<PAGE>   1
                             OFFICE BUILDING LEASE



                         WESTERN STATES VENTURES, LLC,
                    A CALIFORNIA LIMITED LIABILITY COMPANY,
                                 AS "LANDLORD"

                                      AND

                           ABACUS DIRECT CORPORATION,
                            A DELAWARE CORPORATION,
                                  AS "TENANT"


                                  MAY 22, 1998
<PAGE>   2
                                TABLE OF CONTENTS
                                -----------------

<TABLE>
<CAPTION>
                                                                         PAGE(S)
                                                                        -------
<S><C>                                                                      <C>

 1 Parties ....................................................................1
 2 Premises ...................................................................1
 3 Term .......................................................................1
 4 Security Deposit ...........................................................2
 5 Operating Expense Adjustments ..............................................3
 6 Possession .................................................................3
 7 Rent .......................................................................3
 8 Use ........................................................................5
 9 Compliance with Law ........................................................5
10 Alterations and Additions ..................................................5
11 Repairs ....................................................................6
12 Liens ......................................................................7
13 Assignment and Subletting ..................................................7
14 Hold Harmless ..............................................................9
15 Subrogation ...............................................................10
16 Liability Insurance .......................................................10
17 Services and Utilities ....................................................10
18 Property Taxes ............................................................11
19 Rules and Regulations .....................................................11
20 Holding Over ..............................................................11
21 Entry by Landlord .........................................................11
22 Reconstruction ............................................................12
23 Default ...................................................................12
24 Remedies in Default .......................................................13
25 Eminent Domain ............................................................14
26 Estoppel Certificate ......................................................14
27 Parking ...................................................................14
28 Authority of Parties ......................................................14
29 Default by Landlord .......................................................15
30 Option to Expand ..........................................................16
31 First Right of Refusal ....................................................16
32 First Right of Offer ......................................................17
33 Option to Extend ..........................................................17
34 Hazardous Materials .......................................................18
35 General Provisions ........................................................19
36 Brokers ...................................................................21
37 Notice ....................................................................21
</TABLE>

                                       -i-
<PAGE>   3
                             OFFICE BUILDING LEASE
                       (FOR USE IN THE STATE OF COLORADO)



1.       PARTIES

         This Office Building Lease ("LEASE"), dated for reference purposes
         only May 22, 1998 ("LEASE DATE"), is entered into between WESTERN
         STATES VENTURES, LLC, a California limited liability company (herein
         called "LANDLORD"), and ABACUS DIRECT CORPORATION, a Delaware
         corporation (herein called "TENANT").

2.       PREMISES

         (a)     Landlord does hereby lease to Tenant and Tenant hereby leases
         from Landlord that certain space (herein called "PREMISES"),
         consisting of approximately seventy-five thousand (75,000) rentable
         square feet, known as "SUITE 400," at the building ("BUILDING"),
         located at [To Be Determined/bounded by Highway 128 and 120th Street],
         Broomfield, Colorado, commonly known as "EL DORADO RIDGE," shown on
         Exhibit A attached hereto and hereby made a part hereof, including the
         Tenant Improvements ("TENANT IMPROVEMENTS") to be constructed in
         accordance with the "WORK LETTER AGREEMENT" attached as Exhibit B
         hereto. The Premises shall consist of the entire fourth, third,
         second floor, and a portion of the first floor. Said Lease is subject
         to the terms, covenants and conditions herein set forth and the Tenant
         covenants as a material part of the consideration for this Lease to
         keep and perform each and all of said terms, covenants and conditions
         by it to be kept and performed and that this Lease is made upon the
         condition of said performance. El Dorado Ridge is anticipated, upon
         completion of construction, to have two (2) separate buildings, the
         first, known as "BUILDING ONE," consisting of approximately one
         hundred five thousand (105,000) rentable square feet, generally
         described in Exhibit B-1 and the second, the Building referenced in
         this Lease. The Building, Building One and the related common
         improvements are collectively referred to as the "PROJECT."

         (b)     The demise of the Premises contained herein shall include a
         non-exclusive right for Tenant to use all portions of the Building and
         the common areas thereof designated by Landlord for the common use of
         all tenants including, without limitation, hallways, restrooms, stairs,
         entrances, lobby areas, elevators, parking spaces, driveways and
         loading areas. Landlord shall not alter or reduce the common areas or
         the Premises in a manner which unreasonably interferes with Tenant's
         use or enjoyment of the Premises.

         (c)     Tenant acknowledges that, as of the Lease Date, Landlord has
         not commenced construction of the Project, which construction is
         anticipated to begin following the Lease Date when determined by
         Landlord. In this regard, Landlord intends to complete construction of
         the Building and Tenant Improvements in accordance with the provisions
         of the Work Letter Agreement on or before the Expected Occupancy Date
         (as hereinafter defined).  Prior to the Commencement Date, Landlord
         shall cause the Building to be measured to determine the rentable and
         usable square footage of the Building and the Premises. Such
         measurement shall be in compliance with the Building Owners and
         Managers Association Standard Method for Measuring Floor Area within
         Office Buildings (ANSI Z65.1-1996).  With regard to such determination,
         Landlord agrees that a R/U ratio of 1.059% shall not be exceeded for
         full floor occupancy, and a R/U ratio of 1.1284% shall not be exceeded
         for partial floor occupancy.  Landlord shall provide Tenant with a
         written summary, certified by its architect, setting forth the
         determination of the usable and rentable square footage of the
         Premises prior to the Commencement Date consistent with the
         above-described measurement standard, which measurement shall be
         binding and conclusive upon the parties. Such measurements shall be
         confirmed in the First Amendment to Lease and Acknowledgement (as
         hereinafter defined).

         (d)     As of the Commencement Date, Landlord represents and warrants
         that the Building (excluding any areas within the Premises constructed
         by and/or designed by Tenant), to the extent constructed by Landlord,
         its agents, employees, contractors and/or subcontractors, shall (i)
         comply with all applicable laws, and (ii) have been constructed in
         accordance with the specifications for the Building ("BASE BUILDING
         SPECIFICATIONS") set forth in Exhibit B-2 attached hereto.

3.       TERM

         This Lease is effective between Landlord and Tenant as of the Lease
         Date. The term of this Lease shall commence upon the earlier of the
         following dates ("COMMENCEMENT DATE"): (i) the date on which the
         Premises are Substantially Completed (as defined below), which is
         expected to be on April 1, 1999 ("EXPECTED OCCUPANCY DATE"); (ii) the
         date on which the Premises would have been Substantially Completed had
         there been no delays caused by or attributable to Tenant; or (iii) the
         date upon which Tenant takes possession of the Premises with
         Landlord's written consent. Notwithstanding the foregoing, excepting
         Tenant taking possession of the Premises pursuant to subsection (iii)
         above prior to April 1, 1999, in no event shall Tenant be required to
         take possession of the Premises prior to (a) April 1, 1999, or (b) the
         date that the lobby for the Building is substantially completed
         consistent with the Lobby Specifications (as defined in the Work
         Letter Agreement).  Within thirty (30) days after the Commencement
         Date, Landlord and Tenant shall execute and deliver an amendment to
         this Lease ("FIRST AMENDMENT TO LEASE AND ACKNOWLEDGEMENT") setting
         forth the Commencement Date and the expiration date of the term of the
         Lease, the rentable area of the Premises and adjustments to the Base
         Rent as a result of an increase or decrease in the rentable area of
         the Premises which shall be in the form





                                      -1-
<PAGE>   4
         attached hereto as Exhibit C. The Premises shall be deemed to be
         "SUBSTANTIALLY COMPLETE" when (i) Tenant has direct access to the
         Premises with building services ready to be furnished to Premises and
         all construction to be performed by Landlord, as set forth in the Work
         Letter Agreement has been completed, with the exception of the Punch
         List Items (as hereinafter defined) that do not materially adversely
         affect Tenant's use of the Premises as reasonably determined by
         Landlord and Tenant, (ii) all major systems and services to be 
         furnished by Landlord pursuant to the provisions of the Lease are
         operational, and (iii) a permanent certificate of occupancy has been
         issued for the Premises. The term of this Lease shall be for a period
         of seven (7) years following the Commencement Date. Landlord shall
         provide Tenant with its good faith estimation of the date of the
         Commencement Date at least thirty (30) days prior to such date.

4.       POSSESSION

         (a)     If the Landlord, for any reason whatsoever, cannot cause the
         Commencement Date to occur by the Expected Occupancy Date, this Lease
         shall not be void or voidable, nor shall the expiration date of the
         above term be in any way extended, but in that event, excepting delays
         caused by Tenant, all rent shall be abated during the period between
         the commencement of said term and the time When Landlord delivers
         possession.

         (b)     In the event that Landlord shall permit Tenant to occupy the
         Premises prior to the Commencement Date of the term, such occupancy
         shall be subject to all the provisions of this Lease. In this regard,
         Tenant shall be entitled to enter the Premises at least twenty (20)
         days prior to the Commencement Date for the purpose of installation of
         furniture, trade fixtures and equipment, which early occupancy shall
         be subject to the terms and conditions of this Lease, excepting the
         payment of Base Rent. The parties shall use their respective good
         faith efforts to schedule work during such periods so as not to
         unreasonably interfere with their respective efforts (the parties
         acknowledge that such early entrance may be "Phased" concerning
         certain portions of the Premises to allow for the laying of carpet
         therein). Said early possession shall not advance the termination date
         hereinabove provided. Additionally, subject to the provisions of this
         Section, Tenant shall be provided access to the Premises by December
         20, 1998, for the purpose of constructing certain improvements in
         accordance with the provisions of the Work Letter Agreement. In no
         event shall Tenant's use of the Premises pursuant to this Section 4(b)
         be deemed to be Tenant's acceptance of possession of the Premises or
         constitute the Commencement Date.

         (c)     Tenant's taking possession of the Premises shall constitute
         Tenant's acknowledgment that the Premises are in good condition, and
         that Tenant agrees to accept the same in its condition existing as of
         the date of such entry and subject to all applicable municipal,
         county, state and federal statutes, laws, ordinances, including zoning
         ordinances, and regulations governing and relating to the use,
         occupancy or possession of the Premises, subject to the Punch List
         Item (as hereinafter defined). Notwithstanding the foregoing, within
         ten (10) days prior to and within sixty (60) days after the Tenant
         takes possession of the Premises, Tenant shall deliver to Landlord a
         list of items ("PUNCH LIST ITEMS") that Tenant reasonably deems that
         Landlord complete or correct in order for the Premises to be
         reasonably acceptable. The Punch List Items shall not include any
         damages and/or repairs caused by Tenant, its agents, employees,
         contractors or subcontractors. Landlord shall complete and/or correct
         such items set forth on the Punch List Items using its good faith
         efforts and due diligence within thirty (30) days following receipt of
         the Punch List Items; provided, however, that with respect to those
         items that Landlord reasonably contends do not require completion
         and/or correction, Landlord and Tenant shall negotiate in good faith
         for a resolution of such item. If Tenant does not deliver the Punch
         List Items to Landlord within such time periods, Tenant shall be
         deemed to have accepted the condition of the Premises.

         (d)     For a period of one (1) year following the Commencement Date
         ("WARRANTY PERIOD"), Landlord shall warranty the condition of the
         Building and the Premises, to the extent that such improvements will
         be constructed by Landlord, its agents, employees, contractors and
         subcontractors. Following Landlord's receipt of written notice from
         Tenant during the Warranty Period, Landlord shall use its commercially
         reasonable efforts to complete such warranty repair in a timely basis
         as soon as possible. Landlord's repair obligations pursuant to this
         Section 4(d) shall be subject to Tenant's rights pursuant to Sections
         11(d) and (3) of this Lease. The expiration of the Warranty Period
         shall not otherwise affect Landlord's obligations to make certain
         repairs as set forth in Section 11(b) of this Lease or effect the
         enforcement of any applicable warranty provided by any third party
         contractor or materialmen relating to the Building.

         (e)     Notwithstanding any other provision of Section 4 to the
         contrary, in the event that the Commencement Date has not occurred on
         or before May 7, 1999 ("OUTSIDE DELIVERY DATE"), for a period of five
         (5) business days thereafter, as Tenant's sole and exclusive remedy
         (except as set forth in this Section 4(e), Tenant shall have the right
         to extend the date upon which Tenant is required to accept possession
         of the Premises until October 1, 1999 ("DELAYED DELIVERY DATE"), by
         delivery of written notice of such election within such time period;
         provided, however, Tenant may accept possession of the Premises at any
         time prior to the Delay Delivery Date, which acceptance would
         accelerate the Commencement Date to the date of such acceptance. The
         failure of Tenant to make such election within such time period shall
         be deemed Tenant's waiver of such extension right.  In the event that
         Tenant makes such election to extend the Commencement Date of this
         Lease until the Delayed Delivery Date, this Lease shall remain in full
         force and effect, the Commencement Date shall be deemed the Delayed
         Delivery Date, the expiration date of the Lease shall be
         correspondingly extended, and, except as otherwise provided in this
         Section 4(e), all terms and conditions of this Lease shall remain in
         full force and effect. The parties acknowledge and agree that the
         extension of the Commencement Date under the Delayed Delivery Date
         shall cause a material financial impact upon Landlord, accordingly,
         each party agrees to use its best commercially reasonable efforts to
         cause the Commencement Date to occur on or before the Outside Delivery
         Date. Subject to the preceding sentence, the parties acknowledge that
         the reason for the delay of the Commencement Date past the Outside
         Delivery Date is of material importance to the parties. The parties
         hereby agree that in the event the Commencement Date is delayed past
         the Outside Delivery Date due solely to delays caused by Landlord, its
         agents, employees, contractors or subcontractors, provided that Tenant
         has made the election to extend the Commencement Date until the
         Delayed Delivery Date, as provided in this Section 4(e), in addition
         to any Base Rent-free possession granted to Tenant pursuant to





                                      -2-
<PAGE>   5
         Section 5(b) of this Lease, Tenant shall be entitled to thirty-seven
         (37) days of Base Rent-free possession of the Premises beginning upon
         the sixty-first (61st) day following the Commencement Date of this
         Lease, provided, however, if Tenant accepts possession of the Premises
         within thirty-seven (37) days following the Outside Delivery Date,
         such Base Rent-free period shall be accordingly decreased. In the
         event that the Commencement Date is delayed past the Outside Delivery
         Date for any reason other than as set forth in the preceding sentence,
         which includes, but is not limited to, any form of delay caused by
         reasons beyond the control of Landlord or delays caused by Tenant, its
         agents, employees, contractors or subcontractors, the granting of the
         Base Rent-free period pursuant to the preceding sentence shall not be
         applicable.

         (f)     Notwithstanding any other provision of this Section 4 to the
         contrary, in the event that the Commencement Date has not occurred by
         November 15, 1999, for a period of fifteen (15) days thereafter,
         Tenant shall have the right to terminate this Lease by delivery of
         written notice to Landlord, in which case the parties shall have no
         further obligations under this Lease. The failure of Tenant to deliver
         such notice within such time period shall be deemed a waiver of such
         right to terminate.

5.       RENT

         (a)     Tenant agrees to pay to Landlord as "BASE RENT," (annual rent
         divided by twelve (12)), without offset, prior notice or demand, for
         the Premises, on or before the first day of the first full calendar
         month of the term hereof following the Commencement Date and a like
         sum on or before the first day of each and every successive calendar
         month thereafter during the term hereof. Base Rent for any period
         during the term hereof which is for less than one (1) month shall be a
         prorated portion of the monthly installment herein, based upon the
         actual number of days in such month. Said rental shall be paid to
         Landlord, without deduction or offset in lawful money of the United
         States of America, which shall be legal tender at the time of payment
         at the Office of the Building, or to such other person or at such
         other place as Landlord may from time to time designate in writing.

         (b)     The Base Rent during the term of this Lease shall be as
         follows:

<TABLE>
<CAPTION>
                 Term of this Lease                         Annual Base Rent                  Monthly Base Rent
                 (from Commencement Date)                   (per rentable square foot)        (per rentable square foot)
                 ------------------------                   --------------------------        --------------------------
                 <S>                                      <C>                               <C>
                 Months 1 and 2 (first sixty (60))                   $0.00                             $0.00
                 days following Commencement
                 Date
                 Months 3 through 42                                 $15.47                            $1.2892
                 Months 43 through 84                                $16.55                            $1.3792
</TABLE>

         (c)     Any and all amounts due and payable by Tenant and Landlord
         pursuant to this Lease, including, but not limited to Base Rent, shall
         be referred to as "RENT."

