place of business. If a discrepancy
in Tenant's favor is discovered, then Landlord must reimburse Tenant immediately
for any overpayment and must pay for such audit if the discrepancy results in
any overpayment of more than five percent (5%).

    10. PROPERTY TAXES.
        -------------- 

        10.1.  CONTRIBUTION TO TAXES.  In addition to the Base Rent and other 
               ---------------------                                      
Additional Rent, Tenant shall pay to Landlord, as Additional Rent, its share of
the increase in Property Taxes under this Article 10. Tenant's share of the
increase of such taxes shall be determined as provided herein, utilizing the
following definitions:

               10.1.1.  "Property Taxes" shall mean any form of assessment, 
                         --------------                                   
license, fee, rent tax, excise, imposition, charge, levy, penalty (if a result
of Tenant's delinquency), or tax (other than net income, profit, business,
professional, estate, succession inheritance, transfer or franchise taxes),
including, without limitation, all ad valorem, sales and use, value added, gross
receipts, sewer, privilege, or similar taxes, imposed by any authority having
the direct or indirect power to tax, or by any city, county, state or federal
government or any improvement or other district or division thereof, on the
Building or any part thereof, the land upon which the Building is situated, the
parking area serving the Building, or any other legal or equitable interest of
Landlord in the same.

               10.1.2.  The Term "Lease Year" shall mean the period defined in 
                                  ----------          
Section 9.1.2.

               10.1.3.  The term "Base Tax Year" shall mean calendar year 1995.
                                  -------------                                

               10.1.4.  The term "Tenant's Share of Property Taxes" shall mean 
                                  --------------------------------   
the amount of Property Taxes payable during any Lease Year by Landlord
multiplied by Tenant's percentage of the Building described in Section 1.2.

                                      24

 
        10.2.  ADDITIONAL RENT FOR ESTIMATED INCREASES IN TENANT'S SHARE OF 
               ------------------------------------------------------------  
PROPERTY TAXES. Prior to the commencement of each Lease Year (except the Base
- --------------
Tax Year), Landlord shall furnish Tenant with a written statement setting forth
Landlord's reasonable estimate of Tenant's Share of Property Taxes for such
Lease Year. One-twelfth (1/12th) of the amount, if any, by which such estimated
Tenant's Share of Property Taxes exceeds the Tenant's Share of Property Taxes
for the Base Tax Year shall be Additional Rent payable by Tenant as provided in
Article 3.

        10.3.  ACTUAL PROPERTY TAXES.  Within ninety (90) days after the close 
               ---------------------                                        
of each Lease Year during the term hereof, Landlord shall deliver to Tenant a
written statement (to include all relevant tax bills and paid receipts) setting
forth the Tenant's Share of Property Taxes during the preceding Lease Year. If
such amount less Tenant's Share of Property Taxes for the Base Tax Year
("Tenant's Actual Share") exceeds the amount of Property Taxes actually paid by
Tenant to Landlord pursuant to Section 10.2 hereof, Tenant shall pay the amount
of such excess to Landlord as Additional Rent within thirty (30) days after
receipt of such statement by Tenant. If such statement shows Tenant's Actual
Share to be less than the amounts paid by Tenant to Landlord pursuant to Section
10.2, then the amount of such overpayment shall be credited by Landlord to the
next Rent payable by Tenant. In the event such overpayment can not be fully
credited by Landlord to the next monthly Rent or subsequent monthly Rent payable
by Tenant due to the expiration of the term of this Lease, any remaining
overpayment shall be credited by Landlord, until such credit is used up, to any
other charges due under this Lease and, to the extent no such charges are due,
shall be refunded to Tenant by Landlord within thirty (30) days of the Lease
Expiration Date.

        10.4.  TAXES ON PERSONAL PROPERTY PAID FOR BY TENANT AND NOT 
               ------------------------------------------------------
REIMBURSED BY LANDLORD. Tenant shall pay, prior to delinquency, all personal 
- ----------------------
property taxes payable with respect to all property of Tenant located on the
Premises or the Building and shall provide promptly, upon request of Landlord,
written proof of such payment.

        10.5.  END OF TERM.  If this Lease terminates on a day other than the 
               -----------                                                
last day of a Lease Year, the amount of any adjustment between the estimated and
actual Tenant's Share of Property Taxes with respect to the Lease Year in which
such termination occurs shall be prorated on the basis of a 365-day year; and
any amount payable by Landlord to Tenant or Tenant to Landlord with respect to
such adjustment shall be payable within thirty (30) days after delivery by
Landlord to Tenant of the statement of Tenant's Share of Property Taxes with
respect to such Lease Year.

        10.6.  FURTHER ADJUSTMENT.  In the event the average occupancy level 
               ------------------                                     
of the Building for the Base Services Year and/or any subsequent Lease Year was
not ninety-five percent (95%) or more of full occupancy, then the Property Taxes
for such year shall be proportionately adjusted among the tenants by Landlord to
reflect those costs which would have occurred had the Building been ninety-five
percent (95%) occupied during such year.

    11. LIABILITY AND CASUALTY INSURANCE.  Tenant shall, at Tenant's expense, 
        --------------------------------                                
obtain and keep in force during the term of this Lease a policy of comprehensive

                                      25

 
general liability insurance, including personal injury liability, contractual
liability, and completed operations liability (if applicable), insuring Landlord
and Tenant against any liability arising out of the use, occupancy or
maintenance of the Premises.  Such insurance shall be in the amount of not less
than One Million and no/100ths Dollars ($1,000,000.00) for bodily injury and
property damage for any one accident or occurrence.  Fire and casualty insurance
with extended coverage in an amount of not less than Fifty Thousand and
no/100ths Dollars ($50,000.00) covering Tenant's personal property and equipment
shall also be obtained and kept in force during the term of this Lease at
Tenant's expense.  The limit of any of such insurance shall not limit the
liability of Tenant hereunder.  If Tenant fails to procure and maintain such
insurance Landlord may, after ten (10) days notice and opportunity to cure, but
shall not be required to, procure and maintain the same, at Tenant's expense to
be reimbursed by Tenant as Additional Rent within ten (10) days of written
demand.  All insurance required to be obtained by Tenant hereunder shall be
issued by companies reasonably acceptable to Landlord.  Thirty (30) days prior
to the Lease Commencement Date, Tenant shall deliver to Landlord certificates of
liability insurance required herein with loss payable clauses satisfactory to
Landlord.  Any deductible under such insurance policy in excess of Ten Thousand
and no/100ths Dollars ($10,000.00) must be approved by Landlord in writing prior
to issuance of such policy.  No policy shall be cancelable, allowed to lapse
and/or expire and/or be subject to reduction of coverage except upon thirty (30)
days' prior written notice to Landlord.  All such policies shall name Landlord
as named insureds and Tenant's casualty policies shall be written as primary
policies not contributing with and not in excess of coverage which Landlord may
carry.  The policy limits set forth herein shall be subject to periodic review,
and Landlord reserves the right to require that Tenant increase the liability
coverage limits if, in the reasonable opinion of Landlord, the coverage becomes
inadequate and is less than commonly maintained by tenants making similar uses
of similar buildings in the vicinity of the Building.  Tenant shall obtain any
revised or increased coverage required by Landlord within sixty (60) days of any
such notification from Landlord.

    12. FIRE INSURANCE - FIXTURES AND EQUIPMENT.
        --------------------------------------- 

        12.1.  During the term, Landlord shall carry and maintain all risk 
property insurance covering the Building and Landlord's property therein, with
full replacement cost coverage (exclusive of footings and foundations) and in an
amount required by its insurance company to avoid the application of any
coinsurance provision. Landlord's insurance shall be issued by a company that is
licensed to do business in the Commonwealth of Virginia and that has a rating
equal to or exceeding A- from Best's Insurance Guide, and shall be primary and
not contributing.

        12.2.  Tenant shall maintain in full force and effect on all Tenant's 
trade fixtures, equipment and personal property on the Premises, a policy of all
risk property insurance covering the full replacement value of such property.
During the term of this Lease, the proceeds from any such policy of insurance
shall be used for the repair or replacement of the fixtures and equipment so
insured. Landlord shall have no interest in the insurance upon Tenant's
equipment and fixtures and will sign all documents reasonably necessary or
proper in connection with the settlement of any claim or loss by Tenant.
Landlord will not carry insurance on Tenant's possessions. Tenant shall furnish
Landlord with a certificate of insurance evidencing that the

                                      26

 
requirements set forth herein are in full force and effect.  Any deductible in
excess of Ten Thousand and no/100ths Dollars ($10,000.00) under such insurance
must be approved in writing by Landlord prior to issuance of such policy.  The
policy limits set forth herein shall be subject to periodic review, and Landlord
reserves the right to require that Tenant increase the limits if, in the
reasonable opinion of Landlord, the coverage becomes inadequate and is less than
commonly maintained by tenants making similar uses of similar buildings in the
vicinity of the Building.  Tenant shall provide Landlord with notice of loss or
damage to property promptly after such loss or damage occurs.  Tenant shall
provide and keep in force with companies satisfactory to Landlord, business
interruption and/or loss of rental insurance in an amount equivalent to six (6)
months Rent and Additional Rent which shall not contain a deductible greater
than Ten Thousand Dollars ($10,000.00). Tenant shall furnish Landlord with
certificates of insurance naming Landlord as an additional insured.  No policy
shall be cancelable, allowed to lapse and/or expire and/or be subject to
reduction of coverage except upon thirty (30) days' prior written notice to
Landlord.

    13. DAMAGE OR DESTRUCTION.
        --------------------- 

        13.1.  CASUALTY DAMAGE - INSURED.  If the Building or Premises is 
               -------------------------                                     
damaged by fire or other perils covered by extended coverage insurance the
following provisions shall apply:

               13.1.1.  TOTAL DESTRUCTION.  In the event of total destruction 
                        -----------------                                 
of the Building such that the Premises reasonably cannot be rebuilt within one
hundred and eighty (180) days ("Total Destruction"), then, (i) Landlord shall
elect either promptly to commence repair and restoration of the Building and
prosecute the same diligently to completion, in which event this Lease shall
remain in full force and effect (unless Tenant exercises its right to
terminate), or not to repair or restore the Building, in which event this Lease
shall terminate, and (ii) Tenant may elect to terminate this Lease. In either
case, each party shall give the other party written notice of its intention
within sixty (60) days after the occurrence of such destruction. If Landlord
elects not to restore the Building, this Lease shall be deemed to have
terminated as of the date of such total destruction.

               13.1.2.  PARTIAL DESTRUCTION.  In the event of a partial 
                        -------------------                                
destruction of the Building to an extent not exceeding twenty-five percent (25%)
of the value thereof and if the damage thereto is such that the Building may be
repaired or restored within one hundred eighty (180) days from the date of such
destruction and Landlord will receive insurance proceeds sufficient to cover the
cost of such repairs (or would have, had Landlord carried the insurance required
in Section 12.1 of the Lease), Landlord shall commence and proceed diligently
with the work of repair and restoration, in which event this Lease shall
continue in full force and effect. If such repair and restoration requires
longer than one hundred eighty (180) days or the cost thereof exceeds twenty-
five percent (25%) of the value thereof or if the insurance proceeds payable to
Landlord will not be sufficient to cover such cost (and would not have been,
even if Landlord had carried the insurance required in Section 12.1 of the
Lease), (i) Landlord may elect either to so repair and restore, in which event
this Lease shall continue in full force and effect (unless Tenant exercises its
right to terminate), or not to repair or restore, in which event this Lease
shall terminate, and (ii) Tenant may elect to terminate this Lease. In either
case, each party shall give
                                      27

 
written notice to the other party of its intention within sixty (60) days after
the destruction occurs.  If Landlord elects not to repair or restore the
Building, this Lease shall be deemed to have terminated as of the date of such
partial destruction.

