Document:

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                                                                    EXHIBIT 10.8

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                         OFFICE BUILDING LEASE AGREEMENT
                             (FIVE CORPORATE CENTRE)

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LEASE DATE:      December 31, 1999

LANDLORD:        Crescent Resources, Inc., a South Carolina corporation

NOTICE           Post Office Box 1003 [zip code 28201-1003] (If delivered by mail)
ADDRESS OF       400 South Tryon Street, Suite 1300 [zip code 28202] (If personally
LANDLORD:        delivered or delivered by overnight delivery service or telegram)
                 Charlotte, North Carolina
                 Attention:       Treasurer              Telephone: (704) 382-8009
                                                         Facsimile: (704) 382-6385

TENANT:          BlueStar Communications, Inc.

NOTICE           BlueStar Communications, Inc.           (After Lease Commencement
ADDRESS OF       401 Church St., Suite 2400              Address will be Suite 600 of
TENANT:          Nashville, TN 37214                     Five Corporate Centre)

                 Attention: Norton Cutler, Esq.          Telephone: (615) 255-2100
                                                         Facsimile: (615) 346-3875
TENANT'S
CONTACT
PERSON:          Norton Cutler                           Telephone: (615) 255-2100
                                                         Facsimile: (615) 346-3877

BUILDING:        Six (6) story office building known as Five Corporate Centre located
                 on the Land at 801 Crescent Centre Drive, Franklin, Williamson
                 County, Tennessee 37067.

LAND:            That certain tract or parcel of land located in Franklin, Williamson
                 County, Tennessee, and described on Exhibit A attached hereto and
                 incorporated herein by reference.

PREMISES:        Suites 500 and 600 in the Building, as more particularly described
                 on Exhibit B attached hereto and incorporated herein by reference.

NOC
PREMISES:        As shown on exhibit B (4959 square feet)

PREMISES         48,064 square feet located on the following floor(s) in the Building
RENTABLE         and a prorata portion of the common area of such Floors and the
AREA:            Building: Floor Six and a portion of the Floor Five measured in
                 accordance with ANSI/BOMA Z65.1-1996).
                 Common Area factor for multi-tenant floors is 13.5%.
BUILDING         151,833 square feet (measured in accordance with ANSI/BOMA
RENTABLE         Z65.1-1996)
AREA:

LEASE            TERM: Five (5) years and four (4) months, beginning on the Commencement
                 Date. Provided, however, if the Commencement Date is any day other
                 than the first day of a calendar month, the Lease Term shall be
                 extended automatically until midnight on the last day of the
                 calendar month in which the Lease Term otherwise would expire.

RENEWAL          Tenant may renew the Term of this Lease for two (2) five (5) year
TERMS:           terms or one (1) one (1) year term at the end of the original term
                 only upon compliance with the following conditions:
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                     a.   Tenant must give notice of renewal (the "Renewal Notice") to
                          Landlord at least 180 days prior to beginning of a Renewal
                          Term.

                     b.   No Event of Default by Tenant that is not cured within
                          applicable notice and cure periods may exist at the time of
                          giving of the Renewal Notice and/or the beginning of the
                          Renewal Term.

                     c.   Lease must be in full force and effect at the time of the giving
                          of the Renewal Notice and/or the beginning of the Renewal Term.

                     d.   All terms and conditions of original five (5) year term shall
                          apply to each Renewal Term except the Rent shall be as set
                          forth in Exhibit D.

TERM
COMMENCEMENT              May 1, 2000 (but subject to extension as set forth in Section
DATE:                     Two of this Lease)

RENT
COMMENCEMENT
RENT                 September 1, 2000 (intended to be four (4) months [the "Nonpayment
                     Period"] immediately following the Term Commencement Date unless
                     Tenant Delay Factors exist). The Non-payment Period may also be
                     reduced pursuant to Section 2(a) and 2(e)(1) of the Lease.

BASE RENT:           As set forth on Exhibit D.

BASE RENT
ADJUSTMENTS:         As set forth in Exhibit D.

OPERATING
EXPENSE
BASE YEAR:           Year 2000

ELECTRICAL
EXPENSE STOP:        ($0.65) multiplied by the Building Rentable Area, which is a part of
                     the Operating Cost Expense Stop.
ADVANCE
BASE RENTAL
PAYMENT:             N/A.

SECURITY
DEPOSIT:             N/A.

TENANT'S
PROPORTION-
ATE SHARE:           Premises Rentable Area / Building Rentable Area = 31.65%

TENANT
IMPROVEMENT
ALLOWANCE:           $18.00 per rentable square foot contained in the Premises.

TENANT PLANS
AND SPECIFIC-        Plan Submission Deadline: Tenant agrees to cause the construction
ATIONS:              plans for the Tenant Improvements, excluding the NOC) to be
                     submitted to Landlord's engineers not later than January 7, 2000.
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                     NOC Plan Submission Deadline: Tenant agrees to cause the
                     Construction Plans for the Tenant Improvements for its Network
                     Operating Center (the "NOC") to be submitted to Landlord's engineers
                     not later than February 7, 2000.

PARKING
RATIO:               Five (5) space(s) per 1,000 rentable square feet contained in
                     the Premises.

BROKER:              Trammell Crow Company
                     155 Franklin Road - Suite 225
                     Brentwood, TN 37027
                     Agent: Rick Helton
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The foregoing summary (the "Lease Summary") is hereby incorporated into and made
a part of the Lease Agreement. In the event, however, of a conflict between the
terms of the Lease Summary and the terms of the Lease Agreement, the former
shall control.

Initial: ____ (For Landlord)

Initial: ____ (For Tenant)

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                                                          crescent\bluestar.lse

                                      LEASE

1.       LEASE OF PREMISES.

         Landlord (as set forth in the Lease Summary), for and in consideration
of payment of the Rent and the covenants herein to be performed by Tenant (as
set forth in the Lease Summary), does hereby lease unto Tenant and Tenant does
hereby lease from Landlord the Premises upon the following terms and conditions.

2.       TERM.

         (a) The Term of this Lease shall commence on the Term Commencement Date
and Tenant's obligation to pay Base Rent and Additional Rent hereunder shall
commence on the Rent Commencement Date. Improvement Complete shall mean the last
to occur of (1) the Premises having been substantially complete according to
Tenant's plans and specifications (except for punch list items) and Tenant can
move its furniture into the Premises (2) delivery of a certificate of
substantial completion signed by Landlord's architect or (3) delivery of a
Certificate of Occupancy issued by the City of Franklin, Tennessee permitting
furniture installation in the Premises. In the event the Premises are not
Improvement Complete by the Term Commencement Date due to Force Majeure Matters
or Tenant Delay Factors (both as hereinafter defined), Landlord may extend the
time to complete said improvements to the Premises for a period of time equal to
such time as Landlord has been delayed by Force Majeure Matters and/or Tenant
Delay Factors. In the event the Premises are not Improvement Complete in
accordance with the Tenant Plans. In the event Landlord has not caused the
Premises to be Improvement Complete by July 1, 2000, unless Landlord has been
delayed by Tenant Delay Factors, Tenant may terminate this Lease by giving
notice to Landlord not later than August 1, 2000, unless Tenant has taken
occupancy of the Premises. In the event the Term Commencement Date is so
extended, Landlord and Tenant shall execute a supplemental agreement to confirm
the Term Commencement Date once it has been determined. In the event Tenant
occupies the Premises at any time prior to the Term Commencement Date, Tenant's
occupancy shall be subject to all the terms and conditions of this Lease, except
rent payments and payment of Tenant's Proportionate Share of Operating Expenses
both of which shall commence on the Rent Commencement Date. In the event the
Term Commencement Date is extended by Landlord, the parties agree to execute a
Commencement Date Agreement which shall establish the Term Commencement Date and
the Rent Commencement Date so that the Rent Commencement Date is four (4) months
after the Term Commencement Date. The Non-Payment Period shall be reduced by the
period of time equal to the period of time Landlord is delayed in causing the
Premises to be Improvement Complete due to Tenant Delay Factors. The Non-Payment
Period shall be increased by two (2) days for every day after June 1, 2000 that
the Landlord has not caused the Premises to be Improvement Complete as a result
of any reason except for delays caused by Tenant Delay Factors.

         (b) The Tenant shall have the renewal rights as shown in the Lease
Summary.

         (c) "Tenant Delay Factors" shall be defined as delays caused by Tenant,
or Tenant's agents, employees, contractors, subcontractors or licensees
including, but not limited to, failure to deliver Tenant Plans by the required
date as set forth in the Workletter and Lease Summary.

         (d) "Force Majeure Matters" shall be defined as any delays due to any
condition, matter or circumstance beyond the reasonable control of a party
(collectively, "Force Majeure Matters"; each, a "Force Majeure Matter"),
including, without limitation, the following: strikes; unavailability of
materials; lockouts; acts of God; governmental restrictions, war or enemy action
or invasion; civil commotion, insurrection; riot; mob violence; malicious
mischief or sabotage; fire or any other casualty; adverse weather conditions; a
condemnation; failure of a governmental instrumentality to act in a timely
fashion, any litigation or other legal

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proceeding which delays the approval of plans or the issuance of any grading or
building permit for construction, including, without limitation, the issuance of
an injunction enjoining such approval and/or issuance, as the case may be; any
law, order or regulation of any governmental, quasi-governmental, judicial or
military authority; or other similar cause. Without limiting the generality of
the foregoing, in the event a Force Majeure Matter affects Landlord's
construction and delivery obligation(s) relative to the Premises under this
Lease, the Term Commencement Date and Rent Commencement Date shall be extended
by the same number of days as the number of days of delay caused by such Force
Majeure Matter on the critical path of completing such construction and delivery
obligation(s). Except for Tenant's obligations to pay Base Rent, Tenant's
Proportionate Share and any other payments due from Tenant hereunder, the
obligations of both parties under this Lease shall be subject to delays cause by
Force Majeure Matters.

         (e) The Tenant Improvement Allowance shall be applied by Landlord
against the costs of designing, planning and constructing the improvements to
the Premises (the "Tenant Improvements") in accordance with the Tenant Plans
which are to be prepared and approved in accordance with the Workletter attached
as Exhibit C. Landlord shall pay for the cost of the Building Shell Improvements
as described in said Workletter. In the event the cost of the Tenant
Improvements exceed the Tenant Improvement Allowance, Tenant shall be
responsible for bearing and paying such excess costs (the "Excess Costs"), as
follows:

               (1) The Non-Payment Period shall be reduced, and Tenant shall not
         be required to pay Excess Costs until such credit is exhausted.

               (2) After the Premises are Improvement Complete but prior to
         occupancy of the Premises by Tenant, Tenant shall pay to Landlord an
         amount equal to ninety percent (90%) of the Excess Costs (as then
         reasonably estimated by Landlord).

               (3) As soon as the final accounting is prepared and submitted by
         Landlord to Tenant, Tenant shall pay to Landlord the entire unpaid
         balance (less 5% of Excess Costs for punch list items) of the actual
         Excess Costs based on the final costs to Landlord. The aforesaid
         withheld amount shall be promptly paid to Landlord after completion of
         all punch list items.

         The Excess Costs (if any) payable by Tenant under this Paragraph 2(e)
shall be due hereunder at the time specified herein, and failure to make any
such payment when due shall constitute a default of Tenant under this Lease.

         (f) Except as otherwise provided above in this Paragraph 2, all
installations and improvements now or hereafter placed on or in the Premises
shall be for Tenant's account and at Tenant's cost. Tenant shall also pay ad
valorem taxes and increased insurance on or attributable to the Tenant
Improvements (to the extent of the cost of the Tenant Improvements in excess of
the Tenant Improvement Allowance), which cost shall be payable by Tenant to
Landlord as Additional Rent.

3.       RENT.

         (a) Tenant shall pay to Landlord at its principal office, or at such
other address as Landlord shall designate to Tenant in writing from time to
time, the Base Rent set forth on the Lease Summary and in Exhibit D, payable on
the first business day of each calendar month in the monthly installments as set
forth in Exhibit D, in advance, without demand and without set off, except as
expressly permitted herein, beginning as of the Rent Commencement Date and
continuing until the expiration of the Term.

         (b) In the event the Term commences on a day other than the first
business day of a calendar month, the Tenant shall pay to the Landlord, on or
before the Rent Commencement Date, a pro rata portion of the monthly installment
of Base Rent, such pro rata portion to be based on the number of days remaining
in such partial month after the Rent Commencement Date. In event the Term
expires on other than the last business day of a calendar month, the final
month's installment of Base Rent shall be prorated accordingly.

         (c) Tenant hereby further covenants and agrees to pay as and when due,
Additional Rent, as hereinafter set forth. Nonpayment of the same when due shall
constitute a default under this Lease to the same extent, and shall entitle the
Landlord to the same remedies as nonpayment of Base Rent.

         (d) At Landlord's option, if any payment of Base Rent required to be
made by Tenant under the provisions of this Lease is not made by Tenant within
ten (10) days after the due date and Tenant's receipt of written notice of such
non-payment or any other payment that is not made within thirty (30) days of the
due date, Tenant shall pay a one time late charge equal to five percent (5%) of
the amount due. Landlord shall not be required to give Tenant more than two such
notices in any lease year.

4.       TENANT'S PROPORTIONATE SHARE OF OPERATING EXPENSES.

         (a) Beginning as of January 1, 2001, Tenant shall pay Landlord as
Additional Rent a sum equal to Tenant's Proportionate Share (as defined below)
of the amount by which Operating Expenses (as defined below) exceed the
Operating Expenses for the Operating Expense Base Year. If the first and/or last
years of the Term shall not coincide with a calendar year, then Tenant's
Proportionate Share of Operating

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Expenses attributable to the partial calendar year shall be prorated on the
basis of the ratio between the number of days of such partial calendar year and
365. During the Initial Term Controllable Operating Expenses in excess of one
hundred and five percent (105%) of the previous calendar year shall be excluded
from Operating Expenses for the purpose of computing the excess described in the
preceding sentence. "Controllable Operating Expenses" shall mean management fees
and salaries. Landlord agrees to use commercially reasonable efforts to
competitively bid all contracts for services. In addition, any cost incurred by
Landlord in monitoring, reporting, mitigating, removing, encapsulating, or
abating hazardous substances, as defined by laws in effect on the date this
Lease is executed, shall be borne by the Landlord and not included as Operating
Expenses except to the extent that such hazardous substances were placed on the
Premises, Building or Land by the Tenant.

         (b) "Tenant's Proportionate Share" shall mean the percentage set forth
in the Lease Summary. In the event of a mutually agreed change in the size of
the Premises, expansion of the Premises or additions to the Premises, the
calculation of Tenant's Proportionate Share shall be revised appropriately as of
the date of such modification by utilizing the same formula.

         (c) Operating Expenses shall mean and include:

             All expenses relating to the Building, the Land and their common
area and, including all costs of operation, maintenance and management therefor,
ad valorem real estate taxes (excluding interest or penalties for late payment)
and the costs, including, without limitation, of legal and consulting fees, of
contesting or attempting to reduce any of the said taxes (but only to the extent
of the reduction achieved), amortization (in accordance with generally accepted
accounting principles)of capital improvements which are required by applicable
law or which will improve the efficiency of operating, managing or maintaining
the Building or which will reduce Landlord's operating expenses or the rate of
increases thereof, the cost of labor, materials, repairs, insurance, utilities,
and services and such other expenses with respect to the operation, maintenance
and management of the Building, the Land and their common areas, all of which
expenses shall be incurred or paid by or on behalf of Landlord or are properly
chargeable to Landlord's operating expenses in accordance with generally
accepted account principles; as applied to the operation, maintenance and
management of a first class building. The foregoing expenses or costs shall be
grossed up, if necessary, to reflect occupancy of ninety five percent (95%) of
the rentable space in the Building. Provided however, the grossing up of
expenses shall not result in Operating Expenses for the subject year being in
excess of the actual amount of Operating Expenses.

         Notwithstanding the foregoing, Operating Expenses shall not include:

         (1) costs, including marketing costs, legal fees, space planners' fees,
advertising and promotional expenses, and brokerage fees, incurred in connection
with the original construction or development, or original or future leasing, of
the Building, and costs, including permit, license and inspection costs,
incurred with respect to the installation of tenant improvements made for new
tenants in the Building or incurred in renovating or otherwise improving,
decorating, painting or redecorating vacant space for tenants or other occupants
of the Building (excluding, however, such costs relating to any Common Areas or
parking facilities);

         (2) except as otherwise set forth in this subsection, depreciation,
interest and principal payments on mortgages and other debt costs, if any,
penalties and interest, costs of capital repairs and alterations, and costs of
capital improvements and equipment;

         (3) costs for which the Landlord is reimbursed by any tenant or
occupant of the Building (other than pursuant to a provision of such tenant's or
occupant's lease or agreement which otherwise provides that such tenant or
occupant will pay a certain share of such costs) or by any warranty or guaranty
or by insurance by its carrier or any tenant's carrier or by anyone else, and
electric power costs for which any tenant directly contracts with the local
public service company;

         (4) any bad debt loss, rent loss, or reserves for bad debts or rent
loss;

         (5) costs associated with the operation of the business of the entity
which constitutes the Landlord, as the same are distinguished from the costs of
operation of the Property (which shall specifically include, but not be limited
to, accounting costs associated with the operation of the Property). Costs
associated with the operation of the business of the entity which constitutes
the Landlord include costs of corporate accounting and legal matters, costs of
defending any lawsuits with any mortgages (except as the actions of the Tenant
may be in issue), costs of selling, syndicating, financing, mortgaging or
hypothecating any of the Landlord's interest in the Property, and costs incurred
in connection with any disputes between Landlord and its employees between
Landlord and Property management, or between Landlord and other tenants or
occupants, and Landlord's general corporate overhead and general and
administrative expenses;

         (6) the wages and benefits of any employee who does not devote
substantially all of his or her employed time to the Property unless such wages
and benefits are prorated to reflect time spent on operating and managing the
Property vis-s-vis time spent on matters unrelated to operating and managing the
Property; provided, that in no event shall Operating Expenses for purposes of
this Lease include wages and/or benefits attributable to personnel above the
level of Building manager or Building engineer;

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         (7) amount paid as ground rental for the Property by Landlord;

         (8) except for a Property management fee charged by Landlord which will
not exceed the market rate, overhead and profit increment paid to the Landlord
or to subsidiaries or affiliates of the Landlord for services in the Building to
the extent the same exceeds the costs of such services rendered by qualified,
first-class unaffiliated third parties on a competitive basis;

         (9) any compensation paid to clerks, attendants or other persons in
commercial concessions operated by the Landlord;

         (10) rentals and other related expenses incurred in leasing air
conditioning systems, elevators or other equipment which if purchased the cost
of which would be excluded from Operating Expenses as a capital cost under item
(b) above, except equipment not affixed to the Building such as the fitness
center equipment or which is used in providing janitorial or similar services
and, further excepting from this exclusion such equipment rented or leased to
remedy or ameliorate an emergency condition in the Building;

         (11) all items and services for which Tenant or any other tenant in the
Building reimburses Landlord (other than pursuant to a provision of such
tenant's or occupant's lease or agreement which is similar to that provided for
in Article Four hereof or which otherwise provides that such tenant or occupant
will pay a certain share of such costs) or which Landlord provides selectively
to one or more tenants without reimbursement;

         (12) costs, other than those incurred in ordinary maintenance and
repair, for sculpture, paintings, fountains or other objects of art;

         (13) any costs expressly excluded from Operating Expenses elsewhere in
this Lease;

         (14) rent for any office space occupied by Property management
personnel to the extent the size or rental rate of such office space exceeds the
size of fair market rental value of office space occupied by management
personnel of comparable buildings in the vicinity of the Building, with
adjustment where appropriate for the size of the applicable project;

         (15) costs arising from the gross negligence or willful misconduct of
Landlord or its agents, employees, vendors, contractors, or providers of
materials or services;

         (16) costs incurred to comply with laws relating to the removal of
hazardous material (as defined under applicable law) which was in existence in
the Building or on the Property prior to the Commencement Date, and was of such
a nature that a federal, State or municipal governmental authority, if it had
then had knowledge of the presence of such hazardous material, in the state, and
under the conditions that it then existed in the Building or on the Property,
would have then required the removal of such hazardous material or other
remedial or containment action with respect thereto; and costs incurred to
remove, remedy, contain, or treat hazardous material, which hazardous material
is brought into the Building or onto the Property after the date hereof by
Landlord or any tenant of the Building and is of such a nature, at that time,
that a federal, State or municipal governmental authority, if it had then had
knowledge of the presence of such hazardous material, in the state, and under
the conditions, that it then exists in the Building or on the Property, would
have then required the removal of such hazardous material or other remedial or
containment action with respect thereto;

         (17) costs arising from Landlord's charitable or political
contributions;

         (18) any gifts provided to any entity whatsoever, including, but not
limited to, Tenant, other tenants, employees, vendors, contractors, prospective
tenants and agents; and

         (19) the cost of any magazine, newspaper, trade or other subscriptions.

         (20) the cost of correcting defects in the construction, structural
components, design or equipping of the Building or the equipment or mechanical
systems of the Building.

         (21) the cost of repairs or replacements incurred by reason of fire or
other casualty or caused by the exercise of the right of eminent domain
(including pursuant to Section 10 or 11 of this Lease) whether or not insurance
proceeds or a condemnation award are recovered or adequate for such purposes.

         (22) interest, fines or penalties paid by Landlord which are not the
result of action or inaction of Tenant.

         (23) any costs related to asbestos or to causing any part of the
Building to be in compliance with the Americans With Disabilities Act (or other
law relating to handicapped persons) or Occupational and Safety Health Act in
effect on the date this Lease is executed.

If any Operating Expense, though paid in one year, relates to more than one
calendar year, at the option of Landlord such expense may be proportionately
allocated among such related calendar years.

         (d) The Operating Expense Base Year shall be defined as set forth in
the Lease Summary.

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         (e) It is acknowledged and agreed that it will not be possible to
determine the actual amount of the excess (if any) of Operating Expenses for a
given calendar year over Operating Expenses for the Operating Expense Base Year
until after the end of such calendar year. Therefore, until Tenant's liability
for Tenant's Proportionate Share of such excess shall have been finally
determined for a particular calendar year, Tenant shall make payment on account
of such excess as follows:

             (i) Commencing as of January 1, 2001 and continuing throughout
the Term (and any renewal or extension thereof), and subject to the limitation
expressed above, Landlord shall make a good faith estimate of Operating Expenses
for such calendar year and Tenant's Proportionate Share thereof (hereinafter
("Estimated Operating Expenses" and "Tenant's Estimated Proportionate Share"),
and Tenant shall pay to Landlord, as Additional Rent with each monthly
installment of Base Rental, an amount equal to one-twelfth (1/12) of Tenant's
Estimated Proportionate Share of the amount by which Estimated Operating
Expenses for the current calendar year are estimated to exceed the Operating
Cost Expense Stop. Such payments for any partial month shall be paid in advance
at the daily rate equal to the monthly payment divided by the number of days in
the month for which the same is due. On or about December 1 prior to each
calendar year in respect of which Tenant shall be obligated to make payments on
account of excess Operating Expenses during the Term (and any renewal of
extension thereof), Landlord shall furnish to Tenant a statement for such
calendar year of Tenant's Estimated Proportionate Share and of Estimated
Operating Expenses and thereupon, subject to the limitations expressed above, as
of such December 1, Tenant shall make payments under this Paragraph 4(e)(l) in
accordance with such statement.

             (ii) On or before April 1, 2002 and each April 1 thereafter during
the Term (and any renewal or extension thereof), Landlord shall furnish Tenant
with a statement setting forth the total amount of Tenant's Proportionate Share
of the amount by which Operating Expenses for the preceding calendar year
exceeded the Operating Expenses for the Operating Expense Base Year. If any such
statement shall show an overpayment or underpayment of Tenant's Proportionate
Share of excess Operating Expenses for the preceding calendar year, any
overpayment shall be refunded to Tenant or credited against payments due from
Tenant under this Lease, and the full amount of any underpayment shall be paid
to Landlord by Tenant not later than thirty (30) after such statement shall have
been delivered to Tenant.

             (iii) In the event Tenant is required to pay Tenant's Proportionate
Share of Operating Expenses pursuant to this Paragraph 4 Tenant shall have the
right, at Tenant's expense and no more frequently than once per calendar year,
to inspect Landlord's books and records showing Operating Expenses for the
calendar year in question; provided, however, Tenant shall not have the right to
withhold any payments of Tenant's Proportionate Share of excess Operating
Expenses due and payable hereunder the amount of which may be in dispute, and
Tenant must pay the entire amount due and payable hereunder prior to reviewing
Landlord's books and records. In the event Tenant's inspection of Landlord's
books and records reveals a verifiable error in Landlord's computation of
Tenant's Proportionate Share of excess Operating Expenses resulting in an
overpayment by Tenant, Landlord shall reimburse Tenant for such overpayment.
Further, if such inspection reveals an overcharge of more than three percent
(3%), Landlord shall reimburse the cost of such inspection. Landlord's statement
setting forth the total amount of Tenant's Proportionate Share of excess
Operating Expenses furnished to Tenant in accordance with the provisions of this
Paragraph 4 shall be deemed to have been approved by Tenant unless protested by
Tenant in writing within one (1) year after delivery of the Statement or an
amended Statement to Tenant at the Premises.

         (f) Any contest by Landlord of ad valorem real estate taxes shall not
relieve Tenant of the obligation to continue to make payments of Tenant's
Proportionate Share of Operating Expenses during the pendency of such a contest;
provided that promptly upon reduction in the amount of any such taxes, Landlord
shall credit Tenant for Tenant's Proportionate Share of such savings, or refund
the same to Tenant if this Lease has expired or terminated.

         (g) Landlord will at Landlord's expense (not included in the Tenant
Improvement Allowance) install an electrical check meter (a "Check Meter") for
the Premises as part of the Tenant Improvements. The Check Meter will measure
all electricity supplied to the Premises (i) to operate lights and light
fixtures therein, (ii) to operate equipment and fixtures that are connected to
electrical outlets therein and (iii) to operate any HVAC system or unit that
exclusively serves the Premises (or any portion thereof). Landlord shall pay the
local electrical utility company prior to delinquency for the electricity
supplied to the Premises through the Check Meter. Provided, however, in the
event the amount paid by Landlord to the local electrical utility company for
electricity supplied to the Premises (as measured by the Check Meter) for any
given period of time is greater than the allocable portion of the Electrical
Expense Stop (allocated the Premises for the relevant period of time), Landlord
may submit an invoice to Tenant periodically for the cost of such excess
electricity supplied to the Premises and Tenant shall pay the full invoiced
amount (as Additional Rent) to Landlord within thirty (30) days after Tenant's
receipt of each such invoice. The following formula shall be used to determine
the invoice amount for Tenant's excess electrical usage in the Premises:

           Invoice Amount = Total Electrical Costs Per Check Meter - [(Tenant
                            Proportionate Share x Electrical Expense Stop) x
                            (Number of Days in Period / Number of Days in Year)]

For example, presuming (for the purpose of this illustration only) that the
Premises Net Rentable Area is 10,000 square feet, that the Check Meter indicates
$2,000.00 of electricity was supplied to the Premises during a given 90-day
period and that the calendar year in which such 90-day period falls contains 365
days,

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Landlord shall be entitled hereunder to send an invoice to Tenant in the amount
of $566.64 for excess electrical usage in the Premises during such 90-day
period, computed as follows:

              Invoice Amount =    $2,000.00 - [.051 x $98,691.45) x (90 / 365)]
                               =  $2,000.00 - [$5,033.26 x .2466]
                               =  $2,000.00 - $1,241.20
                               =  $758.80

In computing invoices to be sent to Tenant for electricity supplied to the
Premises through the Check Meter, Landlord shall use the same billing rate and
structure as used by the local electrical utility company. Additionally, with
regard to any period of time that Landlord elects to use a Check Meter to bill
Tenant for excess electricity supplied to the Premises, Landlord also shall use
a Check Meter to bill other tenants in the Building for excess electricity
supplied to their respective premises; and in such case, the cost of electricity
supplied to the Premises and to other premises in the Building for which
Landlord separately bills Tenant and other tenants in the Building (i.e., such
electrical costs that exceed the Electrical Expense Stop) shall not be included
in Operating Expenses hereunder. Landlord shall be entitled to bill Tenant
pursuant to this Section 4(g) for excess electrical usage in the Premises
determined by Landlord from time to time during the Lease Term.

         (h) Base Rent and Additional Rent may from time to time be referred to
herein collectively as "Rent".

5.       USE OF PREMISES.

         Tenant shall use and occupy the Premises, only for the following
purposes: general office, network operations, lab space, technical space,
storage and other incidental uses. Tenant shall not use or occupy the Premises
for any other purposes or business without the prior written consent of
Landlord. Tenant covenants and agrees to comply with each of the Rules and
Regulations set forth in Exhibit E. Landlord represents and warrants that any
certificate of occupancy for the Building is not violated by the aforementioned
uses, and that such uses are permitted by all applicable governmental laws,
ordinances, rules and regulations. Landlord acknowledges that Tenant will have
no obligation under this Lease to actually occupy the Premises during the Term.
In the event Tenant fails to occupy the Premises during all or any portion of
the Term or in the event Tenant vacates the Premises prior to the expiration or
earlier termination of this Lease, such action or omission, as the case may be,
shall not constitute an event of default hereunder.

6.       REPAIRS.

         (a) Except as provided herein, Tenant shall keep the interior,
non-structural portions of the Premises in good repair, and Tenant shall upon
the expiration of the term of this Lease, yield and deliver up the Premises in
good and tenantable condition ordinary wear and tear and damage by fire or other
casualty excepted.

         (b) In the event that the Landlord shall reasonably deem it necessary
or be required by any governmental authority to repair, alter, remove,
reconstruct or improve any part of the Premises or of the Building in which the
Premises are located (unless the same result from Tenant's act, neglect, default
or mode of operation and the same is not covered by Landlord's insurance in
which event Tenant shall make all such repairs, alterations and improvements),
then the same shall be made by Landlord at Landlord's sole cost and expense with
reasonable dispatch; provided, however, the making of such repairs, alterations
or improvements shall not interfere with Tenant's use of the Premises or a
reduction of the usable square footage in the Premises.

         (c) Landlord shall (i) operate, manage and maintain the Building as a
first class office building; (ii) provide services to the common areas thereof
in a manner consistent therewith; and (iii) make all repairs necessary to
maintain the Building in good working order and repair, including, without
limitation, repairs that arise out of or relate to (A) the Building systems and
the structural elements of the Building and the Premises (including, but not
limited to, the heating, ventilation, air conditioning, sanitary, water,
electrical power, lighting, sprinkler, elevator and fire safety systems, toilets
and plumbing facilities, floor slabs, walls, roof and exterior architectural
finish); (B) the negligence or wrongful act(s) of Landlord, its agents,
employees or contractors; or (C) Landlord's breach of its obligations under the
Lease.

7.       ALTERATIONS AFTER THE INITIAL IMPROVEMENTS.

         Tenant may make non-structural alterations, additions, repairs,
improvements or changes in or to Premises without the prior written consent of
Landlord. All such alterations, additions or improvements (collectively the
"Additions") made by Tenant, not including moveable office furniture and
equipment, which are attached or affixed to the Premises so as to become an
integral part thereof shall become a part of the Premises when made. Tenant
agrees to hold Landlord forever harmless from any and all claims and liabilities
(except those arising out of Landlord's sole negligence or willful misconduct)
which may arise out of or be connected with said improvements, alterations or
additions and agrees that if any contractor,

                                       6
<PAGE>   10

subcontractor or materialmen's lien is filed against the Premises or the Land
and Building as a result of Tenant's Additions or other work, Tenant shall cause
the same to be discharged within thirty (30) days after the same are filed. All
such improvements, alterations, additions or installations shall comply with all
insurance requirements and with all laws, ordinances, rules and regulations of
all Governmental Authorities.