6.       SECURITY DEPOSIT

         (None)

7.       OPERATING EXPENSE ADJUSTMENTS

         (a)     For the purpose of this Lease, "DIRECT EXPENSES" shall mean
         all direct costs of every kind or nature which Landlord shall pay or
         become obligated to pay because of or in connection with management,
         ownership, maintenance, repair, replacement, preservation and
         operation of the Building and the common areas thereof (various
         Project expenses, which are common to both the Building and Building
         One shall be included within Direct Expenses on a prorata basis (e.g.
         maintenance and cleaning of parking areas)), as determined by
         standard accounting practices, calculated, with regard to Direct
         Expenses which vary with occupancy only, assuming the Building is
         ninety-five percent (95%) occupied, and shall include the following
         costs by way of illustration, but not to be limited to: real property
         taxes, assessments, bonds (or any substitute therefor) rent taxes,
         gross receipt taxes (whether assessed against the Landlord or assessed
         against the Tenant and collected by the Landlord, or both
         (collectively, "REAL ESTATE TAXES")); the establishment of normal and
         customary reasonable annual reserves for capital improvements and
         structural repairs; water and sewer charges; insurance premiums for
         any form of insurance deemed reasonably prudent by Landlord
         ("INSURANCE"), provided that (i) such Insurance is in a form and
         amounts that other landlords of comparable first-class buildings in
         the vicinity of the Building are requiring, and (ii) such Insurance is
         actually purchased; utilities of all types servicing the Building and
         the common areas ("UTILITIES") (electricity servicing the Premises is
         being paid by Tenant directly to the utility provider, accordingly,
         such cost shall not be included in Direct Expenses); janitorial
         services in accordance with the specification set forth in Exhibit D
         attached hereto ("JANITORIAL SERVICES"); labor; costs incurred in the
         management of the Building, if any; air conditioning and heating;
         elevator maintenance; supplies; materials; equipment and tools;
         including maintenance, costs, and upkeep of all parking and common
         areas (Direct Expenses shall not include depreciation on the Building
         of which the Premises are a part or equipment therein, loan payments,
         executive salaries or real estate brokers' commissions, or cost of
         tenant improvements installed by Landlord; or attorneys' fees incurred
         by Landlord resulting from disputes or lease transactions with
         existing tenants of the Building; provided that attorneys' fees
         incurred by Landlord which are for the general benefit of all tenants
         of the Building shall be included in Direct Expenses; and any expenses
         concerning the repair of defects in the Building which are covered by
         and corrected pursuant to manufacturer warranties). For the purposes
         of determining Tenant's Share (as hereinafter defined) of Direct
         Expense, from calendar year to calendar year during the term of this
         Lease, Landlord and Tenant agree that increases in Direct Expenses,
         excepting the cost of Real Estate Taxes, Insurance and Utilities,
         shall not exceed the Direct Expense Cap (as defined below). The Direct
         Expense CAP shall not apply to Tenant's Share of the cost of Real
         Estate Taxes, Insurance, and Utilities, which costs shall be billed at
         actual cost and Tenant shall be responsible for Tenant's Share of such
         costs. For the purpose of this Section 7(a), "DIRECT EXPENSE CAP" shall
         mean (i) for the first (1st) year of the term of this Lease, the
         amount of Five and 25/100ths Dollars ($5.25) per rentable square foot





                                      -3-
<PAGE>   6
         of the Premises; (ii) for second (2nd) year of the term of this Lease,
         the lesser of (a) the actual amount of Direct Expenses, less Real
         Estate Taxes, Insurance, and Utilities, paid by Landlord for the
         immediately preceding calendar year multiplied by one hundred five
         percent (105%), or (b) the amount of Five and 51/100ths Dollars ($5.51)
         per rentable square foot of the Premises; (iii) for third (3rd) year of
         the term of this Lease, the lesser of (a) the actual amount of Direct
         Expenses, less Real Estate Taxes, Insurance, and Utilities, paid by
         Landlord for the immediately preceding calendar year multiplied by one
         hundred five percent (105%), or (b) the amount of Five and 79/100ths
         Dollars ($5.79) per rentable square foot of the Premises; (iv) for
         fourth (4th) year of the term of this Lease, the lesser of (a) the
         actual amount of Direct Expenses, less Real Estate Taxes, Insurance,
         and Utilities, paid by Landlord for the immediately preceding calendar
         year multiplied by one hundred five percent (105%), or (b) the amount
         of Six and 08/100ths Dollars ($6.08) per rentable square foot of the
         Premises; (v) for fifth (5th) year of the term of this Lease, the
         lesser of (a) the actual amount of Direct Expenses, less Real Estate
         Taxes, Insurance, and Utilities, paid by Landlord for the immediately
         preceding calendar year multiplied by one hundred five percent (105%),
         or (b) the amount of Six and 38/100ths Dollars ($6.38) per rentable
         square foot of the Premises; (vi) for sixth (6th) year of the term of
         this Lease, the lesser of (a) the actual amount of Direct Expenses,
         less Real Estate Taxes, Insurance, and Utilities, paid by Landlord for
         the immediately preceding calendar year multiplied by one hundred five
         percent (105%), or (b) the amount of Six and 70/100ths Dollars ($6.70)
         per rentable square foot of the Premises; and (vii) for seventh (7th)
         year of the term of this Lease, the lesser of (a) the actual amount of
         Direct Expenses, less Real Estate Taxes, Insurance, and Utilities, paid
         by Landlord for the immediately preceding calendar year multiplied by
         one hundred five percent (105%), or (b) the amount of Seven and
         04/100ths Dollars ($7.04) per rentable square foot of the Premises.
         Notwithstanding the definition of Direct Expenses, such expenses shall
         not include the costs set forth in Exhibit E.

         (b)     For the first year following the Commencement Date, Landlord
         estimates such amount of Direct Expenses for the Building to be Five
         and 25/100ths Dollars ($5.25) per rentable square foot, however actual
         expenses may vary (the parties acknowledge that such estimate has been
         decreased by $1.00 per rentable square foot in recognition of Tenant's
         obligation to pay electrical services for the Premises directly to the
         utility provider). Tenant shall pay its proportionate share of Direct
         Expenses ("TENANT'S SHARE"), as determined by comparing the rentable
         square footage of the Premises to the rentable square footage of the
         Building, which percentage shall be confirmed in the First Amendment to
         Lease and Acknowledgement. Landlord shall give to Tenant on or before
         the first day of March of each year a statement ("EXPENSE STATEMENT")
         of the actual amount of Direct Expenses for the previous year, but
         failure by Landlord to give such statement by said date shall not
         constitute a waiver by Landlord of its right to collect any amount
         payable hereunder. Landlord shall, in each Expense Statement, estimate
         Direct Expenses for the then current year and such estimate shall be
         used as an estimate for said current year and this amount shall be
         divided into twelve (12) equal monthly installments and Tenant shall
         pay to Landlord, concurrently with the regular monthly rent payment
         next due following the receipt of such statement, an amount equal to
         one (1) monthly installment multiplied by the number of months from
         January in the calendar year in which said statement is submitted to
         the month of such payment, both months inclusive. Subsequent
         installments shall be payable concurrently with the regular monthly
         rent payment for the balance of that calendar year and shall continue
         until the next Expense Statement is rendered. If the next or any
         succeeding year results in an increase in Direct Expenses, then upon
         receipt of an Expense Statement from Landlord, Tenant shall pay a lump
         sum equal to Tenant's Share of such total increase in Direct Expenses,
         less the total of the monthly installments of Direct Expenses paid in
         the previous calendar year. If, in any comparison year the Tenant's
         Share of Direct Expenses be less than the preceding year, then upon
         receipt of the Expense Statement, any overpayment made by Tenant on the
         monthly installments basis provided above shall be credited towards the
         next monthly rent falling due and the estimated monthly installment of
         Direct Expenses to be paid shall be adjusted to reflect such lower
         Direct Expenses.

         (c)     Even though the term has expired and Tenant has vacated the
         Premises, when the final determination is made of Tenant's Share of
         Direct Expenses for the year in which this Lease terminates, Tenant
         shall, within thirty (30) days following such determination, pay any
         increase due over the estimated expenses paid and conversely any
         overpayment made in the event said expenses decrease shall be
         immediately rebated by Landlord to Tenant. Notwithstanding anything
         contained in this Article, the rent payable by Tenant shall in no event
         be less than the rent specified in Article 5 hereinabove.

         (d)     For a period of one (1) year after receipt of the Expenses
         Statement, Tenant shall be entitled, upon thirty (30) days prior
         written notice and during normal business hours, at the office of the
         Building's property manager or such other place as Landlord shall
         designate, to inspect and examine those books and records of Landlord
         relating to the determination of Direct Expenses for the immediately
         preceding comparison year. Failure of Tenant to request such inspection
         within such time period shall render such Expenses Statement conclusive
         and binding on Tenant. If, after inspection and examination of such
         books and records, Tenant disputes the amounts of the Direct Expenses
         charged by Landlord, Tenant may, by written notice to Landlord, request
         an independent audit of such books and records. The independent audit
         of the books and records shall be conducted by either a qualified
         expense auditor (with not less than ten (10) years experience in
         auditing of commercial office projects, or a certified public
         accountant ("AUDITOR")) acceptable to both Landlord and Tenant (the
         Auditor shall be paid on an hourly basis and no contingent fee payments
         shall be permitted). The audit shall be limited to the determination of
         the amount of Direct Expenses for the subject comparison year. If the
         audit discloses that the amount of Direct Expenses billed to Tenant was
         incorrect, the appropriate party shall pay to the other party the
         deficiency or overpayment, as applicable. All costs and expenses of the
         audit shall be paid by Tenant unless the audit shows that Landlord
         overstated Direct Expenses for the subject comparison year by more than
         five percent (5.00%), in which case Landlord shall pay all costs and
         expenses of the audit.  Tenant and the Auditor shall keep any
         information gained from such audit confidential and shall not disclose
         it to any other party. The exercise by Tenant of the audit rights
         hereunder shall not relieve Tenant of its obligation to timely pay all
         sums due hereunder, including, without limitation, the disputed portion
         of Direct Expenses.

         (e)     Upon not less than sixty (60) days advance written notice,
         Tenant shall have the right to assume from Landlord responsibility to
         provide Janitorial Services for the Leased Premises; provided that (i)
         Tenant is not in default of the provisions of this Lease, and (ii) the
         level of such service shall comply with





                                      -4-
<PAGE>   7
         the specifications set forth on Exhibit D attached hereto. In the
         event that Tenant elects to assume the obligation to provide
         Janitorial Services as provided herein, Landlord shall have no
         obligation or liability as a result of actions taken by such
         janitorial staff, Tenant shall cause such janitorial staff to comply
         with the rules and regulations of the Building, such services shall be
         consistent with the operation of other first-class office building in
         the vicinity of the Building, and such expense previously included in
         Direct Expenses shall be excluded for the purpose of determining
         Tenant's Share thereof.

         (f)     At any time during the term of this Lease, Tenant may request
         Landlord, by delivery of written notice, to challenge the amount of
         Real Estate Taxes currently assessed against the Building; provided,
         however, Landlord shall not be obligated to commence such challenge
         if, in Landlord's good faith estimation, such challenge would not
         prevail. If Landlord indicates in writing that it will not commence
         such challenge, Tenant, at Tenant's sole cost and expense, shall have
         the right to challenge the amount of the Real Estate Taxes with the
         appropriate governmental entities; provided that Tenant shall
         indemnify, defend and hold Landlord and the Property harmless from any
         and all claims, damages and expenses resulting from such action. To
         the extent that Tenant is successful in such challenge, Landlord shall
         reimburse Tenant for its costs incurred in prosecuting such challenge
         to the extent of Landlord's savings in Real Estate Taxes.

8.       USE

         (a)     Tenant shall use the Premises for general office purposes and
         related uses, and shall not use or permit the Premises to be used for
         any other purpose. Subject to the provisions of this Lease, Tenant
         shall be entitled to twenty-four (24) hours a day, seven (7) days a
         week, three hundred sixty-five (365) days a year access to the
         Premises.

         (b)     Except for permissible use of the Premises as set forth in
         this Lease, Tenant shall not do or permit anything to be done in or
         about the Premises nor bring or keep anything therein which will in
         any way increase the existing rate of or affect any fire or other
         insurance upon the building or any of its contents, or cause
         cancellation of any insurance policy covering said Building or any
         part thereof or any of its contents. Excepting the use of the
         Premises as permitted in Section 8(a), Tenant shall not do or permit
         anything to be done in or about the Premises which will in any way
         obstruct or interfere with the rights of other tenants or occupants of
         the Building or injure or annoy them or use or allow the Premises to
         be used for any immoral or unlawful purpose, nor shall Tenant cause,
         maintain or permit any nuisance in, on or about the Premises. Tenant
         shall not commit or suffer to be committed any waste in or upon the
         Premises.

         (c)     Neither Tenant, nor any assignee, sublessee or occupier of any
         portion of the Premises, shall permit the introduction, placement,
         use, generation, manufacture, storage, disposal or transportation in
         or around the Premises of any hazardous, poisonous or toxic substance,
         material or waste of any kind that may be hazardous to health and/or
         the environment, including, without limitation, substances from time
         to time identified as such by federal and/or state laws and
         regulations, without the prior written consent of Landlord; provided,
         however, Tenant shall be entitled to possess and maintain within the
         Premises reasonable amounts of such hazardous materials which are
         customarily used in connection with general office uses.

9.       COMPLIANCE WITH LAW

         Tenant shall, at its sole cost and expense, promptly comply with all
         laws, statutes, ordinances and governmental rules, regulations or
         requirements now in force or which may hereafter be in force, which
         includes, but is not limited to access laws for individuals with
         disabilities (commonly referred to as "ADA"), and with the requirements
         of any board of fire insurance underwriters or other similar bodies
         now or hereafter constituted, relating to, or affecting the condition,
         use or occupancy of the Premises, excluding structural changes not
         related to or affected by Tenant's improvements or acts. In the event
         additions, alterations or other accommodations to the Premises, the
         Building, or any other property owned by Landlord are required as a
         result of Tenant's occupancy or actions, Tenant shall be solely
         responsible for and shall indemnify, defend and hold harmless
         Landlord, its successors and assigns, for, from and against any loss,
         damage, cost, claim, expense, or liability directly or indirectly
         arising out or attributable to such occupancy or action. Subject to
         the foregoing, Landlord, following the Commencement Date, shall be
         responsible for compliance with all laws, statutes, ordinances and
         governmental rules, regulations or requirements affecting the
         Building, including ADA, to the extent that such compliance is
         required for general office use and not related to Tenant's specific
         use of the Premises. The judgment of any court of competent
         jurisdiction or the admission of Tenant in any action against Tenant,
         whether Landlord be a party thereto or not, that Tenant has violated
         any law, statue, ordinance or governmental rule, regulation or
         requirement, shall be conclusive of the fact as between the Landlord
         and Tenant.