        13.2.  TERMINATION.  Upon any termination of this Lease under any of the
               -----------                                                      
provisions of this Article, Tenant shall surrender the Premises in accordance
with the provisions of Article 25.

        13.3.  RENT ABATEMENT.  In the event of repair and restoration as 
               --------------                                             
herein provided, the monthly installments of Rent shall be equitably abated
based on the amount of the Tenant's loss of use of the Premises occasioned
thereby; provided, however, if the damage is due, directly or indirectly, to the
fault or neglect of Tenant, its officers, contractors, licensees, agents,
servants, employees, guests, invitees or visitors, there shall be no abatement
of Rent, except to the extent Landlord receives proceeds from any applicable
insurance policy of Tenant to compensate Landlord for loss of Rent. Tenant shall
not be entitled to any compensation or damages for loss of use of the whole or
any part of said Premises and/or any inconvenience or annoyance occasioned by
such damage, repair or restoration.

        13.4.  DELAY.  Tenant shall not be released from any of its obligations 
               -----                                                       
under this Lease except to the extent and upon the conditions expressly stated
in this Article. Notwithstanding anything to the contrary contained in this
Article, if Landlord has elected to repair or restore and is thereafter delayed
or prevented from repairing or restoring within one (1) year after the
occurrence of such damage or destruction by reason of acts of God, war,
governmental restrictions, inability to procure the necessary labor or
materials, or other causes beyond the control of Landlord, Landlord shall, at
the option of Landlord or Tenant, be relieved of its obligation to make such
repairs or restoration and, in the event Landlord or Tenant exercises such
option, Tenant shall be released from its obligations under this Lease as of the
end of such one (1) year period.

        13.5.  UNINSURED DAMAGE.  Notwithstanding anything to the contrary 
               ----------------                                            
contained in this Article, if damage to the Building or the Premises is due to
any cause other than fire or other peril covered by extended coverage insurance,
Landlord may elect to terminate this Lease.

        13.6.  REPAIR OBLIGATION.  If Landlord is obligated to or elects to 
               -----------------                                              
repair or restore as herein provided, Landlord shall repair or restore only
those portions of the Building and Premises which were originally provided at
Landlord's expense; and the repair and restoration of areas or items not
provided at Landlord's expense shall be the obligation of Tenant.

        13.7.  END OF TERM.  Notwithstanding anything to the contrary contained 
               -----------                                                 
in this Article, Landlord or Tenant may elect to terminate this Lease in the
event of damage to the Building or the Premises occurring during the last (12)
months of the term of the Lease or any extension thereof; and Landlord shall not
have any obligation to repair or restore the Premises or the Building during the
last twelve (12) months of the term of this Lease or any extension thereof.

                                      28

 
    14. ALTERATIONS AND ADDITIONS:  REMOVAL OF FIXTURES.
        ----------------------------------------------- 

        14.1.  CONSENT REQUIRED.  Tenant shall not make or allow to be made any
               ----------------                                                
alterations, additions or improvements (collectively "Alterations") to or on the
Premises without first obtaining the written consent of Landlord, not to be
unreasonably withheld, conditioned or delayed.

        14.2.  REQUEST FOR ALTERATIONS.  Any request for Alterations to be made 
               -----------------------                                       
to the Premises by Tenant shall be made in writing, which shall include detailed
plans and specifications of the proposed Alterations prepared by an architect
approved by Landlord and licensed in the jurisdiction in which the Premises is
located, together with the names and addresses of the proposed contractors and
subcontractors, all of whom shall be approved and licensed as aforesaid. Tenant
shall upon demand reimburse Landlord as Additional Rent for all reasonable cost
and expense actually incurred in reviewing the plans and specifications and
inspecting the work on behalf of Landlord (by persons other than employees of
Landlord) including without limitation, the cost of any engineers and/or
architects retained by Landlord to review same and inspect the work on behalf of
Landlord.

        14.3.  NATURE OF ALTERATIONS.  Any Alterations, including, but not 
               ---------------------                                      
limited to, wall covering, paneling and built in cabinet work (but excepting
moveable furniture and trade fixtures), shall be made at Tenant's sole expense,
according to plans and specifications approved in writing by Landlord, in
compliance with all applicable laws, by a licensed contractor, and in a good and
workmanlike manner conforming in quality and design with the Premises existing
as of the Lease Commencement Date, shall not diminish the value of the Building
or the Premises and (excluding all telecommunications equipment, computer
equipment and cabling, supplemental HVAC equipment and Tenant's generator(s) and
related equipment, which shall be removed by Tenant in accordance with Section
14.5 below, at Tenant's sole cost and expense at the expiration of the Lease
term) shall at once become a part of the realty and shall be surrendered with
the Premises (unless otherwise required by Landlord as set forth in Section 14.5
below).

        14.4.  REPAIRS.  Tenant shall be responsible for making any and all 
               -------                                                     
repairs and replacements to the Alterations during the term of this Lease (as
same may be extended) and maintaining the same in good order and condition.
Notwithstanding anything to the contrary contained in this Lease, should there
be a fire or other casualty to the Premises, it is agreed by the parties that
the Landlord shall not be responsible to restore any Alterations made by Tenant
regardless of whether such Alterations were approved by Landlord and the Tenant
shall be responsible to restore the same at its sole cost and expense.

        14.5.  EXPIRATION/TERMINATION OF LEASE.  Upon the expiration or sooner 
               -------------------------------                             
termination of the term hereof, Tenant shall, upon written demand by Landlord,
at Tenant's sole expense, with due diligence, remove any Alterations made by
Tenant, which at the time of Landlord's approval of such Alterations were
designated by Landlord to be removed, and repair any damage to the Premises
caused by such removal. In no event shall Tenant be required to remove the
Tenant work performed pursuant to Exhibit C and C-1. Notwithstanding the
                                  ---------     ---
foregoing, Tenant shall be required to remove Tenant's telecommunications
equipment, computer
                                      29

 
equipment and cabling, supplemental HVAC equipment and generator at the
termination of this Lease and repair any damage to the Premises caused by such
removal.  Tenant shall remove all of Tenant's moveable property and trade
fixtures which can be removed without damage to the Premises at the termination
of this Lease, either by expiration of the term or other cause, and shall pay
Landlord any damages for injury to the Premises or Building resulting from such
removal.  If Tenant shall fail to remove any of its property at the time Tenant
vacates the Premises, such property shall be deemed to have been abandoned by
Tenant and Landlord may, in accordance with the provisions of applicable
statutes governing commercial landlord and tenant matters, without liability for
the loss thereof or damage thereto, either remove and store such property, such
storage to be for the account and at the expense of Tenant, or otherwise dispose
of such property in Landlord's sole and absolute discretion, all at the expense
of Tenant.  If Landlord elects to store such property and Tenant fails to pay
the cost of storing any such property within thirty (30) days of demand
therefor, Landlord may sell any or all such property at public or private sale,
without notice to Tenant, and shall apply the proceeds of such sale to the
following costs in the following order: (i) the cost and expense of such sale,
including reasonable attorneys' fees, (ii) the payment of the costs or charges
for storing any such property, and (iii) the payment of any other sums which may
then be or thereafter become due Landlord from Tenant under any of the terms of
this Lease.  The balance, if any, shall be paid to Tenant.

    15. ACCEPTANCE OF PREMISES.  Landlord has expressly agreed in this Lease to
        ----------------------                                          
perform certain tenant improvement work in the Premises as set forth in Exhibit
C.  The acceptance of the Premises by Tenant shall be deemed to have occurred
five (5) days after substantial completion in accordance with Exhibit C; at such
time, Tenant shall be deemed to have accepted the Premises in their then
condition except for any "punch list" items (as that term is used in the
construction industry) noted by Tenant in writing to Landlord within such five
(5) day period pursuant to any inspection of the Premises made by Tenant within
such five (5) day period.  Landlord shall complete the punch list items within
thirty (30) days.  If the completion of the punch list is not possible within
said thirty (30) day period due to reasons beyond Landlord's control, Landlord
shall diligently pursue completion of the punch list.  The existence of such
punch list items shall not postpone the Lease Commencement Date of this Lease
nor the obligation of Tenant to pay Rent or any other charges due under this
Lease.

    16. TENANT IMPROVEMENTS.  The provisions governing the planning, 
        -------------------                                                
construction, scope of work and terms of payment are set forth in EXHIBIT C, 
                                                                  ---------  
which is attached hereto and incorporated herein by this reference.

    17. ACCESS.  Tenant shall permit Landlord to enter the Premises at all 
        ------                                                                
reasonable times with reasonable prior notice (except in case of emergencies) to
inspect the same; to show the Premises to prospective Tenants (within twelve
months of the expiration of the term of this Lease), prospective lenders,
purchasers and investors; to exercise its rights under this Lease; to clean,
repair, alter or improve the Premises or the Building; to discharge Tenant's
obligations when Tenant has failed to do so within the time required under this
Lease or within a reasonable time after written notice from Landlord, whichever
is earlier; to post notices of nonresponsibility and similar notices and "For
Sale" signs at any time and to place "For Lease" signs upon or adjacent to the
Building at any time within twelve (12) months of the expiration of the term of

                                      30

 
this Lease.  Tenant shall permit Landlord and its agents to enter the Premises
at any time in the event of an emergency.  When reasonably necessary, Landlord
may temporarily close entrances, doors, corridors, elevators or other facilities
without liability to Tenant by reason of such closure so long as Landlord
provides reasonable access to the Building and the Premises.

          If any entry or work by Landlord would materially adversely affect
Tenant's ability to operate its business in the Premises, Landlord shall
undertake such entry or work (except in the event of an emergency) after Normal
Business Hours.

    18. WAIVER OF SUBROGATION.
        --------------------- 

        18.1.  TENANT'S WAIVER.  Whether due to the negligence of Landlord or 
               ---------------                                                
Landlord's agents or employees, or any other cause and notwithstanding any other
provision of this Lease, Tenant hereby releases Landlord and Landlord's agents
and employees from responsibility for and waives its entire claim of recovery
for (i) any loss or damage to the real or personal property of Tenant located in
the Building, including the Building itself, arising out of any of the perils
which are (or could have been) covered by Tenant's property insurance policy,
with extended coverage endorsements, or (ii) loss resulting from business
interruption or loss of rental income, at the Premises, arising out of any of
the perils which are (or could have been) covered by the business interruption
or by the loss of rental income insurance policy held by Tenant. Tenant shall
cause its insurance carrier(s) to consent to such waiver of all rights of
subrogation against Landlord.

        18.2.  LANDLORD'S WAIVER.  Whether due to the negligence of Tenant or 
               -----------------                                            
Tenant's agents or employees, or any other cause and notwithstanding any other
provision of this Lease, Landlord hereby releases Tenant and Tenant's agents and
employees from responsibility for and waives its entire claim of recovery for
(i) any loss or damage to the real or personal property of Landlord located in
the Building, including the Building itself, arising out of any of the perils
which are (or could have been) covered by Landlord's property insurance policy,
with extended coverage endorsements, or (ii) loss resulting from business
interruption or loss of rental income, at the Premises, arising out of any of
the perils which are (or could have been) covered by the business interruption
or by the loss of rental income insurance policy held by Landlord. Landlord
shall cause its insurance carrier(s) to consent to such waiver of all rights of
subrogation against Tenant.