8.       ASSIGNMENT AND SUBLETTING.

         (a) Tenant shall not assign or transfer, this Lease or sublet all or
any part of Premises without having received Landlord's prior written consent,
which consent shall not be withheld by Landlord if the assignee or subtenant is
compatible with the tenant mix of a Class A office building in Landlord's
reasonable discretion. Provided however, Tenant shall have the right to assign
or transfer this Lease, or sublet all or any part of the Premises, to a parent,
affiliate or subsidiary of Tenant or to an entity acquiring all or substantially
all of the assets of Tenant or in connection with a merger or consolidation
without the prior written consent of Landlord. No such written consent or
approval, if granted, shall be deemed to permit any subsequent assignment or
subletting.

         (b) Regardless of Landlord's consent, no subletting or assignment shall
release Tenant of Tenant's obligation or alter the primary liability of Tenant
to pay Base Rent, Tenant's Proportionate Share and Additional Rent and to
perform all other obligations to be performed by Tenant hereunder. The
acceptance of rental by Landlord from any other person shall not be deemed to be
a waiver by Landlord of any provision hereof. In the event of default by any
assignee of Tenant or any successor of Tenant in the performance of any of the
terms hereof, Landlord may proceed directly against Tenant without the necessity
of exhausting remedies against such assignee or successor. Landlord may consent
to subsequent assignment or subletting of this Lease or amendments or
modifications to this Lease with assignees of Tenant, without notifying Tenant,
or any successor of Tenant, and without obtaining its or their consent thereto
and such action shall not relieve Tenant of liability under this Lease. Tenant
shall be entitled to retain all profit from any permitted assignment or
subletting.

9.       INDEMNIFICATION AND TENANT'S LIABILITY INSURANCE.

         (a) Each party shall indemnify and hold harmless the other party from
and against any and all costs, expenses, (including reasonable counsel fees),
liabilities, losses, damages, suits, actions, fines, penalties, claims or
demands of any kind and asserted by or on behalf of any person or Governmental
Authority, arising out of or in any way connected with, and neither party shall
not be liable to the other on account of (i) any failure by the other party to
perform any of the agreements, terms, covenants or conditions of this Lease
required to be performed by the other party (ii) any failure by the other party
to comply with any statutes, ordinances, regulations or orders of any
Governmental Authority, or (iii) any accident, death, or personal injury, or
damage to or loss or theft of property, which shall occur in or about the
Premises occasioned wholly or in part by reason of any act or omission of
Tenant, its agents, contractors, licensees, invitees or employees.

         (b) During the term of this Lease or any renewal thereof, Tenant shall
obtain and promptly pay all premiums for general public liability insurance
against claims for personal injury, death or property damage occurring upon, in
or about the Premises with carriers and in amounts reasonably satisfactory to
Landlord but with minimum limits of not less than One Million Dollars
($1,000,000.00) combined single limit on account of bodily injuries or death or
damage to property and all such policies and renewals thereof shall name the
Landlord and any mortgagee of Landlord and the Tenant as additional insureds.
All policies of insurance shall provide (i) that no material change or
cancellation of said policies shall be made without thirty (30) days' prior
written notice to Landlord and Tenant, (ii) that any loss shall be payable
notwithstanding any act or negligence of the Tenant or the Landlord which might
otherwise result in the forfeiture of said insurance, and (iii) that the
insurance company issuing the same shall not have right of subrogation against
the Landlord or Landlord's insurer. On or before the Term Commencement Date of
the term of this Lease, and thereafter not less than fifteen (15) days prior to
the expiration dates of said policy or policies, Tenant shall provide copies of
policies or certificates of insurance evidencing coverages required by this
Lease. All the insurance required under this Lease shall be issued by insurance
companies authorized to do business in the State of Tennessee and reasonably
acceptable to Landlord.

10.      FIRE OR OTHER CASUALTY.

         (a) If the Premises are partially damaged by fire or other casualty so
that the Premises are not materially unusable by Tenant, the damages shall be
repaired by Landlord and until such repairs shall be substantially completed,
and Rent shall be abated proportionately from the date of such fire or other
casualty according to the part of the Premises which is unusable by Tenant.
Landlord agrees to repair such damage within a reasonable period of time after
receipt of notice of such damage, subject to any delays caused by Force Majeure
Matters. Landlord shall notify Tenant within thirty (30) days following the date
of the casualty of (i) the estimated repair period; and (ii) if Landlord is
entitled to terminate this Lease, whether Landlord elects to do so.

         (b) Any thing above to the contrary notwithstanding, if the Premises or
Building are damaged by fire or other casualty and, are rendered substantially
unusable by reason of such fire or other casualty

                                       7
<PAGE>   11
and such damage cannot be repaired using reasonable diligence within one hundred
and twenty (120) days either Landlord or Tenant shall have the right to
terminate this Lease. Said right shall be exercised by notice in writing
delivered to Tenant within thirty (30) days from and after notice from the
Landlord to Tenant of the amount of time to restore, to terminate this Lease. In
such event, this Lease and the tenancy hereby created shall cease as of the date
of said casualty. Tenant shall also have the right to terminate this Lease if
Landlord does not fully restore the Premises within one hundred eighty (180)
days following the casualty, or if the Premises are rendered untenantable within
the last twelve (12) months of the Term.

         (c) Landlord's liability for the repair of damage resulting from fire
or other casualty shall not exceed in any event the amount of insurance proceeds
actually paid to Landlord by the insurance carrier free and prorated between all
tenants of the Building whose leased premises have suffered damage. Landlord
shall not be liable for any inconvenience or annoyance to Tenant or injury to
the business of Tenant resulting in any way from such damage or the repair
thereof, provided Landlord used reasonable efforts to complete said restoration
in a manner which causes as little inconvenience to Tenant as necessary under
the circumstances.

11.      CONDEMNATION.

         (a) If the entire Building and Land, any portion thereof which includes
a substantial part of the Premises or such portions which prevent the operation
of the Building on a financially sound basis, shall be taken or condemned by any
condemning authority for any public use or purpose, or should be sold in lieu of
condemnation or if Tenant reasonably determines that it cannot operate its
corporate headquarters and operations from the remaining Premises the term of
this Lease shall end upon, and not before, the date when the possession of the
part so taken shall be required for such use or purpose, and without
apportionment of the condemnation award which shall be the sole property of the
Landlord. Tenant expressly subordinates its interest in any award to the right
of any first deed of trust holder to have its indebtedness satisfied from said
award.

         (b) If this Lease is not so terminated upon any such taking or sale and
if a portion of the Premises is affected thereby, the Base Rent payable
hereunder shall be diminished by an equitable amount, and Landlord shall, to the
extent Landlord deems feasible, restore the Building and the Premises to
substantially their former condition, except Landlord's obligation to restore
shall not exceed the amount of condemnation proceeds actually received by
Landlord and prorated between all tenants of the Building whose leased premises
have been damaged.

         (c) To the extent Tenant can make a separate claim from the condemning
authority (and not reduce the amount of Landlord's award), Tenant may claim and
receive therefrom Tenant's moving expenses, and the value of Tenant's fixtures
and improvements. Tenant waives any claim it may have for the value of the
unexpired term of this Lease.

12.      QUIET ENJOYMENT.

         If and so long as Tenant pays the Rent reserved hereunder and other
sums due hereunder and observes and performs all of the covenants, conditions
and provisions on Tenant's part to be observed and performed hereunder within
applicable notice and cure periods, Tenant shall and may peaceably and quietly
have, hold and enjoy the Premises for the entire term hereof, subject to all
provisions of this Lease.

13.      SUBORDINATION AND ATTORNMENT.

         Without limitation of any of the provisions of this Lease, and provided
Tenant's possession during the Term shall not be distributed so long as Tenant
is not in default under the terms hereof, this Lease is subject and subordinate
to all first mortgages or deeds of trust which may now or hereafter affect the
real property of which the Premises form a part, and to all renewals,
modification, consolidations, replacements and extensions thereof unless
otherwise required by any mortgagee or beneficiary under any deed of trust or
ground lessor. Upon the written request of any such owner, purchaser, lessor or
mortgagee, or beneficiary (the "Beneficiary") under any deed of trust, Tenant
agrees to execute a subordination non-disturbance and attornment agreement
confirming such subordination provided the Beneficiary agrees not to disturb
Tenant's possession during the term of this Lease so long as Tenant is not in
default under the terms hereof. Landlord warrants no mortgages or deeds of trust
currently encumber the Building.

14.      WAIVER OF CLAIMS.

         Unless caused by their negligence, willful misconduct or breach of this
Lease, Landlord and Landlord's agents, servants, and employees shall not be
liable for, and Tenant hereby releases and relieves Landlord, its agents,
servants, and employees from all liability in connection with any and all loss
of life, personal injury, damage to or loss of property, or invitees, licensees,
visitors, or any other person, firm, corporation or entity, in or about or
arising out of, in or upon the Premises, the Building, or the Land.

15.      LANDLORD'S OBLIGATIONS.

         Landlord's obligations hereunder shall be binding upon Landlord only
for the period of time that Landlord is in ownership of the Building; and upon
termination of that ownership, Tenant, except as to any

                                       8

<PAGE>   12

obligations which have then matured, shall look solely to Landlord's successor
in interest in the Building for the satisfaction of each and every obligation of
Landlord hereunder provided such successor assumes in writing the obligations of
Landlord. Landlord shall provide the Cleaning and Janitorial Services set forth
in Exhibit G and the services set forth on Exhibit H.

16.      WAIVER.

         The failure or delay on the part of either party to enforce or exercise
at any time any of the provisions, rights or remedies in this Lease shall in no
way be construed to be a waiver thereof, nor in any way to affect the validity
of this Lease or any part hereof, or the right of the party to thereafter
enforce each and every such provision, right or remedy. No waiver of any breach
of this Lease shall be held to be a waiver of any other or subsequent breach.
The receipt by Landlord of Rent, or any other payment by Tenant at a time when
the Rent or the payment of any other sum due hereunder is in default under this
Lease shall not be construed as a waiver of such default. The receipt by
Landlord of a lesser amount than the Rent or any other sum due shall not be
construed to be other than a payment on account of the Rent or any other sums
then due, which may be applied in such manner as Landlord deems appropriate, nor
shall any statement on Tenant's check or any letter accompanying Tenant's check
be deemed an accord and satisfaction. Landlord may accept any such payment
without prejudice to Landlord's right to recover the balance of the Rent due or
to pursue any other remedies provided in this Lease. No act or thing done by
Landlord or Landlord's agents or employees during the Term of this Lease shall
be deemed an acceptance of a surrender of the Premises, and no agreement to
accept such a surrender shall be valid unless in writing and signed by the
Landlord.

17.      DEFAULTS AND REMEDIES.

         All rights and remedies of Landlord herein enumerated shall be
cumulative, and none shall exclude any other rights or remedies allowed by law
or in equity. The occurrence of any of the following shall constitute a default
and breach of this Lease by Tenant:

         (a) Tenant shall fail, neglect or refuse to pay any installment of Base
Rent promptly within ten (10) days of receipt of Landlord's written notice
(which notice Landlord will not be required to provide more than two times in
any Lease Year, or to pay any other monies agreed to by it to be paid promptly
when and as the same shall become due and payable under the terms hereof; or if

         (b) Tenant shall fail, neglect or refuse to keep and perform any of the
other covenants, conditions, stipulations or agreements herein contained, and
such default shall continue for a period of more than thirty (30) days after
notice thereof is given in writing to Tenant by Landlord (provided, however,
that if the cause for giving such notice involves the making of repairs or other
matters reasonably requiring a longer period of time than said thirty (30) day
period, Tenant shall be deemed to have complied with such notice so long as it
has commenced to comply with said notice within said thirty (30) day period and
is diligently prosecuting compliance of said notice);

         In the event of any such default or breach of this Lease by Tenant,
Landlord have any or all of the remedies hereunder set forth, and further, in
the event of such default or breach of this Lease by Tenant, the Tenant does
hereby authorize and fully empower Landlord or Landlord's agent to cancel or
annul this Lease at once and re-enter the Premises and remove all persons and
their property therein, and such property may be stored in a public warehouse or
elsewhere at the cost of the Tenant, all without service of notice or resort to
legal process and without being deemed guilty of any manner of trespass and
without prejudice to any remedies which might otherwise be used by Landlord. The
foregoing rights reserved to Landlord may be exercised by Landlord only to the
extent permitted by applicable law.

         The Landlord may, however, at its option at any time after Tenant's
default re-enter and take possession of said Premises and remove any property
contained therein without such re-entry working a forfeiture of the Rents to be
paid and the covenants, agreements and conditions to be kept and performed by
Tenant for the full term of this Lease. In such event, Landlord shall have the
right, but not the obligation, to divide or subdivide the Premises in any manner
Landlord may determine and to lease or let the same or portions thereof for such
periods of time and at such rentals and for such use and upon such covenants and
conditions as Landlord may elect at its sole discretion, applying the net
rentals from such letting first to the payment of Landlord's expense incurred in
dispossessing Tenant, including, without limitation, reasonable attorney fees,
and the cost and expense of making such improvements, alterations and repairs in
the Premises as may be necessary in order to enable Landlord to re-let the same,
and to the payment of any brokerage commissions or other necessary expenses of
Landlord in connection with such re-letting. The balance, if any, shall be
applied by Landlord, from time to time, on account of the payments due or
payable by Tenant hereunder with the right reserved to Landlord to bring such
action or proceedings for the recovery of any deficits remaining unpaid as
Landlord may deem favorable from time to time without obligation to await the
end of the term hereof for the final determination of Tenant's account. The
failure of Landlord to re-let the Premises or any part or parts thereof shall
not release or affect Tenant's liability for damages. Landlord may make such
alterations, repairs, replacements and/or decorations in the Premises as
Landlord, in Landlord's sole judgment, considers advisable and necessary for the
purpose of re-letting the Premises; and the making of such alterations, repairs,
replacements, and/or decorations shall not operate or be construed to release
Tenant from liability hereunder as aforesaid. In any actions or proceedings
against

                                       9
<PAGE>   13
Tenant for any of the above deficits or "Final Damages", Landlord shall be
entitled to recover reasonable attorneys fees incurred.

             Any balance remaining, however, after full payment and liquidation
of Landlord's account as aforesaid, shall be paid to Tenant with the right
reserved to Landlord at any time to give notice in writing to Tenant of
Landlord's election to cancel and terminate this Lease and require Tenant to pay
"Final Damages" upon the giving of such notice and the simultaneous payment by
Tenant to Landlord of "Final Damages" this Lease shall and the obligations
thereunder on the part of either party to the other shall terminate.

             "Final Damages" means the present worth of the amount by which
"Final Credits" exceeds "Final Debits." "Final Credits" means the annual rent
that would have been payable from the date on which the above election is
exercised to the date on which the term of this Lease would have expired if this
Lease had not been terminated. "Final Debits" means the fair rental value of the
Premises for the same period. Present worth shall be discounted at a rate equal
to the "Base Rate" on the date on which the election is exercised. The discount
shall be compounded monthly. The "Base Rate" means the Base Rate of SunTrust
Bank of Tennessee ("SunTrust") (or its successor) as publicly announced from
time to time. If SunTrust ceases to publicly announce its base rate, the Base
Rate shall be the average prime rate on short term business loans for the month
prior to the month in which the option is exercised as set forth in the Federal
Reserve Statistical Release published by the Board of Governors of the Federal
Reserve System.

         Anything herein to the contrary notwithstanding, nothing herein shall
be construed to cause a waiver of any rights or defenses available to Tenant.
Landlord shall use reasonable efforts to mitigate its damages.

         All payments due under this Lease shall be deemed to be due and payable
by Tenant to Landlord with interest thereon from the date that is ten (10) days
after when the particular amount became due to the date of payment thereof to
Landlord. The aforesaid interest shall be the lesser of highest legal rate then
in effect in the State of Tennessee or the "Prime Rate" quoted by the Wall
Street Journal plus two percent (2%) but not more than the maximum permitted by
applicable law.

         The term "business day" as used herein shall exclude Saturdays,
Sundays, and any holiday observed by federally chartered banks in the United
States.

18.      BANKRUPTCY.

         (a) If there shall be filed against Tenant, in any court, pursuant to
any statute, either of the United States or of any state, a petition in
bankruptcy or insolvency or for reorganization or for the appointment of a
receiver or trustee of all or any portion of Tenant's property and Tenant fails
to secure a discharge thereof within ninety (90) days from the date of such
filing, or if Tenant shall voluntarily file any such petition nor make an
assignment for the benefit of creditors or petition for or enter into an
arrangement, then, in any of such events, this Lease, at the option of Landlord,
may be canceled and terminated without service of notice or resort to legal
process. In the event of a termination of this Lease pursuant to this Paragraph,
neither Tenant nor any person claiming through or under Tenant (whether by
virtue of any statute or any order of any court or otherwise) shall be entitled
to acquire or remain in possession of the Premises, as the case may be, and
Landlord shall have no further liability hereunder to Tenant or any other person
and Tenant or any other such person shall forthwith quit and surrender the
Premises. If this Lease shall be so canceled or terminated, Landlord, in
addition to the other rights and remedies of Landlord contained elsewhere in
this Lease, or under any statute or rule of law, may retain as liquidated
damages any Rent, security deposit and any other money received by Landlord from
Tenant or others on behalf of Tenant.

         (b) In the event of a proceeding involving Tenant under the Bankruptcy
Code, 11 U.S.A 101 et seq., if this Lease is assumed by Tenant's trustee in
bankruptcy (after such trustee has cured all existing defaults, compensated
Landlord for any loss resulting therefrom and provided adequate assurance of
future performance), then this Lease may not be assigned by the trustee to a
third party, unless such party (a) executes and delivers to Landlord an
agreement in recordable form whereby such party assumes and agrees with Landlord
to discharge all obligations of Tenant under this Lease, including, without
limitation, the provisions of Paragraph 7 relating to the permitted use of the
Premises and the manner of operation thereof; (b) has a net worth and operating
experience at least comparable to that possessed by Tenant named herein as of
the execution of this Lease; and (c) grants Landlord, to secure the performance
of such party's obligations under this Lease, a security interest in such
party's merchandise, inventory, personal property, fixtures, furnishings, and
accounts receivable (and the proceeds of all of the foregoing) with respect to
its operations in the Premises, and in connection therewith, such party shall
execute such security agreements, financing statements and other documents (the
forms of which are to be designated by Landlord) as are necessary to perfect
such lien.

19.      TENANT'S REMEDIES.

         In the event Landlord shall fail to perform any of its obligations
hereunder, including without limitation, general building appearance,
maintenance and structural repairs, Tenant shall be entitled to perform such
repairs and maintenance as is reasonably necessary and appropriate in order to
cause compliance with Landlord's obligations provided Tenant has first given
Landlord thirty (30) days' written notice or in the event of emergency repairs
or maintenance, such written notice as is reasonable or available

                                       10
<PAGE>   14
under the circumstances, but not less than twenty-four (24) hours. Landlord
agrees to reimburse Tenant for the cost and expenses incurred by Tenant in
effecting such repairs or maintenance within ten (10) days of the time that
Tenant submits a written claim for reimbursement to Landlord. Upon Landlord's
failure to so reimburse Tenant within said time period, such reimbursement shall
accrue interest from the date thereof at a rate per annum equal to the maximum
rate permitted in the State of Tennessee. The foregoing remedies of Tenant shall
be in addition to all other remedies which Tenant may have.

20.      HOLDING OVER.

         In the event Tenant shall fail to surrender possession of the Premises
upon the expiration or sooner termination of this Lease, Tenant shall, at the
Landlord's sole option, be deemed to be occupying the Premises as a tenant from
month to month and shall pay to Landlord, as an occupancy charge, an amount
equal to the sum of 150% of the Base Rent and Tenant's Proportionate Share of
Operating Expenses, paid during the last month prior to the expiration or
earlier termination of this Lease; provided, however, in such event Tenant shall
not be released from any further direct costs, damages or liabilities suffered
by Landlord and occasioned by Tenant's holding over, and Tenant agrees to
indemnify and hold Landlord harmless therefor.

21.      ENTIRE AGREEMENT.

         This Lease shall constitute the entire agreement of the parties hereto;
all prior agreements between the parties, whether written or oral, are merged
herein and shall be of no force and effect. This Lease cannot be changed,
modified, or discharged orally, but only by an agreement in writing, signed by
the party against whom enforcement of the change, modification, or discharge is
sought.

22.      NOTICES.

         Wherever in this Lease it shall be required or permitted that notice or
demand be given or secured by either party to this Lease to or on the other
party, such notice or demand shall be deemed to have been duly given or served
if in writing and either personally served, sent by private carrier such as
"Federal Express" or forwarded by Registered or Certified Mail, return receipt
requested, postage prepaid, and addressed as set forth in the Lease Summary.

         Each such personally served or private carrier delivered notice shall
be deemed to have been given to or served upon the party to which addressed on
the date the same is received. Each such mailed notice shall be deemed to have
been given to or served upon the party to which addressed on the date which is
three (3) business days after deposit in the United States mail or the next day
if sent by nationally recognized overnight courier. Either party hereto may
change its address to which said notice shall be delivered or mailed by giving
written notice of such change to the other party hereto, as herein provided.

         Tenant agrees to use reasonable efforts to send to Landlord's Mortgagee
copies of all notices to Landlord provided Landlord shall have first given
Tenant the name and address of such mortgagee to receive the same.

23.      SUCCESSORS.

         The respective rights and obligations provided in this Lease shall bind
and shall inure to the benefit of the parties hereto, their legal
representatives, heirs, successors and assigns; provided, however, that no
rights shall inure to the benefit of any successor, subtenant or assignee of
Tenant unless Landlord's written consent for the transfer to such successor,
assignee or subtenant has first been obtained as provided in this Lease.

24.      PARKING COMMON AREAS.

         (a) During the Lease Term, Tenant shall have, without charge, the
non-exclusive right to use, in common with Landlord, other tenants of the
Building, and their respective guests and invitees, the automobile parking
areas, driveways, and footways located on the Land. Notwithstanding the terms
and provisions in the immediately preceding sentence, Tenant and Tenant's guests
and invitees shall not, at any given time, be entitled to use more than Parking
Ratio as set forth in the Lease Summary. Landlord shall maintain such Parking
Ratio during the term of this Lease. Landlord shall not grant any reserved
parking rights to any party.

         (b) As used in this Lease, "Common Areas" shall mean the hallways,
entryways, stairs, elevators, driveways, parking areas, sidewalks, walkways,
loading areas, rest rooms, and all other non-leased areas and facilities in and
about the Building and the Land. Landlord grants Tenant, its employees,
invitees, licensees and visitors a non-exclusive license for the Term of this
Lease to use the Common Areas with others, subject to the terms and conditions
of this Lease.

                                       11

<PAGE>   15
25.      LANDLORD'S INSURANCE.

         Landlord shall, at its sole cost and expense, procure and keep in full
force and effect throughout the term of this Lease, insurance covering the
Building in which the Premises are located. Said insurance shall be equal to the
full replacement cost of the Building, insuring the Building against loss by
fire or other casualty with standard causes of loss special form coverage. Said
insurance shall include "loss of rent" insurance for a period of six (6) months
and shall include the rent due from Tenant for said period under this Lease and
of all other Tenants in the Building. Said insurance shall be purchased from an
insurance company or companies licensed to do business in the State of Tennessee
and shall insure Landlord, Landlord's mortgagee, and the tenants of the
Building, including Tenant, as their interests may appear. Each such policy
shall provide for thirty (30) days' written notice to Tenant and Landlord's
mortgagee of any cancellation.

         Landlord and Tenant shall each cause the respective insurance policies
procured by either of them covering the Building (as to Landlord) and the
Premises and their contents (as to Tenant) to be written in a manner so as to
provide the insuring company waives all right of recovery by way of subrogation
against Landlord or Tenant, as the case may be, in connection with any loss of,
or damage covered by, such policies. Landlord shall also have the right to
terminate this Lease if Landlord does not fully restore the Premises within one
hundred eighty (180) days following a fir or other casualty, or if the Premises
are rendered untenantable within last the twelve (12) months of the Term.
Landlord shall also maintain at all times during the Term, commercial general
liability insurance, including contractual liability, in respect of the Building
and all systems and facilities and the conduct or operation of business therein
and thereon, with Tenant as additional insured, with limits of not less than
Three Million Dollars ($3,000,000) combined single limit for bodily injury and
property damage liability in any one occurrence, and (ii) worker's compensation
insurance in statutory limits.

26.      HAZARDOUS SUBSTANCES.

         (a) The term "Hazardous Substances," as used in this Lease, shall
include, without limitation, flammables, explosives, radioactive materials,
asbestos, polychlorinated biphenyls (PCBs), chemicals known to cause cancer or
reproductive toxicity, pollutants, contaminants, hazardous wastes, toxic
substances or related materials, petroleum and petroleum products, and
substances declared to be hazardous or toxic under any law or regulation now or
hereafter enacted or promulgated by any governmental authority.

         (b) Tenant shall not cause or permit to occur, any violation of any
federal, state, or local law, ordinance, or regulation now or hereafter enacted,
related to environmental conditions on, under, or about the Premises, or arising
from Tenant's use or occupancy of the Premises, including but not limited to,
soil and ground water conditions; or

         (c) Tenant shall not use, generate, release, manufacture, refine,
produce, process, store, or dispose of any Hazardous Substance on, under, or
about the Premises, or the transportation to or from the Premises of any
Hazardous Substance except for normal office supplies and except as specifically
disclosed in this Lease.

         (d) Tenant shall, at Tenant's own expense, comply with all laws
regulating the use, generation, storage, transportation, or disposal of
Hazardous Substances ("Laws").

         (e) Tenant shall, at Tenant's own expense, make all submissions to,
provide all information required by, and comply with all requirements of all
governmental authorities (the "Authorities") under the laws.

         (f) Should any Authority or any third party demand that a cleanup plan
be prepared and that a cleanup be undertaken because of any deposit, spill,
discharge, or other releases of Hazardous Substances that occurs during the term
of this Lease, at or from the Premises, and which arises at any time from
Tenant's use or occupancy of the Premises, then Tenant shall, at Tenant's own
expense, prepare and submit the required plans and all related bonds and other
financial assurances; and Tenant shall carry out all such cleanup plans.

         (g) Tenant shall promptly provide all information regarding the use,
generation, storage, transportation, or disposal of Hazardous Substances that is
requested by Landlord. If Tenant fails to fulfill any duty imposed under this
Paragraph (d) within a reasonable time, Landlord may do so; and in such case,
Tenant shall cooperate with Landlord in order to prepare all documents Landlord
deems necessary or appropriate to determine the applicability of the Laws to the
Premises and Tenant's use thereof, and for compliance therewith, and Tenant
shall execute all documents promptly upon Landlord's request. No such action by
Landlord and no attempt made by Landlord to mitigate damages under any Law shall
constitute a waiver of any of Tenant's obligations under this Paragraph (g).

         (h) Tenant shall indemnify, defend, and hold harmless Landlord, the
manager of the property, and their respective officers, directors,
beneficiaries, shareholders, partners, agents, and employees from all fines,
suits, procedures, claims, and actions of every kind, and all costs associated
therewith (including attorney's and consultants' fees) arising out of or in any
way connected with any deposit, spill, discharge, or other release of Hazardous
Substances that occurs during the term of this Lease, at or from the Premises,
and which arises at any time from Tenant's use or occupancy of the Premises, or
from Tenant's failure to provide all information, make all submissions, and take
all steps required by all Authorities under the Laws and all other environmental
laws.

                                       12
<PAGE>   16
         (i) Landlord represents there is no asbestos in or about the Premises
or the structural common areas of the Property. Anything in this Lease to the
contrary notwithstanding, unless the same shall arise for reason of the acts or
omissions of Tenant, Tenant shall not be responsible for and shall bear no costs
of sampling and cleanup required of any hazardous material relating to any
portion of the Property and Landlord agrees to indemnify and hold Tenant
harmless therefrom.

         (j) The obligations and liabilities under this Paragraph 26 shall
survive the expiration of this Lease.

27.      NEGATIVE COVENANTS OF TENANT.

         Tenant agrees that it will not do or suffer to be done, any act, matter
or thing actually known to Tenant as objectionable to the fire insurance
companies whereby the fire insurance or any other insurance now in force or
hereafter to be placed on the Premises or any part thereof, or on the Building
of which the Premises may be a part, shall become void or suspended, or whereby
the same shall be rated as a more hazardous risk than at the date when Tenant
received possession hereunder, Tenant agrees to pay to Landlord as Additional
Rent, payable upon demand, any and all increase or increases in premiums on
insurance carried by on the Premises, or any part thereof, or on the Building,
caused in any way by the Tenant's use of the Premises for uses other than
general office uses. Tenant also agrees that it will not place upon or load any
floor of the Building exceeding the load for which the Building was designed
unless it first obtains the prior written consent of the Landlord. Such consent
may be conditioned upon the payment by the Tenant all sums which may be
necessary for any excess of consumption of water and/or electricity as may be
occasioned by the operation of said equipment or machinery. Tenant shall not
install any other equipment of any kind or nature whatsoever which will or may
necessitate any changes, replacements, or additions to or require the use of the
water system, plumbing system, heating system, air conditioning system or the
electrical system of the Premises without the prior written consent of the
Landlord.

28.      EMERGENCY REPAIRS.

         Landlord reserves the right to stop services on the heating, air
conditioning, elevator, plumbing and electrical systems, when in Landlord's
reasonable judgment, the same is deemed necessary by reason of accident,
emergency or for repairs, alterations, replacements or improvements thereto
provided that except in case of emergency, Landlord will notify Tenant in
advance, if possible, of any such stoppage and, if ascertainable, its estimated
duration, and will proceed with the work necessary to resume such service as
promptly as possible and in a manner and at times, including after business
hours, so as not to unduly interfere with or impair the Tenant's use and
enjoyment of the Premises.

         If, for any reason, there is a failure to furnish the facilities,
utilities or services specified in this Lease or a condition exists which
interferes substantially with or prevents Tenant's normal use of the Premises or
any part thereof and Landlord does not immediately commence action restore same
or if so commenced, does not continue such action with reasonable diligence
until same are restored, then, in any such event, and upon the giving of five
(5) days' written notice to Landlord, Tenant shall have the option to furnish
such facilities, utilities, or services for its own account as may reasonably,
under the circumstances, be obtained by Tenant, and Tenant may deduct the cost
thereof from the rent due hereunder. If such interruption of service shall
continue for five (5) consecutive days, the Rent and Additional Rent shall
abate, based upon the portion or portions of the Premises affected by such
interruption of service and the degree of adverse effect of the interruption
upon the normal conduct of Tenant's business at the Premises, until such
interruption is remedied. If any such interruption of service shall continue for
more than thirty (30) consecutive days, Tenant may, by written notice to
Landlord given at any time prior to the resumption of service to a reasonable
level, terminate this Lease, and, upon the giving of such notice, this Lease
shall terminate and expire on the date set forth in such notice, which date
shall not be more than ninety (90) days after the date of such notice.

         Except in the case of an emergency, Landlord will give Tenant at least
four (4) days prior notice if Landlord intends to interrupt any services
required to be furnished by Landlord.

         The foregoing interpretation of or failure to provide services shall
not apply to failure of a provider of utilities to provide the same to the
Building unless it results from some action or inaction of Landlord.

29.      ACCESS TO PREMISES.

         Landlord, its employees and agents shall have the right to enter the
Premises at all reasonable times (upon prior notice except in emergency) for the
purpose of examining or inspecting the same, showing the same to prospective
purchasers, mortgagees or tenants, and making such alterations, repairs,
improvements or additions to the Premises or to the Building as Landlord may
deem necessary or desirable. If representatives of Tenant shall not be present
to open and permit entry into the Premises at any time when such entry by
Landlord is necessary or permitted hereunder, Landlord, its employees and agents
may enter by means of a master key (or forcibly in the event of an emergency)
without liability to Tenant and without such entry constituting an eviction of
Tenant or termination of this Lease. In the exercise of Landlord's rights
hereunder, Landlord shall use reasonable efforts not to disrupt the operation of
Tenant's business, and shall be liable for any damage incurred in connection
with any such entry by Landlord.