10.      ALTERATIONS AND ADDITIONS

         (a)     Tenant shall not make or suffer to be made any alterations,
         additions, or improvements (collectively, "ALTERATIONS") to or of the
         Premises, or any part thereof, without first obtaining the written
         consent of Landlord, which shall not be unreasonably withheld;
         provided, however, if the Alterations would adversely affect the
         structure or safety of the Building or its electrical, plumbing, HVAC,
         mechanical or safety systems, or if such Alterations would create an
         obligation on Landlord's part to make modifications to the Building,
         Landlord may withhold its consent in its sole and absolute discretion.
         Notwithstanding the foregoing, without the prior consent of Landlord,
         but with the prior notice to Landlord, Tenant shall be entitled to
         make Alterations within the Premises, provided that (i) the cost of
         construction such Alterations does not exceed Twenty-Five Thousand and
         No/100ths Dollars ($25,000,00) per project In the aggregate, and (ii)
         does not effect the structure or mechanical systems of the Building,
         (iii) such Alterations are not visible from outside of the Premises,
         and (iv) Tenant otherwise complies with the provisions of this Section
         (collectively, "PERMITTED ALTERATIONS"). All Alterations shall comply
         with all applicable laws, statutes and ordinances, which include, but
         are not limited to ADA (Tenant acknowledges that certain Alterations
         may require ADA compliance within the Premises, the Building, and the
         common areas thereof, which costs may be disproportionate to the cost
         of such Alteration). Any Alterations to or of said Premises,
         including, but not limited to, wall covering, paneling, and built-in





                                      -5-
<PAGE>   8

         Landlord shall provide written notice to Tenant prior to the
         construction of such Alteration whether Tenant will be required to
         remove such Alteration and restore the Premises to its original
         condition upon the expiration of the Term, normal wear and tear
         excepted (Tenant shall have no obligation to remove any improvements
         constructed and/or installed within the Premises pursuant to the
         provisions of the Work Letter Agreement). If Landlord so states,
         Tenant, at its own cost shall restore the Premises to its original
         condition upon the expiration of the term; provided, however, Landlord
         may subsequently require any Permitted Alterations be removed at the
         expiration or the earlier termination of the term of this Lease. Upon
         Landlord's approval of the requested Alterations, Tenant shall secure
         all necessary permits after approved by Landlord, if applicable.
         Before Landlord's consent to such Alterations, Tenant shall submit
         detailed specifications, floor plans and necessary permits (if
         applicable) to Landlord for review. In no event shall any Alterations
         affect the structure of the Building or its facade. As a condition to
         its consent, Landlord may request adequate assurance that all
         contractors who will perform such work have in force workman's
         compensation and such other employee and public liability insurance as
         Landlord deems necessary, and where the Alterations are material,
         Landlord may require Tenant or its contractors to post adequate
         completion and performance bonds. In the event Landlord consents to
         the making of any Alterations to the Premises by Tenant, the same
         shall be made by Tenant at Tenant's sole cost and expense, completed
         to the satisfaction of Landlord, and the contractor or person selected
         by Tenant to make the same must first be approved in writing by
         Landlord. If Tenant makes any Alterations to the Premises as provided
         in this Section, the Alterations shall not be commenced until ten (10)
         business days after Landlord has received notice from Tenant stating
         the date the installation of the Alterations is to commence so that
         Landlord can post and record an appropriate notice of
         nonresponsibility.  Tenant shall reimburse Landlord for any reasonable
         expenses incurred by Landlord in connection with the Alterations made
         by Tenant, including any reasonable fees charged by Landlord's
         contractors or consultants to review plans and specifications prepared
         by Tenant, and the customary and reasonable cost of updating the
         existing as-built plans of the Building to reflect the alterations.
         Tenant shall indemnify, defend and hold the Landlord, the Building and
         the Premises free and harmless from any liability, loss, damage, cost,
         attorneys' fees and other expenses incurred on account of such
         construction, or claims by any person performing work or furnishing
         materials or supplies for Tenant or any persons claiming under Tenant.

         (b)     Landlord acknowledges that Tenant desires to cause the
         elevator service to the floors of the Premises which Tenant entirely
         occupies (second, third and fourth floor) to be assessable by Tenant
         key cards only.  Landlord, in accordance with any request by Tenant
         for such modification to the elevator service, shall review and
         approve or disapprove, which approval shall not be unreasonably
         withheld, such request in accordance with the provisions of Section
         10(a) above.

         (c)     Landlord acknowledges that Tenant may desire to have certain
         underground easements for cabling purposes and pipe chase space and
         conduits for telecommunication cabling and fiber optics within certain
         areas of the Building, as well as use certain portions of the roof as
         an observation deck and the location for up to four (4)
         telecommunication devices at designated areas of the roof. Subject to
         Tenant's obligation to pay for all such cost of installation,
         maintenance, repair and damages caused by such use and operation,
         Landlord agrees to review and approve or disapprove, which approval
         will not be unreasonably withheld, any such request in accordance with
         the procedure set forth in Section 10(a) above. Landlord further
         acknowledges that Tenant's business operations contemplate the use of
         sophisticated telecommunications requirements, which may require the
         installation of the items identified in this Section 10(c) and, based
         upon such understanding, Landlord shall reasonably review any related
         request for Alterations. Tenant shall not be charged additional cost
         and/or rent for such usages.

11.      REPAIRS

         (a)     Tenant shall, when and if needed or whenever requested by
         Landlord to do so, at Tenant's sole cost and expense, maintain and
         make all repairs to the Premises and every part thereof, including all
         interior windows and doors, to keep, maintain and preserve the
         Premises in good condition and repair. Tenant shall upon the
         expiration or sooner termination of the term hereof surrender the
         Premises to Landlord in the same condition as when received, less
         reasonable wear and tear and subject to any damages which are not the
         obligation of Tenant to repair pursuant to the provisions of this
         Lease. Tenant acknowledges that Landlord shall have no obligation to
         maintain, repair or replace any telecommunications or computer cabling
         or wiring which is located in the Premises or which exclusively serves
         the Premises (collectively, "CABLING"). Landlord shall have no
         obligation to alter, remodel, improve, repair, decorate or paint the
         Premises or any part thereof and the parties hereto affirm
         that Landlord has made no representations to Tenant respecting the
         condition of the Premises or the Building, except as specifically
         herein set forth. Tenant shall not commit or allow any waste or
         damage to be committed in any portion of the Premises or Building.

         (b)     Notwithstanding Subparagraph 11(a) above, Landlord shall
         repair and maintain in good condition the structural portions of the
         Building, including the roof, basic plumbing, heating, ventilating,
         air conditioning, exterior windows, exterior walls of the Building,
         exterior doors to the Building, all plumbing in bathrooms used in
         common with other tenants of the Building, landscaping of the common
         areas of the Building, the parking facilities of the Building,
         electrical systems installed or furnished by Landlord (collectively,
         "LANDLORD REPAIRS"), unless such maintenance and repairs are caused in
         part or in whole by the act, neglect, fault of or omission of any duty
         by Tenant, its agents, servants, employees or invitees, in which case
         Tenant shall pay to Landlord, as additional rent, the reasonable cost
         of such maintenance and repairs. Landlord shall not be liable for any
         such failure to make any such repairs or to perform any maintenance,
         unless such failure shall persist for an unreasonable time after
         written notice of the need of such repairs or maintenance is given to
         Landlord by Tenant. Following Landlord's receipt of written notice
         from Tenant that a repair contemplated by this Section is required,
         Landlord shall use its commercially reasonable efforts to complete
         such repair in a timely basis as soon as possible. Except as provided
         in paragraph 22 hereof, there shall be no abatement of rent and no
         liability of Landlord by reason of any injury to or interference with
         Tenant's business arising from the making of any repairs, alterations
         or improvements in or to any portion of the Building or the Premises
         or in or to fixtures, appurtenances and equipment therein. Tenant
         waives the right to make repairs at Landlord's expense under any law,
         statute or ordinance now or hereinafter in effect.





                                      -6-
<PAGE>   9
         (c)     Notwithstanding anything to the contrary contained in
         subparagraphs (a) and (b) of this paragraph 11, Tenant shall maintain
         and repair, at its sole cost and expense, all non-base Building
         facilities, if any, including kitchen facilities and heating and air
         conditioning systems, and all plumbing connected to said facilities or
         systems, installed by Tenant or on behalf of Tenant. The provisions of
         this paragraph shall not apply to the basic heating and air
         conditioning system provided by Landlord to all tenants of the
         Building.

         (d)     Notwithstanding any other provisions of this Lease to the
         contrary, upon receipt of written notice (the "FIRST REPAIR NOTICE")
         from Tenant that Landlord Repairs are required, Landlord shall cause
         such repair to be made within a reasonable period of time given the
         circumstances but in no event later than thirty (30) days after it
         receives the First Repair Notice; provided, however, that if the
         repair is of such a nature that it cannot be completed within thirty
         (30) days (which fact shall be indicated in writing delivered to
         Tenant by Landlord), then such longer time as reasonably necessary. If
         Landlord fails to make the repair within the said time period, Tenant
         may give an additional notice (the "SECOND REPAIR NOTICE") to
         Landlord. If Landlord fails to commence thereafter such repair with
         five (5) days after receipt of the Second Repair Notice and thereafter
         diligently pursues said repair to completion, Tenant may perform such
         repair. All repairs performed by Tenant pursuant to this Section shall
         be made by a qualified licensed contractor(s) with sufficient
         expertise in such matters and in accordance with all applicable laws,
         statutes and ordinances. Landlord shall reimburse Tenant for Tenant's
         actual costs incurred within ten (10) days after Landlord's receipt of
         a written demand from Tenant, which demand shall include supporting
         invoices. If Landlord disputes the need for such repair, Landlord
         shall deliver written notice of such disagreement to Tenant within ten
         (10) days after its receipt of the First Repair Notice.
         Notwithstanding such dispute, Tenant may cause such repair to be
         completed pending resolution of such dispute. The dispute shall be
         resolved by a mutually acceptable third party engineer, which
         determination shall be binding upon Landlord and Tenant; provided,
         however, that if the parties cannot agree on an engineer, then the
         dispute shall be resolved by arbitration pursuant to the commercial
         arbitration rules then in effect for the American Arbitration
         Association ("ARBITRATION"). The losing party shall pay the costs of
         the engineer or arbitrator, whichever is applicable. If Landlord is
         obligated to reimburse Tenant for the actual cost of repair and fails
         to do so as provided in this Section, such amount shall accrue
         interest at the rate of fifteen percent (15.00%) per annum until paid
         in full. If such amounts owing from Landlord to Tenant are not paid
         within thirty (30) days following the due date of such payment, Tenant
         shall have abatement rights as set forth in Section 29(f) of this
         Lease.

         (e)     Landlord acknowledges that certain of the Landlord Repairs may
         have to be made on an expedited basis due to a material disruption of
         Tenant's business operations caused by such condition, which condition
         shall be referred to as an "EMERGENCY CONDITION." In this regard, in
         the event an Emergency Condition relating to a Landlord Repair exists,
         Tenant shall deliver to Landlord, by facsimile, a written notice
         ("EMERGENCY NOTICE") describing such Emergency Condition. The
         Emergency Notice shall, in ten (10) point bold typed across the top,
         stating "AN EMERGENCY SITUATION EXISTS AT THE PREMISES REQUIRING YOUR
         IMMEDIATE ATTENTION." In the event that Landlord fails to commence
         repair of the Emergency Condition within twenty-four (24) hours (if
         such situation occurs during non-business hours, Tenant shall utilize
         Landlord's paging system, the procedure for which shall be provided
         to Tenant prior to the Commencement Date), Tenant using licensed
         contractors which are qualified to perform such tasks in compliance
         with applicable laws, shall have the right to make the Landlord
         Repairs; provided, however, such repairs shall be limited to the
         temporary remediation of such Emergency Condition and Landlord shall
         thereafter be responsible for the full repair of such condition.
         Landlord shall reimburse Tenant's actual expenses incurred in making
         such temporary remediation repairs within ten (10) days following
         Landlord's receipt of written demand and supporting invoices. If such
         repayment is not made within such ten (10) day period, such amount
         shall accrue interest at the rate of fifteen percent (15.00%) per
         annum until paid in full. If such amounts owing from Landlord to
         Tenant are not paid within thirty (30) days following the due date of
         such payment, Tenant shall have abatement rights as set forth in
         Section 29(f) of this Lease.

12.      LIENS

         Tenant will not cause or permit any lien to be imposed upon the
         Premises of the Building and will pay all taxes and license fees
         imposed by reason of any improvements made by Tenant to the Premises
         or imposed upon any personal property located in the Premises. Tenant
         shall have the right to contest any such lien; provided that Tenant
         posts the requisite bonds, which are upon terms and conditions
         reasonably acceptable to Landlord, to remove such lien as an
         encumbrance against the Building. Tenant shall provide Landlord with
         prior written notice of any such intention to contest. Tenant agrees
         to give Landlord not less than five (5) days notice prior to
         commencement of any alteration or repair permitted under the terms of
         the Lease so that Landlord may post a notice of non-responsibility. In
         the event that the amount of the estimated cost of any improvements,
         additions or alterations in the Premises is in excess of One Hundred
         Thousand and No/100ths Dollars ($100,000.00), Landlord may require, at
         Tenant's sole cost and expense, a lien and completion bond in an
         amount equal to one and one-half (1-1/2) times all estimated cost of
         any improvements, additions or alterations in the Premises, to insure
         Landlord against any liability for mechanics' and materialmen's liens
         and to insure completion of the work; provided that the provisions of
         this sentence shall not apply to any improvements constructed by
         Tenant within the Premises prior to the Commencement Date.

13.      ASSIGNMENT AND SUBLETTING

         (a)     Tenant shall not, without the prior written consent of
         Landlord, which shall not be unreasonably withheld, delayed or
         conditioned, as provided in this Section 13: (a) assign, mortgage,
         pledge, encumber or otherwise transfer this Lease, the term or estate
         hereby granted, or any interest hereunder; (b) permit the Premises or
         any part thereof to be utilized by anyone other than Tenant (whether
         as concessionaire, franchisee, licensee, permittee or otherwise); or
         (c) except as hereinafter provided, sublet or offer or advertise for
         subletting the Premises or any part thereof. Any assignment, mortgage,
         pledge, encumbrance, transfer or sublease without Landlord's consent
         shall be voidable. Notwithstanding the





                                      -7-
<PAGE>   10
         foregoing and Subsection (b) below, Tenant may assign this Lease or
         sublet the Premises or a portion thereof, without Landlord's consent,
         but with prior written notice, to any corporation, partnership,
         individual or other entity which controls, is controlled by or is
         under common control with Tenant; or to any corporation, partnership,
         individual or other entity, resulting from the merger or consolidation
         with Tenant; or to any person or entity which acquires all of the
         assets of Tenant's business going concern, provided that (i) the
         assignee or subtenant assumes, in full, the obligations of Tenant
         under this Lease, (ii) Tenant remains fully liable under this Lease,
         (iii) the use of the Premises remains unchanged, and (iv) if Tenant
         is no longer a viable and operating business entity, the assignee or
         sublessee has a net worth which is consistent with the
         leasing/financial requirements of Landlord taking into consideration
         the size of the Premises, the rental structure, rights and privileges
         granted to the Tenant pursuant to this Lease, and other concessions
         granted to Tenant pursuant to the provisions of this Lease. Provided
         that Tenant is a corporation, and (i) the stock of Tenant is traded on
         a national exchange, the transfer of stock in Tenant shall not be
         considered an assignment, sublease or transfer under the Lease, or
         (ii) the stock of Tenant is not traded on a national exchange, the
         collective transfer of forty nine percent (49.00%) or less of such
         stock shall not be considered an assignment, sublease or transfer
         under this Lease.

         (b)     If at any time or from time to time during the Term of this
         Lease, Tenant desires to assign this Lease with respect to, or to
         sublet, all or any part of the Premises, then at least thirty (30)
         days prior to the date when Tenant desires the assignment or
         subletting to be effective (the "TRANSFER DATE"), Tenant shall give
         Landlord a notice (the "TRANSFER NOTICE") which shall set forth the
         name, address and business of the proposed assignee or subtenant,
         information (including financial statements and references) concerning
         the character of the proposed assignee or subtenant, in the case of a
         proposed sublease, a detailed description of the space proposed to be
         sublet, which must be a single, self-contained unit (the "SPACE"), any
         rights of the proposed assignee or subtenant to use Tenant's
         improvements and the like, the Transfer Date, and the fixed rent
         and/or other consideration and all other material terms and conditions
         of the proposed assignment or subletting, all in such detail as
         Landlord may reasonably require.

         (c)     Landlord shall be permitted to consider any reasonable factor
         in determining whether or not to withhold its consent to a proposed
         assignment or sublease and Landlord shall make such determination
         within thirty (30) days following Landlord's receipt of the Transfer
         Notice. The failure of Landlord to deliver written notice of such
         determination within such time period shall be deemed Landlord's
         approval thereof. Without limiting the other instances in which it may
         be reasonable for Landlord to withhold its consent to an assignment or
         sublease, it shall be reasonable for Landlord to withhold its consent
         if any of the following conditions are not satisfied:

                 (1)      The proposed transferee shall have a net worth which
         is consistent with the leasing/financial requirements of Landlord
         taking into consideration the size of the Premises, the rental
         structure, rights and privileges granted to the Tenant pursuant to
         this Lease, and other concessions granted to Tenant pursuant to the
         provisions of this Lease;

                 (2)      The proposed use by the transferee shall (i) comply
         with Tenant's permitted use, (ii) be consistent with the general
         character of businesses carried on by tenants of a first-class office
         building, (iii) not increase the likelihood of damage or destruction,
         (iv) not materially increase the density of, occupancy of the Premises
         or increase the amount of pedestrian and other traffic through the
         Building, (v) not be likely to cause an increase in insurance premiums
         for insurance policies applicable to the Building, (vi) not require
         new tenant improvements incompatible with then-existing Building
         systems and components, unless paid for by Tenant, and (vii) unless
         paid by Tenant, not require Landlord to make modifications to the
         Building outside of the Premises (in order, for example, to comply
         with laws such as the ADA);

                 (3)      The proposed transferee shall not be a labor union,
         foreign or domestic governmental entity or public utility company
         which includes, as part of its business operation, customer traffic to
         and from the Premises;

                 (4)      If Landlord has vacant space at the Building suitable
         for such proposed transferee, the proposed transferee shall not be an
         existing tenant or occupant of the Building or a person or entity with
         whom Landlord is then dealing, or with whom Landlord has had any
         dealings within the previous six (6) months, with respect to the
         leasing of space in the Building; and

                 (5)      Any ground lessor or mortgagee whose consent to such
         transfer is required fails to consent thereto. Tenant shall have the
         burden of demonstrating that each of the foregoing conditions has
         been satisfied.