    19. INDEMNIFICATION. Tenant shall defend, indemnify and hold harmless 
        ---------------                                                    
Landlord, its agents, employees, officers, directors, partners and shareholders
from and against any and all third party liabilities, judgments, demands, causes
of action, claims, losses, damages, costs and expenses, including reasonable
attorneys' fees and costs, arising out of the negligence or willful misconduct
or negligence of, Tenant, its officers, contractors, licensees, agents,
servants, employees, guests, invitees, or visitors in or about the Building or
Premises or arising from any breach or default under this Lease by Tenant, or
arising from any accident, injury, or damage caused by the willful misconduct or
negligence of Tenant, occurring in or about the Building or Premises. This
indemnification shall survive termination of this Lease. This provision shall
not be construed to make Tenant responsible for loss, damage, liability or

                                      31

 
expense resulting from injuries to third parties caused by the sole negligence
or willful misconduct of Landlord, or its officers, contractors, licensees,
agents, employees, or invitees.

Landlord shall defend, indemnify and hold harmless Tenant, its agents,
employees, officers, directors, partners and shareholders from and against any
and all third party liabilities, judgments, demands, causes of action, claims,
losses, damages, costs and expenses, including reasonable attorneys' fees and
costs, arising out of the negligence or willful misconduct of, Landlord, its
officers, contractors, licensees, agents, servants, employees, guests, invitees,
or visitors in or about the Building or the Premises or arising from any breach
or default under this Lease by Landlord, or arising from any accident, injury,
or damage caused by willful misconduct or negligence of Landlord, occurring in
or about the Building or Premises.  This indemnification shall survive
termination of this Lease.  This provision shall not be construed to make
Landlord responsible for loss, damage, liability or expense resulting from
injuries to third parties caused by the negligence or willful misconduct of
Tenant, or its officers, contractors, licensees, agents, employees, or invitees.

     20.   ASSIGNMENT AND SUBLETTING.
           ------------------------- 

          20.1.  LANDLORD'S CONSENT.  Tenant shall not assign this Lease, or
                 ------------------
sublease all or any part of the Premises, or permit the use of the Premises by
any party other than Tenant, without the prior written consent of Landlord, such
consent not to be unreasonably withheld, conditioned or delayed. When Tenant
requests Landlord's consent to such assignment or sublease, it shall notify
Landlord in writing of (i) the name and address of the proposed assignee or
subtenant; (ii) the nature and character of the business of the proposed
assignee or subtenant; (iii) financial information including financial
statements of the proposed assignee or subtenant; and (iv) a copy of the
proposed sublet or assignment agreement. Tenant shall thereafter immediately
provide to Landlord any and all other information and documents reasonably
requested by Landlord in order to assist Landlord with its consideration of
Tenant's request hereunder. Without limitation, it shall not be unreasonable if
Landlord denies its consent to a proposed assignment or sublease to an assignee
or subtenant (i) which in Landlord's reasonable opinion does not have sufficient
financial strength to meet its financial obligations under the assignment or
sublease; (ii) which Landlord can demonstrate has a history of committing lease
defaults or otherwise failing to meet its contractual obligations either with
Landlord, its affiliates, or other landlords; or (iii) to any assignee or
sublessee who proposes to use the Premises other than for the uses specifically
permitted under Section 5, above. If the proposed sublet or assignment is for
more than twenty-five percent (25%) of the rentable area of the Premises,
Landlord shall have the option (to be exercised within ten (10) business days
from the submission of Tenant's request and receipt of all other information
requested hereunder) to cancel this Lease with respect to the portion of the
Premises to be subleased or assigned as of the commencement date stated in the
proposed sublease or assignment. If Landlord shall not exercise its option
within the time set forth above, Landlord's consent to any proposed assignment
or sublease shall not be unreasonably withheld.

           20.2. APRROVED SUBLEASES AND ASSIGNMENTS.  If Landlord approves an
                 ----------------------------------                          
assignment or sublease as herein provided, Tenant shall pay to Landlord, as
Additional Rent due 

                                       32

 
under this Lease, as applicable (i) in the case of a sublease, an overage amount
equal to fifty percent (50%) of the difference, if any, between the Rent
allocable to that part of the Premises affected by such sublease pursuant to
this Lease, and the rent paid by the subtenant to Tenant, less any reasonable
and customary expenses incurred by the Tenant in connection with the sublease
(including without limitation tenant improvement costs, free rent, brokerage
fees, legal costs, moving allowance), and (ii) in the case of an assignment, an
overage amount equal to fifty percent (50%) of the premium, if any, received by
Tenant for such assignment. Such overage amounts shall be due and payable by
Tenant to Landlord within thirty (30) days of Tenant's receipt of payment from
the subtenant or assignee. No consent to any assignment or sublease shall
constitute a further waiver of the provisions of this Section, and all
subsequent assignments or subleases may be made only with the prior written
consent of Landlord. An assignee of Tenant, at the option of Landlord, shall
become directly liable to Landlord for all obligations of Tenant hereunder and
shall assume all such obligations in writing in a form reasonably satisfactory
to Landlord, but no sublease or assignment by Tenant shall relieve Tenant of any
liability hereunder. Any assignment or sublease without Landlord's consent shall
be void, and shall, at the option of the Landlord, constitute a default under
this Lease. In the event that Tenant requests that Landlord consider a sublease
or assignment hereunder (except with respect to the exercise by Landlord of its
option to cancel as set forth in Section 20.1), Tenant shall pay (i) Landlord's
reasonable fees, not to exceed Five Hundred and 00/100 Dollars ($500.00) per
transaction, incurred in connection with the consideration of such request, and
(ii) all reasonable attorneys' fees not to exceed $1,000.00 per transaction and
costs incurred by Landlord in connection with the consideration of such request
or such sublease or assignment.

     21.   ADVERTISING.  Tenant shall not display any sign, graphics, notice,
           -----------
picture, or poster, or any advertising matter whatsoever, anywhere in or about
the Premises or the Building at places visible from anywhere outside or at the
entrance to the Premises without first obtaining Landlord's written consent
thereto, such consent to be at Landlord's sole discretion. Tenant shall be
responsible to maintain any permitted signs and remove the same at Lease
termination. If Tenant shall fail to do so, Landlord may do so at Tenant's
expense and Tenant's reimbursement to Landlord for such amount shall be deemed
Additional Rent and shall be due within ten (10) days of Landlord's demand
therefor. Tenant shall be responsible to Landlord for any damage caused by the
installation, use, maintenance or removal of any such signs.

     Tenant shall have signage rights to install a monument style sign in front
of the Building, subject to any applicable governmental laws, ordinances,
regulations, and other requirements at Tenant's expense.  The size, design and
placement of such shall require approval of Landlord, which shall not be
unreasonably withheld or delayed, and all applicable zoning, government
regulations, ordinances and licenses.

     22.   LIENS.  Tenant shall keep the Premises and the Building free from any
           -----                                                                
liens, including but not limited to liens filed against the Premises by any
governmental agency, authority or organization, arising out of any work
performed, materials ordered or obligations incurred by or on behalf of Tenant,
and Tenant hereby agrees to indemnify and hold Landlord, its agents, employees,
independent contractors, officers, directors, partners, and shareholders
harmless from any liability, cost or expense for such liens.  Tenant shall cause
any such lien 

                                       33

 
imposed to be released of record by payment or posting of the proper bond within
ten (10) business days after Tenant learns of same. Tenant shall give Landlord
written notice of Tenant's intention to perform work on the Premises which might
result in any claim of lien, at least ten (10) days prior to the commencement of
such work to enable Landlord to post and record a notice of nonresponsibility or
other notice deemed proper before commencement of any such work. If Tenant fails
to remove any lien within the prescribed ten (10) day period, then Landlord may
do so at Tenant's expense and Tenant's reimbursement to Landlord for such
amount, including reasonable attorneys' fees and costs, shall be deemed
Additional Rent. Tenant shall have no power to do any act or make any contract
which may create or be the foundation for any lien, mortgage or other
encumbrance upon the reversion or other estate of Landlord, or of any interest
of Landlord in the Premises.

     23.   DEFAULT.
           ------- 

           23.1. TENANT'S DEFAULT.  A default under this Lease by Tenant shall
                 ----------------
exist if any of the following occurs:

                 23.1.1. If Tenant fails to pay Rent or any other sum required
to be paid hereunder within five (5) business days after written notice from
Landlord, except as provided in Section 23.1.5 of this Lease; or

                 23.1.2. If Tenant fails to perform any term, covenant or
condition of this Lease except those requiring the payment of money, and Tenant
fails to cure such breach within fifteen (15) days after written notice from
Landlord where such breach could reasonably be cured within such fifteen (15)
day period, provided, however, that where such failure could not reasonably be
cured within the fifteen (15) day period, that Tenant shall not be in default if
it commences such performance within the fifteen (15) day period and diligently
thereafter prosecutes the same to completion; or

                 23.1.3. If, to the extent permitted by applicable law, there
shall be filed by or against Tenant, in any court pursuant to any statute either
of the United States or any state, a petition in bankruptcy or insolvency or for
the reorganization of or for the appointment of a receiver, trustee or
liquidator for all or any portion of the assets of Tenant, and, within thirty
(30) days thereafter, Tenant fails to secure a discharge thereof, or if the
Tenant makes an assignment for the benefit of creditors, or if the Tenant admits
in writing its or their inability to pay its or their debts; or

                 23.1.4. If Tenant shall fail to take possession of and/or
occupy the Premises within the thirty (30) days following the Lease Commencement
Date or if Tenant shall vacate the Premises for a period of fifteen (15) days or
more (without giving Landlord notice of such vacancy) at any time following the
Lease Commencement Date; or

                 23.1.5. The chronic delinquency by Tenant in the payment of
monthly Rent, or any other periodic payments required to be paid by Tenant under
this Lease, shall constitute a default. "Chronic delinquency" shall mean failure
by Tenant to pay Rent, or any 

                                       34

 
other periodic payments required to be paid by Tenant under this Lease within
three (3) days after written notice thereof for any three (3) months
(consecutive or nonconsecutive) during any twelve (12) month period. In the
event of a chronic delinquency, at Landlords' option, Landlord shall have the
additional right to require that Rent be paid by Tenant quarter-annually, in
advance.

           23.2. REMEDIES.  Upon a default, Landlord shall have the following
                 --------
remedies, in addition to all other rights and remedies provided by law or
otherwise provided in this Lease, to which Landlord may resort cumulatively or
in the alternative:

                 23.2.1. Landlord may continue this Lease in full force and
effect, and this Lease shall continue in full force and effect as long as
Landlord does not terminate this Lease, and Landlord shall have the right to
collect Rent and other charges when due.

                 23.2.2. Landlord may terminate Tenant's right to possession of
the Premises at any time by giving written notice to that effect, and relet the
Premises or any part thereof. On the giving of the notice, all of Tenant's
rights in the Premises, shall terminate. Upon such termination, Tenant shall
surrender and vacate the Premises in the condition required by Article 25, and
Landlord may re-enter and take possession of the Premises and all the remaining
improvements or property and eject Tenant or any of the Tenant's subtenants,
assignees or other person or persons claiming any right under or through Tenant
or eject some and not others or eject none. This Lease may also be terminated by
a judgment specifically providing for termination. Any termination under this
Section shall not release Tenant from the payment of any sum then due Landlord
or from any claim for damages or Rent or other sum previously accrued or then
accruing against Tenant. Upon such termination Tenant shall be liable
immediately to Landlord for all costs Landlord incurs in reletting the Premises
or any part thereof, including, without limitation, broker's commissions,
expenses of cleaning and redecorating the Premises required by the reletting and
like costs. Reletting may be for a period shorter or longer than the remaining
term of this Lease. No act by Landlord other than giving written notice to
Tenant or executing a judgment for possession shall terminate this Lease. Acts
of maintenance, efforts to relet the Premises or the appointment of a receiver
on Landlord's initiative to protect Landlord's interest under this Lease shall
not constitute a termination of Tenant's right to possession. When Tenant is
evicted or otherwise vacates the Premises, Landlord has the right, at Tenant's
cost and without liability for the loss thereof or damage thereto, to remove all
Tenant's personal property, which shall be deemed to have been abandoned by
Tenant, and either store same or otherwise dispose of same in Landlord's sole
and absolute discretion. Landlord and Tenant hereby acknowledge that in the
event of such a termination, actual damages to Landlord may be difficult to
ascertain and, accordingly, hereby agree that in such event, the net present
value of the Base Rent due from the date of such termination to the Lease
Expiration Date, discounted at eight percent (8%) per annum, less the fair
rental value of the Premises from the date of such termination or reentry of the
Landlord until the Lease Expiration Date, discounted at eight percent (8%) per
annum, shall thereupon be immediately due and payable to Landlord to compensate
Landlord for Tenant's default and such termination. Tenant waives redemption or
relief from forfeiture under any other present or future law, in the 

                                       35

 
event Tenant is evicted or Landlord takes possession of the Premises pursuant to
judicial process by reason of any default of Tenant hereunder.