                                       13
<PAGE>   17

30.      ESTOPPEL CERTIFICATES.

         (a) Tenant shall, at any time and from time to time, within thirty (30)
days following written request from Landlord, execute, acknowledge and deliver
to Landlord, a written statement certifying that this Lease is in full force and
effect and unmodified (or, if modified, stating the nature of such
modification), confirming the Commencement Date and expiration date of the Term,
certifying the date to which the Rent reserved hereunder has been paid, and
certifying that there are not, to Tenant's knowledge, any uncured defaults on
the part of Landlord hereunder, or specifying such defaults if any are claimed.
Any such statement may be relied upon by a prospective purchaser or mortgagee of
all or any part of the Building or the Land on which the Building is located.

         (b) Landlord shall, at any time and from time to time, within thirty
(30) days following written request from Tenant, execute, acknowledge and
deliver to Tenant a written statement certifying that this Lease is in full
force and effect and unmodified (or, if modified, stating the nature of such
modification), confirming the Commencement Date and expiration date of the Term,
certifying the date to which the Rent reserved hereunder has been paid, and
certifying that there are not, to Landlord's knowledge, any uncured defaults on
the part of Tenant hereunder, or specifying such defaults if any are claimed.
Any such statement may be relied upon by any prospective purchaser of a material
interest in the Tenant or any institutional creditor of Tenant.

31.      EXONERATION.

         It is covenanted and agreed that no personal liability or
responsibility is assumed by nor shall at any time be asserted or enforceable
against Landlord or any partner, Affiliate of Landlord, parent corporation, or
any officer, director or shareholder thereof, or the successors or assigns of
the foregoing, on account of any covenant, undertaking or agreement in this
Lease contained, all such personal liability and responsibility, if any, being
expressly waived and released, it being understood that Tenant shall look solely
to the interest of the Landlord in the Building for satisfaction of any proven
damage of Tenant in the event of a breach by Landlord hereunder.

32.      INTENTIONALLY OMITTED.

33.      BROKERS.

         Landlord and Tenant warrant to each other that they have dealt and
negotiated solely and only with the Broker (as set forth in the Lease Summary)
for this Lease and with no other broker, firm, company or person.

         Tenant and Landlord (for good and valuable consideration) shall
indemnify and hold the other party harmless from and against any and all claims,
suits, proceedings, damages, obligations, liabilities, counsel fees, costs,
losses, expenses, orders and judgments imposed upon, incurred by or asserted
against the other party by reason of the falsity or error of the aforesaid
warranty. The provisions of this Paragraph shall survive the termination of this
Lease.

34.      SURRENDER OF PREMISES.

         At termination of this Lease by lapse of time or otherwise, Tenant
shall surrender the Premises to Landlord, together with all alterations,
additions, and improvements thereto, in broom clean condition and in good order
and repair except for ordinary wear and tear, damage by fire or other casualty,
and damage for which Tenant is not obligated to make repairs under this Lease,
failing this, Landlord may restore Premises to such condition and Tenant shall
pay the cost thereof. Upon such termination, all installations, alterations,
additions, hardware and improvements, including partitions which may have been
installed by either Landlord or Tenant upon Premises, shall remain upon Premises
and shall be Landlord's property unless otherwise provided for in accordance
with the terms hereof, all without compensation, allowance, or credit, except
that Tenant's moveable trade fixtures, office equipment and furniture shall
remain Tenant's property and Tenant shall have the right prior to such
termination to remove the same. Tenant shall surrender Premises to Landlord at
the end of the term hereof, without notice of any kind, and Tenant waives all
right to any such notice as may be provided under any laws now or hereafter in
effect. The provisions of this Paragraph shall survive the termination of this
Lease.

35.      EXHIBITS.

         Attached to this Lease, incorporated herein, and made a part hereof,
are Exhibits "A" to "J", inclusive.

36.      ARBITRATION.  INITIALS:

                         PGE
                       -------
                         RB
                       -------

         (a) Except for the Excluded Issues (as defined herein), any
controversy, dispute or claim arising out of this Lease or the breach or alleged
breach of this Lease shall be settled by arbitration in accordance with the
Commercial Arbitration Rules of the American Arbitration Association currently
in effect (unless the

                                       14
<PAGE>   18
parties mutually agree otherwise). The award rendered by the arbitrator or
arbitrators shall be final and any judgment upon the award rendered by the
arbitrator or arbitrators shall be entered in a state court in Williamson
County, Tennessee. The party hereunder demanding arbitration of any controversy,
dispute or claim arising out of this Lease or any breach or alleged breach of
this Lease shall file a written notice of such demand with the other party and
with the American Arbitration Association. Such written notice shall be given
not later than sixty (60) days after the controversy, dispute or claim arises or
the breach or alleged breach of this Lease occurs. Any arbitration under or
related to this Lease may include any other party that is or may be involved in
the controversy, dispute, claim or breach or alleged breach that is the subject
matter of the arbitration proceeding. Provided, however, and notwithstanding the
foregoing to the contrary, the following matters and issues (the "Excluded
Issues") shall be excluded from the mandatory arbitration provisions of this
Paragraph 36:

             (1) Unless Tenant is disputing the existence of a Tenant default,
Landlord's exercise of its rights and remedies provided for under this Lease
solely to gain possession of the Premises or solely to terminate Tenant's right
of possession to the Premises, which disputes shall be resolved in state court
in Williamson County, Tennessee, subject to appeal pursuant to applicable law;
and

             (2) Disputes regarding whether arbitration hereunder of a
particular controversy, dispute or claim arising out of this Lease or the breach
or alleged breach of this Lease is barred by the applicable statute of
limitations specified in Tennessee law, which disputes relating to whether the
statute of limitations is a bar to a particular controversy, dispute or claim
shall be resolved in state court in Williamson County, Tennessee, subject to
appeal pursuant to applicable law.

         (b) Except with regard to the Excluded Issues (which shall be resolved
as provided below), Landlord and Tenant hereby irrevocably waive any and all
rights they may have to resolve any controversy, dispute or claim arising out of
this Lease or the breach or alleged breach of this Lease in a manner that is
inconsistent with the provisions of this Paragraph 36.

         (c) Neither the parties to this Lease nor the arbitrator or arbitrators
may make any public disclosure of (i) the existence of any controversy, dispute
or claim arising out of this Lease or the breach or alleged breach of this
lease, (ii) the existence of an arbitration proceeding under this Lease or (iii)
the results of any arbitration proceeding under this Lease, unless Landlord and
Tenant both consent in writing to such public disclosure. Provided, however,
this prohibition shall not be deemed or construed to prevent or impede the entry
of any judgment upon an award rendered by the arbitrator or arbitrators in a
state court in Williamson County, Tennessee, as contemplated above.

37.      INTENTIONALLY OMITTED.

38.      AUTHORITY.

         If Tenant is a partnership or corporation, Tenant warrants that the
individual executing this Lease on behalf of said partnership or corporation is
duly authorized to execute and deliver this Lease on behalf of said partnership
or corporation in accordance with the duly adopted resolution of the partners of
the partnership or Board of Directors of said corporation or partnership in
accordance with the bylaws of said corporation, (or under the pertinent
partnership agreements) and that this Lease is binding upon said corporation or
partnership in accordance with its terms.

39.      COMPLIANCE WITH LAWS AND ORDINANCES.

         Tenant agrees that it will, at its sole cost and expense, promptly
fulfill and comply with all laws, ordinances, regulations and requirements of
the City, County, State and Federal Governments and any and all departments
thereof having jurisdiction over the Building and of the National Board of Fire
Underwriters or any other similar body now or hereafter constituted, affecting
the Tenant's occupancy of the Premises or the business conducted therein. The
foregoing obligation of Tenant shall only apply to the extent that the same
shall affect or be applicable to (i) Tenant's manner of use of the Premises (as
opposed to its mere use thereof for ordinary office purposes), (ii) alterations
and improvements made by Tenant of (iii) a breach by Tenant of its obligations
under this Lease. Tenant may, at its expense (and, if necessary, in the name of
but without expense to, Landlord) contest, by appropriate proceedings diligently
prosecuted, the validity, or applicability to the Premises, of any matter if may
be required to comply with pursuant to this paragraph, and may postpone its
compliance therewith until such contest shall be decided; provided however, that
postponement of such compliance shall not materially adversely affect the
occupancy of the Building by its other tenants.

40.      APPLICABLE LAW AND CONSTRUCTION.

         The laws of the State of Tennessee shall govern the validity,
performance and enforcement of this Lease. The invalidity or unenforceability of
any provision of this Lease shall not affect or impair any other provision. The
submission of this document to Tenant for examination does not constitute an
offer to lease, or a reservation of or option to lease, and becomes effective
only upon execution and delivery thereof by Landlord and Tenant. All
negotiations, considerations, representations and understandings between the
parties are incorporated in the Lease. Any index preceding this Lease and the
headings of the paragraphs contained herein are for convenience only and do not
define, limit or construe the contents of such articles

                                       15
<PAGE>   19

or paragraphs. Whenever herein the singular number is used, the same shall
include the plural, and the neuter gender shall include the masculine and
feminine genders.

         IN WITNESS WHEREOF, the parties have executed and delivered this Lease
as of the day and year first above written.

Signed in the Presence of:                 LANDLORD:

Attest/Witness Landlord:                   CRESCENT RESOURCES, INC.

/s/ Yvonne Craig
-------------------------------            By: /s/ Patrick G. Emery
                                              --------------------------------
                                           Name: Patrick G. Emery
                                                ------------------------------
                                           Officer: Regional Vice President
                                                   ---------------------------

Signed in the Presence of:                 TENANT:

Attest/Witness Tenant:                     BLUESTAR COMMUNICATIONS, INC.

/s/ Andrew M. Morin
-------------------------------            By: /s/ R. L. Burtner
                                              --------------------------------
                                           Name: R. L. Burtner
                                                ------------------------------
                                           Officer: Chief Financial Officer
                                                   ---------------------------

                                       16

<PAGE>   20

                                    EXHIBIT A
                                 LANDLORD'S LAND

         Land in Williamson County, Tennessee, being Lot 657 on the Plat of Cool
Springs East Subdivision, Section 17, of record in Plat Book 26, page 141,
Register's Office for Williamson County, Tennessee.

                                       17

<PAGE>   21

                                    EXHIBIT B

                                   FLOOR PLAN

                                       18

<PAGE>   22

                                    EXHIBIT B

                                   FLOOR PLAN

                                       19

<PAGE>   23

                                    EXHIBIT C

                              FIVE CORPORATE CENTRE
                                   WORKLETTER

LANDLORD:    CRESCENT RESOURCES, INC.
TENANT:      BLUESTAR COMMUNICATIONS, INC.
BUILDING:    FIVE CORPORATE CENTRE

                                    RECITALS

         A. This workletter is attached to and forms a part of the certain lease
dated December 31, 1999, (the "Lease"), pursuant to which Landlord has leased to
Tenant certain space (the "Premises") in the Building.

         B. The Lease provides for Landlord to make improvements to the Premises
(the "Tenant Improvements"), and Tenant desires to have Landlord make them,
prior to occupancy, upon the terms and conditions contained in this workletter.

         1. Definitions. In this workletter, some defined terms are used. They
are (in addition to other defined terms):

            (a) Tenant Improvement Allowance: As set forth in Lease Summary and
         is to be applied by Landlord to the cost of Tenant Improvements.

            (b) Tenant Plans: a drawing of the Premises depicting the lay-out of
         all offices, partitions, door locations, types of electrical and data
         and telephone outlets, and equipment, complete in form and content and
         containing sufficient information and detail to allow for competitive
         bidding or negotiated pricing by contractors selected and engaged by
         Landlord and which must include the following (references to Tenant
         Plans shall also include the Construction Plans for the NOC):

         (i)   Architectural Wall Plan

               (a) Include all general construction notes

         (ii)  Reflected Ceiling Plan

         (iii) Electrical, Telephone and Data Plan

         (iv)  Finishes Plan

               (a) Include door schedule

         (v)   Details Plan

               (a) Include millwork details

               (b) Include other specialty items

            (c) Estimated construction costs: a preliminary estimate of the
         costs of the Tenant Improvements that are depicted on the Tenant
         Plans, including all architectural, engineering, contractor, and any
         other costs as can be determined from the Tenant Plans.

            (d) Construction schedule: a schedule depicting the relative
         time frames for various activities related to the construction of the
         Tenant Improvements in the Premises.

            (e) Tenant Cost proposal: a final estimate of costs of the Tenant
         Improvements that are depicted on the Tenant Plans, including all
         space planning, architectural, engineering, contractor, and any other
         costs, and clearly indicating the cost, if any, that is to be paid by
         Tenant pursuant to paragraph 2 (e) of the Lease.

            (f) Maximum approved cost: the sum of the Tenant Improvement
         Allowance and any additional amount that Tenant has agreed to pay for
         the Tenant Improvements.

            (g) Cost of the Tenant Improvements: the cost includes, but is
         not limited to, the following:

                    (1) All architectural and engineering fees and expenses,
             including but not limited to cost of preparation of Tenant Plans,
             working drawings, cost estimates, etc.

                    (2) All permits and taxes.

                                       20

<PAGE>   24

            (h) Change order: any change, modification, or addition to the
         final Tenant Plans or working drawings after Tenant has approved the
         same.

            (i) Building Shell Improvements: component elements utilized
         in the design and construction of the Tenant Improvements that have
         been pre-selected by the Landlord to ensure uniformity of quality,
         function, and appearance throughout the Building as set forth on
         Schedule 1 attached hereto, the cost of which shall be in addition to
         the Tenant Improvement Allowance and shall be borne by Landlord.

         2. Project Design and Construction. All work will be performed by
designers and contractors selected and engaged by Landlord.

         3. Cost Responsibilities.

            (a) Landlord: Landlord will pay up to the amount of the Tenant
         Improvement Allowance for the cost of the Tenant Improvements.

            (b) Tenant: Tenant will pay (subject to Section 2(e)(1) of the
         Lease) for Excess Costs which may include but are not limited to:

                    (1) The amount by which the maximum Approved Cost exceeds
            the Tenant Improvements Allowance.

                    (2) Tenant-initiated change orders, modifications, or
            additions to the Tenant Improvements after the Tenant Plans are
            final to the extent not offset by change by change and release
            from other cost savings from other change orders.

                    (3) All costs in excess of the Tenant Improvement Allowance
            that are not included in (1) or (2).

         4. Landlord's Approval. Landlord, in its sole discretion, may withhold
its approval of any final Tenant Plans, working drawings, or change order that:

            (a) Exceeds or adversely affects the structural integrity of the
         building, or any part of the heating, ventilating, air conditioning,
         plumbing, mechanical, electrical, communication, or other systems of
         the building;

            (b) Is not approved by the holder of any mortgage or deed of trust
         encumbering the building at the time the work is proposed;

            (c) Would not be approved by a prudent owner of property similar to
         the building;

            (d) Violates any agreement that affects the Building or binds
         Landlord;

            (e) Landlord reasonably believes will increase the cost of operation
         or maintenance of any of the systems of the Building; provided
         however, it is understood that Tenant may operate for business
         twenty-four (24) hours a day, seven (7) days a week on the Premises
         and that Tenant will have separately metered HVAC units for its space
         or will pay for additional HVAC pursuant to Subsection (b) of
         Exhibit H.

            (f) Landlord reasonably believes will reduce the market value of the
         Premises or the Building at the end of the term;

            (g) Does not conform to applicable building code or is not approved
         by any governmental, quasi-governmental, or utility authority with
         jurisdiction over the Premises; or

            (h) Does not conform to the Building Shell Improvements.

         5. Schedule of Improvement Activities.

            (a) In the event the Tenant Plans are not approved by the parties as
         of the date hereof, Tenant shall on or before the date of the Plan
         Submission Deadline and NOC Plan Submission Deadline set forth in the
         Lease Summary submit to Landlord the construction plans ("Tenant
         Plans") for the Tenant Improvements.

            (b) Within ten (10) business days after receipt of Tenant's Plans
         under (a), Landlord's architect will (if necessary) expeditiously
         cause Tenant Plans to be prepared in form sufficient to comply with
         local building codes to mechanical, electrical, plumbing and sprinkler
         engineering requirements.

            (c) After the Tenant's Plans have been completed as set forth in (6)
         above. Landlord shall within two (2)business days request bids from
         three (3) contractors and shall within seven (7)

                                       21
<PAGE>   25

         business days after bids are sent out select the Contractor with the
         lowest bid to construct the Tenant Improvements. Landlord will
         promptly cause to be prepared a preliminary estimate of the cost of
         the Tenant Improvements as set forth in the Tenant Plans (the
         "estimated construction costs"). If the estimated construction cost is
         less than the Tenant Improvement Allowance, the estimated construction
         cost will be deemed approved without a required response from Tenant.
         If the estimated construction costs are more than the Tenant
         Improvement Allowance, Landlord will so notify Tenant in writing and
         Tenant will establish the Maximum Approved Cost by either:

                    (1) Agreeing in writing to pay the amount by which the
               estimated construction cost exceeds the Tenant Improvement
               Allowance or;

                    (2) Agreeing to have the final Tenant Plans revised by
               Landlord's architect in order to assure that the estimated
               construction cost is either:

                    (A) No more than the Tenant Improvement Allowance; or

                    (B) Exceeds the Tenant Improvement Allowance by an amount
               that Tenant agrees to pay pursuant to (1).

Tenant will give immediate attention to establishing the Maximum Approved Cost
and shall respond to Landlord within three (3) business days. Upon Tenant's
timely fulfillment of its obligations in either clause (1) or clause (2), the
Maximum Approved Cost will be established.

            (d) Upon establishment of the Maximum Approved Cost, Landlord
         will cause to be prepared and delivered to Tenant the construction
         schedule.

            (e) Immediately upon approval of the Maximum Approved Cost, Landlord
         will cause application to be made to the appropriate governmental
         authorities for necessary approvals and building permits. Upon receipt
         of the necessary approvals and permits, Landlord will begin
         construction of the Tenant Improvements, and complete the same by the
         Term Commencement Date.

         6. Payment by Tenant. The amount payable by Tenant shall be paid as set
forth in Section 2 of the Lease. Tenant shall receive a credit against Base Rent
for any portion of the Tenant Improvement Allowance that is not used.

         7. Change Orders. Tenant may authorize changes to the Tenant
Improvements during construction only by written instructions to Landlord's
representative on a form approved by Landlord. All such changes will be subject
to Landlord's prior written approval in accordance with paragraph 4. Prior to
commencing any change, Landlord will prepare and deliver to Tenant, for Tenant's
approval, a change order setting forth the total cost of such change, which will
include associated architectural, engineering, construction contractor's costs
and fees, completion schedule changes. If Tenant fails to approve such change
order within 5 business days after delivery by Landlord, Tenant will be deemed
to have withdrawn the proposed change and Landlord will not proceed to perform
the change. Upon Landlord's receipt of Tenant's approval, Landlord will proceed
with the change.

         8. Completion and Commencement Date. Tenant's obligation for payment of
rent pursuant to the lease will commence on the Rent Commencement Date; however,
the Rent Commencement Date and the date for payment of rent may be delayed on a
day-by-day basis for each day the substantial completion of the Tenant
Improvements are delayed by Landlord or its contractors or agents. The payment
of rent will not be delayed by a delay of substantial completion due to Tenant.
The following are some examples of delays ("Tenant Delay Factors") that will not
affect the Rent Commencement Date and the date on which rent is to commence
under the lease:

            (a) Late submissions of preliminary information;

            (b) Change orders requested by Tenant that actually cause a delay;

            (c) Delays in obtaining construction materials requested by
         Tenant that do not conform to the Building Standard Specifications;

            (d) Tenant's failure to approve timely any item requiring
         Tenant's approval; and

            (e) Delays by Tenant according to paragraph 5.

In the event that substantial completion of the Tenant Improvements is delayed
by Landlord, its contractors, or agents, the Commencement Date will be the date
of substantial completion of the Tenant Improvements, subject only to the
completion of Landlord's punch-list items (that is, those items which do not
materially interfere with Tenant's use and enjoyment of the Premises). Landlord
and Tenant will confirm the Commencement Date in accordance with applicable
terms of the lease.

                                       22

<PAGE>   26

         9. Condition of the Premises.

            (a) Prior to the Commencement Date, Tenant will conduct a
         walk-through inspection of the Premises with Landlord and prepare a
         punch-list of items needing additional work by Landlord. Other than the
         items specified in the punch-list and latent defect (as defined below),
         by taking possession of the Premises, Tenant will be deemed to have
         accepted the Premises in their condition on the date of delivery of
         possession and to have acknowledged that Landlord has installed the
         Tenant Improvements as required by this workletter and that there are
         no items needing additional work or repair. The punch-list will not
         include any damage to the Premises caused by Tenant's move-in or early
         access, if permitted. Damage caused by Tenant will be repaired or
         corrected by Landlord at Tenant's expense. Tenant acknowledges that
         neither Landlord nor its agents or employees have made any
         representations or warranties as to the suitability or fitness of the
         Premises for the conduct of Tenant's business or for any other purpose,
         nor has Landlord or its agents or employees agreed to undertake any
         alterations or construct any Tenant Improvements to the Premises except
         as expressly provided in their lease and this workletter. If Tenant
         fails to submit a punch-list to Landlord within thirty (30) days after
         the Term Commencement Date, it will be deemed that there are no items
         needing additional work or repair. Landlord's contractor will complete
         all punch-list items within 30 days or within such additional period as
         is reasonably necessary after the walk-through inspection or as soon as
         practicable after such walk-through.

            (b) A "latent defect" is a defect in the condition of the Premises,
         caused by Landlord's failure to construct the Tenant Improvements in a
         good and workman-like manner and in accordance with the working
         drawings, which would not ordinarily be observed during a walk-through
         inspection. If Tenant notifies Landlord of a latent defect within one
         year following the Commencement Date, then Landlord, at its expense,
         will repair the latent defect as soon as practicable. Except as set
         forth in this paragraph 9, Landlord will have no obligation or
         liability to Tenant for latent defects. Landlord shall make available
         to Tenant all contractor warranties with regard to Tenant
         Improvements.

         The terms hereof are approved.

                                        LANDLORD:

                                        CRESCENT RESOURCES, INC.

                                        By: /s/ Patrick G. Emery
                                           ------------------------------------
                                        Name: Patrick G. Emery
                                             ----------------------------------
                                        Officer: Regional Vice President
                                                -------------------------------

                                        TENANT:

                                        BLUESTAR COMMUNICATIONS, INC.

                                        By: /s/ R. L. Burtner
                                           ------------------------------------
                                        Name: R. L. Burtner
                                             ----------------------------------

                                        Officer:  Chief Finance Officer
                                                 ------------------------------

                                       23

<PAGE>   27

                                   SCHEDULE I

1.   Building Shell Improvements. Landlord, at Landlord's sole cost without
     deduction from the Tenant Improvement Allowance, shall complete the
     following as part of the Building Shell Improvements:

     -    2' x 2' ceiling grid installed at 8' 10" above the finished floor
     -    2' x 2' tegular acoustical ceiling tile (to be stacked on the floor in
          the Premises)
     -    columns wrapped with drywall
     -    high efficiency 2' x 4', 3 lamp fixtures with 18 cell parabolic lenses
          and lights at a ratio of one fixture per 75 square feet of Premises
          Net Usable Area (to be stacked on the floor in the Premises)
     -    low pressure and medium pressure duct work installed on an open plan
     -    interior VAV boxes installed with thermostats
     -    perimeter VAV boxes installed to perimeter slot diffusers
     -    Building standard fire sprinkler system (in accordance with applicable
          code requirements), with heads turned up installed on an open plan
     -    demising walls: Landlord shall pay for the cost of the demising walls
          between the Premises and the Common Areas and the cost of the demising
          walls between the Premises and other tenant space in the Building
     -    blinds for exterior windows
     -    men's and women's restrooms (one each for each floor to be used in
          common)
     -    drinking fountains in common areas
     -    electric closet for typical Tenant floor
     -    electronically controlled card key access system to the Building
     -    slab with conduit to main panel for Tenant's back-up generator.
          Connection and generator to be at Tenant's expense and may be paid
          from Tenant Improvement Allowance.

                                       24

<PAGE>   28

                                    EXHIBIT D
                                  RENT SCHEDULE

          Project:                   Five Corporate Centre
          Tenant:                    BlueStar Communications

<TABLE>
<CAPTION>

------------------------------------------------------------------------------------------------------------------------
            Year              Net Rate    Escalation   Expense Stop*    Gross Rate**    Monthly Rent      Annual Rent
------------------------------------------------------------------------------------------------------------------------
     <S>                      <C>         <C>          <C>              <C>             <C>              <C>
              1               $ 13.35       0.00%        $ 5.65          $ 19.00        $ 76,101.33      $  913,216.00
------------------------------------------------------------------------------------------------------------------------
              2               $ 13.75       3.00%        $ 5.65          $ 19.40        $ 77,703.47      $  932,441.60
------------------------------------------------------------------------------------------------------------------------
              3               $ 14.16       3.00%        $ 5.65          $ 19.81        $ 79,345.65      $  952,147.84
------------------------------------------------------------------------------------------------------------------------
              4               $ 14.59       3.00%        $ 5.65          $ 20.24        $ 81,067.95      $  972,815.36
------------------------------------------------------------------------------------------------------------------------
              5               $ 15.03       3.00%        $ 5.65          $ 20.68        $ 82,830.29      $  993,963.52
------------------------------------------------------------------------------------------------------------------------
       Extension Year         $ 15.48       3.00%        $ 5.65          $ 21.13        $ 84,632.69      $1,015,592.32
------------------------------------------------------------------------------------------------------------------------
      1st Renewal Year        $ 16.25       5.00%        $ 5.65          $ 21.90        $ 87,716.80      $1,052,601.60
------------------------------------------------------------------------------------------------------------------------
      2nd Renewal Year        $ 16.74       3.00%        $ 5.65          $ 22.39        $ 89,679.41      $1,076,152.96
------------------------------------------------------------------------------------------------------------------------
      3rd Renewal Year        $ 17.24       3.00%        $ 5.65          $ 22.89        $ 91,682.08      $1,100,184.96
------------------------------------------------------------------------------------------------------------------------
      4th Renewal Year        $ 17.76       3.00%        $ 5.65          $ 23.41        $ 93,764.85      $1,125,178.24
------------------------------------------------------------------------------------------------------------------------
      5th Renewal Year        $ 18.29       3.00%        $ 5.65          $ 23.94        $ 95,887.68      $1,150,652.16
------------------------------------------------------------------------------------------------------------------------
      6th Renewal Year        $ 19.20       5.00%        $ 5.65          $ 24.85        $ 99,532.53      $1,194,390.40
------------------------------------------------------------------------------------------------------------------------
      7th Renewal Year        $ 19.78       3.00%        $ 5.65          $ 25.43        $101,855.63      $1,222,267.52
------------------------------------------------------------------------------------------------------------------------
      8th Renewal Year        $ 20.37       3.00%        $ 5.65          $ 26.02        $104,218.77      $1,250,625.28
------------------------------------------------------------------------------------------------------------------------
      9th Renewal Year        $ 20.98       3.00%        $ 5.65          $ 26.63        $106,662.03      $1,279,944.32
------------------------------------------------------------------------------------------------------------------------
      10th Renewal Year       $ 21.61       3.00%        $ 5.65          $ 27.23        $109,185.39      $1,310,224.64
------------------------------------------------------------------------------------------------------------------------
</TABLE>

         *Initial Year Expense Stop Estimate
         **Does not reflect increases in operating expenses

The increases in Base Rent as set forth above do not reflect Tenant's obligation
to pay Tenant's proportionate Share of the amount by which Operating Expenses
exceed the Operating Cost Expense stop all as described in Section 4 of the
Lease.

Year one commences on the Term Commencement Date. The original term is years one
through five and four months. Base Rent for the last four (4) months of the
original term after the end of year five shall be the same as for the Rent for
year 5.

The parties understand the Annual rent shall be recomputed after the Operating
Expenses for the Operating Expense Base Year (2000) have been established as
provided in Section 4 of the Lease. The actual Operating Expense stop shall then
be determined by dividing the Operating Expenses by the Building Rentable Area.
The resulting factor shall then be added to the Net Rate as escalated to
determine the Gross Annual Rent.

                                       25

<PAGE>   29
                                    EXHIBIT E

                              RULES AND REGULATIONS

         1. Sidewalks, doorways, vestibules, halls, stairways, and similar areas
shall not be obstructed nor shall refuse, furniture, boxes or other items be
placed therein by an tenant or its officers, agents, servants, and employees, or
be used for any purpose other than ingress and egress to and from premises in
the Building, or for going from one part of the Building to another part of the
Building. Canvassing, soliciting and peddling in the Building are prohibited.

         2. Plumbing, fixtures, and appliances shall be used only for the
purposes for which constructed, and no unsuitable material shall be placed
therein.

         3. No signs, directories, posters, advertisements, or notices shall be
painted of affixed on or to any of the windows or doors, or in corridors or
other parts of the Building, except in such color, size, and style, and in such
places, as shall be first approved in writing by Landlord in its discretion.
However, the prohibition in the immediately preceding sentence shall not limit
or restrict any tenant's right to maintain within the premises occupied by such
tenant any signs, directories, posters, advertisements, or notices so long as
such items are not visible from the exterior of the premises occupied by such
tenant or from the Common Areas of the Building. Building standard suite
identification signs will be prepared by landlord at Landlord's expense. Any
change in the identification sign desired by Tenant shall be at Tenant's
expense. Landlord shall have the right to remove all unapproved signs without
notice to any tenant, at the expense of the responsible tenant.

         4. No tenant shall do, or permit anything to be done, in or about the
Building, or bring or keep anything therein, that will in any way increase the
rate of fire or other insurance on the Building, or on property kept therein or
otherwise increase the possibility of fire or other casualty.

         5. Landlord shall have the power to prescribe the weight and position
of heavy equipment or objects which may overstress any portion of the floor. All
damage done to the Building by the improper placing of such heavy items will be
repaired at the sole expense of the responsible tenant.

         6. Each tenant shall notify the Building manager when safes or other
heavy equipment are to be taken in or out of the Building, and the moving shall
be done after written permission is obtained from Landlord on such conditions as
Landlord shall require.

         7. All deliveries must be made via the service entrance and service
elevator, when provided, during normal working hours. Landlord's written
approval must be obtained for any delivery after normal working hours.

         8. Each tenant shall cooperate with Landlord's employees in keeping
such tenant's premises neat and clean.

         9. Each tenant shall not cause or permit any improper noises in the
building, allow any unpleasant odors to emanate from the Premises, or otherwise
interfere, injure or annoy in any way other tenants or persons having business
with them. However, Landlord acknowledges that, if permitted by the applicable
lease, a tenant may operate a food services facility within the premises of such
tenant for the sole use and benefit of the occupants of such premises and that
such food services facility may emit odors normally associated with the
operation of such on-site food services facilities.

         10. No animals shall be brought into or kept in or about the Building.

         11. When conditions are such that a tenant must dispose of crates,
boxes, etc. on the sidewalk, it will be the responsibility of such tenant to
dispose of same prior to 7:30 a.m. or after 5:30 p.m.

         12. No machinery of any kind, other than ordinary office machines such
as typewriters, computers, fax machines, scanners, information processing
systems, copy machines, communications equipment and calculators, shall be
operated in any premises in the Building without the prior written consent of
Landlord, nor shall any tenant use or keep in the Building any inflammable or
explosive fluid or substance (including live Christmas trees and ornaments), or
any illuminating materials. No space heaters or fans shall be operated in the
Building. Landlord agrees Tenant may install separate and maintain the equipment
necessary to operate its business on the Premises.