         (d)     Provided Landlord has consented to such assignment or
         subletting, Tenant shall be entitled to enter into such Assignment or
         Sublease with the third party identified in the Transfer Notice
         subject to the following conditions:

                 (1)      At the time of the transfer, no event of material
         default under this Lease shall have occurred and be continuing;

                 (2)      The assignment or sublease shall be on the same terms
         set forth in the Transfer Notice given to Landlord;

                 (3)      No assignment or sublease shall be valid and no
         assignee or sublessee shall take possession until an executed
         counterpart of the assignment or sublease has been delivered to
         Landlord;

                 (4)      No assignee or sublessee shall have a right further
         to assign or sublet without Landlord's consent thereto in each
         instance, which consent in the case of a future assignment or
         sublease should not be unreasonably withheld;

                 (5)      Any assignee shall have assumed in writing the
         obligations of Tenant under this Lease;





                                      -8-
<PAGE>   11
                 (6)      Any subtenant shall have agreed in writing to comply
         with all applicable terms and conditions of this Lease with respect to
         the Space;

                 (7)      In the event Tenant sublets the entire Premises or
         any part thereof, Tenant shall deliver to Landlord fifty percent
         (50.00%) of any excess rent within thirty (30) days of Tenant's
         receipt thereof pursuant to such subletting. As used herein, "EXCESS
         RENT" shall mean any sums or economic consideration per square foot of
         the Premises received by Tenant pursuant to such subletting in excess
         of the amount of the rent per square foot of the Premises payable by
         Tenant under this Lease applicable to the part or parts of the
         Premises so sublet; provided, however, that no excess payment shall be
         payable until Tenant shall have recovered therefrom all of the costs
         incurred by Tenant for brokerage commissions, tenant improvement work
         approved by Landlord, reasonable attorneys fees, and reasonable
         marketing fees, in conjunction with such sublease; and

                 (8)      In the event Tenant assigns this Lease, Tenant shall
         deliver to Landlord fifty percent (50.00%) of any excess payment
         within thirty (30) days of Tenant's receipt thereof pursuant to such
         assignment. As used herein, "EXCESS PAYMENT" shall mean the amount of
         payment received for such assignment of this Lease (to the extent
         applicable only to this Lease) in excess of the rent payable by Tenant
         under this Lease; provided, however, that no excess payment shall be
         payable until Tenant shall have recovered therefrom all of the costs
         incurred by Tenant for brokerage commissions, tenant improvement work
         approved by Landlord, reasonable attorneys fees, and reasonable
         marketing fees, in conjunction with such assignment.

         (e)     No subletting or assignment shall release Tenant of Tenant's
         obligations under this Lease or alter the liability of Tenant to pay
         the rent and to perform all other obligations to be performed by
         Tenant hereunder.  The acceptance of rent by Landlord from any other
         person shall not be deemed to be a waiver by Landlord of any provision
         hereof. Consent to one assignment or subletting shall not be deemed
         consent to any subsequent assignment or subletting. In the event of
         default by an assignee or subtenant 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, subtenant or successor. Provided that
         Landlord has provided Tenant with prior written notice, Landlord may
         consent to subsequent assignments of the Lease or sublettings or
         amendments or modifications to the Lease with assignees of Tenant.

         (f)     If Tenant assigns the Lease or sublets the Premises or
         requests the consent of Landlord to any assignment or subletting or if
         Tenant requests the consent of Landlord for any act that Tenant
         proposes to do, then Tenant shall, upon demand, pay Landlord an
         administrative fee of Five Hundred and No/100ths Dollars ($500.00).

14.      HOLD HARMLESS

         Subject to the provisions of Section 15 below and to the extent not
         funded and paid to Landlord by any insurance maintained by Tenant,
         Tenant shall indemnify, defend and hold harmless Landlord against and
         from any and all claims, damages, liabilities, and expenses (including
         reasonable attorneys' fees) to the extent arising from Tenant's use of
         the Premises for the conduct of its business or from any activity, work
         or other thing done, permitted or suffered by the Tenant in or about
         the Building, and shall further indemnify, defend and hold harmless
         Landlord against and from any and all claims to the extent arising from
         any breach or default in the performance of any obligation on Tenant's
         part to be performed under the terms of this Lease, or from any act or
         negligence of the Tenant, or any officer, agent, employee, guest or
         invitee of Tenant, and from all and against all reasonable cost,
         attorney's fees, expenses and liabilities incurred in or about any such
         claim or any action or proceeding brought thereon, and, if any case,
         action or proceeding be brought against Landlord by reason of any such
         claim, Tenant upon notice from Landlord shall defend the same at
         Tenant's expense by counsel selected by Tenant and approved in writing
         by Landlord such approval not to be unreasonably withheld or delayed.
         Notwithstanding the preceding sentence, such indemnification by Tenant
         and such assumption and waiver of claims shall not include damage or
         injury to the extent caused by the negligence or willful misconduct of
         Landlord, its agents, employees or contractors. Subject to Section 15
         below and to the extent not funded and paid to Landlord by any
         insurance maintained by Tenant, Landlord shall indemnify, defend and
         hold harmless Tenant against and from any and all claims, damages,
         liabilities, and expenses (including reasonable attorneys' fees) to the
         extent arising from any breach or default in the performance of any
         obligation on Landlord's part to be performed under the terms of this
         Lease, or from any act or negligence of Landlord, or any officer,
         agent, employee, guest or invitee of Landlord, and from and against all
         reasonable costs, attorneys' fees, expenses and liabilities incurred in
         or about any such claim or any action or proceeding brought thereon,
         and, if any case, action or proceeding be brought against Tenant by
         reason of any such claim, Landlord upon notice from Tenant, shall
         defend same at Landlord's expense by counsel selected by Landlord and
         approved in writing by Tenant, such approval not to be unreasonably
         withheld or delayed. Notwithstanding any other provision of this Lease
         to the contrary, Landlord shall not be responsible for any damages
         relating to Tenant's loss of business resulting from an event requiring
         indemnification pursuant to this Section.

         Landlord shall not be liable to Tenant and Tenant hereby waives all
         claims against Landlord or its affiliates for any injury or damage to
         any person or property occurring or incurred in connection with or in
         any way relating to the Premises, the Building or the Property from any
         cause, excepting the gross negligence or willful misconduct of
         Landlord. Without limiting the foregoing, neither Landlord nor any of
         its Affiliates shall be liable for and there shall be no abatement of
         rent for (i) any damage to Tenant's property stored with or entrusted
         to Affiliates of Landlord, (ii) loss of or damage to any property by
         theft or any other wrongful or illegal act, or (iii) 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 or the Project or from the pipes, appliances,
         appurtenances or plumbing works therein or from the roof, street or
         sub-surface or from any other place or resulting from dampness or any
         other cause whatsoever or from the acts or omissions of other tenants,
         occupants or other visitors to the Building or





                                      -9-
<PAGE>   12
         the Project or from any other cause whatsoever, or (iv) any diminution
         or shutting off of light, air or view by any structure which may be
         erected on lands adjacent to the Building, whether within or outside
         of the Property. Tenant agrees that in no case shall Landlord ever be
         responsible or liable on any theory for any injury to Tenant's
         business, loss of profits, loss of income or any other form of
         consequential and/or punitive damage. Tenant shall give prompt notice
         to Landlord in the event of (a) the occurrence of a fire or accident
         in the Premises or in the Building, or (b) the discovery of any defect
         therein or in the fixtures or equipment thereof. Notwithstanding any
         other provision of this Lease to the contrary, Tenant waives any
         claims based on damage or injury resulting from Landlord's failure to
         police or provide security for the Property.

15.      SUBROGATION

         Landlord and Tenant hereby mutually waive their respective rights of
         recovery against each other for any loss or damage that is or would be
         insured by fire, extended coverage and other property insurance
         policies existing for the benefits of the respective parties or
         required to be obtained by the releasing party pursuant to the
         provisions of the Lease. Each party shall obtain any special
         endorsements, if required by their insurer to evidence compliance with
         the aforementioned waiver.

16.      LIABILITY INSURANCE

         (a)     All insurance required to be carried by Tenant hereunder shall
         be issued by responsible insurance companies which are rated by Best
         Insurance Reports as A:VII or better and acceptable to Landlord and
         Landlord's lender and licensed or authorized to do business in the
         State of Colorado. Each policy shall name Landlord, and at Landlord's
         request any mortgagee of Landlord, as an additional insured, as their
         respective interests may appear. Each policy shall contain (i) a
         separation of insureds condition, (ii) a provision that such policy
         and the coverage evidenced thereby shall be primary and
         non-contributing with respect to any policies carried by Landlord and
         that any coverage carried by Landlord shall be excess insurance for
         Landlord's interest only, and (iii) a waiver by the insurer of any
         right of subrogation against Landlord, its agents, employees and
         representatives, which arises or might arise by reason of any payment
         under such policy or by reason of any act or omission of Landlord, its
         agents, employees or representatives. A copy of each paid up policy
         (authenticated by the insurer) or certificate of the insurer
         evidencing the existence and amount of each insurance policy required
         hereunder shall be delivered to Landlord before the date Tenant is
         given possession of the Premises, and thereafter, within thirty (30)
         days after any demand by Landlord therefor, Landlord may, at any time
         and from time to time, inspect and/or copy any insurance policies
         required to be maintained by Tenant hereunder. No such policy shall be
         cancelable, materially changed or reduced in coverage except after
         thirty (30) days' written notice to Landlord and Landlord's lender.
         Tenant shall furnish Landlord with renewals or "binders" of any such
         policy at least ten (10) days prior to the expiration thereof. Tenant
         agrees that if Tenant does not take out and maintain such insurance,
         Landlord may (but shall not be required to) procure said insurance on
         Tenant's behalf and charge the Tenant the premiums, which shall be
         payable upon demand. Tenant shall have the right to provide such
         insurance coverage pursuant to blanket policies obtained by the
         Tenant, provided such blanket policies expressly afford coverage to
         the Premises, Landlord, Landlord's mortgagee and Tenant as required by
         this Lease.

         (b)     Beginning on the date Tenant is given access to the Premises
         for any purpose and continuing until expiration of the term of the
         Lease, Tenant shall procure, pay for and maintain in effect policies
         of property insurance covering trade fixtures, merchandise and other
         personal property from time to time, in, on or about the Premises. The
         proceeds of such insurance shall be used for the repair or replacement
         of the property so insured. Upon termination of this Lease following a
         casualty as set forth herein, the proceeds under (i) shall be paid to
         Landlord, and the proceeds under (ii) above shall be paid to Tenant.

         (c)     Beginning on the date Tenant is given access to the Premises
         for any purpose and continuing until expiration of the Term of the
         Lease, Tenant shall procure, pay for and maintain in effect workers'
         compensation and employer's liability insurance and commercial general
         liability insurance which includes coverage for personal injury,
         contractual liability and Tenant's independent contractors. The
         commercial general liability should be procured and maintained with
         not less than Two Million and No/100ths Dollars ($2,000,000.00) per
         occurrence combined single limit, and a Five Million and No/100ths
         Dollars ($5,000,000.00) aggregate limit, for bodily injury, personal
         injury or property damage liability. If such insurance covers more
         than one location, and general aggregate limit shall apply on a per
         location basis.

         (d)     Whenever, in Landlord's reasonable judgment, but not more than
         twice during the Term, good business practice or change in conditions
         indicate a need for additional or different types of insurance,
         Tenant shall upon request of Landlord obtain such insurance at its own
         expense.

         (e)     Landlord shall obtain and keep in force during the term of
         this Lease, (i) a policy of commercial general liability insurance in
         amounts not less than required by Tenant in Section 16(c) above, and
         (ii) fire, extended coverage and other property insurance policies of
         the type typically maintained by property owners of Class A office
         buildings located in the vicinity of the Building in Boulder County,
         insuring the Building and related improvements constituting common
         areas for the Building at full replacement cost. The premiums for such
         insurance shall constitute Direct Expenses chargeable to tenants of
         the Building in accordance with Section 7 above.

17.      SERVICES AND UTILITIES

         (a)     Tenant shall be solely responsible for obtaining service and
         thereafter paying the cost of all electrical service required for
         Tenant's use of the Premises, which includes, but is not limited to,
         electrical services required for the heating and air conditioning
         system ("HVAC") for the Premises, and the use of the Premises by
         Tenant. In this regard, the Premises shall be separately metered for
         electrical consumption and Tenant shall pay all such amounts due prior
         to delinquency. As provided in the Work Letter Agreement (which
         includes the agreed upon electrical specifications for the Premises),
         Landlord





                                      -10-
<PAGE>   13

         shall cause all electrical distribution to be installed within the
         Premises. The failure of such electrical service to be provided to the
         Premises, or any cessation thereof, shall not render Landlord liable
         in any respect for damages to either person or property, nor be
         construed an eviction of Tenant, nor cause an abatement of rent, or
         relieve Tenant from the fulfillment of any covenant or agreement
         thereof. Whenever heat generating machines or equipment are used in
         the Premises or Tenant's use of the Premises beyond customary business
         hours (7:00 a.m. to 7:00 p.m., Monday through Friday, and 7:00 a.m. to
         12:00 p.m. on Saturdays (federal and state holidays excepted)
         ("BUSINESS HOURS")) adversely affect the temperature otherwise
         maintained by the air conditioning system, Landlord reserves the right
         to install supplementary air conditioning units for the Premises and
         the cost thereof, including the cost of installation, and the cost of
         operation and maintenance thereof, shall be paid by Tenant to Landlord
         upon demand by Landlord. Tenant shall be entitled to access to the
         Premises twenty-four (24) hours a day, seven (7) days a week. Landlord
         shall maintain and keep lighted the common stairs, common entries and
         toilet rooms in the Building. Subject to Tenant's obligation to pay
         for the required electricity, Landlord shall cause the HVAC to
         maintain the Premises at an approximate range of between 72 degrees
         and 74 degrees Fahrenheit (plus or minus 2 degrees Fahrenheit) during
         the Business Hours, which service shall be provided to the Premises by
         HVAC system described in the Work Letter Agreement.  As set forth in
         the Work Letter Agreement, the Premises shall comply with the
         requirements of ASHRAE Standard 62-1989 (20 CFM per occupant for
         office type occupancy or as otherwise required by applicable law).
         Landlord shall not be liable for, and Tenant shall not be entitled to,
         any reduction of rental by reason of Landlord's failure to furnish any
         of the foregoing when such failure is caused by accident, breakage,
         repairs, strikes, lockouts or other labor disturbances or labor
         disputes of any character, or by any other cause similar or
         dissimilar, beyond the reasonable control of Landlord. Landlord shall
         not be liable under any circumstances for a loss of or injury to
         property; person or Tenant's business occurring through or in
         connection with or incidental to failure to furnish such utilities.

         (b)     If Tenant shall require water in excess of that usually
         furnished or supplied for the use of the Premises as general office
         space, Tenant shall pay Landlord for such excessive use (in excess of
         water consumption provided for general office use for tenants in the
         vicinity of the Building) upon written demand by Landlord. If Tenant's
         utility requirements are excessive, Landlord may cause a water meter
         to be installed in the Premises so as to measure the amount of water
         consumed for any such use. The cost of any such meters and of
         installations, maintenance and repair thereof shall be paid for by the
         Tenant and Tenant agrees to pay to Landlord promptly upon demand
         therefore by Landlord for all such water currently consumed as shown
         by said meters, at the rates charged for such services by the local
         utility furnishing the same, plus any additional expense incurred in
         keeping account of the water will be established by an estimate made
         by a utility company, in which case such expense shall not be included
         within Direct Expenses.