                 23.2.3. Landlord may, except as may otherwise have been agreed
to between the parties pursuant to landlord lien waivers, with or without
terminating this Lease, re-enter the Premises by judicial process and remove all
persons and property from the Premises; such property shall be deemed to have
been abandoned by Tenant and may either be removed and stored in a public
warehouse or elsewhere or otherwise disposed of in the Landlord's sole and
absolute discretion, all at the cost of the Tenant. The parties hereby agree
that Landlord shall not be liable for the loss of such property or any damages
thereto. No re-entry or taking possession of the Premises by Landlord pursuant
to this Section shall be construed as an election to terminate this Lease unless
(i) a written notice of such intention is given to Tenant, or (ii) Tenant is
evicted from the Premises.

                 23.2.4. Landlord's rights pursuant to this Article, including
without limitation, Landlord's rights to collect Base Rent, Additional Rent and
other charges due under this Lease, shall survive any termination of the Lease,
whether such termination is effected pursuant to this Article or otherwise.
Notwithstanding anything to the contrary contained herein, Landlord, prior to
termination of the Lease or re-entry of the Premises, shall have no obligation
or duty to mitigate or attempt to offset any damages which are or may be
suffered by Landlord as a result of any default of Tenant under the Lease. From
and after termination of the Lease or re-entry of the Premises, Landlord shall
use commercially reasonable efforts to mitigate its damages. Any payment by
Tenant of a sum of money less than the entire amount due Landlord at the time of
such payment shall be applied to the obligations of Tenant then furthest in
arrears. No endorsement or statement on any check or accompanying any payment
shall be deemed an accord and satisfaction and any payment accepted by Landlord
shall be without prejudice to Landlord's right to obtain the balance due or
pursue any other remedy available to Landlord both in law and in equity.

                 23.2.5. Landlord agrees to use good faith, commercially
reasonable efforts to relet the Premises and otherwise to mitigate its damages
in the event of a default by Tenant. The foregoing notwithstanding (i) Landlord
shall not be obligated to show any preference between the Premises and any other
vacant space in the Building with regard to any such reletting; (ii) Landlord
may make such leasing concession (including but not limited to rental
abatement/free rent, tenant improvement allowances, and the like) as Landlord
deems appropriate in its sole but reasonable judgment; (iii) Landlord shall have
the right to attempt to relet the Premises in whole or in any subdivided part,
or in combination with other vacant space in the Building, and to apportion the
rentals and concessions thereunder in any fashion Landlord deems appropriate, in
its sole but reasonable judgment; and (iv) Landlord's inability to relet the
Premises or any part thereof, or to collect rent after any such reletting,
despite its good faith efforts, shall not constitute a violation of Landlord's
duty to mitigate under this Section 23.2.5.

     24.   SUBORDINATION.  Landlord represents and warrants that as of the date
           -------------
hereof there are no existing deeds of trust or other liens against the Building.
Upon request of Landlord, Tenant will, in writing, subordinate its rights
hereunder to any holder of the lien of any mortgage,

                                       36

 
deed of trust, ground lease or underlying lease hereafter in force against the
Premises (the "Landlord's Mortgage"), and to all advances made or hereafter to
be made upon the security thereof; provided, however, that Tenant shall grant
such subordination only if Tenant simultaneously receives in a form reasonably
acceptable to Tenant and Landlord, a non-disturbance agreement from and executed
by Landlord's Mortgagee for the benefit of Tenant. Tenant shall execute and
return to Landlord any such subordination documents within twenty (20) business
days of Landlord's written request. Such non-disturbance agreement shall provide
in the event any proceedings are brought for foreclosure, or in the event of the
exercise of the power of sale under any mortgage or deed of trust made by the
Landlord covering the Premises, that Tenant shall attorn to the purchaser at any
such foreclosure, or to the grantee of a deed in lieu of foreclosure, and
recognize such purchaser or grantee as the Landlord under this Lease, provided
such purchaser or grantee assumes in writing Landlord's obligations under this
Lease.

     25.   SURRENDER OF POSSESSION.  Upon expiration of the term of this Lease
           -----------------------
or as otherwise provided hereunder, Tenant shall promptly and peacefully
surrender the Premises to Landlord in as good condition as when received by
Tenant from Landlord or as thereafter improved, reasonable use and wear and tear
(to the reasonable satisfaction of Landlord) and damage by storm, fire,
lightning, earthquake or other casualty excepted. If the Premises are not
surrendered in accordance with the terms of this Lease, Tenant shall indemnify
Landlord and its agents, employees, independent contractors, officers,
directors, partners, and shareholders against any loss or liability including
reasonable attorneys' fees and costs, and including liability to succeeding
tenants, resulting from delay by Tenant in so surrendering the Premises. This
indemnification shall survive termination of this Lease.

     26.   NON-WAIVER.  Waiver by Landlord of any breach of any term, covenant
           ----------
or condition herein contained shall not be deemed to be a waiver of such term,
covenant, or condition(s); or any subsequent breach of the same or any other
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 preceding breach at the time of acceptance of such Rent. No provision of
this Lease shall be deemed to have been waived or modified by Landlord or Tenant
unless such waiver or modification shall be in writing and signed by the party
against whom such waiver or modification is sought to be enforced.

     27.   HOLDOVER.  If Tenant shall, without the written consent of Landlord,
           --------
hold over after the expiration of the term of this Lease such tenancy shall be
deemed a month-to-month tenancy, which tenancy may be terminated by either party
upon thirty (30) days written notice to the other party. During such tenancy,
Tenant agrees to pay to Landlord, each month, the greater of the fair market
rental value for the Premises or one hundred fifty percent (150%) of the Rent
payable by Tenant for the last month of the term of this Lease.

     28.   CONDEMNATION.  If twenty (20) percent or more of the Premises or of
           ------------
such portions of the Building as may be required for the reasonable use of the
Premises, are taken by eminent domain or sale under threat of condemnation by
eminent domain, this Lease shall automatically terminate as of the date title
vests in the condemning authority, and all Rent and other payments shall be paid
to that date. Landlord reserves all rights to damages to the Premises

                                       37

 
for any partial or entire taking by eminent domain, and Tenant hereby assigns to
Landlord any right Tenant may have to such damages or award, and Tenant shall
make no claim against Landlord or the condemning authority for damages for
termination of the leasehold interest or interference with Tenant's business.
Tenant shall have the right to claim and recover from the condemning authority
compensation for any loss which Tenant may incur for Tenant's moving expenses,
business interruption or taking of Tenant's personal property (not including
Tenant's leasehold interest).

     29.   NOTICES.  All notices and demands which may be required or permitted
           -------
to be given to either party hereunder shall be in writing, and shall be sent by
overnight courier or United States mail, postage prepaid, certified or
registered with return receipt requested, to the addresses set forth below, or
to such other person or place as each party may from time to time designate in a
notice to the other. Notice shall be deemed received upon delivery, if sent by
overnight courier, or upon the earlier of, if sent by mail, actual receipt or
the third day after deposit in the United States mail, postage prepaid. Notices
shall be addressed as follows:

          If to Landlord:                  If to Tenant:

          Aetna Life Insurance Company     1801 K Street, N.W.
          c/o Trammell Crow Company        Suite 201
          1115 30th Street, NW             Washington, D.C.  20006
          Washington, DC  20007            Attn.:  Mr. C. Raymond Marvin

                                           with a copy to:

                                           Philip M. Horowitz, Esq.
                                           Arter & Hadden
                                           1801 K Street, N.W.
                                           Suite 400K
                                           Washington, D.C.  20006


     30.   MORTGAGEE PROTECTION.  Tenant agrees to give any mortgagee(s) and/or
           --------------------
trust deed holder(s), by overnight courier or certified or registered mail,
return receipt requested, a copy of any notice of default served upon the
Landlord, provided that prior to such notice Tenant has been notified in writing
(by way of notice of assignment of rents and leases, or otherwise) of the
addresses of such mortgagee(s) and/or trust deed holder(s). Tenant further
agrees that if Landlord shall have failed to cure such default within the time
provided for in this Lease, then the mortgagee(s) and/or trust deed holder(s)
shall have an additional thirty (30) days within which to cure such default or
if such default cannot be cured within that time, then such additional time as
may be necessary if within such thirty (30) days any mortgagee and/or trust deed
holder(s) has commenced and is diligently pursuing the remedies necessary to
cure such default (including but not limited to commencement of foreclosure
proceedings, if necessary to effect such cure), in which event this Lease shall
not be terminated while such remedies are being so diligently pursued.

                                       38

 
     31.   COSTS AND ATTORNEYS' FEES.  If Tenant or Landlord shall employ an
           -------------------------
attorney with regard to any act, omission or activity of the other with regard
to this Lease, including any suit by Landlord for the recovery of Rent or other
payments due hereunder or possession of the Premises, the losing party shall pay
the prevailing party a reasonable sum for attorneys' fees and costs, including
without limitation those incurred in connection with any litigation, at trial,
and on appeal, and such attorneys' fees and costs shall be deemed to have
accrued on the commencement of such action.

     32.   BROKERS.  Tenant represents and warrants to Landlord that neither it
           -------
nor its officers or agents nor anyone acting on its behalf has dealt with any
real estate broker other than Murrey and Associates in the negotiating or making
of this Lease, and Tenant agrees to indemnify and hold Landlord, its agents,
employees, partners, directors, shareholders and independent contractors
harmless from all liabilities, costs, demands, judgments, settlements, claims,
and losses, including reasonable attorneys' fees and costs, incurred by Landlord
in conjunction with any such claim or claims of any other broker or brokers
claiming to have interested Tenant in the Building or Premises or claiming to
have caused Tenant to enter into this Lease.

     33.   LANDLORD'S LIABILITY.
           -------------------- 

           33.1. Anything in this Lease to the contrary notwithstanding,
covenants, undertakings and agreements herein made on the part of Landlord are
made and intended not for the purpose of binding Landlord personally or the
assets of Landlord but are made and intended to bind only the Landlord's
interest in the Premises and Building (including the rent account, insurance
proceeds and any condemnation award) , as the same may, from time to time, be
encumbered and no personal liability shall at any time be asserted or
enforceable against Landlord or its stockholders, officers or partners or their
respective heirs, legal representatives, successors and assigns on account of
the Lease or on account of any covenant, undertaking or agreement of Landlord in
this Lease.

           33.2. Landlord shall not be liable for any damage or injury which may
be sustained by Tenant or any other person from water by reason of the breakage,
leakage or obstruction of the roof, roof drains, sprinkler systems, water or
soil pipes or any other leakage in or about the Premises, or resulting from the
sole negligence or willful misconduct on the part of any of Landlord's other
tenants, their agents or employees. Landlord shall not be liable for any loss of
property from any cause whatsoever, including not by way of limitation, theft,
vandalism or burglary from the Premises, and Tenant covenants and agrees to make
no claim for any such loss at any time.