         13. No motorcycles or similar motorized vehicles will be allowed in the
Building.

         14. No nails, hooks, or screws shall be driven into or inserted in any
part of the Building, except for hanging decorations or as otherwise approved by
Building maintenance personnel. Notwithstanding the foregoing, a tenant may
decorate the interior of such tenant's premises at such tenant's sole discretion
provided such decorations do not impact the structural integrity of the Building
and cannot be seen from the exterior of the Building or from any Common Areas of
the Building.

         15. Landlord has the right to evacuate the Building in the event of an
emergency or catastrophe.

         16. No food and/or beverages shall be distributed from any tenant's
office without the prior written approval of the Building manager. But a tenant
may prepare coffee and similar beverages and warm typical luncheon items for the
consumption of such tenant's employees and invitees. Furthermore, Landlord
acknowledges that, if permitted by the applicable lease, a tenant may operate a
food services facility within the premises of such tenant for the sole use and
benefit of the occupants of such premises.

         17. No additional locks shall be placed upon any doors without the
prior written consent of Landlord. All necessary keys or access cards or codes
shall be furnished by Landlord, and the same shall be surrendered upon
termination of the applicable lease, and each tenant shall then give Landlord or
Landlord's agent an explanation of the combination of all locks on the doors or
vaults. Replacement key or access cards or codes (i.e., replacements for keys or
access cards or codes previously issued by Landlord) shall be obtained only from
Landlord, and Tenant shall pay to Landlord (as Additional Rent, with thirty (30)
days after Tenant receives an invoice therefor) the actual costs incurred by
Landlord in obtaining and issuing replacement keys or access cards or codes for
keys or access cards or codes previously issued.

         18. Tenants will not locate furnishings or cabinets adjacent to
mechanical or electrical access panels or over air conditioning outlets so as to
prevent operating personnel from servicing such units as routine or emergency
access may require. Cost or moving such furnishings for Landlord's access will
be for the responsible tenant's account. The lighting and air conditioning
equipment of the Building will remain the exclusive charge of the Building
designated personnel.

         19. Each tenant shall comply with reasonable parking rules and
regulations as may be posted and distributed by Landlord from time to time.

                                       26
<PAGE>   30

         20. No portion of the building shall be used for the purpose of lodging
rooms.

         21. Prior written approval, which shall be at Landlord's sole
discretion, must be obtained for installation of window shades, blinds, drapes,
or any other window treatment of any kind whatsoever. Landlord will control all
internal lighting that may be visible from the exterior of the Building and
shall have the right to change any unapproved lighting, without notice to the
responsible tenant, at the responsible tenant's expense.

         22. All Tenant alterations shall be done by Landlord or by licensed
contractors and/or workmen.

                                       27

<PAGE>   31

                                    EXHIBIT F

                              INTENTIONALLY DELETED

                                       28

<PAGE>   32

                                    EXHIBIT G

                        CLEANING AND JANITORIAL SERVICES

     LANDLORD SHALL FURNISH CLEANING AND JANITORIAL SERVICES TO THE PREMISES
AS DESCRIBED BELOW:

DAILY (Monday - Friday):

     -    Sweep, dry mop or vacuum, as appropriate, all floor areas; remove
          material such as gum and tar which has adhered to the floor.

     -    Empty and damp wipe all ash trays, waste baskets and containers,
          remove all trash from the leased premises.

     -    Dust all cleared horizontal surfaces with treated dust cloth,
          including furniture, files, telephones, equipment that can be reached
          without a ladder.

     -    Spot wash to remove smudges, marks and fingerprints from such areas
          that can be reached without a ladder.

     -    Clean water fountains, cafeteria tables and chairs.

     -    Damp mop all non-resilient floors such as terrazzo and ceramic tile.

     -    Clear freight and passenger elevator cabs and landing doors.

     -    Clean mirrors, soap dispensers, shelves, wash basins, exposed
          plumbing, dispenser and disposal container exteriors, damp wipe all
          ledges, toilet stalls and toilet doors.

     -    Clean toilets and urinals with detergent disinfectants.

     -    Furnish and refill all soap, toilet, sanitary napkin and towel
          dispensers.

     -    Spot clean carpet stains.

     -    Wash glass in Building directory, entrance doors and frames.

     -    Remove all litter from the parking lot and grounds.

WEEKLY:

     -    Dust vertical blinds and louvers.

     -    Spot wash interior partition glass and door glass to remove smudge
          marks.

     -    Sweep all stairs areas.

     -    Dust all baseboards.

     -    Vacuum or brush all fabric covered chairs.

MONTHLY:

     -    Scrub and recondition resilient floor areas.

     -    Wash all stairwell landings and treads.

     -    Wash all interior glass both sides.

QUARTERLY:

     -    High dust all horizontal and vertical surfaces not reached in nightly
          cleaning.

     -    Vacuum all ceiling and wall air supply and exhaust diffusers and
          grills.

     -    Wash and polish vertical terrazzo and marble surfaces.

     -    Bonnet carpeted areas.

SEMI-ANNUALLY:

     -    Vacuum drapes, cornices and wall hanging.

     -    Dust all storage areas and shelves and contents.

     -    Damp wash diffusers, grills, and other such items.

ANNUALLY (or earlier as needed):

     -    Strip and refinish all resilient floors.

     -    Wash all building exterior glass both sides.

     -    Clean light fixtures, reflectors, globes, diffusers and trim.

                                       29
<PAGE>   33

     -    Wash walls in corridors, lounges, classrooms, demonstration areas,
          cafeterias, break rooms, washrooms.

     -    Clean all vertical surfaces not attended to during nightly, weekly,
          quarterly or semi-annually cleaning.

                                       30

<PAGE>   34

                                    EXHIBIT H

                      SERVICES TO BE FURNISHED BY LANDLORD

         Landlord agrees to furnish Tenant the following services:

         (a) Hot and cold water at those points of supply provided for general
use of other tenants in the Building.

         (b) Except with regard to any HVAC system or unit that exclusively
serves the Premises (or any portion thereof), which shall be Tenant's, Landlord
shall furnish central heat and air conditioning sufficient for the comfortable
occupancy of the Premises. Provided, however, central heating and air
conditioning service at times other than for "Normal Business Hours" for the
Building (which are 7:00 a.m. to 7:00 p.m. on Mondays through Fridays and 8:00
a.m. to 1:00 p.m. on Saturdays, exclusive of normal business holidays), shall be
furnished only on the written request of Tenant delivered to Landlord on the
following schedule:

             (1) For evenings Monday through Friday - prior to 3:00 p.m. on the
                 day when such service is required;

             (2) For Saturday afternoon, Saturday evening and Sunday - prior to
                 3:00 p.m. on Friday; and

             (3) For normal business holidays - prior to the times set forth
                 above for the last day prior to such holiday.

Tenant shall bear the entire cost (as Additional Rent) of such additional
heating and air conditioning used by Tenant at time other than Normal Business
Hours, and Tenant shall pay such costs within thirty (30) days following demand
by Landlord. The cost to be charged by Landlord to Tenant hereunder for heating
and air conditioning service used by Tenant during times other than Normal
Business hours shall be $35.00 per hour, subject to increase in such hourly rate
from time to time during the Lease Term to reimburse Landlord for increases in
the cost to Landlord of electricity consumed in providing the heating and air
conditioning service.

         If heat-generating machines of equipment shall be used in the Premises
by Tenant which affect the temperature otherwise maintained by the Building HVAC
system, Landlord shall have the right (at Landlord's option) to install (or to
require Tenant to install) one or more HVAC systems or units that exclusively
serve the Premises (or the portion thereof where such heat-generating machines
or equipment are located). The cost of any such separate HVAC systems or units
that exclusively serve the Premises, including the cost of installation and the
cost of operation and maintenance thereof, shall be borne by Tenant.

         (c) Electrical service to serve the Common Areas and the Premises,
subject to the terms of Paragraph 4(g) herein.

         (d) Routine maintenance and electric lighting service for all Common
Areas of the Building in the manner and to the extent deemed by Landlord to be
standard.

         (e) Janitorial service, in accordance with the schedule attached hereto
as Exhibit G, Mondays through Fridays, exclusive of normal business holidays;
provided, however, if Tenant's floor covering or other improvements require
special treatment, Tenant shall pay the additional cleaning cost attributable
thereto as Additional Rent upon presentation of a statement therefor by
Landlord.

         (f) All Building standard fluorescent and incandescent light bulb
replacement in the Common Areas and all light bulb replacement in the Premises.
Provided, however, Tenant shall promptly pay to Landlord, as Additional Rent,
costs incurred by Landlord in replacing light bulbs, in the Premises (including
the cost of purchasing such light bulbs) if and to the extent such replacement
cost exceeds the replacement cost for Building standard light bulbs. As used
herein, "Building standard light bulbs" shall be deemed to refer to 2' x 4', 3
lamp F40/CW with energy saving ballasts.

         (g) Tenant, its employees, and its invitees who have been registered
with Landlord shall have access to the Premises (including elevator service) by
a code or card access system seven (7) days a week, twenty-four (24) hours a
day. Tenant shall receive an allotment of codes or cards for all of its
employees and for its invitees who are registered with Landlord. Landlord shall
bear the cost of each such code or card initially issued, provided Tenant shall
pay to Landlord (as Additional Rent, within thirty (30) days after Tenant
receives an invoice therefor) the actual costs incurred by Landlord in obtaining
and issuing replacement codes or cards for codes or cards previously issued.
Landlord, however, shall have no liability to Tenant, its employees, agents,
invitees or licensees for losses due to theft or burglary or for damages done by
unauthorized persons on the Premises, and Landlord shall not be required to
insure against any such losses. Tenant shall cooperate fully with Landlord's
efforts to maintain security in the Building during times other than Normal
Business Hours and shall follow all regulations promulgated by Landlord with
respect thereto.

                                       31

<PAGE>   35

                                    EXHIBIT I

                                  TENANT PLANS

                                       32

<PAGE>   36

                                    EXHIBIT J

                    ADDITIONAL TERMS AND CONDITIONS OF LEASE

1. The following shall be added to the Lease as Section 41:

   41. ACCESS TO RISER CABLE. Landlord grants to Tenant the right to install,
repair, maintain and remove its telecommunications equipment (the "Equipment")
in the main aggregate phone closet in the Building, and to access and to use the
vertical and horizontal conduits, risers, and collocation space within the main
aggregate phone closet in the Building. Tenant shall maintain the Equipment as
it deems necessary in its sole discretion. In the event this Lease expires or is
earlier terminated as provided herein. Tenant promptly shall remove the
Equipment, unless Tenant is providing telecommunications services to other
tenants in the Building, in which case Tenant shall be permitted to maintain the
Equipment in the Building. Tenant may solicit other tenants of the Building on a
non-discriminatory basis so long as such solicitation is performed in a
professional manner. Landlord shall provide reasonable security to the main
aggregate phone closet and provide Tenant with access to the main aggregate
phone closet on an as needed basis. Tenant represents and warrants that the rise
cable used in connection with providing telecommunications services to tenants
will not preclude other telecommunications providers from accessing or providing
services to tenants in the Building. Tenant agrees to promptly repair any and
all damage resulting to the Building from tenant's installation or removal of
its equipment.

   2. The following shall be added to the Lease as Section 42:

      42.   FIFTH FLOOR EXPANSION:

   Tenant shall have the ongoing right of first opportunity to lease any space
on the Fourth and Fifth Floor of the Building subject to any rights of other
tenants of the Building in effect on the date of this Lease. The Base Rent shall
be the same Rent in effect under this Lease at the time such space is added to
this Lease. In the event Landlord receives a letter of intent by a third party
for all or any portion of the available space on the Fifth Floor. Tenant shall
have seven (7) business days thereafter to sign an amendment to this Lease. The
Amendment shall provide for a Tenant Improvement Allowance equal to $3.60 per
rentable square foot of the additional space multiplied by the number of years
(or fraction thereof) remaining in the Initial Term if the space is "shell"
(previously unconstructed) or $2.00 per rentable space foot if it contains
existing Tenant Improvements. The Tenant Improvements shall be constructed
basically in accordance with the same mechanism as set forth in the Work Letter.

   3. The following shall be added as Section 43:

      43.   ALLOWANCE:

   Within thirty (30) days after the Tem Commencement Date, Landlord shall pay
Tenant the sum of $1.00 per rentable square feet of space in the Premises as a
moving allowance (the "Additional Allowance"). Any "Excess Costs" as defined the
Lease shall first be deducted from the Additional Allowance.

   4. The following shall be added as Section 44:

      44.   DIRECTORY:

   Landlord shall provide and maintain, at its expense, a Building director
posted in the first (1st) floor lobby of the Building, listing only the names of
the tenants in the Building. Such directory shall be reasonably located for the
convenience of guests and invitees of tenants of the Building. Landlord shall
provide to Tenant, at no charge, its proportionate share of the listings on said
directory. Landlord shall also provide to Tenant all such additional initial and
replacement lists as Tenant shall reasonably require, at Landlord's standard
charge therefor.

   5. The following shall be added as Section 45:

       45.   RULES AND REGULATIONS:

   Landlord shall (i) not discriminate against Tenant in enforcing the rules and
regulations, (ii) not unreasonably withhold or delay its consent from Tenant for
any approval required under the rules and regulations, and (iii) exercise its
judgment in good faith in any instance providing for the exercise of its
judgment in the rules and regulations. Landlord shall use reasonable efforts to
secure compliance by all tenants and other occupants with the rules and
regulations.

                                       33<PAGE>   1
                                                                    EXHIBIT 10.9

                                  OFFICE LEASE

                                   L & C TOWER
                         FOURTH AVENUE AND CHURCH STREET
                              NASHVILLE, TENNESSEE

                 LANDLORD: LC TOWER, L.L.C., A DELAWARE LIMITED
                                LIABILITY COMPANY

            TENANT: BLUESTAR COMMUNICATIONS, A TENNESSEE CORPORATION

               DATED FOR REFERENCE PURPOSES AS OF: APRIL 16, 1999

<PAGE>   2

                                TABLE OF CONTENTS

<TABLE>
<S>                                                                                                             <C>
ARTICLE 1 PREMISES AND TERM.......................................................................................1

ARTICLE 2 BASE RENT...............................................................................................1

ARTICLE 3 ADDITIONAL RENT.........................................................................................2

ARTICLE 4 COMMENCEMENT OF TERM....................................................................................3

ARTICLE 5 CONDITION OF PREMISES...................................................................................4

ARTICLE 6 USE AND RULES...........................................................................................5

ARTICLE 7 SERVICES AND UTILITIES..................................................................................5

ARTICLE 8 ALTERATIONS AND LIENS...................................................................................8

ARTICLE 9 REPAIRS.................................................................................................8

ARTICLE 10 CASUALTY DAMAGE........................................................................................9

ARTICLE 11 INSURANCE; SUBROGATION................................................................................10

ARTICLE 12 CONDEMNATION..........................................................................................11

ARTICLE 13 RETURN OF POSSESSION..................................................................................11

ARTICLE 14 HOLDING OVER..........................................................................................12

ARTICLE 15 NO WAIVER.............................................................................................12

ARTICLE 16 ATTORNEYS' FEES AND JURY TRIAL; VENUE.................................................................13

ARTICLE 17 PERSONAL PROPERTY TAXES, RENT TAXES AND OTHER TAXES...................................................13

ARTICLE 18 TENANT'S AUTHORITY....................................................................................13

ARTICLE 19 SUBORDINATION, ATTORNMENT AND MORTGAGEE PROTECTION....................................................14

ARTICLE 20 ESTOPPEL CERTIFICATE..................................................................................15

ARTICLE 21 ASSIGNMENT AND SUBLETTING.............................................................................15

ARTICLE 22 RIGHTS RESERVED BY LANDLORD...........................................................................17

ARTICLE 23 LANDLORD'S REMEDIES...................................................................................18

ARTICLE 24 LANDLORD'S RIGHT TO CURE..............................................................................21

ARTICLE 25 CAPTIONS, DEFINITIONS AND SEVERABILITY................................................................22

ARTICLE 26 CONVEYANCE BY LANDLORD AND LIABILITY..................................................................26

ARTICLE 27 WAIVER AND INDEMNIFICATION............................................................................26
</TABLE>

<PAGE>   3

<TABLE>
<S>                                                                                                             <C>
ARTICLE 28 SAFETY AND SECURITY DEVICES, SERVICES AND PROGRAMS....................................................27

ARTICLE 29 COMMUNICATIONS AND COMPUTER LINES.....................................................................27

ARTICLE 30 HAZARDOUS MATERIALS...................................................................................28

ARTICLE 31 MISCELLANEOUS.........................................................................................30

ARTICLE 32 OFFER.................................................................................................31

ARTICLE 33 NOTICES...............................................................................................31

ARTICLE 34 REAL ESTATE BROKERS...................................................................................32

ARTICLE 35 SECURITY DEPOSIT......................................................................................32

ARTICLE 36 FINANCIAL STATEMENTS..................................................................................33

ARTICLE 37 LANDLORD'S LIEN.......................................................................................33

ARTICLE 38 ADA...................................................................................................33

ARTICLE 39 LANDLORD'S CONTRIBUTION FOR WORK; PROGRESS PAYMENTS...................................................34

ARTICLE 40 ENTIRE AGREEMENT......................................................................................34

ARTICLE 41 LANDLORD'S AUTHORITY..................................................................................34

ARTICLE 42 Parking...............................................................................................35
</TABLE>

RIDER ONE-RULES

EXHIBITS

         EXHIBIT A THE PREMISES
         EXHIBIT B JANITORIAL SPECIFICATIONS
         EXHIBIT B-1 HVAC SPECIFICATIONS

                                       ii
<PAGE>   4

                                  OFFICE LEASE

         THIS LEASE is made as of the 16th day of April, 1999, between LC TOWER,
L.L.C., a Delaware limited liability company ("Landlord"), and BlueStar
Communications, a Tennessee Corporation whose address is L&C Tower, 401 Church
Street, 24th Floor, Nashville, TN 37219 ("Tenant").

                                   WITNESSETH:

                                    ARTICLE 1
                                PREMISES AND TERM

         Landlord hereby leases to Tenant and Tenant hereby leases from Landlord
that certain space ("Premises") described or shown on Exhibit A attached hereto,
on the 24th and 27th floor ("Tower Premises") and on the 4th and 5th floor in
the Annex Building ("Annex Premises") of the L & C Tower, 401 Church Street,
Nashville, Tennessee (the "Building"), subject to and conditioned upon the
provisions herein contained. The term ("Term") of this Lease shall commence on
the 1st day of May, 1999 ("Commencement Date"), and end on the 30th day of
April, 2000 for the Tower Premises and end on the 30th day of April, 2002 for
the Annex Premises ("Expiration Date"), unless sooner terminated as provided
herein. The Commencement Date shall be subject to adjustment as provided in
Article 4. Landlord and Tenant agree that, for purposes of this Lease, except as
otherwise provided herein, the rentable area of the Premises shall be deemed to
be 8,536 square feet in the Tower Premises and 4,711 square feet in the Annex
Premises for a combined total of 13,247 square feet of Premises, and the
rentable area of the Property shall be deemed to be 274,226 square feet,
irrespective of whether the same shall be more or less as a result of variations
resulting from actual constructions and completion of the Premises or any other
premises for occupancy.

                                    ARTICLE 2
                                    BASE RENT

         Tenant shall pay Landlord an annual base rent (herein called "Base
Rent") for the Premises at the annual rates and amounts shown on the Base Rent
Schedule below, payable in equal monthly installments in advance on or before
the first day of each calendar month during the Term, except that Base Rent for
the first full calendar month for which Base Rent shall be due, shall be paid
when Tenant executes this Lease. If the Term commences on a day other than the
first day of a calendar month, or ends on a day other than the last day of a
calendar month, then the Base Rent for such month shall be prorated on the basis
of 1/30th of the monthly Base Rent for each day of such month.

                               BASE RENT SCHEDULE

<TABLE>
<CAPTION>
                                                 Annual Rate of Base Rent Per     Annual Base Rent for the
                                                 Square Foot                      Premises (and monthly
                   Period                        Of Rentable Area                 installment)
                   ------                        ----------------                 ------------
<S>                                              <C>                            <C>
Commencement Date to and including the day
before the first anniversary of the              $12.58 Annex Premises          $ 178,768.38
Commencement Date:  05/01/1999 - 04/30/2000      $14.00 Tower Premises           ($14,897.37)

First anniversary of the Commencement Date to    $13.58 Annex Premises only     $ 63,975.38
the Expiration Date:  05/01/2000 - 04/30/2002                                    ($5,331.28)
</TABLE>

                                       1
<PAGE>   5

                                    ARTICLE 3
                                 ADDITIONAL RENT

         (A) TAXES. During the Term, Tenant shall pay Landlord an amount equal
to Tenant's Prorata Share of Taxes in excess of the amount of Property Taxes
paid in the 1999 calendar year in the manner described below. The terms "Taxes"
and "Tenant's Prorata Share" shall have the meanings specified therefor in
Article 25.

         (B) OPERATING EXPENSES. Tenant shall pay Landlord an amount equal to
Tenant's Prorata Share of Operating Expenses in excess of the amount of
Operating Expenses paid in 1999 calendar year in the manner described below. The
terms "Operating Expenses" and "Tenant's Prorata Share" shall have the meanings
specified therefor in Article 25. Tenant shall also pay for all submetered
electric service to the Annex Premises quarterly.

         (C) MANNER OF PAYMENT. Taxes and Operating Expenses shall be paid in
the following manner:

         (i) Landlord may reasonably estimate in advance the amounts Tenant
shall owe for Taxes and Operating Expenses in excess of Taxes and Operating
Expenses paid in the 1999 calendar year for any full or partial calendar year of
the Term. In such event, Tenant shall pay such estimated amounts, on a monthly
basis, on or before the first day of each calendar month, together with Tenant's
payment of Base Rent. Such estimate may be reasonably adjusted from time to time
by Landlord.

         (ii) Within 120 days after the end of each calendar year, or as soon
thereafter as practicable, Landlord shall provide a statement (the "Statement")
to Tenant showing: (a) the amount of actual Taxes and Operating Expenses for
such calendar year, with a listing of amounts for major categories of Operating
Expenses, (b) any amount paid by Tenant towards Taxes and Operating Expenses
during such calendar year on an estimated basis, and (c) any revised estimate of
Tenant's obligations for Taxes and Operating Expenses for the current calendar
year in excess of Taxes and Operating Expenses paid in the 1999 calendar year.

         (iii) If the Statement shows that Tenant's estimated payments were less
than Tenant's actual obligations for Taxes and Operating Expenses for such year,
Tenant shall pay the difference. If the Statement shows an increase in Tenant's
estimated payments for the current calendar year, Tenant shall pay the
difference between the new and former estimates, for the period from January 1
of the current calendar year through the month in which the Statement is sent.
Tenant shall make such payments within thirty (30) days after Landlord sends the
Statement. Tenant's obligations to make the foregoing payments shall survive the
expiration or earlier termination of this Lease.

         (iv) If the Statement shows that Tenant's estimated payments exceeded
Tenant's actual obligations for Taxes and Operating Expenses, Tenant shall
receive a credit for the difference against payments of Rent next due. If the
Term shall have expired and no further Rent shall be due, Tenant shall receive a
refund of such difference, within thirty (30) days after Landlord sends the
Statement.

         (v) Landlord reserves the right to reasonably change, from time to
time, the manner or timing of the foregoing payments. In lieu of providing one
Statement covering Taxes and Operating Expenses, Landlord may provide separate
statements, at the same or different times. No delay by Landlord in providing
the Statement (or separate statements) shall be deemed a default by Landlord or
a waiver of Landlord's right to require payment of Tenant's obligations for
actual or estimated Taxes or Operating Expenses.

         (D) PRORATION. If the Term commences other than on January 1, or ends
other than on December 31, Tenant's obligations to pay estimated and actual
amounts towards Taxes and Operating Expenses for such first or final calendar
years shall be prorated to reflect the portion of such years included in the
Term. Such proration shall be made by multiplying the total estimated

                                       2
<PAGE>   6

or actual (as the case may be) Taxes and Operating Expenses, for such calendar
years by a fraction, the numerator of which shall be the number of days of the
Term during such calendar year, and the denominator of which shall be 365. A
similar proration shall be made each time Tenant's Prorata Share changes during
any calendar year.

         (E) LANDLORD'S RECORDS. Landlord shall maintain records respecting
Taxes and Operating Expenses and determine the same in accordance with sound
accounting and management practices, consistently applied. Although this Lease
contemplates the computation of Taxes and Operating Expenses on a cash basis,
Landlord shall make reasonable and appropriate accrual adjustments to ensure
that each calendar year includes substantially the same recurring items.
Landlord reserves the right to change to a full accrual system of accounting so
long as the same is consistently applied and Tenant's obligations are not
materially adversely affected. Tenant or its representative shall have the right
to examine such records upon reasonable prior notice specifying such records
Tenant desires to examine, during normal business hours at the place or places
where such records are normally kept by sending such notice no later than
forty-five (45) days following the furnishing of the Statement. Tenant may take
exception to matters included in Taxes or Operating Expenses, or Landlord's
computation of Tenant's Prorata Share of either, by sending notice specifying
such exception and the reasons therefor to Landlord no later than ninety (90)
days after Landlord makes such records available for examination. Such Statement
shall be considered final, except as to matters to which exception is taken
after examination of Landlord's records in the foregoing manner and within the
foregoing times. Tenant acknowledges that Landlord's ability to budget and incur
expenses depends on the finality of such Statement, and accordingly agrees that
time is of the essence of this Paragraph. If Tenant takes exception to any
matter contained in the Statement as provided herein, Landlord shall refer the
matter to an independent certified public accountant, whose certification as to
the proper amount shall be final and conclusive as between Landlord and Tenant.
Tenant shall promptly pay the cost of such certification, unless such
certification determines that Tenant was overbilled by more than four percent
(4%). Pending resolution of any such exceptions in the foregoing manner, Tenant
shall continue paying Tenant's Prorata Share of Taxes and Operating Expenses in
the amounts determined by Landlord, subject to adjustment after any such
exceptions are so resolved.

         (F) RENT AND OTHER CHARGES. Base Rent, Taxes, Operating Expenses, and
any other amounts which Tenant is or becomes obligated to pay Landlord under
this Lease or other agreement entered in connection herewith, are sometimes
herein referred to collectively as "Rent," and all remedies applicable to the
non-payment of Rent shall be applicable thereto. Rent shall be paid at any
office maintained by Landlord or its agent at the Property or at such other
place as Landlord may designate.

         (G) INDEPENDENT COVENANTS. The obligation of Tenant to pay Rent
hereunder and the obligation of Tenant to perform Tenant's other covenants and
duties hereunder constitute independent unconditional obligations to be
performed at all times provided for hereunder. Except as expressly provided in
this Lease, Tenant waives and relinquishes all rights which Tenant might have to
claim any nature of lien, or to withhold, abate or deduct from, or offset
against, Rent except as specifically provided herein.

                                    ARTICLE 4
                              COMMENCEMENT OF TERM

         The Commencement Date set forth in Article 1 shall be delayed and Rent
shall be abated to the extent that Landlord fails for any reason, including, but
not limited to, holding over by prior occupants, to deliver possession of the
Premises to Tenant on or before May 1, 1999 (the "Delivery Date") for Tenant to
occupy space. If Landlord fails to deliver possession of the Premises as
aforesaid on or before the date which is one hundred fifty (150) days from the
Delivery Date, as the Delivery Date is extended by delays caused by Force
Majeure (as hereinafter defined), then, as Tenant's sole and exclusive remedy,
Tenant shall have the right to terminate this Lease without further liability of
Landlord or Tenant, by written notice to Landlord given within the ten (10)-day
period immediately following such one hundred fifty (150)-day period, as such
one hundred fifty (150)-day period may be extended by delays caused by Force
Majeure, but, in any case, such notice of termination shall not be effective if
Landlord delivers possession of the Premises prior to the end of such ten
(10)-day period. Notwithstanding anything in the foregoing sentence to the
contrary, if Landlord is performing work in the Premises to make it ready for
Tenant to perform the Work and if substantial completion of such work by
Landlord is

                                       3
<PAGE>   7

delayed, in whole or in part, by any act or omission by Tenant or any of
Tenant's contractors, agents, or employees ("Tenant Delay"), then delivery of
possession shall be deemed to have occurred on the date substantial completion
by Landlord would have occurred but for any such Tenant Delay. Any delay in the
Delivery Date shall not subject Landlord to liability for loss or damage
resulting therefrom, and Tenant's sole recourse with respect thereto shall be
the abatement of Rent and right to terminate this Lease as described above. Upon
any such termination, Landlord and Tenant shall be entirely relieved of their
obligations hereunder, and any Security Deposit and Rent payments shall be
returned to Tenant; provided, however, any of Tenant's indemnity obligations
pursuant to this Lease shall survive such termination. If the Delivery Date is
delayed, the Expiration Date shall not be similarly extended, unless Landlord
shall so elect (in which case, the parties shall confirm the same writing).

         As used herein, "Force Majeure" shall mean fire or other casualty,
strikes, lock-outs or other labor troubles, shortages of equipment or materials,
governmental requirements, power shortages or outages, acts or omissions of
Tenant or other Persons, or other causes beyond Landlord's reasonable control.

         In the event that, pursuant to the provisions of this Article 4, the
Commencement Date shall be a date other than the date originally fixed for the
Commencement Date in Article 1 of this Lease, Tenant agrees, upon demand of
Landlord, to execute, acknowledge, and deliver to Landlord a signed instrument,
in form satisfactory to Landlord, setting forth the Commencement Date.

                                    ARTICLE 5
                              CONDITION OF PREMISES

         Tenant's taking possession of the Premises or any portion thereof for
any purpose shall be conclusive evidence against Tenant that the Premises and
the Property, Systems and Equipment (as defined in Article 25) were then in good
order and satisfactory condition, and Tenant represents and warrants that Tenant
has had ample opportunity to inspect the Premises, and agrees to accept the same
"as is" except as specifically set forth in Article 39. No promises of Landlord
to alter, remodel, improve, repair, decorate or clean the Premises or any part
thereof, or the Building, or any part thereof, have been made, and no
representation, either express or implied, respecting the habitability,
suitability, quality, fitness for any particular purpose, or condition of the
Premises or the Building has been made to Tenant by or on behalf of Landlord,
except to the extent expressly set forth in this Lease.

                                    ARTICLE 6
                                  USE AND RULES

         Tenant shall use the Premises for offices in the Tower Premises and the
operation of networking equipment and all equipment and appurtenances thereto
for the operation of a telecommunication operation in the Annex Premises and no
other purpose whatsoever, in compliance with all applicable Laws and without
disturbing or interfering with any other tenant or occupant of the Property.
Tenant shall not use the Premises in any manner so as to cause a cancellation of
Landlord's insurance policies, or an increase in the premiums thereunder. Tenant
shall comply with all rules set forth in Rider One attached hereto (the
"Rules"). Landlord shall have the right to reasonably amend such Rules and
supplement the same with other reasonable Rules relating to the Property, for
the promotion of safety, care, cleanliness or good order therein, and all such
amendments or new Rules shall be binding upon Tenant after five (5) days notice
thereof to Tenant provided same do not materially affect Tenant's rights under
the Lease and use of the Premises unless mandated by municipal, county, state,
federal or other government law, statute, code, and/or regulation. All Rules
shall be applied on a non-discriminatory basis, but nothing herein shall be
construed to give Tenant or any other Person (as defined in Article 25) any
claim, demand or cause of action against Landlord arising out of the violation
of such Rules by any other tenant, occupant, or visitor of the Property, or out
of the enforcement or waiver of the Rules by Landlord in any particular
instance.