         (c)     Tenant acknowledges that the use of the HVAC system during
         non-Business Hours shall result in excessive wear and tear on such
         system, accordingly, if Tenant intends to utilize non-Business Hours
         HVAC service on a regular reoccurring basis (more than two (2) hours a
         day, for in excess of an average of seven (7) days a calendar month,
         for three (3) consecutive calendar months), Landlord shall have the
         right to obtain a service agreement for such system, which provides
         for maintenance, repair and replacement, the cost of which shall be
         paid directly by Tenant (such costs shall not be within the definition 
         of Direct Expenses).

18.      PROPERTY TAXES

         Tenant shall pay all taxes and assessments against any personal
         property, trade fixtures, or other improvements on the Premises
         belonging to Tenant. Tenant shall also pay any sales, use or rental
         tax related to Tenant's property or business which may be assessed by
         any governmental body during the term of this Lease. Tenant shall pay
         such taxes and assessments billed separately to Tenant prior to
         delinquency. Tenant shall have the right to contest any tax or
         assessment levied as described in this Section; provided that Tenant
         posts the requisite bonds, which are upon terms and conditions
         reasonably acceptable to Landlord, to remove and/or avoid any form of
         lien as an encumbrance against the Building. Tenant shall provide
         Landlord with prior written notice of any such intention to contest.
         In the event such taxes and assessments are billed to Landlord, Tenant
         shall pay to Landlord its share of same within thirty (30) days after
         delivery to Tenant by Landlord of a statement in writing, setting
         forth the amount of such taxes or assessments applicable to Tenant's
         property. Tenant shall have the right to dispute such taxes with the
         taxing authorities provided that adequate assurances, as reasonably
         determined by Landlord, to pay such amount are made by Tenant. Amounts
         payable by Tenant pursuant to this Section 18 shall not be included
         within Direct Expenses and, in no event, shall any amount payable
         hereunder be included within the definition of Real Estate Taxes.

19.      RULES AND REGULATIONS

         Tenant shall faithfully observe and comply with the rules and
         regulations that Landlord shall from time to time promulgate. Landlord
         reserves the right from time to time to make all reasonable
         modifications to said rules, which are normal and customary in the
         market and nondiscriminatory. The additions and modifications to those
         rules shall be binding upon Tenant upon delivery of a copy of them to
         Tenant; provided that no such modification shall increase expenses
         otherwise payable by Tenant, or increase duties or obligations owing
         by Tenant pursuant to this Lease. Landlord shall not be responsible to
         Tenant for the nonperformance of any said rules by any other tenants
         or occupants.

20.      HOLDING OVER

         If Tenant remains in possession of the Premises or any part thereof
         after expiration of the term hereof, without the expressed written
         consent of Landlord, such occupancy shall be a tenancy from
         month-to-month at a rental in the amount of one hundred fifty percent 
         (150%) multiplied by the last monthly rental, plus all other charges 
         payable hereunder, and upon all the terms hereof applicable to a
         month-to-month tenancy. If either party desires to terminate such
         month-to-month tenancy, it shall give the other party not less than
         thirty (30) days advance written notice of the date of such
         termination.





                                      -11-
<PAGE>   14
21.      ENTRY BY LANDLORD

         Subject to Tenant's security procedures ("TENANT SECURITY
         PROCEDURES"), a written summary of which Tenant shall provide to
         Landlord within sixty (60) days following the Commencement Date,
         Landlord reserves and shall at any and all reasonable times have the
         right to enter the Premises, inspect the same, supply janitorial
         service and any other service to be provided by Landlord to Tenant
         hereunder, to submit said Premises to prospective purchasers or
         tenants, to post notices of non-responsibility, and to improve or
         repair the Premises and any portion of the Building of which the
         Premises are a part that Landlord may deem necessary or desirable,
         without abatement of rent and may for that purpose erect scaffolding
         and other necessary structures where reasonably required by the
         character of the work to be performed, always providing that the
         entrance to the Premises shall not be blocked thereby, and further
         providing that the business of the Tenant shall not be interfered with
         unreasonably. Tenant hereby waives any claim for damages or for any
         injury or inconvenience to or interference with Tenant's business, any
         loss of occupancy or quiet enjoyment of the Premises, and any
         other loss occasioned thereby, provided that Landlord's activities have
         been reasonable. Any such entrance shall be done in a manner that
         minimizes interference with Tenant's business operations at the
         Premises. For each of the aforesaid purposes, subject to Tenant
         Security Procedures, Landlord shall at all times have and retain a key
         with which to unlock all of the doors in, upon and about the Premises,
         excluding Tenant's vaults, safes and files, and Landlord shall have
         the right to use any and all means which Landlord may deem proper to
         open said doors in an emergency, in order to obtain entry to the
         Premises without liability to Tenant, except for any failure to
         exercise due care for Tenant's property. Any entry to the Premises
         obtained by Landlord by any of said means, or otherwise shall not
         under any circumstances be construed or deemed to be a forcible or
         unlawful entry into, or a detainer of the premises, or an eviction of
         Tenant from the Premises or any portion thereof.

22.      RECONSTRUCTION

         (a)     In the event the Premises or the Building of which the
         Premises are a part are damaged by fire or other perils covered by
         extended coverage insurance carried by Landlord, Landlord agrees to
         forthwith repair the same; and this Lease shall remain in full force
         and effect, except that Tenant shall be entitled to a proportionate
         reduction of the rent, which shall be negotiated in good faith, while
         such repairs are being made, such proportionate reduction to be based
         upon the extent to which the making of such repairs shall materially
         interfere with the business carried on by the Tenant in the Premises
         which is not mitigated by any business interruption insurance carried
         by Tenant. If the damage is due to the fault or neglect of Tenant or
         its employees, there shall be no abatement of rent.

         (b)     In the event the Premises or the Building or a part are damaged
         by fire or other perils not covered by extended coverage insurance,
         then Landlord shall forthwith repair the same, provided the extent of
         the destruction be less than twenty percent (20%) of the then full
         replacement cost of the Premises or the Building of which the Premises
         are a part. In the event the destruction of the Premises or the
         Building is to an extent greater than twenty percent (20%) of the full
         replacement cost, the Landlord shall have the option: (1) to repair or
         restore such damage, this Lease continuing in full force and effect,
         but the rent to be proportionately reduced as hereinabove in this
         Article provided; or (2) give notice to Tenant at any time within
         ninety (90) days after such damage terminating this Lease as of the
         date specified in such notice, which date shall be no less than sixty
         (60) days and no more than ninety (90) days after the giving of such
         notice.  In the event of giving such notice, this Lease shall expire
         and all interest of the Tenant in the Premises shall terminate on the
         date so specified in such notice and the rent, reduced by a
         proportionate amount based upon the extent, if any, to which such
         damage materially interfered with the business carried on by the
         Tenant in the Premises, shall be paid up to date of said such
         termination.

         (c)     Notwithstanding anything to the contrary contained in this
         Article, Landlord shall not have any obligation whatsoever to repair,
         reconstruct or restore the Premises when the damage, in excess of
         fifteen percent (15%) of the replacement cost of the Building,
         resulting from any casualty covered under this Article occurs during
         the last twelve (12) months of the term of this Lease or any extension
         thereof. If Landlord elects not to repair, reconstruct or restore the
         Premises during such twelve (12) month period, this Lease shall be
         deemed terminated on the date of such damage.

         (d)     Landlord shall not be required to repair any damage caused by
         fire or other cause, or to make any repairs or replacements of any
         panels, decoration, office fixtures, railings, floor covering,
         partitions, or any other property installed in the Premises by Tenant.

         (e)     The Tenant shall not be entitled to any compensation or
         damages from Landlord for loss of the use of the whole or any part of
         the Premises, Tenant's personal property or any inconvenience or
         annoyance occasioned by such damage, repair, reconstruction or
         restoration.

         (f)     Tenant may elect to terminate this Lease at any time during
         the term hereof, if the Premises are destroyed or rendered
         untenantable to an extent that they cannot be repaired within two
         hundred twenty-five (225) days following the casualty, as reasonably
         determined by Landlord in writing delivered to Tenant within
         forty-five (45) days following the date of such damage, by delivery of
         written notice of such election within fifteen (15) days following
         Tenant's receipt of such notice. Thereafter, in the event that such
         repairs are not substantially complete within such two hundred
         twenty-five (225) day period, as may be extended by delays caused by
         Tenant for a period of fifteen (15) days thereafter, Tenant shall have
         the right to terminate this Lease by delivery of written notice of
         such election. The termination of this Lease pursuant to this Section
         22(f) shall be effective upon Landlord's receipt of such notice.

23.      DEFAULT

         The occurrence of any one or more of the following events shall
         constitute a default and breach of this Lease by Tenant:





                                      -12-
<PAGE>   15
         (a)     The abandonment, without payment or rent, or vacating of the
         Premises by Tenant (must be in excess of ten (10) business days).

         (b)     The failure by Tenant to make any payment of rent or any other
         payment required to be made by Tenant hereunder within ten (10) days
         following Tenant's receipt of written notice from Landlord that such
         amount is due.

         (c)     The failure by Tenant to observe or perform any of the
         covenants, conditions or provisions of this Lease to be observed or
         performed by the Tenant, other than described in Article 23(a) above,
         where such failure shall continue for a period of thirty (30) days
         after written notice thereof by Landlord to Tenant; provided, however,
         that if the nature of Tenant's default is such that more than thirty
         (30) days are reasonably required for its cure, then Tenant shall not
         be deemed to be in default if Tenant commences such cure within said
         thirty (30)-day period and thereafter diligently prosecutes such cure
         to completion.

         (d)     The making by Tenant of any general assignment or general
         arrangement for the benefit of creditors; or the filing by or against
         Tenant of a petition to have Tenant adjudged bankrupt, or a petition
         or reorganization or arrangement under any law relating to bankruptcy
         (unless, in the case of a petition filed against Tenant, the same is
         dismissed within sixty (60) days); or the appointment of a trustee or
         a receiver to take possession of substantially all of Tenant's assets
         located at the Premises or of Tenant's interest in this Lease, where
         possession is not restored to Tenant within thirty (30) days; or the
         attachment, execution or other judicial seizure of substantially all
         of Tenant's assets located at the Premises or of Tenant's interest in
         this Lease where such seizure is not discharged in thirty (30) days.

24.      REMEDIES IN DEFAULT

         In the event of Tenant's default, Landlord may:

         (a)     Terminate Tenant's right to possession of the Premises by any
         lawful means, in which case this Lease shall terminate and Tenant
         shall immediately surrender possession of the Premises to Landlord. In
         such event, Landlord shall be entitled to recover from Tenant:

                          (1) the worth at the time of the award of any unpaid
                 rent which had been earned at the time of such termination;
                 plus

                          (2) the worth at the time of the award of the amount
                 by which the unpaid rent which would have been earned after
                 termination until the time of award exceeds the amount of such
                 rental loss which Tenant proves could have been reasonably
                 avoided; plus

                          (3) the worth at the time of the award of the amount
                 by which the unpaid rent for the balance of the term after the
                 time of award exceeds the amount of such rental loss which
                 Tenant proves could be reasonably avoided; plus

                          (4) any other amount necessary to compensate Landlord
                 for all the detriment proximately caused by Tenant's failure
                 to perform its obligations under this Lease or which in the
                 ordinary course of things would be likely to result therefrom
                 (including, without limitation, the cost of recovering
                 possession of the Premises, reasonable and necessary expenses
                 of reletting including necessary renovation and alteration of
                 the Premises to make the Premises and/or portions thereof
                 tenantable for general office purposes consistent with the
                 finish of the Premises as improved pursuant to the Work Letter
                 Agreement, reasonable attorneys' fees, and real estate
                 commissions actually paid and that portion of the leasing
                 commission paid by Landlord and applicable to the unexpired
                 portion of this Lease); plus

                          (5) such other amounts in addition to or in lieu of
                 the foregoing as may be permitted from time to time by
                 applicable Colorado law.

                          As used in Subsections (1) and (2) above, the
                 "WORTH AT THE TIME OF THE AWARD" shall be computed by allowing
                 interest at the lesser of ten percent (10%) per annum, or the
                 maximum rate permitted by law per annum. As used in Subsection
                 (3) above, the "WORTH AT THE TIME OF AWARD" shall be computed
                 by discounting such amount at the discount rate of the Federal
                 Reserve Bank of San Francisco at the time of award plus one
                 percent (1%).

         (b)     Continue this Lease in full force and effect, and the Lease
         will continue in effect, as long as Landlord does not terminate
         Tenant's right to possession, and Landlord shall have the right to
         collect rent when due. During the period Tenant is in default,
         Landlord may enter the Premises and relet them, or any part of them,
         to third parties for Tenant's account. Tenant shall be liable
         immediately to Landlord for all costs Landlord reasonably incurs
         in reletting the Premises, including, without limitation, brokers'
         commissions, expenses of remodeling the Premises required by the
         reletting, and like costs. Reletting can be for a period shorter or
         longer than the remaining term of this Lease (provided, however, in no
         event shall Tenant be responsible for any cost relating to such
         reletting after the expiration of the term of this Lease). Tenant
         shall pay to landlord the rent due under this Lease on the dates the
         rent is due, less the rent Landlord receives from any reletting. In no
         event shall Tenant be entitled to any excess rent received by
         Landlord. No act by Landlord allowed by this paragraph shall terminate
         this Lease unless Landlord notifies Tenant in writing that Landlord
         elects to terminate this Lease. After Tenant's default and for as long
         as Landlord does not terminate Tenant's right to possession of the
         Premises, if Tenant obtains Landlord's consent, Tenant shall have the
         right to assign or sublet its interest in this Lease, but Tenant shall
         not be released from liability.

         (c)     Cause a receiver to be appointed to collect rent. Neither the
         filing of a petition for the appointment of a receiver nor the
         appointment itself shall constitute an election by Landlord to
         terminate the Lease.





                                      -13-
<PAGE>   16
         (d)     Cure the default at Tenant's cost. If Landlord at any time, by
         reason of Tenant's default, reasonably pays any sum or does any act
         that requires the payment of any sum, the sum paid by Landlord shall
         be due immediately from Tenant to Landlord at the time the sum is
         paid, and if paid at a later date shall bear interest at the lesser of
         ten percent (10%) per annum, or the maximum rate permitted by law. The
         sum, together with interest on it, shall be additional rent.

         (e)     The foregoing remedies are not exclusive; they are cumulative,
         in addition to any remedies now or later allowed by law, to any
         equitable remedies Landlord may have, and to any remedies Landlord may
         have under bankruptcy laws or laws affecting creditors' rights
         generally. The waiver by Landlord of any breach of any term, covenant
         or condition of this Lease shall not be deemed a waiver of such term,
         covenant or condition or of any subsequent breach of the same or any
         other term, covenant or condition. Acceptance of rent by Landlord
         subsequent to any breach hereof shall not be deemed a waiver of any
         proceeding breach other than a failure to pay the particular rent so
         accepted, regardless of Landlord's knowledge of any breach at the time
         of such acceptance of rent. Landlord shall not be deemed to have
         waived any term, covenant or condition unless Landlord gives Tenant
         written notice of such waiver.

         (f)     Notwithstanding anything to the contrary contained elsewhere
         in this Lease, Landlord shall use reasonable efforts to relet the
         Premises to mitigate its damages under this Section 24; provided,
         however, that so long as Landlord uses such reasonable efforts,
         Landlord shall in no way be responsible or liable for any failure
         to relet the Premises, or any part thereof, or any failure to collect
         any rent due upon such reletting; and Landlord shall not be required
         to spend its own funds, to give the Premises priority over or equal
         priority with any other facilities owned by Landlord or its affiliates
         or other space available for rent in the Building or to compromise in
         any way the terms, uses or creditworthiness of a Tenant upon or to
         which it would customarily lease space such as the Premises; and
         Landlord shall be entitled, in its sole discretion, to seek a single
         tenant for the entire Premises, even though it may take a
         substantially longer period to obtain such a tenant and its efforts
         may be unsuccessful; and this requirement shall not affect in any way
         Tenant's obligations to obtain Landlord's consent to a sublease or
         assignment.