     34.   ESTOPPEL CERTIFICATES.  Tenant shall, from time to time, within ten
           ---------------------
(10) days of Landlord's written request, execute, acknowledge and deliver to
Landlord or its designee a written statement stating: the date the Lease was
executed and the date it expires; the date Tenant entered occupancy of the
Premises; the amount of Base Rent, Additional Rent and other charges due
hereunder and the date to which such amounts have been paid; that this Lease is
in

                                       39

 
full force and effect has not been assigned, modified, supplemented or amended
in any way (or specifying the date and terms of any agreement so affecting this
Lease) ; that this Lease represents the entire agreement between the parties as
to this leasing; that all conditions under this Lease to be performed by the
Landlord have been satisfied (or specifying any such conditions that have not
been satisfied); that all required contributions by Landlord to Tenant on
account of Tenant's improvements have been received (or specifying contributions
that have not been received) that on the date of such statement there are no
existing defenses or offset which the Tenant has against the enforcement of this
Lease by the Landlord (or if so, specifying the same); that no Rent has been
paid more than one (1) month in advance; that no security has been deposited
with Landlord (or, if so, the amount thereof) ; or any other matters evidencing
the status of the Lease, as may be reasonably required either by a lender making
a loan to Landlord to be secured by a deed of trust or mortgage against the
Building, or a purchaser of the Building. It is intended that any such statement
delivered pursuant to this Article may be relied upon by a prospective purchaser
of Landlord's interest or a mortgagee of Landlord's interest or assignee of any
mortgage upon Landlord's interest in the Building. If Tenant fails to respond
within ten (10) days of receipt by Tenant of a written request by Landlord as
herein provided, Tenant shall be deemed to have given such certificate as above
provided without modification and shall be deemed to have admitted the accuracy
of any information supplied by Landlord to a prospective purchaser or mortgagee.

     35.   FINANCIAL STATEMENTS.  Within ten (10) days after Landlord's request
           --------------------
but no more than once per year, Tenant shall deliver to Landlord the current
financial statements of Tenant, and financial statements of each of the two (2)
years prior to the current financial statements year, with an opinion of a
certified public accountant, including a balance sheet and profit and loss
statement for the most recent prior year, all prepared in accordance with
generally accepted accounting principles consistently applied. Tenant also
agrees, within five (5) days of Landlord's request, to provide such further
financial information (such as quarterly statements) as Landlord may request.
Landlord shall keep confidential all financial information received from Tenant,
and shall not disclose any such financial information to any third party
individual or entity other than current or prospective lenders, current or
prospective investors or partners, and any licensed commercial real estate
appraiser so long as such parties agree to keep Tenant's financial information
confidential.

     36.   TRANSFER OF LANDLORD'S INTEREST.  In the event of any transfer(s) of
           -------------------------------                                     
Landlord's interest in the Premises or the Building, other than a transfer for
security purposes only, the transferor shall be automatically relieved of any
and all obligations and liabilities on the part of Landlord accruing from and
after the date of such transfer so long as the transferee assures in writing
Landlord's obligation under this Lease, and Tenant agrees to attorn to the
transferee.

     37.   RIGHT TO PERFORM.  If Tenant shall fail to pay any sum of money,
           ----------------
other than Rent, required to be paid by it hereunder, or if Tenant shall fail to
perform any other act on its part to be performed hereunder which such failure
shall continue for fifteen (15) days, then, in addition to a default if provided
by Section 23.1, Landlord may, but shall not be obligated so to do, and without
waiving or releasing Tenant from any obligations of Tenant, make any such

                                       40

 
payment or perform any such other act on Tenant's part to be made or performed
as provided in this Lease.  Notwithstanding the foregoing, in the event of an
emergency, 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, Landlord may, but shall not be obligated so
to do, and without waiving or releasing Tenant from any obligations of Tenant,
immediately make any such payment or perform any such other act on Tenant's part
to be made or performed as provided in this Lease.  Landlord shall have (in
addition to any other right or remedy of Landlord) the same rights and remedies
in the event of the nonpayment of sums due under this Article as in the case of
default by Tenant in the payment of Rent.  All sums paid by Landlord and all
penalties, interest and costs in connection therewith, shall be due and payable
by Tenant as Additional Rent on the next day after such payment by Landlord,
together with interest thereon equal to the prime rate of interest as published
in The Wall Street Journal (or any successor publication thereto) from time to
   -----------------------                                                    
time, plus two percent (2%).

     38.   SUBSTITUTED PREMISES.   INTENTIONALLY DELETED.
           --------------------                          

     39.   SALES AND AUCTIONS.  No retail sales may be conducted at, upon or in
           ------------------
the Premises. Tenant may not use the exterior walls and doorways of the Premises
for storage. Tenant agrees not to install any exterior lighting, amplifiers or
similar devices in or about the Premises. Tenant shall not conduct or permit to
be conducted any sale by auction in, upon or from the Premises whether said
auction be voluntary, involuntary, pursuant to any assignment for the payment of
creditors or pursuant to any bankruptcy or other insolvency proceeding.

     40.   ROOFTOP EQUIPMENT.  Tenant may install, at its sole cost,
           -----------------                                        
telecommunications equipment (the "Rooftop Equipment") on the roof of the
Building, subject to Landlord's prior written approval, not to be unreasonably
withheld, conditioned or delayed, of plans and specifications for the Rooftop
Equipment and the type and placement of all cabling and wiring ancillary
thereto.  Tenant shall be responsible for paying all reasonable out-of-pocket,
third party costs associated with Landlord's review of such plans and
specifications for the Rooftop Equipment (if any) . Landlord shall not charge
Tenant additional rent for the use of space on the roof for the Rooftop
Equipment.  Tenant shall be responsible for obtaining and maintaining all
approvals, permits and licenses required by Fairfax County, Reston or any
federal, state or local government for installation and operation of the Rooftop
Equipment and shall pay all fees attendant thereto.  If the Rooftop Equipment is
installed, Tenant shall have sole responsibility for the maintenance, repair and
replacement thereof and of all cabling and wiring ancillary thereto and Tenant
will be responsible for bearing the costs to repair any damage caused to the
roof or Building by the installation of the Rooftop Equipment.  At the
expiration or earlier termination of this Lease, Tenant shall remove the Rooftop
Equipment and all cabling and wiring ancillary thereto and shall be responsible
to repair any damage caused to the roof or Building in connection with such
removal.

Notwithstanding the foregoing, Tenant covenants and agrees that:

(a)  The Rooftop Equipment shall not unreasonably interfere with the standard
use of the building by other tenants;

                                       41

 
(b)  Tenant shall pay any increase in Landlord's insurance rates occasioned by
the installation or operation of the Rooftop Equipment;

(c)  Tenant shall fully insure against damage occasioned by the installation
and/or operation of the Rooftop Equipment (subject to the provisions of
Sections 12.1 and 18.2 of the Lease);

(d)  Landlord shall retain the right to designate the placement of the Rooftop
Equipment and to require such reasonable "screening" type improvements to
the building as may be required to maintain its cosmetic appearance; and

(e)  If Tenant accesses the roof without a designated representative of
Landlord, the burden of proof for any damages subsequent to such access
shall be upon Tenant.

     41.   SECURITY. Tenant hereby agrees to the exercise by Landlord and its
           --------
agents and employees, within their sole discretion, of such security measures as
it deems necessary for the Building so long as such measures do not adversely
affect Tenant's use of the Premises or the Building for its business operations.
The Building shall be open during Normal Business Hours and Landlord shall
provide Tenant with access to the Building during other than Normal Business
Hours through a card-key (or equivalent) system.

     42.   AUTHORITY OF TENANT.  Tenant warrants to Landlord that Tenant, if
           -------------------
other than an individual, is a validly existing legal entity under the laws of
the state of its formation, that it is duly qualified to do business in the
State in which the Premises are located, that its entry into and performance of
this Lease has been duly authorized, that, if Tenant is not an individual, the
officers(s) , partner (s) or trustee (s) , as applicable, executing this Lease
on Tenant's behalf are duly authorized to do so, and that this Lease is binding
upon Tenant.

     43.   NO ACCORD OR SATISFACTION.  No payment by Tenant or receipt by
           -------------------------
Landlord of a lesser amount than the Rent and other sums due hereunder shall be
deemed to be other than on account of the earliest Rent or other sums due, nor
shall any endorsement or statement on any check or accompanying any check or
payment be deemed an accord and satisfaction; and Landlord may accept such check
or payment without prejudice to Landlord's right to recover the balance of such
Rent or other sum and to pursue any other remedy provided in this Lease.

     44.   MODIFICATIONS FOR LENDER.  If in connection with obtaining financing
           ------------------------
for the Building or any portion thereof, Landlord's lender shall request
reasonable modifications to this Lease as a condition to such financing, Tenant
shall not unreasonably withhold, delay, or defer its consent to such
modification provided such modifications do not increase the Rent or Tenant's
obligations under this Lease or adversely affect Tenant's rights hereunder.

     45.   PARKING. Tenant's occupancy of the Premises shall include the use of
           -------                                                             
eighty-six (86) parking spaces at no cost or expense to Tenant, of which two (2)
shall be reserved to Tenant, and the remaining eighty-four (84) of which shall
be used in common with other tenants, 

                                       42

 
invitees and visitors of the Building. Tenant shall have the right to park in
the Building parking facilities in common with other tenants of the Building.
Tenant agrees not to overburden the parking facilities and agrees to cooperate
with Landlord and other tenants in use of the parking facilities. Landlord
reserves the right in its reasonable discretion to determine whether the parking
facilities are becoming overburdened and to allocate and assign parking spaces
among Tenant and other tenants, and to reconfigure the parking area and modify
the existing ingress to and egress from the parking area as Landlord shall deem
appropriate.

     46.   GENERAL PROVISIONS.
           ------------------ 

           46.1. ACCEPTANCE.  The submission of this Lease by Landlord does not
                 ----------                                                    
constitute an offer by Landlord or other option for, or restriction of, the
Premises, and this Lease shall only become effective and binding upon Landlord,
upon full execution hereof by Landlord and delivery of a signed copy to Tenant.

           46.2. JOINT OBLIGATION.  If there be more than one Tenant, the
                 ----------------
obligations hereunder imposed shall be joint and several.

           46.3. MARGINAL HEADINGS, ETC.  The marginal headings, Table of
                 ----------------------
Contents, lease summary sheet and titles to the articles and sections of this
Lease are not a part of the Lease and shall have no effect upon the construction
or interpretation of any part hereof.

           46.4. CHOICE OF LAW.  This Lease shall be governed by and construed
                 -------------
in accordance with the laws of the State in which the Premises are located.

           46.5. SUCCESSORS AND ASSIGNS.  The covenants and conditions herein
                 ----------------------                                      
contained, subject to the provisions as to assignment, inure to and bind the
heirs, successors, executors, administrators and assigns of the parties hereto.

           46.6. RECORDATION. Neither Landlord nor Tenant shall record this
                 -----------
Lease, but a short-form memorandum hereof may be recorded at the request of
Landlord or Tenant.

           46.7. QUIET POSSESSION.  Upon Tenant's paying the Rent and other
                 ----------------
charges due hereunder and observing and performing all of the covenants,
conditions and provisions on Tenant's part to be observed and performed
hereunder, Tenant shall have quiet possession of the Premises for the term
hereof, subject to all the provisions of this Lease.

           46.8. PARTIAL INVALIDITY.  Any provision of this Lease which shall
                 ------------------
prove to be invalid, void, or illegal shall in no way affect, impair or
invalidate any other provision hereof and such other provision(s) shall remain
in full force and effect.

           46.9. CUMULATIVE REMEDIES.  No remedy or election hereunder shall be
                 -------------------
deemed exclusive but shall, whenever possible, be cumulative with all other
remedies at law or in equity.