                                       4
<PAGE>   8

                                    ARTICLE 7
                             SERVICES AND UTILITIES

         (a) Landlord shall provide the following services and utilities (the
cost of which shall be included in Operating Expenses) as long as Tenant is not
in Default (as hereinafter defined) under any of the covenants of this Lease:

         (i) In the Tower Premises only, heat and air-cooling for occupancy of
the Premises under normal business operations in accordance with the HVAC
Specifications attached hereto as Exhibit B-1 from the hours of 8:00 a.m. until
6:00 p.m. Monday through Friday and 8:00 a.m. until 1:00 p.m. Saturday, except
on Holidays (as defined in Article 25). Landlord shall not be responsible for
inadequate air-cooling or ventilation to the extent the same occurs because
Tenant uses any item of equipment consuming more than 500 watts at rated
capacity without providing adequate air-conditioning and ventilation therefor.
Provided Tenant has submitted HVAC equipment specifications to Landlord and
provided Landlord has approved same prior to its installation, Tenant shall have
the right to control Tenant-installed heat and air cooling for the Annex
Premises.

         (ii) Domestic water for drinking, lavatory and toilet purposes at those
points of supply provided for nonexclusive general use of other tenants at the
Property. Tenant shall pay Landlord as additional rent at rates fixed by
Landlord for domestic water and hot water furnished for any other purpose.

         (iii) Office cleaning, and trash removal service Monday through Friday
or Sunday through Thursday in and about the Premises in accordance with Exhibit
B attached hereto and made a part hereof. Tenant shall not provide or use any
other janitor or cleaning service. Landlord may impose reasonable charges for
any cleaning service performed by Landlord in the Premises above or beyond the
levels or quantities described in Exhibit B, and Tenant shall promptly pay such
charges as additional rent hereunder.

         (iv) Operatorless passenger elevator service and freight elevator
service (subject to scheduling by Landlord) in common with Landlord and other
tenants and their contractors, agents and visitors.

         (b) Landlord and Tenant agree that Tenant shall submeter its Annex
Premises at Tenant's cost, and all electric costs shall be paid for by the
Tenant as additional rent paid to the Landlord in an amount to be determined by
Landlord, based upon the actual cost thereof of electric current consumption
separately metered, plus an amount equal to fifteen percent (15%) of such cost
as an overhead and supervision fee.

         Pertaining to the Tower Premises only, no electric current shall be
used except that furnished or approved by Landlord, nor shall electric cable or
wire be brought into the Leased Premises, except upon the written consent and
approval of the Landlord, such approval not to be unreasonably withheld. Tenant
shall use only office machines and equipment that operate on the Building's
standard electric circuits, but which in no event shall overload the Building's
standard electric circuits from which the Tenant obtains electric current.

         Provided Tenant has submitted generator equipment specifications to
Landlord and provided Landlord has approved same, Tenant shall have the right to
install a generator for the Annex Premises. It is acknowledged that Tenant shall
have its own generator as an electrical power back-up source for the Annex
Premises and that the use of said back-up source in the event of a power failure
is permissible under this Lease without the prior approval of Landlord. Landlord
shall bear no responsibility for the maintenance and/or operation of Tenant's
generator. Tenant shall hold Landlord harmless from any damage or malfunction of
said generator, unless such damage or malfunction is from the gross negligence
or willful misconduct of Landlord, its employees or agents.

                                       5
<PAGE>   9

         (c) Telephone service shall not be furnished by Landlord. Landlord
shall permit Tenant to receive such service direct from any telephone company
serving the area at Tenant's cost, and shall permit Landlord's telephone
building riser cable, to the extent available, to be used for such purposes.
Tenant shall also have the right to install/drop its own riser cable. Landlord
shall require Tenant to contract directly for such access with a company which
is managing the use of the telephone cable riser in the Building. However,
Landlord acknowledges that the telephone company serving Tenant shall have
access to the Premises and Landlord's telephone building riser cable and chase
way to the extent necessary for the installation, maintenance and repair of
Tenant's telephone service, and Tenant acknowledges that it shall arrange with
Landlord for access to common area telephone closets; Landlord shall provide
Tenant with prompt access to common telephone closets upon request. Tenant shall
make all necessary arrangements with the telephone company for paying for the
telephone service furnished by it to Tenant, and Tenant shall pay for all
charges for telephone service and riser cable access. Neither Tenant nor
Tenant's telephone company nor their respective agents, employees, licensees,
invitees or contractors shall make any alterations, additions or repairs to
Landlord's telephone building riser cable, telephone wires, telephone junction
boxes or telephone wire conduits, without the prior written consent of Landlord.
Tenant shall be liable for any damage done to Landlord's telephone building
riser cable, telephone wires, telephone junction boxes or telephone wire
conduits as a result of Tenant or Tenant's telephone company's or their
respective agents, employees, licensees, invitees or contractors alteration,
addition, maintenance or repair of Tenant's telephone system and Landlord may,
at its option, repair such damage and Tenant shall upon demand by Landlord
reimburse Landlord for all costs of such repair and damages.

         (d) As to the Tower Premises only, Landlord may, but shall have no
obligation to, provide such extra utilities or services as Tenant may from time
to time request, if the same are reasonable and feasible for Landlord to provide
and do not involve modifications or additions to the Property or existing
Systems and Equipment (as defined in Article 25), and if Landlord shall receive
Tenant's request within a reasonable period prior to the time such extra
utilities or services are required. Landlord may comply with written or oral
requests by any officer or employee of Tenant, unless Tenant shall notify
Landlord of, or Landlord shall request, the names of authorized individuals (up
to 3 for each floor on which the Premises are located) and procedures for
written requests Tenant shall, for such extra utilities or services, pay such
charges as Landlord shall from time to time reasonably establish. All charges
for such extra utilities or services shall be due at the same time as the
installment of Base Rent with which the same are billed, or if billed
separately, shall be due within twenty (20) days after such billing. Failure by
Tenant to promptly pay Landlord's proper charges for extra utilities or services
shall give Landlord the right, in addition to any other remedies available to
Landlord, to discontinue furnishing such utilities or services, and no such
discontinuance shall be deemed an eviction or disturbance of Tenant's use of the
Premises or render Landlord liable for damages or relieve Tenant from
performance of Tenant's obligations under this Lease.

         As to the Annex Premises only, the Annex Premises shall be separately
metered with no limitations on the amount of electricity used by Tenant, and
Tenant shall pay the cost for same (not to exceed Landlord's cost) to Landlord
quarterly.

         (e) Landlord may install and operate meters or any other reasonable
system for monitoring or estimating any services or utilities used by Tenant in
excess of those required to be provided by Landlord under this Article
(including a system for Landlord's engineer to reasonably estimate any such
excess usage). If such system indicates such excess services or utilities,
Tenant shall pay Landlord's reasonable charges for installing and operating such
system and any supplementary air-conditioning, ventilation, heat, electrical or
other systems or equipment (or adjustments or modifications to the existing
Systems and Equipment), and Landlord's reasonable charges for such amount of
excess services or utilities used by Tenant.

         (f) Tenant agrees that Landlord does not warrant that any services or
utilities will be free from shortages, failures, variations, or interruptions
caused by repairs, maintenance, replacements, improvements, alterations, changes
of service, strikes, lockouts, labor controversies, accidents, inability to
obtain services, fuel, steam, flood, water or supplies, governmental
requirements or requests, act or omission of Tenant or any other tenant or
occupant of the Building, or other causes beyond Landlord's control. None of the
same shall be deemed an eviction or disturbance of Tenant's use and possession
of the Premises or any part thereof, or render Landlord liable to Tenant for
abatement of Rent, or otherwise or relieve Tenant from performance of Tenant's
obligations under this Lease. Landlord and Landlord's beneficiaries (if Landlord
is a trustee of a land trust), and their respective agents shall in no event be
liable to

                                       6
<PAGE>   10

Tenant for damages by reason of loss of profits, business interruption or other
consequential damages.

         (g) Whenever, in Landlord's reasonable judgment, Tenant's use or
occupancy of the Premises, including lighting, personnel, heat generating
machines or equipment, or airborne emissions of smoke or other particulates,
individually or cumulatively, causes the design loads for the system providing
heat and air-cooling to be exceeded, or otherwise affects adversely the
temperature, humidity or air quality otherwise maintained by the heating,
ventilating and air handling or conditioning system in the Premises or the
Building, Landlord may, but shall not be obligated to, temper such excess loads
by installing supplementary heating or air handling or air cooling units in the
Premises or elsewhere where necessary. In such event, the cost of such units and
the expense of installation, including, without limitation, the cost of
preparing working drawings and specifications, plus fifteen percent (15%) of
such cost as an overhead and supervision fee, shall be paid by Tenant as
additional rent within ten (10) days after Landlord's demand therefor.
Alternatively, Landlord may require Tenant to install such supplementary heating
or air handling or air cooling units at Tenant's sole expense. Landlord may
operate and maintain any such supplementary units, but shall have no continuing
obligation to do so or liability in connection therewith. The expense resulting
from the operation and maintenance of any such supplementary heating or air
handling or cooling units, including rent for space occupied by any
supplementary heating or air handling or cooling units installed in rentable
area outside the Premises, shall be paid by Tenant to Landlord as additional
rent at rates fixed by Landlord.

         (h) Compliance with any mandatory or voluntary energy conservation
measures or other legal requirements instituted by any appropriate governmental
authority shall not be considered a violation of any terms of this Lease and
shall not entitle Tenant to terminate this Lease or require abatement or
reduction of Rent hereunder, unless compliance with same materially affects
Tenant's use of the Premises as set forth herein.

         (i) Notwithstanding anything contained in the Lease to the contrary,
Landlord acknowledges that Tenant will be installing a generator and related
equipment on the roof of the Annex Building and Landlord agrees to cooperate
with Tenant in all appropriate and necessary linking with Tenant's operations in
the Building, provided Tenant has submitted generator equipment specifications
to Landlord and provided Landlord has approved same, such approval not to be
unreasonably withheld. Landlord shall bear no responsibility for the maintenance
and/or operation of Tenant's generator. Tenant shall hold Landlord harmless
from any damage or malfunction of said generator, unless such damage or
malfunction is from the gross negligence or willful misconduct of Landlord, its
employees or agents.

         (j) Notwithstanding anything contained in this Article 7 to the
contrary, Landlord shall not restrict Tenant's right to install and maintain
(either by its own employees or third parties) all wiring, linkups, cables and
equipment necessary to Tenant's networking and telecommunication operation
provided installation and maintenance of same does not materially affect base
building systems to include but not limited to HVAC, electrical, fire safety,
and plumbing systems.

                                    ARTICLE 8
                              ALTERATIONS AND LIENS

         Tenant shall make no additions, changes, alterations or improvements
("Alterations") to the Premises or the Systems and Equipment (as defined in
Article 25) pertaining to the Premises without in each instance the prior
written consent of Landlord. Landlord may impose such requirements upon Tenant
as Landlord may deem to be necessary or advisable as a condition of such
consent, including without limitation, submitting plans and specifications for
Landlord's prior written approval, obtaining necessary permits, posting bonds,
obtaining insurance, prior approval of contractors, subcontractors and
suppliers, prior receipt of copies of all contracts and subcontracts, contractor
and subcontractor lien waivers, affidavits listing all contractors,
subcontractors and suppliers, use of union labor, affidavits from engineers
acceptable to Landlord stating that the Alterations will not adversely affect
the Systems and Equipment or the structure of the Property, and requirements as
to the manner and times in which such Alterations shall be done. All Alterations
shall be at Tenant's expense and shall comply with all insurance requirements
and with all Laws. All Alterations shall be performed in a good and workmanlike
manner and all materials used shall be of a quality comparable to or better than
those in the Premises and Property and shall be in accordance with plans and
specifications approved by

                                       7
<PAGE>   11

Landlord, and Landlord may require that all such Alterations be performed under
Landlord's supervision. In all cases, Tenant shall pay Landlord a reasonable fee
not to exceed fifteen percent (15%) of the cost of the Alterations to cover
Landlord's overhead in reviewing Tenant's plans and specifications and
performing any supervision of the Alterations. Landlord's approval of Tenant's
plans and specifications shall create no responsibility or liability on the part
of Landlord and their agents for the completeness, design, sufficiency, or
compliance with Laws of such plans and specifications. If Landlord consents to
or supervises the Alterations, consent or supervision shall not be deemed a
warranty by Landlord or their agents as to the adequacy of the workmanship or
quality or materials, and Landlord hereby expressly disclaims any responsibility
or liability for the same except for that which is cause by Landlord's gross
negligence or willfull misconduct. Landlord shall under no circumstances have
any obligation to repair, maintain or replace any portion of the Alterations.

         Tenant shall keep the Property and Premises free from any mechanic's,
materialman's or similar liens or other such encumbrances in connection with any
Alterations on or respecting the Premises and shall indemnify and hold Landlord
harmless from and against any claims, liabilities, judgments, or costs
(including attorneys' fees) arising out of the same or in connection therewith.
Tenant shall give Landlord notice at least twenty (20) days prior to the
commencement of any Alterations on the Premises (or such additional time as may
be necessary under applicable Laws), to afford Landlord the opportunity of
posting and recording appropriate notices of non-responsibility. Tenant shall
remove any such lien or encumbrance by bond or otherwise within ten (10) days
after written notice by Landlord, and if Tenant shall fail to do so, Landlord
may pay the amount necessary to remove such lien or encumbrance, without being
responsible for investigating the validity thereof. The amount so paid, with
interest at the Default Rate (as defined in Article 25) on the amounts owed by
Tenant to Landlord, shall be deemed additional Rent under this Lease payable
upon demand, without limitation as to other remedies available to Landlord under
this Lease. Nothing contained in this Lease shall authorize Tenant to do any act
which shall subject Landlord's title to the Property or Premises to any liens or
encumbrances whether claimed by operation of law or express or implied contract.
Any claim to a lien or encumbrance upon the Property or Premises arising in
connection with any Alterations on or respecting the Premises not performed by
or at the request of Landlord shall be null and void, or at Landlord's option
shall attach only against Tenant's interest in the Premises and shall in all
respects be subordinate to Landlord's title to the Property and Premises.
Nothing contained herein shall prohibit Tenant from contesting the validity of
any lien.

                                    ARTICLE 9
                                     REPAIRS

         Tenant shall, at its own expense, keep the Premises in good and
sanitary condition and working order and repair (including, without limitation,
any and all carpeting, wallcovering, doors, plumbing and other fixtures,
equipment, alterations, and improvements contained within the Premises and
exclusively servicing the Premises, whether any of the foregoing was installed
by Landlord or Tenant), and in conformity with all Laws, except if Landlord
elects to make such repairs at Tenant's expense as hereinafter provided. Tenant
shall promptly and adequately repair all damage to the Premises caused by Tenant
or any of its employees, agents, licensees, invitees or contractors, including
replacing or repairing all damaged or broken glass, fixtures and appurtenances
resulting from any such damage, with materials approved in advance by Landlord
and within any reasonable period of time approved by Landlord. Landlord may, but
shall have no obligation to, elect to make any or all repairs on Tenant's behalf
at Tenant's sole cost or, upon Tenant's request, perform any such repairs at
Tenant's sole cost. In either case where Landlord has made such election to
perform repairs, Tenant shall pay the cost thereof and, in addition, Tenant
shall pay to Landlord an amount equal to fifteen percent (15%) of such cost as
an overhead and supervision fee. If Tenant does not make repairs within a
reasonable time and adequately when required to do so (Landlord having not
previously elected to do so), Landlord may, but need not, make such repairs and
replacements and Tenant shall pay Landlord, on written demand, the cost thereof.
Subject to the foregoing, at Landlord's election, any repairs, maintenance or
replacements made by Tenant shall either be through Landlord for such reasonable
charges as Landlord may from time to time establish, or such contractors as
Landlord generally uses at the Property or such other contractors as Landlord
shall first approve in writing, and in a first class, workmanlike manner
approved by Landlord in advance in writing, such approval not to be unreasonably
withheld. If Tenant does not promptly make such arrangements, Landlord may, but
need not, make such repairs, maintenance and replacements, and the costs paid or
incurred by Landlord therefor, with interest at the Default Rate (as defined in
Article 25) on the amounts owed by Tenant to Landlord, shall be reimbursed by
Tenant promptly after request

                                       8
<PAGE>   12

by Landlord. Tenant shall indemnify Landlord and pay for any repairs,
maintenance and replacements to areas of the Property outside the Premises,
caused, in whole or in part, as a result of moving any furniture, fixtures, or
other property to or from the Premises, or by Tenant or its employees, agents,
contractors, or visitors (notwithstanding anything to the contrary contained in
this Lease). Except as provided in the preceding sentence, or for damage covered
under Article 10, Landlord shall keep the common areas of the Property in good
and sanitary condition, working order and repair (the cost of which shall be
included in Operating Expenses, as described in Article 25, except as limited
therein).

                                   ARTICLE 10
                               CASUALTY INSURANCE

         (a) If the Premises or any common areas of the Property providing
access thereto shall be damaged by fire or other casualty, and except as
otherwise provided in this Article 10, Landlord shall restore the same to the
Base Building improvements, but in no event shall Landlord be obligated to
expend any sums in excess of insurance proceeds available to Landlord or which
should have been available if Landlord was adequately insured pursuant to
Article 11 (e) of this Lease. Such restoration shall be to substantially the
condition prior to the casualty, except for modifications required by zoning and
building codes and other Laws or by any Mortgagee or Ground Lessor, any other
modifications to the common areas deemed reasonably desirable by Landlord and
except that Landlord shall not be required to repair or replace any of Tenant's
furniture, furnishings, fixtures or equipment, or any alterations or
improvements, additions or alterations made by or on behalf of Tenant in the
Premises, including improvements performed by Tenant or Landlord pursuant to the
Workletter, if any. Landlord shall not be liable for any inconvenience or
annoyance to Tenant or its visitors, or injury to Tenant's business resulting in
any way from such damage or the repair thereof. However, Landlord shall allow
Tenant a proportionate abatement of Rent during the time and to the extent the
Premises are unfit for occupancy for the purposes permitted under this Lease and
not occupied by Tenant as a result thereof (unless Tenant or its employees or
agents caused the damage). Notwithstanding anything contained in this Article 10
to the contrary, Landlord may elect to terminate this Lease by notifying Tenant
in writing of such termination within sixty (60) days after the date of damage
(such termination notice to include a termination date providing at least ninety
(90) days for Tenant to vacate the Premises), if the Property shall be
materially damaged by Tenant or its employees or agents, or if the Property
shall be damaged by fire or other casualty or cause such that: (i) repairs to
the Premises and access thereto or to the Building cannot reasonably be
completed within 120 days after the casualty without the payment of overtime or
other premiums, (ii) more than 25% of the Premises is affected by the damage,
and fewer than 24 months remain in the Term, or any material damage occurs to
the Premises during the last 12 months of the Term, (iii) any Mortgagee or
Ground Lessor shall require that the insurance proceeds or any portion thereof
be used to retire the Mortgage debt (or shall terminate the Ground Lease, as the
case may be), or the damage is not fully covered by Landlord's insurance
policies, or (iv) the cost of the repairs, alterations, restoration or
improvement work would exceed 25% of the replacement value of the Building, or
the nature of such work would make termination of this Lease necessary. Tenant
agrees that Landlord's obligation to restore, and the abatement of Rent provided
herein, shall be Tenant's sole recourse in the event of such damage, and waives
any other rights Tenant may have under any applicable Law to terminate the Lease
by reason of damage to the Premises or Property. In the event of termination of
this Lease pursuant to this Article 10, Rent shall be apportioned on a per diem
basis and be paid to the date of termination. Tenant acknowledges that this
Article represents the entire agreement between the parties respecting damage to
the Premises or Property.

         In the event of damage to the Premises or to the Building which
Landlord is obligated to or elects to repair pursuant to this Article, if
Landlord shall not have commenced such repairs within one hundred eighty (180)
days of the date of the casualty or, once commenced, Landlord fails to restore
the Premises (to a state whereby Tenant can commence its work) within twelve
(12) months, Tenant may elect to terminate this Lease upon thirty (30) days
prior written notice to Landlord.

         (b) In the event of any such fire or other casualty, and if this Lease
is not terminated pursuant to the foregoing provisions of this Article 10,
Tenant shall repair and restore any portion of alterations, additions or
improvements made by or on behalf of Tenant in the Premises which Landlord is
not required to restore under paragraph 10(a) hereof excluding any restoration
to the Base Building Improvements not covered by Tenant's insurance.

                                       9
<PAGE>   13

                                   ARTICLE 11
                             INSURANCE; SUBROGATION

         (a) Tenant shall maintain during the Term or at any earlier time that
Tenant is entitled to occupy the Premises, comprehensive (or commercial) public
liability insurance with the broad form commercial liability endorsement,
including contractual liability insurance covering Tenant's indemnity
obligations hereunder, insuring against claims for death, bodily injury,
personal injury and property damage or destruction (including loss of use
thereof) occurring upon, in or about the Premises in an amount of not less than
$2,000,000 for any one occurrence. Tenant shall also maintain during the Term
worker compensation insurance as required by statute, and primary,
noncontributory, "all-risk" property damage insurance covering all additions,
improvements and alterations to the Premises, and all of Tenant's personal
property, business records, fixtures and equipment, for damage or other loss
caused by fire or other casualty or cause including, but not limited to, fire,
vandalism and malicious mischief, theft, water damage of any type, including
sprinkler leakage, bursting or stoppage of pipes, explosion, business
interruption, and other insurable risks included in extended coverage policies,
in amounts not less than the full insurable replacement value of such additions,
improvements and alterations, and property and full insurable value of such
other interests of Tenant (subject to reasonable deductible amounts).

         (b) Prior to the Commencement Date and any earlier time that Tenant is
entitled to occupy the Premises, or any portion thereof, Tenant shall provide
Landlord with certified copies of policies (with proof of payment in full of the
annual premium) evidencing such coverage (and, with respect to liability
coverage, naming, as additional insureds, Landlord, or any Building manager, all
Mortgagees (as hereinafter defined), and if Landlord requires, Landlord's
architect or contractor who may perform services or work in, on, about or in
connection with the Premises; and their respective agents, contractors,
managers, members, partners and employees, as their interests may appear.
Tenant's policies shall state that such insurance coverage may not be changed,
amended, nor renewed or cancelled without at least thirty (30) days' prior
written notice to Landlord. Such policies shall provide renewal certificates to
Landlord at least twenty (20) days prior to expiration of such policies.
Landlord shall have the right, from time to time, to require that Tenant
increase the amount and/or type of coverage required to be maintained by Tenant
under this Lease in accordance with standard business practice for similar
property in the Nashville area. Each policy evidencing the insurance to be
carried by Tenant under this Lease shall contain a clause that such policy and
the coverage as evidenced thereby shall be primary with respect to any policies
carried by Landlord, and that any coverage carried by Landlord shall be excess
insurance. Except as provided to the contrary herein, any insurance carried by
Landlord or Tenant shall be for the sole benefit of the party carrying such
insurance. All insurance required hereunder to be carried by Tenant shall be on
an "occurrence" rather than a "claims made" basis, and shall be provided by
insurers acceptable to Landlord and licensed in the State of Tennessee. Such
insurer shall at all times during the Term have a policyholder's rating of not
less than "A- and 7" in the most current edition of Best's Reports.

         (c) By this Article, Landlord and Tenant intend that their respective
property loss risks shall be borne by responsible insurance carriers to the
extent above provided, and Landlord and Tenant hereby agree to look solely to
and seek recovery only from, their respective insurance carriers in the event of
a property loss to the extent that such coverage is agreed to be provided
hereunder. The parties each hereby waive all rights and claims against each
other, for such losses, and waive all rights of subrogation of their respective
insurers. The parties agree that their respective insurance policies are now, or
shall be, endorsed such that said waiver of subrogation shall not affect the
right of the insured to recover thereunder.

         (d) Tenant shall comply with all applicable Laws, all orders and
decrees of court and all requirements of other governmental authority, and shall
not directly or indirectly make any use of the Premises which may thereby be
prohibited or be dangerous to person or property or which may jeopardize any
insurance coverage, or cause any increase in the cost of insurance or require
additional insurance coverage; or which shall be hazardous or toxic or violate
any environmental laws.

         (e) Landlord shall maintain all such insurance policies as are standard
and commercially prudent for landlords to maintain in the Nashville area for
similar properties.

                                       10
<PAGE>   14

                                   ARTICLE 12
                                  CONDEMNATION

         If the whole or any material part of the Premises or Property shall be
taken by power of eminent domain or condemned by any competent authority for any
public or quasi-public use or purpose, or if any adjacent property or street
shall be so taken or condemned, or reconfigured or vacated by such authority in
such manner as to require the use, reconstruction or remodeling of any part of
the Premises or Property, or if Landlord shall grant a deed or other instrument
in lieu of such taking by eminent domain or condemnation, the Term of this Lease
shall end upon and not before the earlier of the date when the possession of the
part so taken shall be required for such use or purpose, and the effective date
of the taking. Landlord shall be entitled to receive the entire award or payment
in connection therewith, except that Tenant shall have the right to file any
separate claim available to Tenant for any taking of Tenant's personal property
and fixtures belonging to Tenant and removable by Tenant upon expiration of the
Term, and for moving expenses (so long as such claim does not diminish the award
available to Landlord or any Holder, and such claim is payable separately to
Tenant). All Rent shall be apportioned as of the date of such termination, or
the date of such taking, whichever shall first occur. If any part of the
Premises shall be taken, and this Lease shall not be so terminated, the Rent
shall be proportionately abated.

                                   ARTICLE 13
                              RETURN OF POSSESSION

         At the expiration or earlier termination of this Lease or Tenant's
right of possession, Tenant shall surrender possession of the Premises in the
condition required under Article 9, ordinary wear and tear and damage due to
casualty not covered by either party's insurance excepted, and shall surrender
all keys any key cards, and any parking stickers or cards, to Landlord, and
advise Landlord as to the combination of any locks vaults then remaining in the
Premises, and shall remove all trade fixtures and personal property and shall
promptly remove all wiring and cabling. All improvements, fixtures and other
items in or upon the Premises (except trade fixtures and personal property
belonging to Tenant, whether installed by Tenant or Landlord) shall be
Landlord's property and shall remain upon the Premises, all without
compensation, allowance or credit to Tenant. Without limiting anything contained
in the immediately preceding sentence, Tenant shall promptly repair any damage
to the Premises occasioned by Tenant's removal of its trade fixtures or personal
property. If Tenant shall fail to perform any repairs or restoration, or fail to
remove any items from the Premises required hereunder, Landlord may do so, and
Tenant shall pay Landlord the cost thereof upon demand. All property removed
from the Premises by Landlord pursuant to any provisions of this Lease or any
Law may be handled or stored by Landlord at Tenant's expense, and Landlord shall
in no event be responsible for the value, preservation or safekeeping thereof.
Any property not removed from the Premises or retaken from storage by Tenant
within thirty (30) days after expiration or earlier termination of this Lease or
Tenant's right to possession, shall at Landlord's option be conclusively deemed
to have been conveyed by Tenant to Landlord as if by bill of sale without
payment by Landlord. Unless prohibited by applicable Law, Landlord shall have a
lien against such property for the costs incurred in removing and storing the
same.

                                       11
<PAGE>   15

                                   ARTICLE 14
                                  HOLDING OVER

         Unless Landlord expressly agrees otherwise in writing, Tenant shall pay
Landlord 150% of the amount of Rent then applicable (or the highest amount
permitted by Law, whichever shall be less) prorated on a per diem basis for each
day Tenant shall retain possession of the Premises or any part thereof after
expiration or earlier termination of this Lease. The foregoing provisions shall
not serve as permission for Tenant to hold-over, nor serve to extend the Term
(although Tenant shall remain bound to comply with all provisions of this Lease
until Tenant vacates the Premises, and shall be subject to the provisions of
Article 13). Notwithstanding the foregoing to the contrary, at any time before
or after expiration or earlier termination of the Lease, Landlord may serve
notice advising Tenant of the amount of Rent and other terms required, should
Tenant desire to enter a month-to-month tenancy (and if Tenant shall hold over
more than one full calendar month after such notice, Tenant shall thereafter be
deemed a month-to-month tenant, on the terms and provisions of this Lease then
in effect, as modified by Landlord's notice, and except that Tenant shall not be
entitled to any renewal or expansion rights contained in this Lease or any
amendments hereto).

                                   ARTICLE 15
                                    NO WAIVER

         No provision of this Lease will be deemed waived by either party unless
expressly waived in writing signed by the waiving party. No waiver shall be
implied by delay or any other act or omission of either party. No waiver by
either party of any provision of this Lease shall be deemed a waiver of such
provision with respect to any subsequent matter relating to such provision, and
Landlord's consent or approval respecting any action by Tenant shall not
constitute a waiver of the requirement for obtaining Landlord's consent or
approval respecting any subsequent action. Acceptance of Rent by Landlord shall
not constitute a waiver of any breach by Tenant of any term or provision of this
Lease. No acceptance of a lesser amount than the Rent herein stipulated shall be
deemed a waiver of Landlord's right to receive the full amount due, nor shall
any endorsement or statement on any check or payment or any letter accompanying
such 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 full amount due. The acceptance of Rent or of the performance of any other
term or provision from any Person other than Tenant, including any Transferee,
shall not constitute a waiver of Landlord's right to approve any Transfer.

                                   ARTICLE 16
                      ATTORNEYS' FEES AND JURY TRIAL; VENUE

         (a) Tenant shall pay all of Landlord's costs, charges and expenses,
including, without limitation, court costs and reasonable attorney's fees,
incurred in enforcing Tenant's obligations under this Lease or incurred by
Landlord in any litigation, negotiation or transaction in which Tenant causes
Landlord, without Landlord's fault, to become involved or concerned. Landlord
shall pay all of Tenant's costs, charges and expenses, including and without
limitation, court costs and reasonable attorney's fees, (i) in enforcing
Landlord's obligations under this Lease, or (ii) incurred by Tenant in any
litigation, negotiation, or transaction in which Landlord causes Tenant, without
Tenant's fault, to become involved or concerned.

         (b) IN THE INTEREST OF OBTAINING A SPEEDIER AND LESS COSTLY HEARING OF
ANY DISPUTE, THE PARTIES HEREBY EACH IRREVOCABLY WAIVE THE RIGHT TO TRIAL BY
JURY.

         (c) If either Landlord or Tenant desires to bring an action against the
other in connection with this Lease, such action shall be brought in the federal
or state courts located in Nashville, Davidson County, Tennessee. Landlord and
Tenant consent to the jurisdiction of such courts and waive any right to have
such action transferred from such courts on the grounds of improper venue or
inconvenient forum.

                                       12
<PAGE>   16

                                   ARTICLE 17
               PERSONAL PROPERTY TAXES, RENT TAXES AND OTHER TAXES

         Tenant shall pay prior to delinquency all taxes, charges or other
governmental impositions assessed against or levied upon Tenant's fixtures,
furnishings, equipment and personal property located in the Premises, and any
Alterations to the Premises under Article 8. Whenever possible, Tenant shall
cause all such items to be assessed and billed separately, from the property of
Landlord. In the event any such items shall be assessed and billed with the
property of Landlord, Tenant shall pay Landlord its share of such taxes, charges
or other governmental impositions within thirty (30) days after Landlord
delivers a statement and a copy of the assessment or other documentation showing
the amount of Impositions applicable to Tenant's property. Tenant shall pay any
rent tax or sales tax, service tax, transfer tax or value added tax, or any
other applicable tax on the Rent or services herein or otherwise respecting this
Lease.