25.      EMINENT DOMAIN

         If more than twenty-five percent (25%) of the Premises shall be taken
         or appropriated by any public or quasi-public authority under the
         power of eminent domain, either party hereto shall have the right, at
         its option to terminate this Lease, and Landlord shall be entitled to
         any and all income, rent award, or any interest therein whatsoever
         which may be paid or made in connection with such public or
         quasi-public use or purpose, and Tenant shall have no claim against
         Landlord for the value of any unexpired term of this Lease. If either
         less than or more than twenty-five percent (25%) of the Premises is
         taken, and neither party elects to terminate as herein provided, the
         rental thereafter to be paid shall be equitably reduced. If
         twenty-five percent (25%) or more of the Building other than the
         Premises may be so taken or appropriated, Landlord shall have the
         right at its option to terminate this Lease and shall be entitled to
         the entire award as above provided. Notwithstanding the foregoing,
         subject to applicable law, Tenant may seek payment from the condemning
         authority for reimbursement for unamortized tenant improvements
         installed by Tenant, at its cost, goodwill, and relocation expenses,
         provided such recovery does not adversely affect Landlord's ability to
         recover amounts from such condemning authority. In the event that,
         Tenant is not permitted to seek such award separately pursuant to
         applicable law, Tenant shall be permitted to jointly pursue such award
         with Landlord, provided such recovery does not adversely affect
         Landlord's ability to recover amounts from such condemning authority.

26.      ESTOPPEL CERTIFICATE

         Within ten (10) days following any written request which Landlord may
         make from time to time, Tenant shall execute and deliver to Landlord a
         statement certifying: (i) the date of commencement of this Lease; (ii)
         the fact that this Lease is unmodified and in full force and effect
         (or if there have been modifications hereto, that this Lease is in
         full force and effect, as modified, and stating the date and nature
         of such modifications); (iii) the date to which the rental and other
         sums payable under this Lease have been paid; (iv) the fact that there
         are no current defaults under this Lease by either Landlord or Tenant,
         except as specified in Tenant's statement; and (v) such other matters
         requested by Landlord. Landlord and Tenant intend that any statement
         delivered pursuant to this paragraph 26 may be relied upon by any
         mortgagee, beneficiary, purchaser or prospective purchaser of the
         Building or any interest therein. Tenant shall also have the right to
         request an estoppel certificate from Landlord pursuant to the
         provisions of this Section 26.

27.      PARKING

         Tenant shall have the right to park in the Building's parking
         facilities in common with other tenants of the Building upon terms and
         conditions as may from time to time be established by Landlord. Such
         parking right shall be upon a ratio of four and 50/100ths (4.50) spaces
         for each one thousand (1,000) rentable square feet within the
         Premises. Tenant agrees not to overburden the parking facilities and
         agrees to cooperate with Landlord and other Tenants in the use of the
         parking facilities. Landlord reserves the right in its reasonable
         discretion to determine whether the parking facilities are becoming
         crowded and to allocate and assign parking spaces among Tenant and the
         other tenants, and to alter, relocate, or otherwise change the parking
         facilities and to take measures with respect to the parking area from
         time to time in order to comply with the policies of any
         transportation management association or any governmental ordinance,
         law or regulation, subject to maintaining the above-specified parking
         ratio. Landlord shall have the right, in addition to pursuing any
         other legal remedy available, to tow any vehicle belonging to Tenant
         or Tenant's employees which is not in compliance with the regulations
         for the parking facility then in effect if a violation continues
         after the first notice of such violation, at the expense of the towed
         party; nothing in this Lease, however, shall require Landlord to tow
         parked cars or take other actions to free occupied spaces for Tenant's
         use. Landlord shall not be liable for any claims, losses, damages,
         expenses or demands with respect to injury or damage to the vehicles
         of Tenant or Tenant's customers or employees that park in the parking
         areas of the Project, except for such loss or damage as may be caused
         by Landlord's gross negligence or willful misconduct.





                                      -14-
<PAGE>   17
28.      AUTHORITY OF PARTIES

         If a party to this Lease is a corporation or partnership, each
         individual executing this Lease on behalf of said corporation or
         partnership represents and warrants that he is duly authorized to
         execute and deliver this Lease on behalf of said corporation or
         partnership, in accordance with a duly adopted resolution or other
         document, and that this Lease is binding upon said corporation or
         partnership, as appropriate in accordance with its terms. The
         individuals signing on behalf of a corporate entity are executing this
         Lease in their respective corporate capacities and there shall be no
         individual liability imposed upon such signatories in such case.

29.      DEFAULT BY LANDLORD

         (a)     Landlord shall not be deemed to be in default in the
         performance of any obligation required to be performed by it hereunder
         unless and until it has failed to perform such obligations within
         twenty (20) days after written notice by Tenant to Landlord specifying
         wherein Landlord has failed to perform such obligation; provided,
         however, that if the nature of Landlord's obligation is such that more
         than twenty (20) days are required for its performance, then Landlord
         shall not be deemed to be in default if it shall commence such
         performance within such twenty (20)-day period and thereafter
         diligently prosecute the same to completion. In no event shall
         Landlord be liable to Tenant for loss of profits, business
         interruption, or consequential damages if Landlord performs its
         obligations within the time periods specified in this paragraph.

         (b)     Tenant agrees to give any mortgagee and/or trust deed holders,
         by registered mail, a copy of any Notice of Default served upon the
         Landlord, provided that prior to such notice Tenant has been notified
         in writing of the address of such mortgagee and/or trust deed holder.
         Tenant further agrees that if Landlord shall have failed to cure such
         default within the time provided for in this Lease, then the
         mortgagees and/or trust deed holders shall have an additional thirty
         (30) days within which to cure such default, or if such default cannot
         be cured within that time, then such additional time as may be
         necessary if within thirty (30) days mortgagee and/or trust deed
         holder has commenced and is diligently pursuing the remedies necessary
         to cure such default (including, but not limited to, commencement of
         foreclosure proceedings, if necessary to effect such cure), in which
         event this Lease shall not be terminated while remedies are being so
         diligently pursued.

         (c)     Notwithstanding any other provisions of this Lease to the
         contrary, but subject to the provisions of Section 29(a) and 29(b)
         above, upon receipt of written notice (the "FIRST DEFAULT NOTICE") from
         Tenant that Landlord has failed to perform any of its obligations as
         expressly set forth in this Lease (collectively, "LANDLORD
         OBLIGATIONS"), Landlord shall perform such obligation within a
         reasonable period of time given the circumstances but in no event
         later than thirty (30) days after it receives the First Default
         Notice; provided, however, that if the completion of such obligation
         is of such a nature that it cannot be completed within thirty (30)
         days, then such longer time as reasonably necessary. If Landlord fails
         to complete such obligation within the said time period, Tenant may
         give an additional notice (the "SECOND DEFAULT NOTICE") to Landlord.
         If Landlord fails to commence to complete such obligation within five
         (5) days after receipt of the Second Default Notice and thereafter
         diligently pursues the completion of such obligation, Tenant may
         complete such obligation. All obligations of Landlord performed by
         Tenant pursuant to this Section shall be made by a qualified licensed
         contractor(s) and/or qualified persons with sufficient expertise in
         such matters and in accordance with all applicable laws, statutes and
         ordinances. Landlord shall reimburse Tenant for Tenant's actual costs
         incurred within ten (10) days after Landlord's receipt of a written
         demand from Tenant, which demand shall include supporting invoices. If
         Landlord disputes the need for the completion of such obligation,
         Landlord shall deliver written notice of such disagreement to Tenant
         within ten (10) days after its receipt of the First Default Notice.
         The dispute shall be resolved by a mutually acceptable third party,
         which determination shall be binding upon Landlord and Tenant;
         provided, however, that if the parties cannot agree on such third
         party, then the dispute shall be resolved by arbitration pursuant to
         the commercial arbitration rules then in effect for the American
         Arbitration Association ("ARBITRATION"). The losing party shall pay the
         costs of the third party or arbitrator, whichever is applicable. If
         Landlord is obligated to reimburse Tenant for the actual cost and
         fails to do so as provided in this subsection, such amount shall
         accrue interest at the rate of fifteen percent (15.00%) per annum
         until paid in full. If such amounts owing from Landlord to Tenant are
         not paid within thirty (30) days following the due date of such
         payment, Tenant shall have abatement rights as set forth in Section
         29(f) of this Lease.

         (d)     Landlord acknowledges that certain of the Landlord Obligations
         may have to be made on an expedited basis due to a material disruption
         of Tenant's business operations caused by such condition, which
         condition shall be referred to as an "EMERGENCY CONDITION." In this
         regard, in the event an Emergency Condition relating to a Landlord
         Obligation exists, Tenant shall deliver to Landlord, by facsimile, a
         written notice ("EMERGENCY NOTICE") describing such Emergency
         Condition. In the event that Landlord fails to commence repair of the
         Emergency Condition within forty-eight (48) hours (if such situation
         occurs during non-business hours, Tenant shall utilize Landlord's
         paging system, the procedure for which shall be provided to Tenant
         prior to the Commencement Date), Tenant, using license contractors
         and/or persons which are qualified to perform such tasks in compliance
         with applicable laws, shall have the right to perform the Landlord
         Obligation; provided, however, such repairs shall be limited to the
         temporary remediation of such Emergency Condition and Landlord shall
         thereafter be responsible for the full repair of such condition.
         Landlord shall reimburse Tenant's actual expenses incurred in making
         such temporary remediation repairs within fifteen (15) days following
         Landlord's receipt of written demand and supporting invoices. If such
         repayment is not made within such fifteen (15) day period, such amount
         shall accrue interest at the rate of fifteen percent (15.00%) per
         annum until paid in full.  If such amounts owing from Landlord to
         Tenant are not paid within thirty (30) days following the due date of
         such payment, Tenant shall have abatement rights as set forth in
         Section 29(f) of this Lease.





                                      -15-
<PAGE>   18
         (e)     If Tenant has provided Landlord with the notice described in
         Section 11(d) and/or (e) of this Lease, Tenant may not thereafter
         utilize the provisions of Sections 29(c) and 29(d) for the same event.

         (f)     In the event that Landlord has not reimbursed amounts owing to
         Tenant pursuant to Sections 11(d), 11(e), 29(c) and/or 29(d) of this
         Lease within thirty (30) days following the due date for such payment,
         Tenant shall be entitled to offset such amount due and owing from the
         next payment of Base Rent due and payable under this Lease. Such
         offset right shall continue until all amounts owing are paid in full.

30.      OPTION TO EXPAND

         Tenant desires to have certain expansion rights with regard to the
         remaining vacant space within the Building, hereinafter referred to as
         the "EXPANSION SPACE." Landlord is willing to grant such expansion
         rights in accordance with the terms and conditions of this Section.

         (a)     At any time between the Lease Date and August 1, 1998 ("OPTION
         WINDOW"), Tenant shall have the right to expand ("OPTION TO EXPAND")
         the Premises to include the Expansion Area by providing Landlord with
         written notice ("EXPANSION NOTICE") of such election; provided,
         however, that if Tenant is in material default beyond any applicable
         cure period under the Lease on the date of giving such notice, such
         notice shall be null and void at the election of Landlord.

         (b)     If Tenant elects to exercise its Option to Expand, the
         Expansion Space shall be deemed to be leased under all the terms and
         conditions of this Lease and shall constitute a portion of the
         "Premises" for all purposes, and the term of Tenant's lease of the
         Expansion Space shall be coterminous with the term of this Lease with
         respect to the original Premises. The date that is the sooner to occur
         of the date that Landlord Substantially Completes the leasehold
         improvements pursuant to the Expansion Space Work Letter Agreement (as
         hereinafter defined), the date that the Expansion Space would have
         been Substantially Complete absent Tenant delays, or the date that
         Tenant commences occupancy of the Expansion Space, is hereinafter
         referred to as the "OCCUPANCY DATE." To the extent reasonably
         requested by Landlord, Tenant shall execute an amendment to this Lease
         evidencing the lease of the Expansion Space.

         (c)     The Base Rent for the Expansion Space shall be the Base Rent
         for the original Premises, on a per square foot of rentable area
         basis, and shall be subject to increase at the same times and in the
         same manner as Base Rent is adjusted pursuant to Section 5 of the
         Lease. Tenant's obligation to pay Base Rent and other rent respecting
         the Expansion Space shall commence on the Occupancy Date.

         (d)     As a condition to Tenant's right to expand into the Expansion
         Space, Tenant shall continue, both before and after the exercise of
         the option to expand, to occupy the Premises originally demised under
         this Lease, and furthermore, as of the time of the exercise of the
         option, and at the time Tenant takes possession of such Expansion
         Space, Tenant shall not be in default under this Lease, unless waived
         by Landlord.

         (e)     Within ten (10) days following Landlord's receipt of the
         Expansion Notice, and as a condition precedent to the lease of the
         Expansion Space to Tenant, Tenant and Landlord shall enter into a work
         letter agreement ("EXPANSION SPACE WORK LETTER AGREEMENT") which shall
         be in a form similar to the Work Letter Agreement. Among other
         provisions, the Expansion Space Work Letter Agreement shall provide
         that the Occupancy Date shall occur on the latter of (i) the date that
         improvements described by the Expansion Space Work Letter Agreement are
         Substantially Complete (as defined in Section 3 of this Lease), or (ii)
         the Commencement Date for the Premises.  Tenant delays affecting the
         construction of the improvements pursuant to the Expansion Space Work
         Letter Agreement shall not extend Tenant's obligation to pay Base Rent
         for the Expansion Space on the Occupancy Date.  The Expansion Space
         Work Letter Agreement shall also provide that Landlord grants Tenant an
         amount equal to the Allowance (as defined in the Work Letter
         Agreement), expressed on a per rentable square foot basis, multiplied
         by the rentable square footage of the Expansion Space, to be utilized
         for the cost of such construction.

         (f)     As of the Occupancy Date, the Tenant's Share used for purposes
         of calculating Direct Expenses shall be increased in order to reflect
         the addition of the Expansion Space to the Premises.

31.      FIRST RIGHT OF REFUSAL

         (a)     Tenant desires to have certain first right of refusal ("FIRST
         RIGHT OF REFUSAL") rights with regard to the remaining vacant portion
         of the Building, or any portion thereof, which space is hereinafter
         referred to as the "FRR SPACE." Landlord is willing to grant such in
         accordance with the terms and conditions of this Section.

         (b)     Landlord shall notify Tenant in writing ("INTERESTED PARTY
         NOTICE") of any third party ("INTERESTED PARTY") who expresses a bona
         fide interest in leasing the FRR Space, or any portion thereof, as
         evidenced by a proposed letter of intent, or similar document,
         submitted to Landlord by the Interested Party, which Landlord is
         willing to accept. The Interested Party Notice shall include a copy of
         said letter of intent or similar such document. Landlord, using its
         good faith efforts, shall provide Tenant with at least fourteen (14)
         days prior notice ("PRE-ACCEPTANCE NOTICE") of its intent to accept an
         offer from an Interested Party. For a period of seven (7) days
         following Tenant's receipt of the Interested Party Notice (if Landlord
         has not delivered a Pre-Acceptance Notice with regard to such
         Interested Party, such period shall be extended to fourteen (14) days
         following the Tenant's receipt of the Interested Party Notice), Tenant
         may exercise its First Right of Refusal to lease the FRR Space by
         providing Landlord with written notice of such election ("ELECTION
         NOTICE"); provided, however, that if Tenant is in material default
         beyond any applicable cure period under this Lease on the date of
         giving such notice, such notice shall be null and void at the election
         of Landlord. The failure of Tenant to deliver the Election Notice to
         Landlord





                                      -16-
<PAGE>   19
         within such time period shall be deemed Tenant's waiver of the Right of
         Refusal and Landlord shall be free to lease the space identified in the
         Interested Party Notice to the Interested Party.

         (c)     Subject to subsection (i) below, if Tenant elects to exercise
         its Right of Refusal, the FRR Space shall be deemed to be leased under
         all the terms and conditions of this Lease and shall constitute a
         portion of the "Premises" for all purposes, and the term of Tenant's
         lease of the FRR Space shall be coterminous with the term of this Lease
         with respect to the original Premises.  The date that is the sooner to
         occur of the day that Landlord Substantially Completes the leasehold
         improvements pursuant to the FRR Space Work Letter, the date that the
         FRR Space would have been completed absent Tenant delays, or the day
         that Tenant commences occupancy of the FRR Space, is hereinafter
         referred to as the "OCCUPANCY DATE". To the extent reasonably required
         by Landlord, Tenant shall execute an amendment to this Lease evidencing
         the lease of the FRR Space.