                                       43

 
           46.10. ENTIRE AGREEMENT.  This Lease contains the entire agreement of
                  ----------------
the parties hereto and no representations, inducements, promises or agreements,
oral or otherwise, between the parties, not embodied herein, shall be of any
force or effect.

           46.11. LABOR DISPUTES.  Tenant agrees that it will not at any time,
                  --------------
either directly or indirectly, employ or permit the employment of any
contractor, mechanic or laborer, or permit any materials in the Premises, in
connection with any services, provisions, alterations or maintenance, if the use
of such contractor, mechanic or laborer or such materials creates any
difficulty, strike or jurisdictional dispute with other contractors, mechanics
or laborers engaged by Landlord or others, or disturbs the construction,
maintenance, cleaning, janitorial services, repair, management, security or
operation of the Building or any part thereof. In the event of any interference
or conflict, Tenant, upon demand of Landlord, shall cause all contractors,
mechanics or laborers, or all materials causing such interference, difficulty or
conflict, to leave or be removed from the Building immediately.

           46.12. WAIVER OF COUNTERCLAIM.  Tenant hereby waives the right to
                  ----------------------
interpose any counterclaim (other than a compulsory counterclaim) of whatever
description in any summary proceeding.

           46.13. TIME IS OF THE ESSENCE.  Time is of the essence of this Lease.
                  ----------------------
Unless specifically provided otherwise, all references to terms of days or
months shall be construed as references to calendar days or calendar months,
respectively.

           46.14. EXECUTION.  This Lease may be executed in any number of
                  ---------
counterparts, each of which shall be deemed an original and any of which shall
be deemed to be complete in itself and may be introduced into evidence or used
for any purpose without the production of the other counterparts.

           46.15. FORCE MAJEURE.  A party to this Lease shall be excused from
                  -------------
the performance of its duties and obligations under this Lease, except
obligations for the payment of money such as Base Rent, for the period of delay,
but in no event longer than ninety (90) days, caused by labor disputes,
governmental regulations, riots, war, insurrection, acts of God or other causes
beyond the control of the party whose performance is being excused (but such
causes shall not include insufficiency of funds).

           46.16. NO JOINT VENTURE.  This Lease does not and shall not be
                  ----------------
construed to create a partnership, joint venture or any other relationship other
than that of landlord and tenant.

     47.   RULES AND REGULATIONS.  Tenant agrees to comply with such reasonable
           ---------------------
rules and regulations as Landlord may adopt from time to time for the orderly
and proper operation of the Building and parking and other common areas. Such
rules may include but shall not be limited to the following: (i) restricting of
employee parking to a limited, designated area or areas; and (ii) regulation of
the removal, storage and disposal of Tenant's refuse and other rubbish at the
sole cost and expense of Tenant. The rules and regulations shall be binding upon
Tenant upon delivery of a copy of them to Tenant. Landlord shall not be
responsible to Tenant 

                                       44

 
for the nonperformance of any of said rules and regulations by any other tenants
or occupants of the Building. Landlord shall not discriminate against Tenant in
the enforcement of any rule or regulation.

     48.   NO WARRANTIES OR REPRESENTATIONS BY LANDLORD.  Tenant acknowledges
           --------------------------------------------
and agrees that, except as expressly set forth in this Lease, neither Landlord
nor any agent or representatives of Landlord have made, and Landlord is not
liable or responsible for or bound in any manner by any express or implied
representations, warranties, covenants, agreements, obligations, guarantees,
statements, information or inducements pertaining to the Premises or any part
hereof, the title and physical condition thereof, the quantity, character,
fitness and quality thereof, merchantability, fitness for particular purpose,
the income, expenses or operation thereof, the value and profitability thereof,
the uses which can be made thereof or any other matter or thing whatsoever with
respect thereto. Tenant acknowledges, agrees, represents and warrants that it
has had the opportunity and has in fact inspected the Premises, and that it has
had access to information and data relating to all of same as Tenant has
considered necessary, prudent, appropriate or desirable for the purposes of this
transaction and, without limiting the foregoing, that Tenant and its agents and
representatives have independently inspected, examined, analyzed and appraised
all of same, including the condition, value and profitability thereof. Without
limiting the foregoing, Tenant acknowledges and agrees that, except as expressly
set forth in this Lease, Landlord is not liable or responsible for or bound in
any manner by (and Tenant has no relief upon) any oral or written or supplied
guarantees, statements, information or inducements pertaining to the Premises or
any part hereof, such condition and such operation and any other information
respecting same furnished by or obtained from Landlord or any agent or
representative of Landlord.

     49.   LANDLORD'S CONSENT OR APPROVAL.
           ------------------------------ 

           49.1. With respect to any provision of this Lease which provides that
Tenant shall obtain Landlord's prior consent or approval, Landlord may withhold
such consent or approval for any reason at its sole discretion, unless the
provision specifically states that the consent or approval will not be
unreasonably withheld.

     50.   WAIVER OF TRIAL BY JURY.  LANDLORD AND TENANT WAIVE THE RIGHT TO A
           -----------------------
TRIAL BY JURY IN ANY ACTION OR PROCEEDING BASED UPON, OR RELATED TO, THE SUBJECT
MATTER OF THIS LEASE. THIS WAIVER IS KNOWINGLY, INTENTIONALLY, AND VOLUNTARILY
MADE BY TENANT AND TENANT ACKNOWLEDGES THAT NEITHER LANDLORD NOR ANY PERSON
ACTING ON BEHALF OF LANDLORD HAS MADE ANY REPRESENTATIONS OF FACT TO INDUCE THIS
WAIVER OF TRIAL BY JURY OR IN ANY WAY TO MODIFY OR NULLIFY ITS EFFECT. TENANT
FURTHER ACKNOWLEDGES THAT IT HAS BEEN REPRESENTED (OR HAS HAD THE OPPORTUNITY TO
BE REPRESENTED) IN THE SIGNING OF THIS LEASE AND IN THE MAKING OF THIS WAIVER BY
INDEPENDENT LEGAL COUNSEL, SELECTED OF ITS OWN FREE WILL, AND THAT IT HAS HAD
THE OPPORTUNITY TO DISCUSS THIS WAIVER WITH COUNSEL. TENANT FURTHER ACKNOWLEDGES
THAT IT HAS READ AND UNDERSTANDS THE MEANING AND 

                                       45

 
RAMIFICATIONS OF THIS WAIVER PROVISION AND AS EVIDENCE OF SAME HAS EXECUTED THIS
LEASE.

Initials:

Landlord:         /s/                      Tenant:           /s/
         ----------------------                   -------------------------


IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease, in triplicate,
on the day and year first above written.

TENANT:                                    LANDLORD:
- ------                                     -------- 



By:               /s/                      By:               /s/
   --------------------------------           ---------------------------------
Printed Name:  C. Raymond Marvin           Printed Name:  Thomas G.[eligible]
Its:  President                            Its:  Assistant Vice President
    -------------------------------            --------------------------------
Date:  12/6/94                             Date:  2/8/94
     ------------------------------             -------------------------------

                                       46

 
                                  EXHIBIT "A"
                                  -----------

                     LOCATION AND DESCRIPTION OF PREMISES


    Description of Premises pursuant to a lease dated December 6, 1994, by and
between Aetna Life Insurance Company ("Landlord") and Telephone Business
Meetings, Inc., dba Access Conference Call Service ("Tenant"):  Nineteen
Thousand Seven Hundred Sixty-five (19,765) square feet on the second (2nd) floor
of 1861 Wiehle Avenue, the 73,685 square foot building located at 1861 Wiehle
Avenue, Reston, Virginia 22090.

        Note:  Landlord and Tenant shall mutually agree on the exact location of
               the 19,765 square foot Premises on the approximately 25,141
               square foot second floor.



                              [Diagram Inserted]

                                       47

 
                                  EXHIBIT "B"
                                  -----------

                                RENT INCREASES


    Rent during the third and subsequent years of the initial term shall be
increased by three percent (3%) over the preceding year's Rent.

                                       48

 
                              AGREEMENT OF LEASE

                                by and between

                         AETNA LIFE INSURANCE COMPANY

                                      and

         TELEPHONE BUSINESS MEETINGS, INC. dba ACCESS CONFERENCE CALL

                                   EXHIBIT C

                   Plans and Specifications for the Premises

The following are the Standard Improvement Items, the Standard Allowance of each
of which the Landlord shall provide at its expenses as part of the improvements
to be made to the premises.

1.  PARTITIONING

    1.1.  Standard interior partitions shall be constructed of one-half inch
(1/2") gypsum drywall on each side of three and five-eighths inch (3-5/8") steel
studs, from slab to ceiling.  Such drywall shall be taped, spackeled, finished
and painted.

    1.2.  All corridor and demising partitions shall be sound-insulated with 3-
1/2" of batt insulation, finished gypsum drywall, and shall be constructed
according to applicable building code provisions.

    1.3.  The Standard Allowance shall be eighty-three lineal feet of interior
partition and N/A lineal feet of demising partition for each one thousand (1000)
square feet of floor area.  All interior standard partitions and one-half of the
demising partitions between the Premises and other leasable space shall be
charged against such Standard Allowance.

2.  DOORS

    2.1.  Standard interior doors shall be solid-core, paint grade, shall be
painted to match the partitioning, and shall include building standard hardware.
The Standard Allowance shall be one door for each three hundred fifty square
feet of floor area.

    2.2.  Standard suite entrance doors shall be made of solid core wood, and
shall include a building standard lockset.

                                       49

 
3.  ELECTRICAL SERVICE

    3.1.  Electric lights shall be three bulb, flush-mounted, energy miser,
fluorescent fixtures having dimensions of two feet (2') by four feet (4'), and
capable of providing seventy (70') foot candles at desk height.  One light
fixture shall be provided for each eighty-five square feet of floor.

    3.2.  The Standard Allowance shall be one interior wall-mounted duplex, 110-
volt receptacle for each one hundred fifty square feet of floor area, and one
light switch for each three hundred fifty square feet of floor area.

    3.3. The Standard Allowance shall not include any special outlet, any outlet
not located on a drywall partition, or any separate circuit, all of which shall
be provided at the Tenant's expense.

4.  FLOOR COVERING

    4.1. The Landlord shall provide and install carpeting throughout the
Premises using the Landlord's building standard, type and grade (Wunda Weve-
Centurion Decathlon-Antron III nylon, or equal) of such color as is selected by
the Tenant from the Landlord's standard selections.

    4.2. The Landlord shall provide a dark brown or black four-inch (4") high
base for each partition covered by the Standard Allowance.

5.  WINDOW COVERING

    The Landlord shall provide for each exterior window architectural narrow
slat venetian blinds of a standard color.

6.  WALL FINISHES

    The Landlord shall provide two (2) coats of paint on all partitions, doors
and columns covered by the Standard Allowance using such paint color as is
selected by the Tenant from the selections provided by the Landlord.

7.  GRAPHICS

    The Landlord shall provide the suite number for the Premises, using the
Landlord's standard type for the Building.  Any additional lettering requested
by the Tenant shall conform to such standard type and shall be provided at the
Tenant's expense.

8.  CEILING

                                       50

 
    8.1. The Landlord shall provide throughout the Premises an acoustical tile
ceiling comprised of two-foot (2') by four-foot (4') panels, having an exposed
grid system.

    8.2. The ceiling shall have a minimum height of eight feet, two inches
(8'2").

9.  HEATING, VENTILATING AND AIR-CONDITIONING SYSTEM

    Tenant will be responsible for all construction costs associated with
changes to existing building heating, ventilation, air conditioning and
electrical systems due to Tenant requirements which exceed or differ from
building standards.

10. FLOOR LOAD

    Floor load capabilities are designed for normal office space use.  The
Tenant shall notify the Landlord before the preparation of working drawings for
the Premises of any concentration of floor loads which the Tenant may desire,
and shall bear any additional cost incurred by the Landlord in accommodating the
same.