                                   ARTICLE 18
                               TENANT'S AUTHORITY

         In case Tenant is a corporation, Tenant (a) represents and warrants
that this Lease has been duly authorized, executed and delivered by and on
behalf of Tenant and constitutes the valid and binding agreement of Tenant in
accordance with the terms hereof, and (b) if Landlord so requests, Tenant shall
deliver to Landlord, concurrently with the delivery of this Lease executed by
Tenant, certified resolutions of the board of directors (and shareholders, if
required) authorizing Tenant's execution and delivery of this Lease and the
performance of Tenant's obligations hereunder. As to any Tenant which is ever a
partnership, each and every present and future partner in Tenant shall be and
remain at all times jointly and severally liable hereunder, and to the extent
permitted by law, the death, resignation or withdrawal of any general partner
shall not release the liability of such partner under the terms of this Lease
unless and until Landlord shall have consented in writing to such release.
Landlord may request and Tenant shall provide a written confirmation from
Tenant's future partners from time to time of their agreement to be so bound by
this Lease. If Tenant is a partnership or corporation whose stock is not
publicly traded, or a limited liability company, then at the time this Lease is
executed and from time to time thereafter, at Landlord's request, Tenant shall
furnish Landlord with a list of Tenant's partners or shareholders or managers
and members, as the case may be.

                                   ARTICLE 19
               SUBORDINATION, ATTORNMENT AND MORTGAGEE PROTECTION

         (a) Landlord may have heretofore or may hereafter encumber with a
security interest, assignment, mortgage or trust deed the Building, the Property
or any interest therein, and may have heretofore and may hereafter sell and
lease back the Property, or any part thereof, and may have heretofore or may
hereafter assign or encumber the leasehold estate under such lease with an
assignment, mortgage or trust deed. (Any such security interest, assignment,
mortgage or trust deed is herein called a "Mortgage" and the holder of any such
security interest, assignment, mortgage or the beneficiary under any such trust
deed is herein called a "Mortgagee". Any such lease of the underlying land is
herein called a "Ground Lease", and the lessor under any such lease is herein
called a "Ground Lessor". Any Mortgage which is a first lien against the
Building, the Property, the leasehold estate under a Ground Lease or any
interest therein is herein called a "First Mortgage" and the holder or
beneficiary of any First Mortgage is herein called a "First Mortgagee").

                                       13
<PAGE>   17

         (b) Tenant's rights under this Lease are subject and subordinate to the
operation and effect of any Mortgage, whether the same shall be in existence as
of the date hereof or created hereafter, and to any and all advances made
thereunder and to the interest thereon, and to all renewals, replacements,
supplements, amendments, modifications and extensions thereof. Tenant's
acknowledgement and agreement of subordination provided for in this Section is
self-operative and no further instrument of subordination shall be required;
however, upon the request of Landlord, Mortgagee or Ground Lessor, Tenant will
promptly execute and deliver such subordination, attornment or similar
instruments, agreement or agreements as may be reasonably required by such
Mortgagee or Ground Lessor. In the event of any subsequent Mortgage and a
request to Tenant to execute such agreement, Mortgagee shall provide to Tenant
non-disturbance and attornment recognizing this Lease and Tenant's rights
hereunder.

         (c) It is further agreed that (i) if any Mortgage shall be foreclosed,
or if any Ground Lease be terminated, (A) the liability of the Mortgagee or
Ground Lessor, or purchaser at such foreclosure sale or the liability of a
subsequent owner designated as Landlord under this Lease shall exist only so
long as such Mortgagee, purchaser or owner is the owner of the Building, the
Property, and such liability shall not continue or survive after further
transfer of ownership; (B) the Mortgagee or Ground Lessor or their successors or
assigns that succeeds to the interest of the Landlord in the Building or the
Property or acquires the right to possession of the Building or the Property,
shall not be (1) liable for any act or omission of the party named above as the
Landlord under this Lease; (2) liable for the performance of Landlord's
covenants pursuant to the provisions of this Lease which arise and accrue prior
to such entity succeeding to the interest of Landlord under this Lease or
acquiring such right to possession; (3) subject to any offsets or defenses which
Tenant may have at any time against Landlord; (4) bound by any Rent which Tenant
may have paid previously for more than one (1) month; or (5) liable for the
performance of any covenant of Landlord under this Lease which is capable of
performance only by the original Landlord; and (C) upon request of the
Mortgagee, if the Mortgage shall be foreclosed, Tenant will attorn, as Tenant
under this Lease, to the purchaser at any foreclosure sale under any Mortgage or
upon request of the Ground Lessor, if any Ground Lease shall be terminated,
Tenant will attorn as Tenant under this Lease to the Ground Lessor, and Tenant
will execute such instruments as may be necessary or appropriate to evidence
such attornment; and (ii) this Lease may not be modified or amended so as to
reduce the rent or shorten the Term, or so as to adversely affect in any other
respect to any material extent the rights of Landlord or Tenant, nor shall this
Lease be cancelled or surrendered, without the prior written consent, in each
instance, of the First Mortgagee or any Ground Lessor. Landlord shall use
reasonable efforts to obtain a non-disturbance and attornment agreement for
Tenant from any mortgagee or successor in interest to Landlord so long as Tenant
is not in default beyond any applicable notice or cure period.

         (d) Should any prospective Mortgagee or Ground Lessor require a
modification or modifications of this Lease, which modification or modifications
will not cause an increased cost or expense to Tenant or in any other way
materially and adversely change the rights and obligations of Tenant hereunder,
then, and in such event, Tenant agrees that this Lease may be so modified and
agrees to execute whatever documents are required therefor and deliver the same
to Landlord within fifteen (15) days following the request therefor. Should any
prospective Mortgagee or Ground Lessor require execution of a short form of
lease for recording (containing, among other customary provisions, the names of
the parties, a description of the Premises and the Term of this Lease), Tenant
agrees to execute such short form of lease and deliver the same to Landlord
within fifteen (15) days following the request therefor.

         (e) Tenant agrees to give any Mortgagee and Ground Lessor, by
registered or certified mail, a copy of any notice or claim of default served
upon Landlord by Tenant, provided that prior to such notice Tenant has been
notified in writing (by way of service on Tenant a copy of an assignment of
Landlord's interests in leases, or otherwise) of the address of such Mortgagee
and Ground Lessor. Tenant further agrees that if Landlord shall have failed to
cure such default within twenty (20) days after such notice to Landlord (or if
such default cannot be cured or corrected within that time, then such additional
time as may be necessary if Landlord has commenced within such twenty (20) days
and is diligently pursuing the remedies or steps necessary to cure or correct
such default), then the Mortgagee or Ground Lessor shall have an additional
thirty (30) days within which to cure or correct such default (or if such
default cannot be cured or corrected within that time, then such additional time
as may be necessary if such Mortgagee or Ground Lessor has commenced within such
thirty (30) days and is diligently pursuing the remedies or steps necessary to
cure or correct such default) before Tenant may exercise any right or remedy
which it may have on account of any such default of Landlord.

                                       14
<PAGE>   18

                                   ARTICLE 20
                              ESTOPPEL CERTIFICATE

         Tenant agrees that from time to time upon not less than five (5) days
prior request by Landlord, or any existing or prospective Mortgagee or Ground
Lessor, Tenant will, and Tenant will cause any subtenant, licensee,
concessionaire or other occupant of the Premises claiming by, through or under
Tenant to, complete, execute and deliver to Landlord or Landlord's designee or
to any Mortgagee or Ground Lessor, a written estoppel certificate certifying to
Tenant's actual knowledge (a) that this Lease is unmodified and in full force
and effect (or if there have been modifications, that this Lease as modified is
in full force and effect and identifying the modifications); (b) the date upon
which Tenant began paying Rent and the dates to which the Rent and other charges
have been paid; (c) that Landlord is not in default under any provision of this
Lease, or, if in default, the nature thereof in detail; (d) that the Premises
have been completed in accordance with the terms hereof and Tenant is in
occupancy and paying Rent on a current basis with no rental offsets or claims;
(e) that there has been no prepayment of Rent other than that provided for in
this Lease; (f) that there are no actions, whether voluntary or otherwise,
pending against Tenant under the Bankruptcy Code or the bankruptcy, insolvency,
reorganization, liquidation, dissolution, compensation, receivership or other
laws of any state for the relief of debtors; and (g) such other matters as may
be required by Landlord, Mortgagee or Ground Lessor, including, without
limitation, any other information concerning the status of this Lease or the
parties' performance hereunder reasonably requested by the party to whom such
estoppel certificate is to be addressed. Tenant's failure to complete, execute
and deliver any such estoppel certificate within the aforesaid 5-day period
shall be deemed to be a Default under this Lease, or, alternatively, at
Landlord's election, Tenant shall be deemed to have agreed with the matters set
forth in an estoppel letter prepared and delivered by Landlord.

                                   ARTICLE 21
                            ASSIGNMENT AND SUBLETTING

         (A) TRANSFERS. Tenant shall not, without the prior written consent of
Landlord, which consent Landlord, at Landlord's sole and exclusive discretion,
may withhold: (i) assign, mortgage, pledge, hypothecate, encumber, or permit any
lien to attach to, or otherwise transfer, this Lease or any interest hereunder,
by operation of law or otherwise. (ii) sublet the Premises or any part thereof,
or (iii) permit the use of the Premises by any Persons (as defined in Article
25) other than Tenant and its employees (all of the foregoing are hereinafter
sometimes referred to collectively as "Transfers" and any Person to whom any
Transfer is made or sought to be made is hereinafter sometimes referred to as a
"Transferee"). If Tenant shall desire Landlord's consent to any Transfer, Tenant
shall notify Landlord in writing, which notice shall include: (a) the proposed
effective date (which shall not be less than 30 nor more than 180 days after
Tenant's notice), (b) the portion of the Premises to be Transferred (herein
called the "Subject Space"), (c) the terms of the proposed Transfer and the
consideration therefor, the name and address of the proposed Transferee, and a
copy of all documentation pertaining to the proposed Transfer, and (d) current
financial statements of the proposed Transferee certified by an officer, partner
or owner thereof and any other information to enable Landlord to determine the
financial responsibility, character, and reputation of the proposed Transferee,
nature of such Transferee's business and proposed use of the Subject Space, and
such other information as Landlord may reasonably require. Any Transfer made
without complying with this Article shall at Landlord's option be null, void and
of no effect, or shall constitute a Default under this Lease. Whether or not
Landlord shall grant consent, Tenant shall pay, within thirty (30) days after
written request by Landlord, $300.00 towards Landlord's review and processing
expenses, plus any reasonable legal fees incurred by Landlord in connection with
any proposed Transfer.

         Notwithstanding anything to the contrary contained here, Tenant shall
have the right to assign this Lease, with the Landlord's written approval
obtained in each and every case, such approval not to be unreasonably withheld,
to (i) a parent company, (ii) a majority owned subsidiary, (iii) a subsidiary of
Tenant's parent corporation, (iv) a corporation merging with Tenant, (v) a
corporation resulting from a merger between Tenant and another corporation, and
(vi) any entity buying all or a majority of Tenant's assets. Assignee shall
comply with all terms and conditions of this Lease.

                                       15
<PAGE>   19

         (B) TRANSFER PREMIUM. If Landlord consents to a Transfer, and as a
condition thereto which the parties hereby agree is reasonable, Tenant shall pay
Landlord one hundred percent (100%) of any Transfer Premium derived by Tenant
from such Transfer. "Transfer Premium" shall mean all rent, additional rent or
other consideration paid by such Transferee in excess of the Rent payable by
Tenant under this Lease (on a monthly basis during the Term, and on a per
rentable square foot basis, if less than all of the Premises is transferred),
after deducting the reasonable expenses incurred by Tenant for any changes,
alterations and improvements to the Premises, any other economic concessions or
services provided to the Transferee, and any customary brokerage commissions
paid in connection with the Transfer as well as amounts paid to Tenant as
compensation for leasehold improvements, trade fixtures, equipment or other
personal property sold or leased to the Transferee). If part of the
consideration for such Transfer shall be payable other than in cash, Landlord's
share of such non-cash consideration shall be in such form as is reasonably
satisfactory to Landlord. The Transfer Premium due Landlord hereunder shall be
paid within five (5) days after Tenant receives any Transfer Premium from the
Transferee.

         (C) RECAPTURE. Notwithstanding anything to the contrary contained in
this Article, Landlord shall have the option, by giving written notice to Tenant
within thirty (30) days after receipt of Tenant's notice of any proposed
Transfer, to recapture the Subject Space. Such recapture notice shall cancel and
terminate this Lease with respect to the Subject Space as of the date stated in
Tenant's notice as the effective date of the proposed Transfer (or at Landlord's
option, shall cause the Transfer to be made to Landlord or its agent, in which
case the parties shall execute the Transfer documentation promptly thereafter)
unless Landlord receives from Tenant a notice withdrawing its request for
transfer within five (5) days of Tenant's receipt of the recapture notice. If
this Lease shall be cancelled with respect to less than the entire Premises, the
Rent reserved herein shall be prorated on the basis of the number of rentable
square feet retained by Tenant in proportion to the number of rentable square
feet contained in the Premises. This Lease as so amended shall continue
thereafter in full force and effect, and upon request of either party, the
parties shall execute written confirmation of the same.

         (D) TERMS OF CONSENT. If Landlord consents to a Transfer: (a) the terms
and conditions of this Lease, including among other things, the original named
Tenant's liability for the Subject Space, and Rent with respect thereto, shall
in no way be deemed to have been released, waived or modified, (b) such consent
shall not be deemed consent to any further Transfer by either Tenant or a
Transferee, (c) no Transferee shall succeed to any rights provided in this Lease
or any amendment hereto to extend the Term of this Lease, expand the Premises,
or lease additional space, any such rights being deemed personal to Tenant, (d)
Tenant shall deliver to Landlord promptly after execution, an original executed
copy of all documentation pertaining to the Transfer in form reasonably
acceptable to Landlord, and (e) Tenant shall furnish upon Landlord's request a
complete statement, certified by an independent certified public accountant, or
Tenant's chief financial officer, setting forth in detail the computation of any
Transfer Premium Tenant has derived and shall derive from such Transfer.
Landlord or its authorized representatives shall have the right at all
reasonable times to audit the books, records and papers of Tenant relating to
any Transfer, and shall have the right to make copies thereof. If the Transfer
Premium respecting any Transfer shall be found understated, Tenant shall within
thirty (30) days after demand pay the deficiency, and if understated by more
than 2%, Tenant shall pay Landlord's costs of such audit. Any sublease hereunder
shall be subordinate and subject to the provisions of this Lease, and if this
Lease shall be terminated during the term of any sublease, Landlord shall have
the right to: (i) treat such sublease as cancelled and repossess the Subject
Space by any lawful means, or (ii) require that such subtenant attorn to and
recognize Landlord as its landlord under any such sublease. If Tenant shall
Default and fail to cure within the time permitted for cure under Article 23(A),
Landlord is hereby irrevocably authorized, as Tenant's agent and
attorney-in-fact, to direct any Transferee to make all payments under or in
connection with the Transfer directly to Landlord (which Landlord shall apply
towards Tenant's obligations under this Lease) until such Default is cured.

         (E) SUBSEQUENT CONSENTS. Consent by Landlord to any assignment,
subletting, use, occupancy, transfer or encumbrance, or any other Transfer made
pursuant to this Lease, shall not operate to relieve Tenant from any covenant or
obligation hereunder or be deemed to be a consent to or relieve Tenant from
obtaining Landlord's consent to any subsequent assignment, subletting, use,
occupancy, transfer of encumbrance by Tenant or anyone claiming by, through or
under Tenant.

                                       16
<PAGE>   20

         (F) CERTAIN TRANSFERS. For purposes of this Lease, the term "Transfer"
shall also include (i) if Tenant is a partnership, the withdrawal or change,
voluntary, involuntary or by operation of law, of a majority of the partners, or
a transfer of a majority of partnership interests, or the dissolution of the
partnership; (ii) if Tenant is a limited liability company, the withdrawal or
change, voluntary, involuntary, or by operation of law, of a majority of
members, or a transfer of a majority of the membership interests, or the
dissolution of the limited liability company; and (iii) if Tenant is a closely
held corporation (i.e., whose stock is not publicly held and not traded through
an exchange or over the counter), the dissolution, merger, consolidation or
other reorganization of Tenant, or: (1) the sale or other transfer of more than
an aggregate of 50% of the voting shares of Tenant (other than to immediate
family members by reason of gift or death) or (2) the sale, mortgage,
hypothecation or pledge of more than an aggregate of 50% of Tenant's net assets.
Upon execution of this Lease, Tenant shall deliver to Landlord a list of all of
its shareholders, members, or partners, as the case may be.

                                   ARTICLE 22
                           RIGHTS RESERVED BY LANDLORD

         Except to the extent expressly limited herein, Landlord reserves full
rights to control the Property (which rights may be exercised without subjecting
Landlord to claims for constructive eviction, abatement of Rent, damages or
other claims of any kind), including more particularly, but without limitation,
the following rights:

         (A) To change the name or street address of the Property; install and
maintain signs on the exterior and interior of the Property; retain at all
times, and use in appropriate instances, keys to all doors within and into the
Premises; grant to any Person the right to conduct any business or render any
service at the Property, whether or not it is the same or similar to the use
permitted Tenant by this Lease; and have access for Landlord and other tenants
of the property to any mail chutes located on the Premises according to the
rules of the United States Postal Service.

         (B) To enter the Premises at reasonable hours for reasonable purposes
upon reasonable prior notice, including inspection and supplying cleaning
service or other services to be provided Tenant hereunder, to show the Premises
to current and prospective mortgage lenders, ground lessors, insurers, and
prospective purchasers, tenants and brokers, at reasonable hours, and if Tenant
shall abandon the Premises at any time, or shall vacate the same during the last
3 months of the Term, to decorate, remodel, repair, or alter the Premises.

         (C) To limit or prevent access to the Property, shut down elevator
service, activate elevator emergency controls, or otherwise take such action or
preventative measures deemed necessary by Landlord for the safety of tenants or
other occupants of the Property or the protection of the Property and other
property located thereon or therein, in case of fire, invasion, insurrection,
riot, civil disorder, public excitement or other dangerous condition, or threat
thereof.

         (D) To decorate and to make alterations, additions and improvements,
structural or otherwise, in or to the Property or any part thereof, and any
adjacent building, structure, parking facility, land, street or alley (including
without limitation changes and reductions in corridors, lobbies, parking
facilities and other public areas and the installation of kiosks, planters,
sculptures, displays, escalators, mezzanines, and other structures, facilities,
amenities and features therein, and changes for the purpose of connection with
or entrance into or use of the Property in conjunction with any adjoining or
adjacent building or buildings, now existing or hereafter constructed). In
connection with such matters or with any other repairs, maintenance,
improvements or alterations, in or about the Property, Landlord may erect
scaffolding and other structures reasonably required, and during such operations
may enter upon the Premises and take into and upon or through the Premises, all
materials required to make such repairs, maintenance, alterations or
improvements, and may close public entry ways, other public areas, restrooms,
stairways or corridors.

         (E) Intentionally deleted.

                                       17
<PAGE>   21

                                   ARTICLE 23
                               LANDLORD'S REMEDIES

         (A) DEFAULT. The occurrence of any one or more of the following events
shall constitute a "Default" by Tenant, which if not cured within any applicable
time permitted for cure below, shall give rise to Landlord's remedies set forth
in Paragraph (B), below: (i) failure by Tenant to make when due any payment of
Rent, unless such failure is cured within five (5) days after notice; provided,
however, that once Landlord has given Tenant two (2) such notices during any
twelve (12)-month period, Landlord shall not be required to give further written
notice, and thereafter the failure or refusal by Tenant to timely make any
payment of Rent when due within the following twelve (12) months shall be a
Default without further notice; (ii) failure by Tenant to observe or perform any
of the terms or conditions of this Lease to be observed or performed by Tenant
other than the payment of Rent, or as provided below, unless such failure is
cured within thirty (30) days after notice, or such shorter period expressly
provided elsewhere in this Lease (provided, if the nature of Tenant's failure is
such that more time is reasonably required in order to cure, Tenant shall not be
in Default if Tenant commences to cure within such period and thereafter
reasonably seeks to cure such failure to completion); (iii) failure by Tenant to
promptly remove any hazardous condition which Tenant has created or permitted;
(iv) failure by Tenant to comply with the Rules, unless such failure is cured
within ten (10) days after notice (provided, if the nature of Tenant's failure
is such that more time is reasonably required in order to cure, Tenant shall not
be in Default if Tenant commences to cure within such period and thereafter
reasonably seeks to cure such failure to completion); (v) vacation of all or a
substantial portion of the Premises for more than thirty (30) consecutive days,
or the failure to take possession of the Premises within sixty (60) days after
the Commencement Date, (vi) (a) making by Tenant or any guarantor of this Lease
("Guarantor") of any general assignment for the benefit of creditors; (b) filing
by or against Tenant or any Guarantor of a petition to have Tenant or such
Guarantor adjudged a bankrupt or a petition for reorganization or arrangement
under any Law relating to bankruptcy, insolvency, receivership or other relief
for debtors (unless, in the case of a petition filed against Tenant or such
Guarantor, the same is dismissed within sixty (60) days), (c) appointment of a
trustee or receiver to take possession of substantially all of Tenant's assets
located on the Premises or of Tenant's interest in this Lease, where possession
is not restored to Tenant within thirty (30) days, (d) attachment, execution or
other judicial seizure of substantially all of Tenant's assets located on the
Premises or of Tenant's interest in this Lease, (e) Tenant's or any Guarantor's
convening of a meeting of its creditors or any class thereof for the purpose of
effecting a moratorium upon or composition of its debts, or (f) Tenant's or any
Guarantor's insolvency or admission of an inability to pay its debts as they
mature: (vii) any material misrepresentation herein, or material
misrepresentation or omission in any financial statements or other materials
provided by Tenant or any Guarantor in connection with negotiating or entering
this Lease or in connection with any Transfer under Article 21; or (viii)
cancellation of any guaranty of this Lease by any Guarantor. Failure by Tenant
to comply with the same term or condition of this Lease on three occasions
during any twelve month period shall cause any failure to comply with such term
or condition during the succeeding twelve month period, at Landlord's option, to
constitute an incurable Default, if Landlord has given Tenant notice of each
such failure within ten (10) days after each such failure occurs. The notice and
cure periods provided herein are in lieu of, and not in addition to, any notice
and cure periods provided by Law.

         (B) REMEDIES. If a Default occurs and is not cured within any
applicable time permitted under Paragraph (A), Landlord shall have the rights
and remedies hereinafter set forth, which shall be distinct, separate and
cumulative with and in addition to any other right or remedy allowed under any
Law or, other provisions of this Lease:

         (i) Landlord may terminate this Lease, in which event the Term of this
Lease shall end, and repossess the Premises by detainer suit, summary
proceedings or other lawful means, and recover from Tenant all the fixed dollar
amounts of Rent accrued and unpaid for the period up to and including such
termination date, as well as all other additional sums payable by Tenant, or for
which Tenant is liable or in respect of which Tenant has agreed to indemnify
Landlord under any of the provisions of this Lease, which may be then owing or
unpaid, and all costs and expenses, including without limitation court costs and
reasonable attorney's fees incurred by Landlord in the enforcement of its rights
and remedies hereunder, and, in addition, Landlord shall be entitled to recover
as damages for loss of the bargain and not as a penalty (a) the unamortized cost
(assuming level amortization at 10% interest over the Term) of leasehold
improvements, additions, and alterations, if any, made by or paid for by
Landlord and/or construction allowance made pursuant to this Lease and the
Workletter, (b) the aggregate sum which at the time of such termination
represents the excess, if any, of the present value of the aggregate rents at
the same annual rate for the remainder of the Term pursuant to the applicable
provisions of Article 2 and

                                       18
<PAGE>   22

Article 3 of this Lease, over the then present value of the then aggregate fair
rental value of the Premises for the balance of the Term (taking into account
any period required to re-lease the Premises and prepare the Premises for
occupancy for a new tenant), such present value to be computed in each case on
the basis of a six percent (6%) per annum discount from the respective dates
upon which such rentals would have been payable hereunder had this Lease not
been terminated, and (c) any damages in addition thereto, including the Costs of
Re-letting (as defined below), reasonable attorneys' fees and court costs, which
Landlord shall have sustained by reason of the breach of any of the covenants of
this lease other than for the payment of rent. For purposes of computing such
damages, Tenant's Prorata Share of Taxes and Operating Expenses shall be
projected, based upon the average rate of increase, if any in such items from
the Commencement Date through the time of termination.

         (ii) If applicable Law permits, Landlord may terminate Tenant's right
of possession and repossess the Premises by detainer suit, summary proceedings
or other lawful means, without terminating this Lease (and if such Law permits,
and Landlord shall not have expressly terminated the Lease in writing, any
termination shall be deemed a termination of Tenant's right of possession only).
In such event, Landlord may recover: (a) any unpaid Rent as of the date
possession is terminated, including interest at the Default Rate, (b) any unpaid
Rent which accrues during the Term from the date possession is terminated
through the stated end of the Term, including interest at the Default Rate, less
any Net Re-Letting Proceeds (as defined in Paragraph F) received by Landlord
during such period, and less such loss of Rent that Tenant proves could have
been reasonably avoided, and (c) any other amounts necessary to compensate
Landlord for all damages proximately caused by Tenant's failure to perform its
obligations under this Lease, including without limitation, all Costs of
Reletting (as defined in Paragraph G). Landlord may bring suits for such amounts
or portions thereof, at any time or times as the same accrue or after the same
have accrued, and no suit or recovery of any portion due hereunder shall be
deemed a waiver of Landlord's right to collect all amounts to which Landlord is
entitled hereunder, nor shall the same serve as any defense to any subsequent
suit brought for any amount not theretofore reduced to judgment.

         (iii) Remove from the Premises any furniture, fixtures, equipment or
personal property of Tenant, without liability for trespass or conversion, and
store such items either in the Building or elsewhere at the sole cost of Tenant
and without liability to Landlord. Landlord may retain control over all such
property for the purpose of foreclosing the security interest created by Article
37 hereof. Any of such furniture, fixtures, equipment and personal property not
claimed within thirty (30) days from the date of removal shall be deemed
abandoned.

         (C) MITIGATION OF DAMAGES. If Landlord terminates this Lease or
Tenant's right to possession, Landlord shall use reasonable efforts to mitigate
Landlord's damages, and Tenant shall be entitled to submit proof of such failure
to mitigate as a defense to Landlord's claims hereunder, if mitigation of
damages by Landlord is required by applicable Law; provided, however, Landlord
shall not be required to accept any tenant offered by Tenant or to observe any
instructions given by Tenant relative to such reletting. Landlord may give
priority over leasing the Premises to any other space Landlord desires to lease
in the Building and shall not be required in any case to offer rent, length of
terms or other terms for the Premises which are or would be less favorable to
Landlord than being offered for comparable space of Landlord in the Building. If
Landlord has not terminated this Lease or Tenant's right to possession, Landlord
shall have no obligation to mitigate, and may permit the Premises to remain
vacant or abandoned; in such case, Tenant may seek to mitigate damages by
attempting to sublease the Premises or assign this Lease (subject to Article
21).

         (D) SPECIFIC PERFORMANCE, COLLECTION OF RENT AND ACCELERATION. Landlord
shall at all times have the rights and remedies (which shall be cumulative with
each other and cumulative and in addition to those rights and remedies available
under Paragraph (B), above or any Law or other provision of this Lease), without
prior demand or notice except as required by applicable Law: (i) to seek any
declaratory, injunctive or other equitable relief, and specifically enforce this
Lease, or restrain or enjoin a violation or breach of any provision hereof, and
(ii) to sue for and collect any unpaid Rent which has accrued. Notwithstanding
anything to the contrary contained in this Lease, to the extent not expressly
prohibited by applicable Law, in the event of any Default by Tenant not cured
within any applicable time for cure hereunder, Landlord may terminate this Lease
or Tenant's right to possession and accelerate and declare that all Rent
reserved for the remainder of the Term shall be immediately due and payable (in
which event, Tenant's Prorata Share of Taxes and Operating Expenses for the
remainder of the Term shall be projected based upon, the average rate of
increase, if any, in such items from the Commencement Date through

                                       19
<PAGE>   23

the date of such declarations) provided, Landlord shall, after receiving payment
of the same from Tenant, be obligated to turn over to Tenant any actual Net
Re-Letting Proceeds thereafter received during the remainder of the Term, up to
the amount so received from Tenant pursuant to this provision.

         (E) WAIVER OF NOTICE. Tenant expressly waives the service of any notice
of intention to terminate this Lease or to reenter the Premises and waives the
service of any demand for payment of Rent or for possession and waives the
service of any and every other notice or demand prescribed by any ordinance,
statute or other law (except as expressly otherwise provided in this Lease) and
agrees that the breach of any covenants or agreements provided in this Lease
shall, in and of itself, without the service of any notice or demand whatever
(except as expressly otherwise provided in this Lease), constitute a forcible
detainer by Tenant of the Premises.

         (F) LATE CHARGES AND INTEREST. Tenant shall pay, as additional Rent, a
service charge of One Hundred Dollars ($100.00) for bookkeeping and
administrative expenses, if Rent is not received within five (5) days after its
due date. In addition, any Rent paid more than five (5) days after due shall
accrue interest from the due date at the Default Rate (as defined in Article
25), until payment is received by Landlord. Landlord's acceptance of such
service charge and interest payments shall not be deemed consent by Landlord to
late payments, nor a waiver of Landlord's right to insist upon timely payments
at any time, nor a waiver of any remedies to which Landlord is entitled as a
result of the late payment of Rent.

         (G) CERTAIN DEFINITIONS. "Net Re-Letting Proceeds" shall mean the total
amount of rent and other consideration paid by any Replacement Tenants, less all
Costs of Re-Letting, during a given period of time. "Costs of Re-Letting" shall
include without limitation, all reasonable costs and expenses incurred by
Landlord for any repairs, maintenance, changes, alterations and improvements to
the Premises, brokerage commissions, advertising costs, attorneys' fees, any
customary free rent periods or credits, tenant improvement allowances, take-over
lease obligations and other customary, necessary or appropriate economic
incentives required to enter leases with Replacement Tenants, and costs of
collecting rent from Replacement Tenants. "Replacement Tenants" shall mean any
Persons (as defined in Article 25) to whom Landlord relets the Premises or any
portion thereof pursuant to this Article.

         (H) OTHER MATTERS. No re-entry or repossession, repairs, changes,
alterations and additions, reletting, acceptance of keys from Tenant, or any
other action or omission by Landlord shall be construed as an election by
Landlord to terminate this Lease or Tenant's right to possession, or accept a
surrender of the Premises, nor shall the same operate to release the Tenant in
whole or in part from any of Tenant's obligations hereunder, unless express
written notice of such intention is sent by Landlord or its agent to Tenant. To
the fullest extent permitted by Law, all rent and other consideration paid by
any Replacement Tenants shall be applied: first, to the Costs of Re-Letting,
second, to the payment of any Rent theretofore accrued, and the residue, if any,
shall be held by Landlord and applied to the payment of other obligations of
Tenant to Landlord as the same become due (with any remaining residue to be
retained by Landlord). Rent shall be paid without any prior demand or notice
therefor (except as expressly provided herein) and without any deduction,
set-off or counterclaim, or relief from any valuation or appraisement laws.
Landlord may apply payments received from Tenant to any obligations of Tenant
then accrued, without regard to such obligations as may be designated by Tenant.
Landlord shall be under no obligation to observe or perform any provision of
this Lease on its part to be observed or performed which accrues after the date
of any Default by Tenant hereunder not cured within the times permitted
hereunder. The times set forth herein for the curing of Defaults by Tenant are
of the essence of this Lease. Tenant hereby irrevocably waives any right
otherwise available under any Law to redeem or reinstate this Lease.