         (d)     The Base Rent for the FRR Space shall be the Base Rent for the
         original Premises, on a per square foot of rentable area basis, and
         shall be subject to increase at the same times and in the same manner
         as Base Rent is adjusted pursuant to Section 5 above. Tenant's
         obligation to pay Base Rent and other rent respecting the FRR Space
         shall commence on the Occupancy Date.

         (e)     As a condition to Tenant's right to expand into the FRR Space,
         Tenant shall continue, both before and after this exercise of the First
         Right of Refusal, to occupy the Premises originally demised under this
         Lease, and furthermore, as of the time of the exercise of the option,
         and at the time Tenant takes possession of such FRR Space, Tenant shall
         not be in default under this Lease unless waived by Landlord.

         (f)     Within ten (10) days following Landlord's receipt of the
         Election Notice, and as a condition precedent to the lease of the FRR
         Space to Tenant, Tenant and Landlord shall enter into a work letter
         agreement ("FRR SPACE WORK LETTER AGREEMENT") which shall be in a form
         similar to the Work Letter Agreement. Among other provisions, the FRR
         Space Work Letter Agreement shall provide that the Occupancy Date which
         shall occur on the date that the improvements described by the FRR
         Space Work Letter Agreement are Substantially Complete (as defined in
         Section 3 of this Lease). Tenant delays affecting the construction of
         the improvements pursuant to the FRR Space Work letter shall not extend
         Tenant's obligation to pay Base Rent for the FRR Space on the Occupancy
         Date. The FRR Space Work Letter shall also provide that Landlord grants
         Tenant an amount equal to the unamortized (using the original term as
         an amortization period, on a straight line basis) portion of the
         Allowance (as defined in the Work Letter), expressed on a per rentable
         square foot basis, multiplied by the rentable square footage of the FRR
         Space, to be utilized for the cost of such construction.

         (g)     As of the Occupancy Date, the Tenant's Share used for purposes
         of calculating Direct Expenses shall be increased in order to reflect
         the addition of the FRR Space to the Premises.

         (h)     In the event that Tenant elects or is deemed to have elected to
         not exercise its Right of Refusal and Landlord and the Interested Party
         have not entered into a lease agreement within one hundred twenty (120)
         days following the date of such election by Tenant, the FRR Space shall
         remain subject to Tenant's First Right of Refusal. Tenant's rights as
         provided in this Section 31 shall not terminate if Tenant fails to
         exercise its right of refusal, but shall continue throughout the Terms,
         including any renewal terms, if and when the FRR Space thereafter
         becomes reasonable.

         (i)     Notwithstanding the provisions of subsections (c), (d) and (f)
         above, in the event that the Interested Party Notice is delivered at
         any time after the first three hundred sixty-five (365) days following
         the Commencement Date, and Tenant delivers an Election Notice to
         Landlord, Tenant and Landlord shall enter into a new lease agreement,
         prepared by Landlord, upon the exact terms and conditions set forth in
         the Interested Party Notice within twenty-one (21) days following
         Landlord's receipt of the Interested Party Notice. In the event that
         Landlord and Tenant are unable to reach agreement upon such terms
         within such time period, the Election Notice shall be deemed null and
         void, and Landlord shall be free to negotiate with the Interested Party
         subject to the provisions of subsection (h) above. In the event that
         this subsection (i) is applicable, subsections (c), (d) and (f) above
         shall not be applicable to Tenant's exercise of its First Right of
         Refusal.

32.      FIRST RIGHT OF OFFER

         Following the initial leasing of the entire Building, at any time
         thereafter during (the term of the Lease, upon Landlord's determination
         to lease any Vacant Space within the Building, Landlord shall first
         deliver to Tenant a written notice of such availability ("VACANT SPACE
         NOTICE"). For a period of fifteen (15) days following Tenant's receipt
         of the Vacant Space Notice, Tenant shall have the right to negotiate
         with Landlord regarding the lease of the Vacant Space; provided,
         however, Landlord makes no representation or warranty regarding the
         then market rate which Landlord would be willing to accept or the
         likelihood of reaching agreement upon any lease documentation. In the
         event that Landlord and Tenant do not reach agreement upon such terms
         and conditions regarding such vacant space within such fifteen (15) day
         period for any reason, Landlord shall be free to negotiate with any
         third party the lease of such space, and Tenant shall have no further
         obligation with regard thereto, except as provided in Section 31 of
         this Lease. For the purpose of this Section, "VACANT SPACE" shall mean
         (1) no bona fide written lease agreement exists relative to such space,
         or (2) such space is due to become vacant because a tenant's lease has
         or will expire with no renewal provision.

33.      OPTION TO EXTEND

         At the expiration of the original term hereof, Tenant may extend this
         Lease for two (2) successive five (5) year terms ("EXTENDED TERMS") by
         giving Landlord written notice ("EXTENSION NOTICE") of its intention to
         do so at least twelve (12) months prior to the expiration of the
         original term or first Extended Term, as applicable; provided, however,
         that Tenant is not in material default beyond any applicable cure
         period under the Lease on the date of giving such notice or on the date
         of commencement of the extended term. Such Extended Terms shall be
         upon all of the terms and conditions of this Lease, except that the
         following





                                      -17-
<PAGE>   20
         rights of Tenant during the original term of this Lease shall not apply
         during such extension period: (a) any right to rent-free possession,
         (b) any right to further extension of the term of the Lease beyond the
         Extended Terms set forth hereinabove, (c) any right to continue to pay
         the same Base Rent and (d) any limitation on increases in expenses
         payable by Tenant. Landlord and Tenant hereby acknowledge and agree
         that the Base Rent during each Extended Term shall be the "PREVAILING
         RATE" for the Premises, as determined in accordance with this Section.
         Within fifteen (15) days following Landlord's receipt of the Extension
         Notice, Landlord shall deliver a written notice ("EXTENSION NOTICE") to
         Tenant setting forth Landlord's estimation of the Prevailing Rate for
         the Premises. The parties shall have until the date that is ten (10)
         months prior to the date that the original term, or first Extended
         Term, as applicable, will expire in order to agree on Base Rent during
         such Extended Term. If the parties agree on the Base Rent for the
         Extended Term during that period, they shall immediately execute an
         amendment to this Lease stating the Base Rent. If the parties are
         unable to agree on Base Rent for such Extended Term during that period,
         for a period of ten (10) days thereafter, by providing Landlord with
         written notice, Tenant may elect to (i) withdraw its Extension Notice,
         in which case Tenant shall no longer have any extension rights pursuant
         to this Section 33, or (ii) cause the Prevailing Rate to be established
         by appraisal. The failure of Tenant to make such election within five
         (5) days following Tenant's receipt of written notice from Landlord
         indicating that Tenant has not made such election shall be deemed
         Tenant's election to proceed under subsection (i) above. In the event
         the appraisal procedure is utilized, Landlord and Tenant shall each
         appoint one appraiser at least eight (8) months prior to the expiration
         of the original term; provided, however, that if either party fails to
         designate an appraiser within the time period specified, then the
         appraiser who is designated shall conclusively determine the Prevailing
         Rate. If two (2) appraisers are designated, then they shall submit
         within thirty (30) days after the second thereof has been designated
         their appraisals of the Prevailing Rate. Landlord and Tenant intend
         that the "Prevailing Rate" shall be deemed to be the rent per square
         foot of rentable area of office space that is then being charged for as
         renewal rates office space located in Class "A" office buildings in the
         vicinity of the Building (located within the Broomfield submarket) that
         are comparable in quality and offer similar amenities to the Building
         and involving leases with similar terms and conditions, and involving
         the use of the premises for general office purposes. The office spaces
         used for comparison shall be comparable in size, quality and design to
         the Premises, and such office spaces used for comparison shall be
         comparable to the Premises with respect to their location within such
         buildings. Should the two appraisers be unable to agree within said
         thirty (30) days, the two appraisers shall each submit an independent
         written appraisal and together they shall designate one (1) additional
         person as appraiser within five (5) days following the expiration of
         said thirty (30)-day period; provided, however, that if the difference
         between the two appraisals is five percent (5%) or less of the lowest
         appraisal, then an additional appraiser shall not be designated and the
         Prevailing Rate shall equal the average of the two (2) appraisals that
         are submitted. The third appraiser shall submit an independent written
         appraisal within thirty (30) days following his or her appointment. If
         the two appraisers cannot agree upon a third appraiser, then either
         party hereunder may request that any District Court Judge of the County
         in which the Premises is located appoint such third appraiser. The
         Prevailing Rate shall be equal to the average of the two (2) written
         appraisals which are closest, and the third (3rd) appraisal shall be
         disregarded. Each party shall bear the cost of the appraiser appointed
         by it. If three (3) appraisers are appointed, each party shall bear the
         cost of the appraiser appointed by it and the parties shall share
         equally in the cost of the third appraiser. No person shall be
         appointed or designated an appraiser unless he or she is (i) an
         independent appraiser who is a currently certified member of the
         American Institute of Real Estate Appraisers (with MAI designation) and
         unless he or she has at least five (5) years' experience as an
         appraiser in the County which the Premise is located, or (ii) a real
         estate broker with a minimum of at least ten (10) years' experience in
         leasing of commercial office space in the vicinity of the Project. The
         third appraiser shall not have ever been employed (full-time or
         part-time or on a consulting basis) by Landlord or Tenant. In the event
         that the Prevailing Rate is not established before the commencement of
         such Extended Term, Tenant shall continue to pay the Base Rent then in
         effect; when the Prevailing Rate has been established, the new Base
         Rent shall be retroactively effective as of the beginning of such
         Extended Term, and Tenant shall pay Landlord any deficiency within
         thirty (30) days after the establishment of the new Base Rent. If
         Tenant has overpaid Base Rent during such period such overpayment shall
         be offset against Rent thereafter coming due.

34.      HAZARDOUS MATERIALS

         (a)     For the purpose of this Section 34(a) and this Lease, the
following terms are defined as follows:

                 (i)      "HAZARDOUS MATERIALS" shall mean any substance: (A)
         that now or in the future is regulated or governed by, requires
         investigation or remediation under, or is defined as a hazardous waste,
         hazardous substance, pollutant or contaminant under any governmental
         statute, code, ordinance, regulation, rule or order, and any amendment
         thereto, including for example only and without limitation, the
         Comprehensive Environmental Response Compensation and Liability Act, 42
         U.S.C. Section 9601 et seq., and the Resource Conservation and Recovery
         Act, 42 U.S.C. Section 6901 et seq., or (B) that is toxic, explosive,
         corrosive, flammable, radioactive, carcinogenic, dangerous or otherwise
         hazardous, including for example only and without limitation, gasoline,
         diesel, petroleum hydrocarbons, polychlorinated biphenyls (PCBs),
         asbestos, radon and urea formaldehyde foam insulation.

                 (ii)     "ENVIRONMENTAL REQUIREMENTS" shall mean all present
         and future governmental statutes, codes, ordinances, regulations,
         rules, orders, permits, licenses, approvals, authorizations and other
         requirements of any kind applicable to Hazardous Materials.

                 (iii)    "HANDLE," "HANDLED," or "HANDLING" shall mean any
         installation, handling, generation, storing, treatment, use, disposal,
         discharge, release, manufacture, refinement, presence, migration,
         emission, abatement, removal, transportation, or any other activity of
         any type in connection with or involving Hazardous Materials by Tenant
         or its officers, employees, contractors, assignees, sublessees, agents
         or invitees. The word "contractors" which is contained in the preceding
         sentence shall not include any contractor which installs the Tenant
         Improvements or improvements constructed for the Expansion Space (as
         defined below).





                                      -18-
<PAGE>   21
                 (iv)     "ENVIRONMENTAL LOSSES" shall mean all costs and
         expenses of any kind, damages, foreseeable and unforeseeable
         consequential damages, fines and penalties incurred in connection with
         any violation of and compliance with Environmental Requirements and
         all losses of any kind attributable to the diminution of value, loss
         of use or adverse effects on marketability or use of any portion of
         the Premises or Building.

         (b)     Tenant covenants and warrants that it shall, at its own
         expense, promptly take all actions required by any governmental agency
         or entity in connection with the Handling of Hazardous Materials by
         Tenant at or about the Premises, Building or Project, including
         without limitation, inspection and testing, performing all cleanup,
         removal and remediation work required with respect to those Hazardous
         Materials introduced, released, or deposited by Tenant, complying with
         all closure requirements and post-closure monitoring, and filing all
         required reports or plans. All of the foregoing work and all Handling
         of all Hazardous Materials shall be performed in a good, safe and
         workmanlike manner by consultants qualified and licensed to undertake
         such work and in a manner that will not interfere with Landlord's use,
         operation, leasing and sale of the Project and other tenants' quiet
         enjoyment of their premises in the Property. Tenant shall deliver to
         Landlord prior to delivery to any governmental agency, or promptly
         after receipt from any such agency, copies of all permits, manifests,
         closure or remedial action plans, notices, and all other documents
         relating to the Handling of Hazardous Materials at or about the
         Premises, Building or Project by Tenant. Tenant shall remove at its
         own expense, by bond or otherwise, all liens or charges of any kind
         filed or recorded against the Premises, Building or Project in
         connection with the Handling by Tenant, its agents, employees,
         contractors and/or subcontractors, of Hazardous Materials, within ten
         (10) days after the filing or recording of such lien or charge, and if
         Tenant fails to do so, Landlord shall have the right, but not the
         obligation, to remove the lien or charge at Tenant's expense in any
         manner Landlord deems expedient.

         (c)     Landlord shall have the right, but not the obligation, to
         enter the Premises at any reasonable time, upon prior notice (except
         in the case of emergency), (i) to confirm Tenant's compliance with the
         provisions of this Section, and (ii) to perform Tenant's obligations
         under this Section if Tenant has failed to do so. Landlord shall also
         have the right to engage qualified Hazardous Materials consultants to
         inspect the Premises and review the Handling of Hazardous Materials,
         including review of all permits, reports, plans, and other documents
         regarding same. If Landlord engages a consultant upon the reasonable,
         good faith belief that Tenant is in violation of its obligations under
         this Section 30, Tenant shall pay the costs of Landlord's consultants'
         fees and all costs incurred by Landlord in performing Tenant's
         obligations under this Section. Landlord shall use reasonable efforts
         to minimize any interference with Tenant's business caused by
         Landlord's entry into the Premises, but Landlord shall not be
         responsible for any interference caused thereby.

         (d)     Landlord represents and warrants to Tenant that, to the best
         of Landlord's actual current knowledge, as of the Commencement Date,
         the Building, and the real property on which such improvements are
         constructed, do not contain any Hazardous Materials in violation of
         Environmental Requirements.

35.      GENERAL PROVISIONS

         (i)     Plats and Exhibits. Clauses, plats and exhibits, if any,
         signed by the Landlord and the Tenant endorsed on or affixed to this
         Lease are a part hereof.

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

         (iii)   Joint Obligation. If there be more than one (1) Tenant, the
         obligations hereunder imposed upon Tenants shall be joint and several.

         (iv)    Marginal Headings. The marginal headings and Article titles to
         the Articles of this Lease are not a part of this Lease and shall have
         no effect upon the construction or interpretation of any part hereof.

         (v)     Time. Time is of the essence of this Lease and each and all of
         its provisions in which performance is a factor.

         (vi)    Successors and Assigns. The covenants and conditions herein
         contained, subject to the provisions as to assignment, apply to and
         bind the heirs, successors, executors, administrators and assigns of
         the parties hereto.

         (vii)   Recordation. Neither Landlord nor Tenant shall record this
         Lease or a short form memorandum hereof without the prior written
         consent of the other party.

         (viii)  Quiet Possession. Upon Tenant paying the rent reserved
         hereunder and observing and performing all of the covenants,
         conditions and provisions on Tenant's part to be observed and
         performed hereunder, Tenant shall have quiet possession of the
         Premises for the entire term hereof, subject to all the provisions of
         this Lease.

         (ix)    Limitation on Liability. In consideration of the benefits
         accruing hereunder, Tenant and all successors and assigns covenant and
         agree that, in the event of any actual or alleged failure, breach or
         default hereunder by Landlord: (1) Tenant's sole and exclusive
         recourse shall be against Landlord's interest in the Building and
         Tenant shall not have any right to satisfy any judgment which it may
         have against Landlord from any other assets of Landlord, (2) No
         partner, stockholder, director, officer, employee, beneficiary or
         trustee (collectively, "PARTNER") of Landlord shall be sued or named
         as a party in





                                      -19-
<PAGE>   22

         any suit or action (except as may be necessary to secure jurisdiction
         over Landlord); (3) No service of process shall be made against any
         Partner of Landlord (except as may be necessary to secure jurisdiction
         over Landlord); (4) No Partner of Landlord shall be required to answer
         or otherwise plead to any service of process; and (5) No judgment
         will be taken against any Partner of Landlord.