11. LANDLORD'S CONSTRUCTION OF TENANT'S SPACE

    Landlord and Tenant agree that Landlord shall cause the construction of the
improvements to the Premises in accordance with the plans, design and
specifications prepared by Tenant ("Tenant's Plans"), and the working drawings
prepared by Tenant (i.e., mechanical, electrical and plumbing drawings, the
"Working Drawings").  The Tenant's Plans and Working Drawings shall be prepared
by Tenant and presented to Landlord for approval and review within forty-five
(45) days of the full execution of the Lease.  Notwithstanding the foregoing,
Tenant shall prepare and present to Landlord within thirty (30) days of the full
execution of the Lease, the Tenant Plans and Working Drawings for the computer
room area.

    Following the preparation and approval of Tenant's Plans and the Working
Drawings, Landlord agrees to build-out the Premises as per Tenant's Plans and
the Working Drawings. All construction for the Premises shall be awarded
following a competitive bid format, with Trammell Crow Real Estate Services,
Inc. serving as construction manager ("Construction Manager"). The Construction
Manager shall: (1) prepare a bid package approved by Landlord and Tenant; (2)
solicit bids from a minimum of three qualified general contractors approved by
Landlord and Tenant; (3) prepare a bid analysis for review by Landlord and
Tenant; and (4) award the bid to the lowest qualified general contractor (as
approved by Tenant). On behalf of Landlord and Tenant, the Construction Manager
shall supervise the construction for the Premises, ensuring that: (1) all
construction is performed in a workmanlike manner; (2) all construction is in
compliance with all applicable governmental regulations; and (3) all
construction materials are free of defect (inherent or otherwise).

(i)  Tenant Allowance.  As a material part of this leasing transaction, Landlord
     ----------------                                                           
agrees to provide to Tenant an allowance ("Tenant Improvement Allowance")
of $20.00 per square foot (i.e., a total of 19, 500 sf x $20. 00 psf =
$390,000.00.  Such Tenant Improvement Allowance 

                                       51

 
shall be usable for, but shall not be limited to, the cost of all construction
documents/drawings, permits, actual construction costs (materials and labor),
general contractor fees, reasonable (and documented) moving related expenses
(not to exceed $2.00 per square foot of the total Tenant Improvement Allowance),
and a five percent (5%) construction management fee (such total costs
hereinafter referred to as "Tenant Improvement Costs"). To the extent that the
Tenant Improvement Costs exceed the Tenant Improvement Allowance (a
"Shortfall"), Landlord will bill to Tenant the Shortfall in two (2) equal
installments, due as follows: the first installment of fifty percent (50%) of
the shortfall to be made at the commencement of construction, and the second
installment of fifty percent (50%) upon substantial completion of construction.
To the extent that the Tenant Improvement Costs are less than the Tenant
Improvement Allowance, Landlord shall credit the unused portion of the Tenant
Improvement Allowance against the first rental payment(s) when due or, at
                                                                   --
Tenant's sole option, Landlord shall place the unused portion of the Tenant
Improvement Allowance in an interest-bearing account, and Tenant may use said
unused portion of the Tenant Improvement Allowance for future Tenant
Improvements within the premises. In all events, ten percent (10%) of the total
cost of the job will be held back from the general contractor until all punch
list items are complete, to the reasonable satisfaction of Tenant's architect.

(ii) Delay in Preparation of Tenant's Plans.  If the Tenant does not complete
     --------------------------------------                                  
preparation of the Tenant's Plans and Working Drawings within the time periods
specified above, and such delay causes the Landlord to postpone substantial
completion of the space or delays the Lease Commencement Date, then Tenant shall
pay to Landlord on the date rent would have commenced hereunder in the absence
of such delay, a sum of money equivalent to the Rent for the Premises for the
period during which Tenant would have been obligated to pay rent to the Landlord
had not the Lease Commencement Date been so delayed.

(iii)  Changes to the Tenant Plans.  If changes are made by Tenant to the
       ---------------------------                                       
Tenant's Plans after Landlord's approval, and should these changes to the
Tenant's Plans cause the Landlord to postpone substantial completion of the
space or delay the Lease Commencement Date, then Landlord shall have the right
to refuse to permit the making of such changes unless and until Tenant shall
have committed in writing, in a manner reasonably satisfactory to Landlord, to
pay to Landlord on the date rent would have commenced hereunder in the absence
of such delay, a sum of money equivalent to the Rent for the Premises for the
period during which Tenant would have been obligated to pay rent to the Landlord
had not the Lease Commencement Date been so delayed.

(iv) Notice.  Tenant shall, by notice to Landlord in writing, designate a single
     ------                                                                     
individual who Tenant agrees shall be available to meet and consult with
Landlord at the Premises as Tenant's representative respecting the matters which
are the subject of this Exhibit and who, as between Landlord and Tenant, shall
have the power to legally bind Tenant, in making requests for changes, giving
approval of plans or work, giving directions to the Landlord or the like, under
this Exhibit.

    Landlord shall, by notice to Tenant in writing, designate a single
individual who Landlord agrees shall be available to meet and consult with
Tenant at the Premises as Landlord's 

                                       52

 
representative respecting the matters which are the subject of this Exhibit and
who, as between Landlord and Tenant, shall have the power to legally bind
Landlord, in making requests for changes, giving approval of plans or work,
giving directions to the Tenant or the like, under this Exhibit.

(v)  Substantial Completion.  For purposes of the Lease, "substantially
     ----------------------                                            
complete" means full completion, except for minor or insubstantial details of
construction, decoration or installation.

(vi) Payment.  Any invoice from Landlord not paid by Tenant within 30 days of
     -------                                                                 
receipt thereof will be subject to an interest charge at an annual rate equal to
the average prime interest rate published in The Wall Street Journal during the
                                             -----------------------
period of any such delay in payment. Said interest and invoice payments are to
be treated by Landlord and Tenant as rent due hereunder.

                                       53

 
                                   EXHIBIT D
                                   ---------

                              HVAC SPECIFICATIONS
                              -------------------

    Landlord shall maintain the HVAC system at the following performance
capabilities:

        Summer - Outdoor: 95(degrees) dry bulb/78(degrees) wet bulb
        Summer - Indoor Tolerance (maximum):  76(degrees) dry bulb
        Winter - Outdoor: 14(degrees)F, dry bulb
        Winter - Indoor Tolerance (minimum): 74(degrees) dry bulb

    Relative humidity shall not exceed Fifty Percent (50%), and shall be in a
range to provide reasonable comfort throughout the Premises.

                                       54

 
                                  EXHIBIT "E"

                            CLEANING SPECIFICATIONS
                            -----------------------
                                        

Cleaning services provided five (5) days per week unless otherwise specified.

Cleaning hours Monday through Friday between 6:00 PM and before 8:00 AM of the
following day.

On the last day of the week the work will be done after 6:00 PM, Friday, but
before 8:00 AM, Monday.

No cleaning on holidays.

Lavatories
- ----------

All lavatory floors to be swept and washed with disinfectant nightly.

Tile walls and dividing petition to be washed and disinfected weekly.

Basins, bowls, urinals to be washed and disinfected daily.

Mirrors, shelves, plumbing work, bright work, and enamel surfaces cleaned
nightly.

Waste receptacles will be emptied and cleaned and wash dispensaries to be filled
with appropriate tissues, towels, soap nightly.

Main Lobby, Elevators, Building Exterior and Corridors
- ------------------------------------------------------

Wipe and wash all floors in Main Lobby nightly.

Wipe and/or vacuum elevator floors nightly.

Office Area
- -----------

Furniture and fixtures within reach will be dusted and desk tops will be wiped
clean.  However, desks with loose papers on the top will not be cleaned.

Ash trays to be emptied and cleaned.
Windows sills and baseboards to be dusted and washed when necessary.

Office wastepaper baskets will be emptied nightly.

                                       55

 
Cartons or refuse in excess of that which can be placed in wastebaskets will not
be removed.  Tenants are required to place such unusual refuse in trash cans.

Cleaner will not remove or clean tea or coffee cups or similar containers; also,
if such liquids are spilled in wastebaskets, the wastebaskets will be emptied
but not otherwise cleaned.

Hard floors will be swept daily and washed and waxed monthly.

Carpet will be vacuumed nightly.  Wipe clean all glass, brass and other bright
work weekly.

Dust all pictures, charts, wall hangings monthly that are not reached in nightly
cleaning.

                                       56

 
                                  EXHIBIT "F"
                                  -----------



                                    DIAGRAM

                                       57

 
                          AMENDMENT TO LEASE AGREEMENT
                                        
    This Amendment to Lease Agreement (the "Agreement") is made as of the 28th
day of March, 1995, by and between Aetna Life Insurance Company (Landlord), and
Telephone Business Meetings, Inc. dba Access Conference Call Service (Tenant).

    WHEREAS, by a lease dated December 6, 1994 (hereinafter referred to as the
"Lease"), Landlord leased to Tenant and Tenant leased from Landlord
approximately 19,765 square feet (the "Original Premises") situated in the
building located at 1861 Wiehle Avenue, Reston, Virginia 22090 (the "Building").

    WHEREAS, subject to the terms and conditions hereinafter set forth, Tenant
wishes, and Landlord hereby agrees to allow Tenant to expand its operations to
new premises within the Building consisting of approximately 5,376 square feet
located on the second floor of the building, which is contiguous to the Original
Premises and is more particularly described on Exhibit "A-1" attached hereto and
made a part hereof, all as hereinafter set forth.

    WHEREAS, Landlord and Tenant desire to amend the lease to reflect the terms
of such expansion, and to clarify which terms and provisions are applicable to
the New Premises and the Original Premises, pursuant to the Lease as amended
hereby, all as hereinafter set forth.

    NOW THEREFORE, in consideration of the mutual covenants, promises, and
agreements contained herein and other good and valuable considerations, the
receipt and sufficiency of which is hereby acknowledged, Landlord and Tenant
agree to modify the Lease as follows:

    1.  Expansion.
        --------- 

        Landlord shall deliver to Tenant possession of the New Premises, on
September 1, 1995, (the "Effective Date").  Landlord does hereby lease to
Tenant, and Tenant does hereby lease from Landlord the New Premises, for the
term and upon the conditions hereinafter provided.  The Lease is hereby deemed
amended to incorporate the grant by Landlord to Tenant of a leasehold interest
in and to the New Premises (as and to the extent set forth herein).

    2.  Amendments.
        ---------- 

        Effective on and after the Effective Date, the Lease shall be amended
and modified as follows:

        a.  The Premises, as set forth in Section 1.1 of the Lease, shall also
                                          ------------------------            
include the New Premises and all references to the Premises shall refer to the
New Premises and Original Premises, collectively, unless otherwise specifically
set forth to the contrary.  The size of the Premises as set froth in Section 1.1
of the Lease of "19,765 square feet" shall be deleted and in its place shall be
inserted "25,141 square feet".

                                       58

 
        b.  Tenant's percentage of the Building as defined in Section 1.2 of the
                                                              ------------------
Lease of "26.82%" shall be deleted and in its place shall be inserted "34.12%".
- -----                                                                          

        c.  The Base Rent of Twenty-three Thousand Three Hundred Six and 23/100
Dollars ($23,306.23) per month as defined in Section 1.4 of the Lease shall be
                                             ------------------------         
deleted and in its place shall be inserted Twenty-nine Thousand Six Hundred
Forty-five and 43/100 Dollars ($29,645.43) per month with annual increases as
set forth in Exhibit B of the Lease.  Tenant shall be given an additional rental
abatement equal to Fifteen Thousand Four Hundred Fifty-one and 80/100 Dollars
($15,451.80).

        d.  The provisions governing the construction of the tenant improvements
for the New Premises ("Landlord's Work") shall be the same as those set forth in
Exhibit B to this Agreement attached hereto.  Tenant's obligation to pay Rent
for the New Premises shall commence on the Effective Date of this Agreement.