                                   ARTICLE 24
                            LANDLORD'S RIGHT TO CURE

         If Landlord shall fail to perform any term or provision under this
Lease required to be performed by Landlord, Landlord shall not be deemed to be
in default hereunder nor subject to any claims for damages of any kind, unless
such failure shall have continued for a period of thirty (30) days after written
notice thereof by Tenant to Landlord and to each Mortgagee whose name and
address have been furnished to Tenant; provided, however, if the nature of
Landlord's failure

                                       20
<PAGE>   24

is such that more than thirty (30) days are reasonably required in order to cure
such failure, Landlord shall not be in default if Landlord or such Mortgagee
commences to cure such failure within such thirty (30) day period, and
thereafter reasonably seeks to cure such failure to completion. The
aforementioned periods of time permitted for Landlord or such Mortgagee to cure
shall be extended for any period of time during which Landlord is delayed in, or
prevented from, curing due to fire or other casualty, strikes, lock-outs or
other labor troubles, shortages of equipment or materials, governmental
requirements, power shortages or outages, acts or omissions by Tenant or other
Persons, and other causes beyond Landlord's reasonable control. If Landlord
shall fail to cure within the times permitted for cure herein, Landlord shall be
subject to such remedies as may be available to Tenant including Tenant's right
to terminate this Lease (subject to the other provisions of this Lease);
provided, in recognition that Landlord must receive timely payments of Rent and
operate the Property, Tenant shall have no right of self-help to perform repairs
or any other obligation of Landlord, and shall have no right to withhold,
set-off, or abate Rent. In no event shall Tenant claim that a constructive or
actual eviction has occurred under this Lease or that the Premises have become
unsuitable, prior to the expiration of the notice and cure periods provided
under this Article 24. Any notice of a failure to perform by Landlord shall be
sent to Landlord at the addresses and to the attention of the parties set forth
in Article 33 hereof. Any notice of a failure to perform by Landlord not sent to
Landlord and to each Mortgagee who is entitled to notice or not sent in
compliance with Article 33 hereof shall be of no force or effect. Tenant hereby
agrees and confirms that Tenant's covenant to pay Rent is independent of and not
conditioned upon any other covenants in this Lease.

                                   ARTICLE 25
                     CAPTIONS, DEFINITIONS AND SEVERABILITY

         The captions of the Articles and Paragraphs of this Lease are for
convenience of reference only and shall not be considered or referred to in
resolving questions of interpretation. If any term or provision of this Lease
shall be found invalid, void, illegal, or unenforceable with respect to any
particular Person by a court of competent jurisdiction, it shall not affect,
impair or invalidate any other terms or provisions hereof, or its enforceability
with respect to any other Person, the parties hereto agreeing that they would
have entered into the remaining portion of this Lease notwithstanding the
omission of the portion or portions adjudged invalid, void, illegal, or
unenforceable with respect to such Person.

         (A) "Building" shall mean the structure identified in Article I of this
Lease.

         (B) Intentionally Deleted.

         (C) "Default Rate" shall mean the annual rate of three percent (3%) in
excess of the prime rate of interest announced or published from time to time by
The Wall Street Journal as such rate, changing as and when said prime rate
changes. In the event The Wall Street Journal published more than one prime rate
of interest, the prime rate is defined to mean the higher prime rate of interest
published from time to time by The Wall Street Journal as such rate. In the
event The Wall Street Journal, during the term hereof, shall abolish or abandon
the practice of publishing a prime rate, or should the same become
unascertainable, Landlord shall designate a comparable reference rate which
shall be deemed to be the prime rate for purposes hereof. If for any reason the
accrual of interest at the prime rate is unascertainable, is voided by a court
of competent jurisdiction or for any reason such court finds the interest rate
is different than the rate designated by Landlord, then the "default rate" shall
be deemed to mean the highest rate permitted by law. Notwithstanding anything to
the contrary herein, the default rate shall not exceed the lawful maximum rate
of interest permitted to be paid.

         (D) "Holidays" shall mean all federally observed holidays, including
New Year's Day, President's Day, Memorial Day, Independence Day, Labor Day,
Veterans' Day, Thanksgiving Day, Christmas Day, and to the extent of utilities
or services provided by union members engaged at the Property, such other
holidays observed by such unions.

         (E) "Landlord" and "Tenant" shall be applicable to one or more Persons
as the case may be, and the singular shall include the plural, and the neuter
shall include the masculine and feminine, and if there be more than one, the
obligations thereof shall be joint and several. For purposes of any provisions
indemnifying or limiting the liability of Landlord, the term "Landlord"

                                       21
<PAGE>   25

shall include Landlord's present and future partners, beneficiaries, trustees,
officers, directors, employees, shareholders, principals, agents, affiliates,
successors and assigns.

         (F) "Law" shall mean all federal, state, county and local governmental
and municipal laws, statutes, ordinances, rules, regulations, codes, decrees,
orders and other such requirements, applicable equitable remedies and decisions
by courts in cases where such decisions are considered binding precedents in the
state in which the Property is located, and decisions of federal courts applying
the Laws of such State.

         (G) "Operating Expenses" shall mean all expenses, costs and amounts
(other than Taxes) of every kind and nature which Landlord shall incur or pay
during, or is allocable to, any calendar year any portion of which occurs during
the Term, because of or in connection with the ownership, management, repair,
maintenance, restoration and operation of the Property, including without
limitation, any amounts paid for: (a) utilities for the Property, including, but
not limited to, electricity, power, gas, steam, oil or other fuel, water, sewer,
lighting, heating, air conditioning and ventilating, (b) permits, licenses and
certificates necessary to operate, manage and lease the Property, (c) insurance
costs applicable to the Property, including, but not limited to, the amount of
coverage Landlord may be required to provide under this Lease, and insurance
deductibles, (d) supplies, tools, equipment and materials used in the operation,
repair and maintenance of the Property, (e) accounting, legal, inspection,
consulting, concierge and other services, (f) any equipment rental (or
installment equipment purchase or equipment financing agreements), or management
agreements (including the cost of any management fee actually paid thereunder
and the fair rental value of any office space provided thereunder, up to
customary and reasonable amounts), (g) wages, salaries and other compensation
and benefits (including the fair value of any parking privileges provided) for
all persons engaged in the operation, maintenance or security of the Property,
and employer's Social Security taxes, unemployment taxes or insurance, and any
other taxes which may be levied on such wages, salaries, compensation and
benefits, (h) payments under any easement, operating agreement, tunnel
agreement, declaration, restrictive covenant, or instrument pertaining to the
sharing of costs in any planned development, (i) operation, repair, and
maintenance of all Systems and Equipment and components thereof (including
replacement of components), janitorial service, alarm and security service,
window cleaning, trash removal, elevator maintenance, cleaning of walks, parking
facilities and building walls, removal of ice and snow, replacement of wall and
floor coverings, ceiling tiles and fixtures in lobbies, corridors, restrooms and
other common or public areas or facilities, maintenance and replacement of
shrubs, trees, grass, sod and other landscaped items, irrigation systems,
drainage facilities, fences, curbs, and walkways, and roof repairs, and (j) the
cost of any imputed rental value for, as well as the cost of maintaining and
operating, conference rooms and related common facilities in the Building (but
only to the extent the costs thereof exceed any revenues generated by the use of
such facilities). If the Property is not fully occupied during all or a portion
of any calendar year, Landlord may, in accordance with sound accounting and
management practices, determine the amount of variable Operating Expenses (i.e.
those items which vary according to occupancy levels) that would have been paid
had the Property been fully occupied, and the amount so determined shall be
included as Operating Expenses for such year. Notwithstanding the foregoing,
Operating Expenses shall not, however, include:

                           (i) depreciation, interest and amortization on
                  Mortgages, and other debt costs or ground lease payments, if
                  any, legal fees in connection with leasing, tenant disputes or
                  enforcement of leases; real estate brokers leasing
                  commissions; improvements or alterations to tenant spaces; the
                  cost of providing any service directly to and paid directly
                  by, any tenant; any costs expressly excluded from Operating
                  Expenses elsewhere in this Lease: costs of any items to the
                  extent Landlord receives reimbursement from insurance proceeds
                  or from a third party (such proceeds to be deducted from
                  Operating Expenses in the year in which received); and the
                  costs of complying with governmental requirements relating to
                  hazardous materials or ambient air standards; and

                           (ii) capital expenditures, except those: (a) made
                  primarily to reduce Operating Expenses, or to comply with any
                  Laws or other governmental requirements, or which are intended
                  to enhance the safety of the Building or its occupants, or (b)
                  for replacements (as opposed to additions or new improvements)
                  of nonstructural items located in the common areas of the
                  Property required to keep such areas in good condition;
                  provided, all such permitted capital expenditures (together
                  with financing charges and interest) shall be amortized for
                  purposes of this Lease over the shorter of: (1) their useful
                  lives, (2) the period

                                       22
<PAGE>   26

                  during which the reasonably estimated savings in Operating
                  Expenses equals the expenditures, or (3) five (5) years.

         (H) Intentionally Deleted.

         (I) Intentionally Deleted.

         (J) "Person" shall mean an individual, trust, partnership, limited
liability company, joint venture, association, corporation and any other entity.

         (K) "Property" shall mean the Building, and any common or public areas
or facilities, easements, corridors, lobbies, sidewalks, loading areas,
driveways, landscaped areas, skywalks, and any and all other structures or
facilities operated or maintained in connection with or for the benefit of the
Building, and all parcels or tracts of land on which all or any portion of the
Building or any of the other foregoing items are located, and any fixtures,
machinery, equipment, apparatus, Systems and Equipment, furniture and other
personal property located thereon or therein and used in connection therewith,
whether title is held by Landlord or its affiliates. Possession of areas
necessary for utilities, services, safety and operation of the Property,
including the Systems and Equipment (as defined in Article 25), fire stairways,
perimeter walls, space between the finished ceiling of the Premises and the slab
of the floor or roof of the Property thereabove, and the use thereof together
with the right to install, maintain, operate, repair and replace the Systems and
Equipment, including any of the same in, through, under or above the Premises in
locations that will not materially interfere with Tenant's use of the Premises,
are hereby excepted and reserved by Landlord, and not demised to Tenant.

         (L) "Rent" shall have the meaning specified therefor in Article 3(F).

         (M) "Systems and Equipment" shall mean any plant, machinery,
transformers, duct work, cable, wires, and other equipment, facilities, and
systems designed to supply heat, ventilation, air conditioning and humidity or
any other services or utilities, or comprising or serving as any component or
portion of the electrical, gas, steam, plumbing, sprinkler, communications,
alarm, security, or fire/life/safety systems or equipment, or any other
mechanical, electrical, electronic, computer or other systems or equipment for
the Property.

         (N) "Taxes" shall mean all federal, state, county, or local
governmental or municipal taxes, fees, charges or other impositions of every
kind and nature, whether general, special, ordinary or extraordinary (including,
without limitation, real estate taxes, general and special assessments, transit
taxes, water and sewer rents, taxes based upon the receipt of rent including
gross receipts or sales taxes applicable to the receipt of rent or service or
value added taxes (unless required to be paid by Tenant under Article 17),
personal property taxes imposed upon the fixtures, machinery, equipment,
apparatus, Systems and Equipment, appurtenances, furniture and other personal
property used in connection with the Property) which Landlord shall pay during
any calendar year, any portion of which occurs during the Term (without regard
to any different fiscal year used by such government or municipal authority)
because of or in connection with the ownership, leasing and operation of the
Property. Notwithstanding the foregoing, there shall be excluded from Taxes all
excess profits taxes, franchise taxes, gift taxes, capital stock taxes,
inheritance and succession taxes, estate taxes, state, and federal, and local
income taxes (as opposed to tax on rents, receipts or income attributable to
operations at the Property) and any fines, penalties or interest resulting from
the late or partial payment except for fines, penalties or interest related to
the Tax Appeal process. If the method of taxation of real estate prevailing at
the time of execution hereof shall be, or has been altered, so as to cause the
whole or any part of the taxes now, hereafter or heretofore levied, assessed or
imposed on real estate to be levied, assessed or imposed on Landlord, wholly or
partially, as a capital levy or otherwise, or on or measured by the rents
received therefrom, then such new or altered taxes attributable to the Property
shall be included within the term "Taxes", except that the same shall not
include any enhancement of said tax attributable to other income of Landlord.
Any expenses incurred by Landlord in attempting to protest, reduce or minimize
Taxes shall be included in Taxes in the calendar year such expenses are paid.
Tax refunds shall be deducted from Taxes in the year they are received by
Landlord, but if such refund shall relate to Taxes paid in a prior year of the
Term, and the Lease shall have expired, Landlord shall mail Tenant's Prorata
Share of such net refund (after deducting expenses and attorneys' fees), up to
the amount Tenant paid towards

                                       23
<PAGE>   27

Taxes during such year, to Tenant's last known address. If Taxes for any period
during the Term or any extension thereof, shall be increased after payment
thereof by Landlord, for any reason, including without limitation, error or
reassessment by applicable governmental or municipal authorities, Tenant shall
pay Landlord upon demand Tenant's Prorata Share of such increased Taxes. Tenant
shall pay increased Taxes whether Taxes are increased as a result of increases
in the assessment or valuation of the Property (whether based on a sale, change
in ownership or refinancing of the Property or otherwise), increases in the tax
rates, reduction or elimination of any rollbacks or other deductions available
under current law, scheduled reductions of any tax abatement, as a result of the
elimination, invalidity or withdrawal of any tax abatement, or for any other
cause whatsoever. Notwithstanding the foregoing, if any Taxes shall be paid
based on assessments or bills by a governmental or municipal authority using a
fiscal year other than a calendar year, Landlord may elect to average the
assessments or bills for the subject calendar year, based on the number of
months of such calendar year included in each such assessment or bill.

         (O) "Tenant's Prorata Share" of Taxes and Operating Expenses shall be
the rentable area of the Premises divided by the rentable area of the Property
on the last day of the calendar year for which Taxes or Operating Expenses are
being determined, excluding any parking facilities. Tenant acknowledges that the
"rentable area of the Premises" under this Lease includes the usable area,
without deduction for columns or projections, multiplied by a load or conversion
factor, to reflect a share of certain areas, which may include lobbies,
corridors, mechanical, utility, janitorial, boiler and service rooms and
closets, restrooms, and other public, common and service areas. The "rentable
area of the Property" shall include all rentable area of all space leased or
available for lease at the Property, which Landlord may reasonably re-determine
from time to time, to reflect re-configurations, additions or modifications to,
or changes in the use of, the Property, or any portion(s) thereof. If the
Property or any development of which it is a part, shall contain non-office
uses, Landlord shall have the right to determine in accordance with sound
accounting and management principles Tenant's Prorata Share of Taxes and
Operating Expenses for only the office portion of the Property or of such
development, in which event, Tenant's Prorata Share shall be based on the ratio
of the rentable area of the Premises to the rentable area or such office
portion. Similarly, if the Property shall contain tenants who do not participate
in all or certain categories of Taxes or Operating Expenses on a prorata basis,
Landlord may exclude the amount of Taxes or Operating Expenses or such
categories of the same, as the case may be, attributable to such tenants, and
exclude the rentable area of their premises, in computing Tenant's Prorata
Share.

                                       24
<PAGE>   28

                                   ARTICLE 26
                      CONVEYANCE BY LANDLORD AND LIABILITY

         In case Landlord or any successor owner of the Property or the Building
shall convey or otherwise dispose of any portion thereof in which the Premises
are located, to another Person (and nothing herein shall be construed to
restrict or prevent such conveyance or disposition), such other Person shall
thereupon be and become landlord hereunder and shall be deemed to have fully
assumed and be liable for all obligations of this Lease to be performed by
Landlord which first arise after the date of conveyance, including the return of
any Security Deposit and Tenant shall attorn to such other Person, and Landlord
or such successor owner shall, from and after the date of conveyance, be free of
all liabilities and obligations hereunder not then incurred. Landlord shall use
its best efforts to obtain from such successor in interest written recognition
of Tenant's rights under this Lease. The liability of Landlord to Tenant for any
default by Landlord under this Lease or arising in connection herewith or with
Landlord's operation, management, leasing, repair, renovation, alteration, or
any other matter relating to the Property or the Premises, shall be limited to
the interest of Landlord in the Property. Tenant agrees to look solely to
Landlord's interest in the Property for the recovery of any judgment against
Landlord, and neither Landlord nor Landlord's beneficiary shall be personally
liable for any such judgment or deficiency after execution thereon, regardless
of whether or not any portion of Landlord's duties under this Lease are
undertaken by, or on the behalf of Landlord's beneficiary. The limitations of
liability contained in this Article shall apply equally and inure to the benefit
of the respective present and future members, managers, partners, beneficiaries,
officers, directors, trustees, shareholders, agents and employees, of Landlord
and Landlord's beneficiary, and their respective partners, heirs, successors and
assigns. Under no circumstances shall any present or future director or officer
of Landlord or Landlord's beneficiary (if Landlord or Landlord's beneficiary is
a corporation) or general or limited partner of Landlord or Landlord's
beneficiary (if Landlord or Landlord's beneficiary is a partnership), or present
or future manager or member of Landlord or Landlord's beneficiary (if Landlord
or Landlord's beneficiary is a limited liability company) have any liability for
the performance of Landlord's obligations under this Lease, and notwithstanding
that, if Landlord is a trustee of a land trust, Landlord's beneficiary elects to
perform any of Landlord's obligations under this Lease.

                                   ARTICLE 27
                           WAIVER AND INDEMNIFICATION

         (a) To the extent not expressly prohibited by law, Tenant hereby
releases Landlord from, and waives all claims for, damages to persons or
property sustained by Tenant or by any occupant of the Premises or the Building,
or by any other person, resulting directly or indirectly from fire or other
casualty, or any existing or future condition, defect, matter or thing in the
Premises, the Building or any part thereof, or from any equipment or
appurtenance therein, or from any accident in or about the Building, or from any
act or neglect of any tenant or other occupant of the Building or of any other
person (including but not limited to any injury or damage to persons or property
resulting from fire, explosion, falling plaster, steam, gas, electricity, water
or rain which may leak from any part of the Building) unless caused by the gross
negligence or willful misconduct of Landlord, its agents, employees or
contractors.

         (b) Except to the extent arising from the negligent acts of Landlord or
Tenant or Landlord's or Tenant's agents or employees, each party shall defend,
indemnify and hold harmless the other party from and against any and all claims,
demands, liabilities, damages, judgments, orders, decrees, actions, proceedings,
fines, penalties, costs and expenses, including without limitation, court costs
and attorneys' fees arising from or relating to any loss of life, damage or
injury to person, property or business occurring in or from the Premises, or
caused by or in connection with any violation of this Lease or use of the
Premises or Property by, or any other act or omission of, either party, any
other occupant of the Premises, or any of their respective agents, employees,
contractors or guests. Without limiting the generality of the foregoing, both
Tenant and Landlord specifically acknowledges that the indemnity undertaking
herein shall apply to claims in connection with or arising out of any
"Alterations" as described in Article 8, the installation, maintenance, use or
removal of any "Lines" located in or serving the Premises as described in
Article 29, and the transportation, use, storage, maintenance, generation,
manufacturing, handling, disposal, release or discharge of any "Hazardous
Material" as described in Article 30 (whether or not any of such matters shall
have been theretofore approved by Landlord), except to the extent that any of
the same arises from the intentional or grossly negligent acts of Landlord or
Tenant or Landlord's or Tenant's agents or employees. The

                                       25
<PAGE>   29
terms and provisions of this Article 27 shall survive the expiration or earlier
termination of this Lease.

         (c) For purposes of this Article 27 only, "Landlord" shall include
Landlord, Landlord's agent, or any other Building manager, all Mortgagees, and
their respective agents, servants, shareholders, contractors, managers, members,
directors, officers, partners and employees.

                                   ARTICLE 28
               SAFETY AND SECURITY DEVICES, SERVICES AND PROGRAMS

         The parties acknowledge that safety and security devices, services and
programs provided by Landlord, if any, while intended to deter crime and ensure
safety, may not in given instances prevent theft or other criminal acts, or
ensure safety of persons or property. The risk that any safety or security
device, service or program may not be effective, or may malfunction, or be
circumvented by a criminal, is assumed by Tenant with respect to Tenant's
property and interests, and Tenant shall obtain insurance coverage to the extent
Tenant desires protection against such criminal acts and other losses, as
further described in Article 11. Tenant agrees to cooperate in any reasonable
safety or security program developed by Landlord or required by Law.

                                   ARTICLE 29
                        COMMUNICATIONS AND COMPUTER LINES

         Notwithstanding anything contained herein to the contrary, Tenant may
install, maintain, replace, remove or use any communications or computer wires,
cables and related devices (collectively the "Lines") at the Property in or
serving the Premises, provided: (a) Tenant shall obtain Landlord's prior written
consent, and use an experienced and qualified contractor approved by Landlord,
such approval not to be unreasonably withheld, and comply with all of the other
provisions of Article 8, (b) any such installation, maintenance, replacement,
removal or use shall comply with all Laws applicable thereto and good work
practices, and shall not interfere with the use of any then existing Lines at
the Property, (c) an acceptable number of spare Lines and space for additional
Lines shall be maintained for existing and future occupants of the Property, as
determined in Landlord's reasonable opinion, (d) if Tenant at any time uses any
equipment that may create an electromagnetic field exceeding the normal
insulation ratings of ordinary twisted pair riser cable or cause radiation
higher than normal background radiation, the Lines therefor (including riser
cables) shall be appropriately insulated to prevent such excessive
electromagnetic fields or radiation, (e) as a condition to permitting the
installation of new Lines, Landlord may require that Tenant remove existing
Lines located in or serving the Premises, (f) Tenant's rights shall be subject
to the rights of any regulated telephone company, and (g) Tenant shall pay all
costs in connection therewith. Landlord reserves the right to require that
Tenant remove any Lines located in or serving the Premises which are installed
in violation of these provisions, or which are at any time in violation of any
Laws or represent a dangerous or potentially dangerous condition (whether such
Lines were installed by Tenant or any other party), within three (3) days after
written notice.

         Landlord may (but shall not have the obligation to): (i) install new
Lines at the Property, (ii) create additional space for Lines at the Property,
and (iii) reasonably direct, monitor and/or supervise the installation,
maintenance, replacement and removal of, the allocation and periodic
re-allocation of available space (if any) for, and the allocation of excess
capacity (if any) on, any Lines now or hereafter installed at the Property by
Landlord, Tenant or any other party (but Landlord shall have no right to monitor
or control the information transmitted through such Lines). Such rights shall
not be in limitation of other rights that may be available to Landlord by Law or
otherwise. If Landlord exercises any such rights, Landlord may charge Tenant for
the costs attributable to Tenant, or may include those costs and all other costs
in Operating Expenses under Article 25 (including without limitation, costs for
acquiring and installing Lines and risers to accommodate new Lines and spare
Lines, any associated computerized system and software for maintaining records
of Line connections, and the fees of any consulting engineers and other
experts); provided, any capital expenditures included in Operating Expenses
hereunder shall be amortized (together with reasonable finance charges) over the
period of time prescribed by Article 25.

                                       26
<PAGE>   30

         Notwithstanding anything to the contrary contained in Article 13,
Landlord reserves the right to require that Tenant remove any or all Lines
installed by or for Tenant within or serving the Premises upon termination of
this Lease, provided Landlord notifies Tenant prior to or within thirty (30)
days following such termination. Any Lines not required to be removed pursuant
to this Article shall, at Landlord's option, become the property of Landlord
(without payment by Landlord). If Tenant fails to remove such Lines as required
by Landlord, or violates any other provision of this Article, Landlord may,
after twenty (20) days written notice to Tenant, remove such Lines or remedy
such other violation, at Tenant's expense (without limiting Landlord's other
remedies available under this Lease or applicable Law). Tenant shall not,
without the prior written consent of Landlord in each instance, grant to any
third party a security interest or lien in or on the Lines, and any such
security interest or lien granted without Landlord's written consent shall be
null and void. Except to the extent arising from the intentional or negligent
acts of Landlord or Landlord's agents or employees, Landlord shall have no
liability for damages arising from, and Landlord does not warrant that the
Tenant's use of any Lines will be free from the following (collectively called
"Line Problems"): (x) any eavesdropping or wire-tapping by unauthorized parties,
(y) any failure of any Lines to satisfy Tenant's requirements, or (z) any
shortages, failures, variations, interruptions, disconnections, loss or damage
caused by the installation, maintenance, replacement, use or removal of Lines by
or for other tenants or occupants at the Property, by any failure of the
environmental conditions or the power supply for the Property to conform to any
requirements for the Lines or any associated equipment, or any other problems
associated with any Lines by any other cause. Under no circumstances shall any
Line Problems be deemed an actual or constructive eviction of Tenant, render
Landlord liable to Tenant for abatement of Rent, or relieve Tenant from
performance of Tenant's obligations under this Lease, unless same is caused by
the gross negligence or willful misconduct of Landlord. Landlord in no event
shall be liable for damages by reason of loss of profits, business interruption
or other consequential damage arising from any Line Problems, unless same is
caused by the gross negligence or willful misconduct of Landlord.

                                   ARTICLE 30
                               HAZARDOUS MATERIALS

         Tenant shall not transport, use, store, maintain, generate,
manufacture, handle, dispose, release or discharge any "Hazardous Material" (as
defined below) upon or about the Property, nor permit Tenant's employees,
agents, contractors, and other occupants of the Premises to engage in such
activities upon or about the Property. However, the foregoing provisions shall
not prohibit the transportation to and from, and use, storage, maintenance and
handling within, the Premises of substances customarily used in offices (or such
other business or activity expressly permitted to be undertaken in the Premises
under Article 6), provided: (a) such substances shall be used and maintained
only in such quantities as are reasonably necessary for such permitted use of
the Premises, strictly in accordance with applicable Law and the manufacturers'
instructions therefor, (b) such substances shall not be disposed of, released or
discharged on the Property, and shall be transported to and from the Premises in
compliance with all applicable Laws, and as Landlord shall reasonably require,
(c) if any applicable Law or Landlord's trash removal contractor requires that
any such substances be disposed of separately from ordinary trash, Tenant shall
make arrangements at Tenant's expense for such disposal directly with a
qualified and licensed disposal company at a lawful disposal site (subject to
scheduling and approval by Landlord), and shall ensure that disposal occurs
frequently enough to prevent unnecessary storage of such substances in the
Premises, and (d) any remaining such substances shall be completely, properly
and lawfully removed from the Property upon expiration or earlier termination of
this Lease.

         Tenant shall promptly notify Landlord of: (i) any enforcement, cleanup
or other regulatory action taken or threatened by any governmental or regulatory
authority with respect to the presence of any Hazardous Material on the Premises
or the migration thereof from or to other property, (ii) any demands or claims
made or threatened by any party against Tenant or the Premises relating to any
loss or injury resulting from any Hazardous Material, (iii) any release,
discharge or nonroutine, improper or unlawful disposal or transportation of any
Hazardous Material on or from the Premises, and (iv) any matters where Tenant is
required by Law to give a notice to any governmental or regulatory authority
respecting any Hazardous Materials on the Premises. Landlord shall have the
right (but not the obligation) to join and participate, as a party, in any legal
proceedings or actions affecting the Premises initiated in connection with any
environmental, health or safety Law. At such times as Landlord may reasonably
request, Tenant shall provide Landlord with a written list identifying any
Hazardous Material then used, stored, or maintained upon the Premises, the use
and approximate quantity of each such material, a copy of any material safety
data sheet ("MSDS") issued by the manufacturer therefor, written information

                                       27
<PAGE>   31

concerning the removal, transportation and disposal of the same, and such other
information as Landlord may reasonably require or as may be required by Law. The
term "Hazardous Material" for purposes hereof shall mean any chemical,
substance, material or waste or component thereof which is now or hereafter
listed, defined or regulated as a hazardous or toxic chemical, substance,
material or waste or component thereof by any federal, state or local governing
or regulatory body having jurisdiction, or which would trigger any employee or
community "right-to-know" requirements adopted by any such body, or for which
any such body has adopted any requirements for the preparation or distribution
of an MSDS.

         If any Hazardous Material is released, discharged or disposed of by
Tenant or any other occupant of the Premises, or their employees, agents or
contractors, on or about the Property in violation of the foregoing provisions,
Tenant shall immediately, properly and in compliance with applicable Laws clean
up and remove the Hazardous Material from the Property and any other affected
property and clean or replace any affected personal property (whether or not
owned by Landlord), at Tenant's expense. Such clean up and removal work shall be
subject to Landlord's prior written approval except in emergencies), and shall
include, without limitation, any testing, investigation, and the preparation and
implementation of any remedial action plan required by any governmental body
having jurisdiction or reasonably required by Landlord. If Tenant shall fail to
comply with the provisions of this Article within five (5) days after written
notice by Landlord, or such shorter time as may be required by Law or in order
to minimize any hazard to Persons or property, Landlord may (but shall not be
obligated to) arrange for such compliance directly or as Tenant's agent through
contractors or other parties selected by Landlord, at Tenant's expense (without
limiting Landlord's other remedies under this Lease or applicable Law). If any
Hazardous Material is released, discharged or disposed of on or about the
Property and such release, discharge or disposal is not caused by Tenant or
other occupants of the Premises, or their employees, agents or contractors. In
the event Tenant discovers Hazardous Materials in the Premises during its
initial construction of the Premises, not brought on by Tenant, Tenant shall
notify Landlord and Landlord shall perform any such corrective actions necessary
and required by law as quickly as is reasonably possible under the circumstances
and restore the Premises to the condition existing immediately prior to the
performance of such corrective actions. Upon the discovery of Hazardous
Materials, not placed thereon by Tenant, Tenant shall have the option of
terminating this Lease, only if Landlord fails to take necessary corrective
action within a six-month period. In the event the discovery of Hazardous
Materials shall occur during the term of this Lease and they are not brought on
or cause by Tenant, Tenant shall receive an abatement of all rents and charges
hereunder if Tenant is precluded from doing business in the Premises during any
necessary required corrective action (including restoration of the Leased
Premises) by the Landlord, which Landlord shall perform and complete as
expeditiously as is reasonably possible. In addition Landlord shall restore, at
its cost, any damage to the Premises to its condition originally preceding the
corrective action. In the event Landlord elects not to take such corrective
actions pursuant to this Section or fails to do so within sixty (60) days notice
to Landlord of the existence of Hazardous Materials on the Premises, then
Tenant, as its sole remedy hereunder, may terminate the Lease.

                                   ARTICLE 31
                                  MISCELLANEOUS

         (A) Each of the terms and provisions of this Lease shall be binding
upon and inure to the benefit of the parties hereto, their respective heirs,
executors, administrators, guardians, custodians, successors and assigns,
subject to the provisions of Article 21 respecting Transfers.

         (B) This Lease shall not be recorded. In the event Landlord or Tenant
requests recording, the parties agree to execute, acknowledge and deliver a
memorandum of lease in recordable form.

         (C) This Lease shall be construed in accordance with the Laws of the
state in which the Property is located.

         (D) All obligations or rights of either party arising during or
attributable to the period ending upon expiration or earlier termination of this
Lease shall survive such expiration or earlier termination.

                                       28
<PAGE>   32

         (E) Landlord agrees that, if Tenant timely pays the Rent and performs
the terms and provisions hereunder, and subject to all other terms and
provisions of this Lease, Tenant shall hold and enjoy the Premises during the
Term, free of lawful claims by any Person acting by or through Landlord.

         (F) This Lease does not grant any legal rights to "light and air"
outside the Premises nor any particular view or cityscape visible from the
Premises. Landlord specifically excepts and reserves to itself the use of any
roofs, the exterior portions of the Premises, all rights to and the land and
improvements below the improved floor level of the Premises, to the improvements
and air rights above the Premises, to the improvements and air rights located
outside the demising walls of the Premises and to such areas within the Premises
required for installation of utility lines and other installations required to
serve any occupants of the Building and to maintain and repair same, and no
rights with respect thereto are conferred upon Tenant, unless otherwise
specifically provided herein.

         (G) If the Commencement Date is delayed in accordance with Article 4
for more than one year, either Tenant or Landlord may declare this Lease null
and void, and if the Commencement Date is so delayed for more than seven years,
this Lease shall thereupon become null and void without further action by either
party.