         (x) Late Charges. Tenant hereby acknowledges that late payment by
         Tenant to Landlord of rent or other sums due hereunder will cause
         Landlord to incur costs not contemplated by this Lease, the exact
         amount of which will be extremely difficult to ascertain. Such costs
         include, but are not limited to, processing and accounting charges, and
         late charges which may be imposed upon Landlord by terms of any
         mortgage or trust deed covering the Premises.  Accordingly, if any
         installment of rent or of a sum due from Tenant shall not be received
         by Landlord or Landlord's designee within ten (10) days after Tenant's
         receipt of written notice that such amount is past due, then Tenant
         shall pay to Landlord a late charge equal to five percent (5%) of such
         overdue amount. The parties hereby agree that such late charges
         represent a fair and reasonable estimate of the cost that Landlord will
         incur by reason of the late payment by Tenant. Acceptance of such late
         charges by the Landlord shall in no event constitute a waiver of
         Tenant's default with respect to such overdue amount, nor prevent
         Landlord from exercising any of the other rights and remedies granted
         hereunder.

         (xi) Prior Agreements. This Lease contains all of the agreements of the
         parties hereto with respect to any matter covered or mentioned in this
         Lease, and no prior agreements or understanding pertaining to any such
         matters shall be effective for any purpose. No provision of this Lease
         may be amended or added to, except by an agreement in writing signed by
         the parties hereto or their respective successors in interest. This
         Lease shall not be effective or binding on any party until fully
         executed by both parties hereto.

         (xii) Attorneys' Fees. If any action for breach of or to enforce the
         provisions of this Lease is commenced, the court in such action shall
         award to the party in whose favor a judgment is entered, a reasonable
         sum as attorneys' fees and costs. The losing party in such action shall
         pay such attorneys' fees and costs. Each party shall also indemnify the
         other party against and hold the other party harmless from all costs,
         expenses, demands and liability the other party may incur if the other
         party becomes or is made a party to any claim or action (a) instituted
         by the indemnifying party against any third party, or by any third
         party against the indemnifying party, or by or against any person
         holding any interest under or using the Project by license of or
         agreement with the indemnifying party; (b) for foreclosure of any lien
         for labor or material furnished to or for the indemnifying party or
         such other person; (c) otherwise arising out of or resulting from any
         act or transaction of the indemnifying party or such other person; or
         (d) necessary to protect the other party's interest under this Lease in
         a bankruptcy proceeding, or other proceeding under Title 11 of the
         United States Code, as amended. The indemnifying party shall defend the
         other party against any such claim or action at the indemnifying
         party's expense with counsel reasonably acceptable to the other party,
         or at the other party's election, the indemnifying party shall
         reimburse the other party for any reasonable legal fees or costs the
         other party incurs in any such claim or action.

         (xiii) Inability to Perform. This Lease and the obligations of Tenant
         hereunder shall not be affected or impaired because the Landlord is
         unable to fulfill any of its obligations or furnish services and
         utilities hereunder or is delayed in doing so, if such inability or
         delay is caused by reason of acts of God, strikes, lockouts, labor
         troubles, inability to procure materials, governmental laws or
         regulations, governmental requests for the general public welfare, or
         other causes beyond the reasonable control of Landlord, provided that
         Landlord shall use its commercially reasonable efforts to minimize any
         such delay.

         (xiv) Modification For Lender. If, in connection with obtaining
         construction, interim or permanent financing for the Building, the
         lender shall request reasonable modifications to this Lease as a
         condition to such financing, following consultation with legal counsel,
         Tenant will not unreasonably withhold, delay or defer its consent
         thereto, provided that such modifications do not increase the
         obligations of Tenant hereunder or materially adversely affect the
         leasehold interest hereby created or Tenant's rights hereunder.

         (xv) Sale of Premises by Landlord. In the event of any sale of the
         Building, Landlord shall be and is hereby entirely freed and relieved
         of all liability under any and all of its covenants and obligations
         contained in or derived from this Lease arising out of any act,
         occurrence or omission occurring after the consummation of such sale;
         and the purchaser, at such sale or any subsequent sale of the Premises
         shall be deemed, without any further agreement between the parties or
         their successors in interest or between the parties and any such
         purchaser, to have assumed and agreed to carry out any and all of the
         covenants and obligations of the Landlord under this Lease.

         (xvi) Subordination, Attornment.

                 (1) This Lease is and shall be subordinate to any encumbrance
         now of record or recorded after the date of this Lease affecting the
         Building, other improvements, and land of which the Premises are a
         part. Such subordination is effective without any further act of
         Tenant. If any mortgagee, trustee, or ground lessor shall elect to
         have this Lease and any options granted hereby prior to the lien of
         its mortgage, deed of trust, or ground lease, and shall give written
         notice thereof to Tenant, this Lease and such options shall be deemed
         prior to such mortgage, deed of trust, or ground lease, whether this
         Lease or such options are deeded prior or subsequent to the date of
         said mortgage, deed of trust, or ground lease, or the date of
         recording thereof.

                 (2) In the event any proceedings are brought for foreclosure,
         or in the event of a sale or exchange of the real property on which
         the Building is located, or in the event of the exercise of the power
         of sale under any mortgage or deed of trust made by Landlord covering
         the Premises. Tenant shall attorn to the purchaser upon any such
         foreclosure and sale and recognize such purchaser as the Landlord
         under this Lease.

                 (3) Tenant agrees to execute any documents required to
         effectuate an attornment or to make this Lease or any options granted
         herein prior to the lien of any mortgage, deed of trust, or ground
         lease, as the case may be.




                                    -20-
<PAGE>   23
                 (4) Landlord agrees that Tenant's obligations to subordinate
         under this Section to any existing and future ground lease, mortgage,
         or deed of trust shall be conditioned upon Tenant's receipt of a
         non-disturbance agreement from the party requiring such subordination
         (which party is referred to for the purposes of this Section as the
         "SUPERIOR LIENOR"). Such non-disturbance agreement shall provide, at a
         minimum, that Tenant's possession of the Premises shall not be
         interfered with following a foreclosure, provided Tenant is not in
         default beyond any applicable cure periods. Landlord's obligation with
         respect to such a non-disturbance agreement shall be limited to
         obtaining the non-disturbance agreement in such form as the
         Superior Lienor generally provides in connection with its standard
         commercial loans, however, Tenant shall have the right to negotiate,
         and Landlord shall use its good faith efforts and due diligence in
         assisting Tenant in the negotiation of, revisions to that
         non-disturbance directly with the Superior Lienor. Tenant agrees to
         use its good faith efforts to reach agreement with the Superior Lienor
         upon acceptable terms and conditions of a non-disturbance agreement.

         (xvii) Name. Tenant shall not use the name of the Building or of the
         development in which the Building is situated for any purpose other
         than as an address of the business to be conducted by the Tenant in
         the Premises, except that Tenant may use the Building's name in any of
         Tenant's promotional material.

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

         (xix) Cumulative Remedies. No remedy or election hereunder shall be
         deemed exclusive, but shall, wherever possible, be cumulative with all
         other remedies at law or in equity.

         (xx) Choice of Law. This Lease shall be governed by the laws of the
         state, in which the Premises are located.

         (xxi) Signage. To the extent consistent with (i) any covenants,
         conditions and restrictions encumbering the Building, and (ii)
         applicable laws, statutes and ordinances, Tenant shall be entitled to
         primary Building signage ("BUILDING SIGNAGE") and non-exclusive
         monument signage at the Building ("MONUMENT SIGNAGE"), provided that
         Landlord has approved, in writing, the configuration, size, character,
         materials and location of such signage. The cost of installing the
         Building Signage shall be paid for by Landlord out of Tenant's
         Allowance pursuant to the Work Letter Agreement. The cost of the base
         structure that the Monument Signage is affixed shall be the
         responsibility of Landlord. The maintenance and repair of all such
         signage shall be a Direct Expense allocable to Tenant. Tenant shall be
         responsible for the cost of removal of the Building Signage upon the
         expiration or earlier termination of this Lease.

         (xxii) State Law Conflict. To the maximum extent permitted under the
         laws of the State of Colorado, the parties agree that the provisions
         of this Lease shall control any inconsistency and/or conflict with any
         law of the State of Colorado.

         (xxiii) Surrender of Premises.  On the expiration of this Lease, or
         within five (5) days after the earlier termination of the term, Tenant
         shall surrender to Landlord the Premises in good condition (except for
         ordinary wear and tear and repair and maintenance which is the
         obligation of Tenant and damage and/or destruction which is not the
         obligation of Tenant to repair pursuant to the provisions of this
         Lease).

36.      BROKERS

         Each party warrants that it has had no dealings with any real estate
         broker or agent in connection with the negotiation of this Lease,
         excepting only Cushman & Wakefield and Staubach Company ("BROKERS"),
         and it knows of no other real estate broker or agent who is entitled
         to a commission in connection with this Lease. Landlord shall pay a
         leasing commission to the Brokers in accordance with separate
         documentation.

37.      NOTICE

         All notices and demands required to be sent to the Landlord or Tenant
         under the terms of this Lease shall be personally delivered or sent by
         certified mail, postage prepaid or by overnight courier (i.e., Federal
         Express), to the addresses indicated in the Basic Lease Information,
         or to such other addresses as the parties may from time to time
         designate by notice pursuant to this paragraph. In addition, prior to
         the Commencement Date, notices to Tenant shall be sent to Ms. Barb
         Madden, Associate Director, Facilities, Abacus Direct Corporation,
         8774 Yates Drive, Westminster, Colorado 80030. Notices shall be
         deemed received upon the earlier of (i) if personally delivered, the
         date of delivery to the address of the person to receive such notice
         (ii) if mailed, two (2) days following the date of posting by the U.S.
         Postal Service, and (iii) if by overnight courier, on the business day
         following the deposit of such notice with such courier.



                                    -21-
<PAGE>   24
The parties hereto have executed this Lease at the place and on the dates
specified immediately adjacent to their respective signatures. If this Lease
has been filled in, it has been prepared for submission to your attorney for
his approval. No representation or recommendation is made by the real estate
broker or its agents or employees as to the legal sufficiency, legal effect, or
tax consequences of this Lease or the transactions relating thereto.

<TABLE>
<S>                                             <C>
LANDLORD:                                       TENANT:
                                             
WESTERN STATES VENTURES, LLC, a                 ABACUS DIRECT CORPORATION, a Delaware
California limited liability company            corporation
                                             
By:      /s/ DAVID L. BONUCCELLI                By:      /s/ CARLOS SALA
   -----------------------------------              -----------------------------------
         David L. Bonuccelli                             Carlos Sala
Its:     Managing Member                        Its:     Chief Financial Officer

Date:    6-2-98                                    Date:    5/27/98
      --------------------------------                  -------------------------------
Address:    818 University Avenue               Address:     8774 Yates Drive
            Sacramento, California 95825                     Westminster, Colorado 80030
</TABLE>



                                     -22-
<PAGE>   25
RULES AND REGULATIONS

1.       Except as provided in the Lease, no sign, placard, picture,
         advertisement, name or notice shall be inscribed, displayed or printed
         or affixed on or to any part of the outside or inside of the Building
         without the written consent of Landlord first had and obtained and
         Landlord shall have the right to remove any such sign, placard,
         picture, advertisement, name or notice without notice to and at the
         expense of Tenant.

         All approved signs or lettering on doors shall be printed, painted,
         affixed or inscribed at the expense of Tenant by a person approved of
         by Landlord.

         Tenant shall not place anything or allow anything to be placed near the
         glass of any window, door, partition or wall which may appear unsightly
         from outside the Premises, however, that Landlord may furnish and
         install a building standard window covering at all exterior windows.
         Tenant shall not without prior written consent of Landlord cause or
         otherwise sunscreen any window.

2.       The sidewalks, halls, passages, exits, entrances, elevators and
         stairways shall not be obstructed by any of the tenants or used by
         them for any purpose other than for ingress and egress from their
         respective Premises.

3.       Tenant shall not alter any lock or install any new or additional locks
         or any bolts on any doors or windows of the Premises. In the event of
         the loss of any keys furnished by the Landlord, Tenant shall pay to the
         Landlord the cost thereof.

4.       The toilet rooms, urinals, wash bowls and other 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.

5.       Tenant shall not overload the floor of the Premises or in any way
         deface the Premises or any part thereof.

6.       Tenant may move furniture, freight or equipment into the Building
         without the prior notice to Landlord and all moving of the same into or
         out of the Building shall be done in a way to not unreasonably
         interfere with the other tenants of the Building. Landlord shall have
         the right to prescribe the weight, size and position of all safes and
         other heavy equipment brought into the Building and also the times and
         manner of moving the same in and out of the Building. Safes or other
         heavy objects shall, if considered necessary by Landlord, stand on
         supports of such thickness as is necessary to properly distribute the
         weight. Landlord will not be responsible for loss of or damage to any
         such safe or property from any cause and all damage done to the
         Building by moving or maintaining any such safe or other property shall
         be repaired at the expense of Tenant.

7.       Tenant shall not use, keep, or permit to be used or kept any foul or
         noxious gas or substance in the Premises, or permit to suffer the
         Premises to be occupied or used in a manner offensive or objectionable
         to the Landlord or other occupants of the Building by reason of noise,
         odors and/or vibrations, or interfere in any way with other tenants or
         those having business therein, nor shall any animals or birds be
         brought in or kept in or about the Premises or the Building.


8.       Excepting microwave cooking and incidental cooking for employees and/or
         subtenants of Tenant or a cafeteria installed by Tenant for its
         employees in accordance with Section 10 of the Lease, no cooking shall
         be done or permitted by any Tenant on the Premises, nor shall the
         Premises be used for the storage of merchandise, for washing clothes,
         for lodging, or for any improper, objectionable or immoral purposes.
         Tenant shall, in no event, allow cooking which omits a strong odor
         throughout the Building.

9.       Tenant shall not use or keep in the Promises or the Building any
         kerosene, gasoline or inflammable or combustible fluid or material, or
         use any method of heating or air conditioning other than that supplied
         by Landlord.

10.      Landlord will direct electricians as to where and how telephone and
         communication wires are to be introduced.  No boring or cutting for
         wires will be allowed without the consent of the Landlord. The location
         of telephones, call boxes and other office equipment affixed to the
         Premises shall be subject to the approval of Landlord, not to be
         unreasonably withheld or delayed.

11.      On Saturdays, Sundays and legal holidays, and during non-Building hours
         set forth in the Lease, access to the Building or to the halls,
         corridors, elevators or stairways in the Building, or the Premises may
         be refused unless the person seeking access is known to the person or
         employee of the Building in charge and has a pass or is properly
         identified. The Landlord shall in no case be liable for damages for any
         error with regard to the admission to or exclusion from the Building of
         any person. In case of invasion, mob, riot, public excitement, or other
         commotion, the Landlord reserves the right to prevent access to the
         building during the continuance of the same by closing of the doors or
         otherwise, for the safety of the tenants and protection of property in
         the Building and the Building.

12.      Landlord reserves the right to exclude or expel from the Building any
         person who, in the judgment of the 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 the rules and regulations of the Building.

13.      No vending machine or machines of any description shall be installed,
         maintained or operated upon the Premises without the written consent of
         the Landlord.



                                     -23-
<PAGE>   26
14.      Tenant shall not disturb, solicit, or canvass any occupant of the
         Building and shall cooperate to prevent same; provided, however,
         Tenant shall be entitled to market the business operations of Tenant
         at the Premises, in a professional manner, to other tenants within the
         Building.

15.      Landlord shall have the right to control and operate the public
         portions of the Building, and the public facilities, and heating and
         air conditioning, as well as facilities furnished for the common use
         of the tenants, in such manner as it deems best for the benefit of the
         tenants generally.

16.      All entrance doors in the premises shall be left locked when the
         Premises are not in use, and all doors opening to public corridors
         shall be kept closed except for normal ingress and egress from the
         Premises.

17.      No employee of Tenant shall be permitted to smoke within fifty (50)
         feet of the main and secondary entrance to the Building.



                                     -24-