    3.  Modification.
        ------------ 

        Except as, and to the extent, modified by this Agreement, the Lease
shall continue in full force and effect, unmodified.  This Agreement and the
Lease may be further amended only in writing signed by both Landlord and Tenant.

    4.  Severability.
        ------------ 

        If any term, covenant or condition of this Agreement or its application
to any person or circumstance shall be invalid or unenforceable, then the
remainder of this Agreement, or the application of such term or provision to
persons or circumstances other than those to which it is held invalid or
unenforceable shall not be affected, and each term and provision shall be valid
and enforceable to the fullest extent permitted by law.

                                       59

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


TENANT:                                  LANDLORD:

TELEPHONE BUSINESS MEETINGS, INC.        AETNA LIFE INSURANCE COMPANY
dba ACCESS CONFERENCE CALL SERVICE


By:                                      By:
   --------------------------------         --------------------------------

Printed Name:                            Printed Name:
             ----------------------                   ----------------------
Its:                                     Its:
    -------------------------------          -------------------------------
Date:                                    Date:
     ------------------------------           ------------------------------
Attest:                                  Attest:
       ----------------------------             ----------------------------
Printed Name:                            Printed Name:
             ----------------------                   ----------------------
Its:                                     Its:
    -------------------------------          -------------------------------
Date:                                    Date:
     ------------------------------           ------------------------------

                                       60

 
                   EXPANSION AGREEMENT AND AMENDMENT TO LEASE

                                 BY AND BETWEEN

                          AETNA LIFE INSURANCE COMPANY

                                      AND
                                        
                       TELEPHONE BUSINESS MEETINGS, INC.
                       dba ACCESS CONFERENCE CALL SERVICE



                                  EXHIBIT A-1
                                  -----------


    Description of New Premises pursuant to an Amendment to Lease Agreement
dated the ____ day of March, 1995, by and between Aetna Life Insurance Company
and Telephone Business Meetings, Inc. dba Access Conference Call Service:  Five
Thousand Three Hundred Seventy-six (5,376) square feet on the second floor,
located in the 73,685 square-foot building at 1861 Wiehle Avenue, Reston,
Virginia 22090.



                                   [Diagram]

                                       61

 
                                   EXHIBIT B


                 Plans and Specifications for the New Premises


The following are the Standard Improvement Items, the Standard Allowance of each
of which the Landlord shall provide at its expenses as part of the improvements
to be made to the New Premises.

1.  PARTITIONING

    1.1.  Standard interior partitions shall be constructed of one-half inch
(1/2") gypsum drywall on each side of the three and five-eighths inch (3-5/8")
steel studs, from slab to ceiling.  Such drywall shall be taped, spackeled,
finished and painted.

    1.2.  All corridor and demising partitions shall be sound-insulated with 3-
1/2" of batt insulation, finished gypsum drywall, and shall be constructed
according to applicable building code provisions.

    1.3.  The Standard Allowance shall be eighty-three lineal feet of interior
partition and N/A lineal feet of demising partition for each one thousand (1000)
              ---                                                               
square feet of floor area.  All interior standard partitions and one-half of the
demising partitions between the New Premises and other leasable space shall be
charged against such Standard Allowance.

2.  DOORS

    2.1.  Standard interior doors shall be solid-core, paint grade, shall be
painted to match the partitioning, and shall include building standard hardware.
The Standard Allowance shall be one door for each three hundred fifty square
feet of floor area.

    2.2.  Standard suite entrance doors shall be made of solid core wood, and
shall include a building standard lockset.

3.  ELECTRICAL SERVICE

    3.1.  Electric lights shall be three bulb, flush-mounted, energy miser,
fluorescent fixtures having dimensions of two feet (2') by four feet (4'), and
capable of providing seventy (70') foot-candles at desk height.  One light
fixture shall be provided for each eighty-five square feet of floor.

    3.2.  The Standard Allowance shall be one interior wall-mounted duplex, 110-
volt receptacle for each one hundred fifty square feet of floor area, and one
light switch for each three hundred fifty square feet of floor area.

                                       62

 
    3.3.  The Standard Allowance shall not include any special outlet, any
outlet not located on a drywall partition, or any separate circuit, all of which
shall be provided at the Tenant's expense.

4.  FLOOR COVERING

    4.1.  The Landlord shall provide and install carpeting throughout the New
Premises using the Landlord's building standard, type and grade (Wunda Weve-
Centurion Decathlon-Antron III nylon, or equal) of such color as is selected by
the Tenant from the Landlord's standard selections.

    4.2.  The Landlord shall provide a dark brown or black four-inch (4") high
base for each partition covered by the Standard Allowance.

5.  WINDOW COVERING

    The Landlord shall provide for each exterior window architectural narrow
slat venetian blinds of a standard color.

6.  WALL FINISHES

    The Landlord shall provide two (2) coats of paint on all partitions, doors
and columns covered by the Standard Allowance using such paint color as is
selected by the Tenant from the selections provided by the Landlord.

7.  GRAPHICS

    The Landlord shall provide the suite number for the New Premises, using the
Landlord's standard type for the Building.  Any additional lettering requested
by the Tenant shall conform to such standard type and shall be provided at the
Tenant's expense.

8.  CEILING

    8.1.  The Landlord shall provide throughout the New Premises an acoustical
tile ceiling comprised of two-foot (2') by four-foot (4') panels, having an
exposed grid system.

    8.2.  The ceiling shall have a minimum height of eight feet, two inches
(8'2").

9.  HEATING, VENTILATING AND AIR-CONDITIONING SYSTEM

    Tenant will be responsible for all construction costs associated with
changes to existing building heating, ventilation, air conditioning and
electrical systems due to Tenant requirements which exceed or differ from
building standards.

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10. FLOOR LOAD

    Floor load capabilities are designed for normal office space use.  The
Tenant shall notify the Landlord before the preparation of working drawings for
the New Premises of any concentration of floor loads which the Tenant may
desire, and shall bear any additional cost incurred by the Landlord in
accommodating the same.

11. LANDLORD'S CONSTRUCTION OF TENANTS SPACE

    Landlord and Tenant agree that Landlord shall cause the construction of the
improvements to the New Premises in accordance with the plans, design and
specifications prepared by Tenant ("Tenant's Plans"), and the working drawings
prepared by Tenant (i.e., mechanical, electrical and plumbing drawings, the
"Working Drawings").  The Tenant's Plans and Working Drawings shall be prepared
by Tenant and presented to Landlord for approval and review within forty-five
(45) days of the full execution of the Agreement.

    Following the preparation and approval of Tenant's Plans and the Working
Drawings, Landlord agrees to build-out the New Premises as per Tenant's Plans
and the Working Drawings.  All construction for the New Premises shall be
awarded following a competitive bid format, with Trammell Crow Real Estate
Services, Inc. serving as construction manager ("Construction Manager").  The
Construction Manager shall: (1) prepare a bid package approved by Landlord and
Tenant; (2) solicit bids from a minimum of three qualified general contractors
approved by Landlord and Tenant; (3) prepare a bid analysis for review by
Landlord and Tenant; and (4) award the bid to the lowest qualified general
contractor (as approved by Tenant). On behalf of Landlord and Tenant, the
Construction Manager shall supervise the construction for the New Premises,
ensuring that: (1) all construction is performed in a workmanlike manner; (2)
all construction is in compliance with all applicable governmental regulations;
and (3) all construction materials are free of defect (inherent or otherwise).

     (i)   Tenant Allowance.  As a material part of this leasing transaction,
           ----------------                                                  
     Landlord agrees to provide to Tenant an allowance ("Tenant Improvement
     Allowance") of $20.00 per square foot (i.e., a total of 5,376 sf x $20.00
     psf = $107,520.00).  Such Tenant Improvement Allowance shall be usable for,
     but shall not be limited to, the cost of all construction
     documents/drawings, permits, actual construction costs (materials and
     labor), general contractor fees, reasonable (and documented) moving related
     expenses (not to exceed $2.00 per square foot of the total Tenant
     Improvement Allowance), and a five percent (5%) construction management fee
     (such total costs hereinafter referred to as "Tenant Improvement Costs").
     To the extent that the Tenant Improvement Costs exceed the Tenant
     Improvement Allowance (a "Shortfall"), Landlord will bill to Tenant the
     Shortfall in two (2) equal installments, due as follows:  the first
     installment of fifty percent (50%) of the shortfall to be made at the
     commencement of construction, and the second installment of fifty percent
     (50%) upon substantial completion of construction.  To the extent that the
     Tenant Improvement Costs are less than the Tenant Improvement Allowance,
     Landlord shall credit the unused portion of the Tenant Improvement
     Allowance against the first rental payment(s) when due or, at Tenant's sole
                                                            --                  
     option, 

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     Landlord shall place the unused portion of the Tenant Improvement
     Allowance in an interest-bearing account, and Tenant may use said unused
     portion of the Tenant Improvement Allowance for future Tenant Improvements
     within the New Premises.  In all events, ten percent (10%) of the total
     cost of the job will be held back from the general contractor until all
     punch list items are complete, to the reasonable satisfaction of Tenant's
     architect.

     (ii)  Delay in Preparation of Tenant's Plans.  If the Tenant does not
           --------------------------------------                         
     complete preparation of the Tenant's Plans and Working Drawings within the
     time periods specified above, and such delay causes the Landlord to
     postpone substantial completion of the space or delays the Effective Date,
     then Tenant shall pay to Landlord on the date rent would have commenced
     hereunder in the absence of such delay, a sum of money equivalent to the
     Rent for the New Premises for the period during which Tenant would have
     been obligated to pay rent to the Landlord had not the Effective Date been
     so delayed.

     (iii) Changes to the Tenant Plans.  If changes are made by Tenant to the
           ---------------------------                                       
     Tenant's Plans after Landlord's approval, and should these changes to the
     Tenant's Plans cause the Landlord to postpone substantial completion of the
     space or delay the Effective Date, then Landlord shall have the right to
     refuse to permit the making of such changes unless and until Tenant shall
     have committed in writing, in a manner reasonably satisfactory to Landlord,
     to pay to Landlord on the date rent would have been commenced hereunder in
     the absence of such delay, a sum of money equivalent to the Rent for the
     New Premises for the period during which Tenant would have been obligated
     to pay rent to the Landlord had not the Effective Date been so delayed.

     (iv)  Notice.  Tenant shall, by notice to Landlord in writing, designate a
           ------                                                              
     single individual who Tenant agrees shall be available to meet and consult
     with Landlord at the New Premises as Tenant's representative respecting the
     matters which are the subject of this Exhibit and who, as between Landlord
     and Tenant, shall have the power to legally bind Tenant, in making requests
     for changes, giving approval of plans or work, giving directions to the
     Landlord or the like, under this Exhibit.

           Landlord shall, by notice to Tenant in writing, designate a single
     individual who Landlord agrees shall be available to meet and consult with
     Tenant at the New Premises as Landlord's representative respecting the
     matters which are the subject of this Exhibit and who, as between Landlord
     and Tenant, shall have the power to legally bind Landlord, in making
     requests for changes, giving approval of plans or work, giving directions
     to the Tenant or the like, under this Exhibit.

     (v)   Substantial Completion.  For purposes of the Lease, "substantially
           ----------------------                                            
     complete" means full completion, except for minor or insubstantial details
     of construction, decoration or installation.

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     (vi)  Payment.  Any invoice from Landlord not paid by Tenant within 30 days
           -------                                                              
of receipt thereof will be subject to an interest charge at an annual rate equal
to the average prime interest rate published in The Wall Street Journal during
                                                -----------------------       
the period of any such delay in payment.  Said interest and invoice payments are
to be treated by Landlord and Tenant as rent due hereunder.

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