         (H) Time is of the essence of this Lease and all provisions herein
relating thereto shall be strictly construed.

         (I) Neither Landlord nor Tenant shall not be deemed in default with
respect to any of the terms, covenants and conditions of this Lease on the
party's part to be performed, if said party fails timely to perform the same and
such failure is due in whole or in part to any strike, labor trouble, failure of
power, accidents, Acts of God, acts caused directly or indirectly by the other
party (or its agents, employees, or invitees), or any other cause beyond said
party's reasonable control.

         (J) The voluntary or other surrender of this Lease by Tenant or a
mutual cancellation thereof, shall not constitute a merger; and upon such
surrender or cancellation of this Lease, Landlord shall have the option, in
Landlord's sole discretion, to (a) either terminate all or any existing
subleases or subtenancies, or (b) assume Tenant's interest in any or all
subleases or subtenancies.

         (K) Any and all covenants of Tenant not fully performed on the date of
the expiration of termination of this Lease shall survive such expiration or
termination.

         (L) For purposes of Article 2 hereof or any other provision of this
Lease, if any sum set forth in this Lease is expressed as an amount per square
foot of rentable area or per rentable square foot, or in a similar manner, such
sum shall control over any inconsistent computation or expression of such
amount.

                                   ARTICLE 32
                                      OFFER

         The submission and negotiation of this Lease shall not be deemed an
offer to enter the same by Landlord, but the solicitation of such an offer by
Tenant. Tenant agrees that its execution of this Lease constitutes a firm offer
to enter the same which may not be withdrawn for a period of 30 days after
delivery to Landlord (or such other period as may be expressly provided in any
other agreement signed by the parties). During such period and in reliance on
the foregoing, Landlord may, at Landlord's option (and shall, if required by
applicable Law), deposit any security deposit and Rent, and proceed with any
plans, specifications, alterations or improvements, and permit Tenant to enter
the Premises, but such acts shall not be deemed an acceptance of Tenant's offer
to enter this Lease, and such acceptance shall be evidenced only by Landlord
signing and delivering this Lease to Tenant.

                                       29
<PAGE>   33

                                   ARTICLE 33
                                     NOTICES

         Except as expressly provided to the contrary in this Lease, every
notice or other communication to be given by either party to the other with
respect hereto or to the Premises or Property, shall be in writing and shall not
be effective for any purpose unless the same shall be served personally or by
national air courier service, or United States certified mail, return receipt
requested, postage prepaid, addressed, if to Tenant, at the address first set
forth in the Lease, until the Commencement Date, and thereafter to the Tenant at
the Premises, and if to Landlord and Landlord's agent, addressed as follows:

                  Landlord:             LC Tower, L.L.C.
                                        c/o GEM Investors, Inc.
                                        900 N. Michigan Avenue, Suite 1900
                                        Chicago, Illinois 60611
                                        Attention: Craig Caffarelli

                  Landlord's Agent:     FMS, Inc.
                                        333 Union Street, Suite 400
                                        Nashville, Tennessee 37201
                                        Attention: W. Kirby Davis, Jr.

                  With a copy to:       Wyatt, Tarrant & Combs
                                        1500 Nashville City Center
                                        511 Union Street
                                        Nashville, Tennessee 37219
                                        Attention: Sam J. McAllester III

or such other address or addresses as Tenant or Landlord may from time to time
designate by notice given as above provided. Every notice or other communication
hereunder shall be deemed to have been given as of the third business day
following the date of such mailing (or as of any earlier date evidenced by a
receipt from such national air courier service or the United States Postal
Service) or immediately if personally delivered. Notices not sent in accordance
with the foregoing shall be of no force or effect until received by the
foregoing parties at such addresses required herein. In the event that Tenant
has vacated or abandoned the Premises, notice to Tenant shall be deemed given
pursuant to this Article 33 if sent to Tenant's registered agent, except that if
Tenant has no registered agent or if such registered agent does not accept
notice on behalf of Tenant, notice shall be deemed given to Tenant if sent to
the Tennessee Secretary of State, Nashville, Tennessee.

                                   ARTICLE 34
                               REAL ESTATE BROKERS

         Landlord and Tenant represents and warrants to the other that they have
dealt only with First Management Services (whose commission, if any, shall be
paid by Landlord pursuant to separate agreement) as broker, agent or finder in
connection with this Lease and agrees to indemnify and hold the other harmless
from all damages, judgments, liabilities and expenses (including reasonable
attorneys' fees) arising from any claims or demands of any other broker, agent
or finder with whom said party has dealt for any commission or fee alleged to be
due in connection with its participation in the procurement of said party or the
negotiation with said party of this Lease. Tenant and Landlord shall indemnify,
defend and hold harmless the other from all costs and damages, or claims for
damages, of any type on account of a breach of the foregoing representation and
warranty.

                                       30
<PAGE>   34

                                   ARTICLE 35
                                SECURITY DEPOSIT

         Tenant shall deposit with Landlord the amount of $14,897.37 ("Security
Deposit"), upon Tenant's execution and submission of this Lease. At the end of
the first Lease year (April 30, 2000), the amount of the Security Deposit shall
be reduced to $5,331.28. The Security Deposit shall serve as security for the
prompt, full and faithful performance by Tenant of the terms and provisions of
this Lease. In the event that Tenant is in default hereunder and fails to cure
within any applicable time permitted under this Lease, or in the event that
Tenant owes any amounts to Landlord upon the expiration of this Lease, Landlord
may, from time to time, use or apply the whole or any part of the Security
Deposit for the payment of Tenant's obligations hereunder. The use or
application of the Security Deposit or any portion thereof shall not prevent
Landlord from exercising any other right or remedy provided hereunder or under
any Law and shall not be construed as liquidated damages. In the event the
Security Deposit is reduced by such use or application, Tenant shall deposit
with Landlord within ten (10) days after written notice, an amount sufficient to
restore the full amount of the Security Deposit. Landlord shall not be required
to keep the Security Deposit separate from Landlord's general funds or pay
interest on the Security Deposit. Any remaining portion of the Security Deposit
shall be returned to Tenant within sixty (60) days after Tenant has vacated the
Premises in accordance with Article 13. If the Premises shall be expanded at any
time, or if the Term shall be extended at an increased rate of Rent, the
Security Deposit shall thereupon be proportionately increased.

                                   ARTICLE 36
                              FINANCIAL STATEMENTS

         Tenant represents that it has provided Landlord with true and complete
financial statements (the "Financial Statements") setting forth the financial
condition of Tenant and of each Guarantor as of the date specified in such
statements. Upon Landlord's written request, Tenant shall furnish Landlord with
a written certification from an executive officer, manager, or partner of Tenant
and from each Guarantor describing in reasonable detail any material adverse
change in the financial condition of Tenant and/or each Guarantor (as the case
may be) from that set forth in the respective Financial Statements or stating
that there has been no such change.

                                   ARTICLE 37
                             Intentionally omitted.

                                   ARTICLE 38
                                       ADA

         The parties acknowledge that the Americans With Disabilities Act of
1990 (42 U.S.C. ss.12101 et seq.) and regulations and guidelines promulgated
thereunder, as all of the same may be amended and supplemented from time to time
(collectively referred to herein as the "ADA") establish requirements under
Title III of the ADA ("Title III") pertaining to business operations,
accessibility and barrier removal, and that such requirements may be unclear and
may or may not apply to the Premises and the Building depending on, among other
things: (1) whether Tenant's business operations are deemed a "place of public
accommodation" or a "commercial facility," (2) whether compliance with such
requirements is "readily achievable" or "technically infeasible," and (3)
whether a given alteration affects a "primary function area" or triggers
so-called "path of travel" requirements. The parties acknowledge and agree that
Tenant has been provided an opportunity to inspect the Premises and the Building
sufficient to determine whether or not the Premises and the Building in their
condition current as of the date hereof deviate in any manner from the ADA
Accessibility Guidelines ("ADAAG") or any other requirements under the ADA
pertaining to the accessibility of the Premises or the Building. Tenant further
acknowledges and agrees that except as may otherwise be specifically provided
herein, Tenant accepts the Premises and the Building in "as-is" condition and
agrees that Landlord makes no representation or warranty as to whether the
Premises or the Building conform to the requirements of the ADAAG or any other
requirements under the ADA pertaining to the accessibility of the Premises or
the Building. Tenant has prepared or reviewed the plans and specifications for
the Tenant's Work and has independently determined that such plans and
specifications are in conformance with the ADAAG and any other requirements of
the ADA. Tenant further acknowledges and agrees that to the extent that Landlord
prepared, reviewed or approved any of those plans and specifications, such
action shall in no event be deemed any representation or warranty that the same
comply with any requirements of the ADA. Notwithstanding anything to the
contrary in this Lease, the parties hereby agree to allocate responsibility for
Title III compliance as follows: (a) Tenant shall be responsible for all Title
III compliance and costs in connection with the Premises, including structural
work, if any, and including any leasehold improvements or other work to be
performed in the Premises under or in connection with this Lease, and (b)
Landlord shall perform, and Tenant shall be responsible for the cost of, any
so-called Title III "path of travel" requirements triggered by any construction
activities or alterations in the Premises. Except as set forth above with
respect to

                                       31
<PAGE>   35

Landlord's Title III obligations, Tenant shall be solely responsible
for all other requirements under the ADA relating to the Tenant or any
affiliates or persons or entities related to the Tenant (collectively,
"Affiliates"), operations of the Tenant or Affiliates, or the Premises,
including, without limitation, requirements under Title I of the ADA pertaining
to Tenant's employees.

                                   ARTICLE 39
               LANDLORD'S CONTRIBUTION FOR WORK; PROGRESS PAYMENTS

         Landlord shall provide to Tenant up to Four Thousand Six Hundred
dollars ($4,600.00) towards Tenant Improvements to the Annex Premises within
thirty (30) days of installation of its sprinkler system, fireproofing and HVAC.
Landlord shall provide for the installation of new carpet in the Tower Premises
not to exceed Twelve Thousand Eight Hundred Four dollars ($12,804.00). Landlord
and Tenant shall mutually agree to the carpet selection for the Tower Premises.
Otherwise, Tenant shall accept the Premises in "as-is" condition.

                                   ARTICLE 40
                                ENTIRE AGREEMENT

         This Lease, together with Rider One and Exhibits A through B (WHICH
COLLECTIVELY ARE HEREBY INCORPORATED WHERE REFERRED TO HEREIN AND MADE A PART
HEREOF AS THOUGH FULLY SET FORTH), contains all the terms and provisions between
Landlord and Tenant relating to the matters set forth herein and no prior or
contemporaneous agreement or understanding pertaining to the same shall be of
any force or effect, except any such contemporaneous agreement specifically
referring to and modifying this Lease, signed by both parties. Without
limitation as to the generality of the foregoing, Tenant hereby acknowledges and
agrees that Landlord's leasing agents and field personnel are only authorized to
show the Premises and negotiate terms and conditions for leases subject to
Landlord's final approval, and are not authorized to make any agreements,
representations, understandings or obligations, binding upon Landlord,
respecting the condition of the Premises or Property, suitability of the same
for Tenant's business, or any other matter, and no such agreements,
representations, understandings or obligations not expressly contained herein or
in such contemporaneous agreement shall be of any force or effect. Neither this
Lease, nor any Riders or Exhibits referred to above may be modified, except in
writing signed by both parties.

                                   ARTICLE 41
                              LANDLORD'S AUTHORITY

         Landlord represents to the best of its knowledge that: (I) Landlord is
the owner of fee simple to the Building, and (ii) Landlord has all necessary
power and authority to enter into this Lease. Landlord represents that Landlord
has not received notification from any governmental authority that the Property
is in violation of any environmental or zoning regulations.

                                   ARTICLE 42
                                     PARKING

         During the lease term, Landlord agrees to provide Tenant with fourteen
(14) unreserved parking spaces for the Annex Premises and twenty-six (26)
unreserved parking spaces for the Tower Premises at market rates in Landlord's
Parking Garage, known as Fifth Avenue Parking Garage, provided that Landlord
continues to own and operate said garage. However, if the State of Tennessee (an
existing tenant) should require additional parking, Landlord shall have to
reduce the parking ratio of 3:1000 (3 spaces to 1,000 SF of Premises) down to
1:1,000 (1 space to 1,000 SF of Premises) and therefore Tenant's Annex Premises
would allow for five (5) unreserved parking space and Tenant's Tower Premises
would allow for nine (9) unreserved parking spaces. Unreserved is defined as
parking on the second full-floor level or higher on a first-come-first-served
basis.

                                       32
<PAGE>   36

         IN WITNESS WHEREOF, the parties hereto have caused this Lease to be
executed as of the date first above written.

                                        LANDLORD:

                                        LC TOWER, L.L.C. a Delaware limited
                                        liability company

                                        By:  PERIDOT, INC. Manager

Witness: Marija Tatich                  By: /s/ Craig Caffarelli
        ------------------------            -------------------------------

Its:   Portfolio Manager                Its:  Vice President
       ------------------------             ----------------

                                        TENANT:

                                        BlueStar Communications,
                                        a Tennessee Corporation

Witness:  Melinda Alford                BY: /s/ Fredjoseph Goldner
          --------------                ------------------------------------
                                        BY:      Fredjoseph Goldner

                                        Its: Chief Operating Officer

                                   CERTIFICATE

                          (IF TENANT IS A CORPORATION)

         I, R.L. Burtner, Secretary of BlueStar Communications, Inc., Tenant,
hereby certify that the officer(s) executing the foregoing Lease on behalf of
Tenant was/were duly authorized to act in his capacity as _________________
and ___________________, and his/their action(s) are the action of Tenant.

(Corporate Seal)                                           R.L. Burtner
                                                  -----------------------------
                                                            Secretary

                                       33
<PAGE>   37

                                    EXHIBIT A

                 (FLOOR PLAN(S) SHOWING PREMISES CROSS-HATCHED)

                                       1
<PAGE>   38

                                    EXHIBIT B

                            JANITORIAL SPECIFICATIONS

         Cleaning services, deemed by Landlord to be normal and usual in a first
class office building, as follows:

DAILY - OFFICES:

Empty waste baskets, replace liners as needed.
Dust all free surfaces of furniture, desks and tables.
Dust, mop or sweep all hard floors.
Vacuum all carpeted areas.
Mop tile floors as needed.

DAILY - RESTROOMS:
Clean all glass and mirrors.
Spot clean walls and partitions.
Sweep, damp mop, and sanitize hard floors.
Clean and sanitize all fixtures.
Empty all containers and dispose, insert liners as needed.
Refill all dispensers to normal limits (hand soap, hand towels, toilet tissue,
liners).

WEEKLY - OFFICES:
Clean all horizontal surfaces and sills, ledges, and moldings.
Spot clean carpet as needed.

QUARTERLY - OFFICES:
Clean window blinds.
Detail all areas as needed.

BI-ANNUALLY - OFFICES:
Clean all interior and exterior windows.

Note:    Shampooing and replacement of carpet as required by Tenant shall be
         Tenant's expense.

                                       1
<PAGE>   39

                                   EXHIBIT B-1

                               HVAC SPECIFICATIONS

Heating, Ventilating and Air Conditioning:

<TABLE>
<CAPTION>
Summer Design Conditions                             Winter Design Conditions
------------------------                             ------------------------
<S>                                                  <C>
Outdoor Temperature: 95(Degree)F. Dry Bulb           Outdoor Temperature: -10(Degree)F. Dry Bulb

Outdoor Temperature: 75(Degree)F. Wet Bulb

Indoor Temperature:  72(Degree)F. + 2(Degree)F.      Indoor Temperature: 72(Degree)F. + 2 (Degree) F.
</TABLE>

         All occupied spaces will be air conditioned with the exception of
toilet rooms, storage rooms, and the mechanical room.

         Air conditioning systems will be designed on the basis of occupancy of
one (1) person per one hundred (100) square feet in the rentable area of the
Premises and maximum electrical lighting and receptacle load of five (5) watts
per square foot in the rentable area of the Premises.

         All special HVAC requirements shall be subject to Landlord's approval.

                                       2
<PAGE>   40

                                    RIDER ONE

                                      RULES

         (1) On Saturdays, Sundays and Holidays, and on other days between the
hours of 6:00 P.M. and 8:00 A.M. the following day, or such other hours as
Landlord shall determine from time to time, access to the Property and/or to the
passageways, entrances, exits, shipping areas, halls, corridors, elevators or
stairways and other areas in the Property may be restricted and access gained by
use of a key to the outside doors of the Property, or pursuant to such
reasonable security procedures Landlord may from time to time impose. All such
areas, and all roofs, are not for use of the general public and Landlord shall
in all cases retain the right to control and prevent access thereto by any
persons whose presence in the judgment of Landlord shall be prejudicial to the
safety, character, reputation and interests of the Property and its tenants
provided, however, that nothing herein contained shall be construed to prevent
such access to persons with whom Tenant deals in the normal course of Tenant's
business unless such persons are engaged in activities which are illegal or
violate these Rules. No Tenant and no employee or invitee of Tenant shall enter
into areas reserved for the exclusive use of Landlord, its employees or
invitees. Tenant shall keep doors to corridors and lobbies closed except when
persons are entering or leaving. Landlord warrants that Tenant, its contractors,
agents, servicers and employees shall have continuing access subject to
reasonable security measures) continually, 24 hours per day, seven days per
week at no additional cost to Tenant.

         (2) Tenant shall not paint, display, inscribe, maintain or affix any
sign, placard, picture, advertisement, name, notice, lettering or direction on
any part of the outside or inside of the Property, or on any part of the inside
of the Premises which can be seen from the outside of the Premises without the
prior consent of Landlord, and then only such name or names or matter and in
such color, size, style, character and material as may be first approved by
Landlord in writing. Landlord shall prescribe the suite number and
identification sign for the Premises (which shall be prepared and installed by
Landlord at Tenant's expense). Landlord reserves the right to remove at Tenant's
expense all matter not so installed or approved without notice to Tenant.

         (3) Tenant shall not in any manner use the name of the Property for any
purpose other than that of the business address of the Tenant, or use any
picture or likeness of the Property, in any letterheads, envelopes, circulars,
notices, advertisements, containers or wrapping material without Landlord's
express consent in writing.

         (4) Tenant shall not place anything or allow anything to be placed in
the Premises near the glass of any door, partition, wall or window which may be
unsightly from outside the Premises, and Tenant shall not place or permit to be
placed any article of any kind on any window ledge or on the exterior walls.
Blinds, shades, awnings or other forms of inside or outside window ventilators
or similar devices, shall not be placed in or about the outside windows in the
Premises except to the extent, if any, that the character, shape, color,
material and make thereof is first approved by the Landlord.

         (5) Furniture, freight and other large or heavy articles, and all other
deliveries may be brought into the Property only at times and in the manner
designated by Landlord, and always at the Tenant's sole responsibility and risk.
Landlord may impose reasonable charges for use of freight elevators after or
before normal business hours. All damage done to the Property by moving or
maintaining such furniture, freight or articles shall be repaired by Landlord at
Tenant's expense. Landlord may inspect items brought into the Property or
Premises with respect to weight or dangerous nature. Landlord may require that
all furniture, equipment, cartons and similar articles removed from the Premises
or the Property be listed and a removal permit therefor first be obtained from
Landlord. Tenant shall not take or permit to be taken in or out of other
entrances or elevators of the Property, any item normally taken, or which
Landlord otherwise reasonably requires to be taken, in or out through service
doors or on freight elevators. Tenant shall not allow anything to remain in or
obstruct in any way, any lobby, corridor, sidewalk, passageway, entrance, exit,
hall, stairway, shipping area, or other such area. Tenant shall move all
supplies, furniture and equipment as soon as received directly to the Premises,
and shall move all such items and waste (other than waste customarily removed by
Property employees) that are at any time being taken from the Premises directly
to the areas designated for disposal. Any hand-carts used at the Property shall
have rubber wheels.

                                       1
<PAGE>   41

         (6) Tenant shall not overload any floor or part thereof in the
Premises, or Property, including any public corridors or elevators therein
bringing in or removing any large or heavy articles, and Landlord may direct and
control the location of safes and all other heavy articles and require
supplementary supports at Tenant's expense of such material and dimensions as
Landlord may deem necessary to properly distribute the weight.

         (7) Tenant shall not attach or permit to be attached additional locks
or similar devices to any door or window, change existing locks or the mechanism
thereof, or make or permit to be made any keys for any door other than those
provided by Landlord. If more than two keys for one lock are desired, Landlord
will provide them upon payment therefor by Tenant. Tenant, upon termination of
its tenancy, shall deliver to the Landlord all keys of offices, rooms and toilet
rooms which have been furnished Tenant or which the Tenant shall have had made,
and in the event of loss of any keys so furnished shall pay Landlord therefor.

         (8) If Tenant desires signal, communication, alarm or other utility or
similar service connections installed or changed, Tenant shall not install or
change the same without the prior approval of Landlord, and then only under
Landlord's direction at Tenant's expense. Tenant shall not install in the
Premises any equipment which requires more electric current than Landlord is
required to provide under this Lease, without Landlord's prior approval, and
Tenant shall ascertain from Landlord the maximum amount of load or demand for or
use of electrical current which can safely be permitted in the Premises, taking
into account the capacity of electric wiring in the Property and the Premises
and the needs of tenants of the Property, and shall not in any event connect a
greater load than such safe capacity.

         (9) Tenant shall not obtain for use upon the Premises ice, drinking
water, towel, and other similar services, except from Persons approved by the
Landlord. Any Person engaged by Tenant to provide janitor or other services
shall be subject to direction by the manager or security personnel of the
Property.

         (10) The toilet rooms, urinals, wash bowls and other such apparatus
shall not be used for any purpose other than that for which they were
constructed and no foreign substance of any kind whatsoever shall be thrown
therein and the expense of any breakage, stoppage or damage resulting from the
violation of this Rule shall be borne by the Tenant who, or whose employees or
invitees shall have caused it.

         (11) The janitorial closets, utility closets, telephone closets, broom
closets, electrical closets, storage closets, and other such closets, rooms and
areas shall be used only for the purposes and in the manner designated by
Landlord, and may not be used by tenants, or their contractors, agents,
employees, or other parties without Landlord's prior written consent.

         (12) Landlord reserves the right to exclude or expel from the Property
any person who, in the judgment of Landlord, is intoxicated or under the
influence of liquor or drugs, or who shall in any manner do any act in violation
of any of these Rules. Tenant shall not at any time manufacture, sell, use or
give away, any spirituous, fermented, intoxicating or alcoholic liquors on the
Premises, nor permit any of the same to occur (except in connection with
occasional social or business events conducted in the Premises which do not
violate any Laws nor bother or annoy any other tenants). Tenant shall not at any
time sell, purchase or give away, food in any form by or to any of Tenant's
agents or employees or any other parties on the Premises, nor permit any of the
same to occur (other than in lunch rooms or kitchens for employees as may be
permitted or installed by Landlord, which does not violate any Laws or bother or
annoy any other tenant).

         (13) Tenant shall not make any room-to-room canvass to solicit business
or information or to distribute any article or material to or from other tenants
or occupants of the Property and shall not exhibit, sell or offer to sell, use,
rent or exchange any products or services in or from the Premise unless
ordinarily embraced within the Tenant's use of the Premises specified in the
Lease.

         (14) Tenant shall not waste electricity, water, heat or air
conditioning or other utilities or services, and agrees to cooperate fully with
Landlord to assure the most effective and energy efficient operation of the
Property and shall not allow the adjustment (except by landlord's authorized
Property personnel) of any controls. Tenant shall keep corridor doors closed and
shall

                                       2
<PAGE>   42

not open any windows, except that if the air circulation shall not be in
operation, windows which are openable may be opened with Landlord's consent. As
a condition to claiming any deficiency in the air-conditioning or ventilation
services provided by Landlord, Tenant shall close any blinds or drapes in the
Premises to prevent or minimize direct sunlight.

         (15) Tenant shall conduct no auction, fire or "going out of business
sale" or bankruptcy sale in or from the Premises, and such prohibition shall
apply to Tenant's creditors.

         (16) Tenant shall cooperate and comply with any reasonable safety or
security programs, including fire drills and air raid drills, and the
appointment of "fire wardens" developed by landlord for the Property, or
required by Law. Before leaving the Premises unattended, Tenant shall close and
securely lock all doors or other means of entry to the Premises and shut off all
lights and water faucets in the Premises (except heat to the extent necessary to
prevent the freezing or bursting of pipes).

         (17) Tenant will comply with all municipal, county, state, federal or
other government laws, statutes, codes, regulations and other requirements,
including without limitation, environmental, health, safety and police
requirements and regulations respecting the Premises, now or hereinafter in
force, at its sole cost, and will not use the Premises for and immoral purposes.

         (18) Tenant shall not (i) carry on any business, activity or service
except those ordinarily embraced within the permitted use of the Premises
specified in the lease and more particularly, but without limiting the
generality of the foregoing, shall not (ii) install or operate any internal
combustion engine, boiler, machinery, refrigerating, heating or air conditioning
equipment in or about the Premises, (iii) use the Premises for housing, lodging
or sleeping purposes or for the washing of clothes, (iv) place any radio or
television antennae other than inside of the Premises, (v) operate or permit to
be operated any musical or sound producing instrument or device which may be
heard outside the Premises, (vi) intentionally deleted, (vii) operate any
electrical or other device from which may emanate electrical or other waves
which may interfere with or impair radio, television, microwave, or other
broadcasting or reception from or in the Property or elsewhere, (viii) bring or
permit any bicycle or other vehicle, or dog (except in the company of a blind
person or except where specifically permitted) or other animal or bird in the
Property, (ix) make or permit objectionable noise or odor to emanate from the
Premises, (x) do anything in or about the Premises tending to create or maintain
a nuisance or do any act tending to injure the reputation of the Property, (xi)
throw or permit to be thrown or dropped any article from any window or other
opening in the Property, (xii) use or permit upon the Premises anything that
will invalidate or increase the rate of insurance on any policies of insurance
now or hereafter carried on the Property or violate the certificates of
occupancy issued for the premises or the Property, (iii) use the Premises for
any purpose, or permit upon the Premises anything, that may be dangerous to
persons or property (including but not limited to flammable oils, fluids,
paints, chemicals, firearms or any explosive articles or materials) nor (xiv) do
or permit anything to be done upon the Premises in any way tending to disturb
any other tenant at the Property or the occupants of neighboring property.

         (19) All cleaning and janitorial services for the Building and the
Premises shall be provided exclusively through Landlord, and except with the
written consent of Landlord, no person or persons other than those approved by
Landlord shall be employed by Tenant or permitted to enter the Building for the
purpose of cleaning the same. Landlord shall not in any way be responsible to
Tenant for any loss of property on the Premises, however occurring, or for any
damage to any Tenant's property by the janitor or any other employee or any
other person.

         (20) Any freight elevator shall be available for use by all tenants in
the Building, subject to such reasonable scheduling as landlord in its sole
discretion shall deem appropriate. No equipment, materials, furniture, packages,
supplies, merchandise or other property will be received in the Building or
carried in the elevators except between such hours and in such elevators as
shall be designated by Landlord.

         (21) Tenant shall not use or keep in the Premises any flammable or
combustible fluid or material other than those limited quantities necessary for
the operation or maintenance of office equipment. Tenant shall not use or permit
to be used in the Premises any foul or noxious gas or

                                       3
<PAGE>   43

substance. Tenant shall not use or permit the Premises to be used in a manner
offensive or objectionable to Landlord or any occupancy of the Building by
reason of noise, odors, or vibrations. Tenant shall not bring any animals into
the Building.

         (22) Tenant shall not use any method of heating or air conditioning
other than that supplied or approved by Landlord.

         (23) Tenant shall not use in any space or in the public halls of the
Building any mailcarts or hand trucks except those approved by Landlord.

         (24) Without the written consent of Landlord, Tenant shall not use the
name of the Building in connection with or in promoting or advertising the
business of Tenant except as Tenant's address.

         (25) If the Property shall now or hereafter contain a building garage,
parking structure or other parking area or facility, the following Rules shall
apply in such areas or facilities:

         (i) Parking shall be available in areas designated generally for tenant
parking, for such daily or monthly charges as Landlord may establish from time
to time not to exceed market rates, or as may be provided in any Parking
Agreement attached hereto (which, when signed by both parties as provided
therein, shall thereupon become effective). In all cases, parking for Tenant and
its employees, visitors, contractors and agents shall be on a "first come, first
served," unassigned basis, with Landlord and other tenants at the Property, and
their employees and visitors, and other Persons (as defined in Article 25 of the
Lease) to whom Landlord shall grant the right or who shall otherwise have the
right to use the same, all subject to these Rules, as the same may be amended or
supplemented, and applied on a non-discriminatory basis, all as further
described in Article 6 of the Lease. Notwithstanding the foregoing to the
contrary, Landlord reserves the right to assign specific spaces, and to reserve
spaces for visitors, small cars, handicapped individuals, and other tenants,
visitors of tenants or other Persons, and Tenant and its employees and visitors
shall not park in any such assigned or reserved spaces. Landlord may restrict or
prohibit full size vans and other large vehicles. Notwithstanding anything
contained herein to the contrary, Landlord agrees to provide Tenant with parking
as outlined in Article 42 of this Lease.

         (ii) In case of any violation of these provisions, Landlord may refuse
to permit the violator to park, and may remove the vehicle owned or driven by
the violator from the Property without liability whatsoever, at such violator's
risk and expense. Landlord reserves the right to close all or a portion of the
parking areas or facilities in order to make repairs or perform maintenance
services, or to alter, modify, re-stripe or renovate the same, or if required by
casualty, strike, condemnation, act of God, Law or governmental requirement, or
any other reason beyond Landlord's reasonable control. In the event access is
denied for any reason, any monthly parking charges shall be abated to the extent
access is denied, as Tenant's sole recourse. Tenant acknowledges that such
parking areas or facilities may be operated by an independent contractor not
affiliated with Landlord, and Tenant acknowledges that in such event, Landlord
shall have no liability for claims arising through acts or omissions of such
independent contractor, if such contractor is reputable.

         (iii) Tenant and its employees shall have the right to park at its own
risk on a 24 hour, seven day per week basis, except in reasonable instances
necessary to maintenance of the garage. However, attended hours shall be 6 A.M.
to 8 P.M., Monday through Friday, and 10:00 A.M. to 1:00 P.M. on Saturdays, or
such other hours as may be reasonably established by Landlord or its parking
operator from time to time; cars must be parked entirely within the stall lines,
and only small cars may be parked in areas reserved for small cars; all
directional signs and arrows must be observed; the speed limit shall be 5 miles
per hour; spaces reserved for handicapped parking must be used only by vehicles
properly designated; every parker is required to park and lock his own car:
washing, waxing, cleaning or servicing of any vehicle is prohibited; parking
spaces may be used only for parking automobiles; parking is prohibited in areas:
(a) not striped or designated for parking, (b) aisles, (c) where "no parking"
signs are posted, (d) on ramps, and (e) loading areas and other specially
designated areas. Delivery trucks and vehicles shall use only those areas
designated therefor.

                                       4
<PAGE>   44

         (26) Landlord may waive any one or more of these Rules for the benefit
of Tenant or any other tenant, but no such waiver by Landlord shall be construed
as a waiver of such Rules in favor of Tenant or any other tenant, nor prevent
Landlord from thereafter enforcing any such Rules against any or all of the
tenants of the Building.

         (27) These Rules are in addition to the terms, covenants, agreements
and conditions of any lease of premises in the Building. If these Rules conflict
with any provision of the Lease, the Lease shall control.

         (28) Landlord reserves the right to add to and amend the Rules and to
add reasonable new rules and regulations as, in its sole judgment, may from time
to time be needed for safety and security, for care and cleanliness of the
Building and for the preservation of good order therein. Tenant agrees to abide
by all such Rules and any additional rules and regulations which may be adopted
provided same do not materially affect Tenant's rights under the Lease.

                                       5

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