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                                                                   EXHIBIT 10.06

                                     LEASE

        This lease is made and entered into this 19 day of November, 1996,
between Sheridan Realty Partners, L.P. ("Landlord"), and Abacus Direct,
("Tenant"). Trade Name: Abacus Direct.

PREMISES.

        1.1  Landlord leases to Tenant approximately 27,218 square feet of net
rentable floor space on the 1st, 2nd and 3rd floors of Sheridan Park One (the
"Building"), 8774 Yates Drive, Westminister, CO 80030 be known as Suite Nos.
100, 200, 210 and 310 (the "Premises") as marked on Exhibit "A-1", to be used
for general offices and for no other purpose, on the terms and conditions set
forth herein. The Premises are more particularly described in Exhibit "A"
attached hereto.

TERM.

        2.1  The term of this Lease shall be for three (3) years and zero (0)
months commencing on the 1st day of October, 1996, or such other date set forth
in Article 9 herein, and shall end on the 30th day of September, 1999 unless
sooner terminated pursuant to any of the provisions of this Lease. Landlord and
Tenant agree to execute a written addendum setting forth the commencement date
and termination date if different than set forth above.

BASE RENT.

        3.1  Tenant agrees to pay to Landlord at the principal office of
Landlord, or to such other place or party as may be designated from time to
time by Landlord, as Base Rent for the Premises, without setoff, abatement or
deduction, and without demand, the total sum of $1,006,011.09 payable in
advance in equal monthly installments as follows:

             Year 1:    10/1/96-12/31/96        $19,029.55/mo.
                        1/1/97-3/31/97          $24,610.10/mo.
                        4/1/97-9/30/97          $26,379.65/mo.

             Year 2:    10/1/97-9/30/98         $29,490.76/mo.

             Year 3:    10/1/98-1/31/99         $29,490.76/mo.
                        2/1/99-9/30/99          $30,620.26/mo.

LATE CHARGES.

        4.1  If Tenant fails to make any installment of Base Rent, Additional
Rent or any sum due Landlord hereunder within five (5) days after such amount
is due, then such late payments shall bear a late charge equal to five percent
(5%) of the delinquent payment for the month or portion thereof after the date
such payment was due. Such late charge shall be earned from the day after the
due date to the date paid.

ADDITIONAL RENT.

        5.1  In addition to all other payments to Landlord by Tenant required
hereunder, Tenant shall pay to Landlord in each year or portion thereof during
the term of this lease, or any renewal or extension thereof, as Additional
Rent, Tenant's Pro Rata Share of the amount by which the annual Operating
Expenses, as defined in Article 6, exceeds the budgeted operating expenses for
1996 of $6.26 for 18,931 square feet and the actual operating expenses for 1997
for 8,287 square feet of net rentable area per year. (The "Expense Stop").

        5.2  The term, "Tenant's Pro Rate Share" means the ratio of the net
rentable square feet of floor space of the Premises to the total net rentable
square feet of floor space in the Building and is agreed to be seventy two
point nine one percent (72.91%).

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        5.3  Landlord shall provide to Tenant a statement of Tenant's projected
Pro Rata Share of Operating Expenses at the beginning of each calendar year,
and Tenant shall pay the entire amount due and owing in twelve (12) equal
monthly installments together with the Base Rent payments, to Landlord at the
following address:

                Attn:   Ms. Colleen Overocker
                        Sheridan Realty Partners, L.P.
                        1800 Glenarm Place, Suite 1200
                        Denver, CO 80202

In the event Tenant's Pro Rata Share of the actual Operating Expenses for such
calendar year shall exceed the aggregate of the projected Operating Expenses
installments actually collected by the Landlord from Tenant, Tenant shall pay
to Landlord within thirty (30) days following Tenant's receipt of a statement,
the amount of such excess. However, if Tenant's Pro Rata Share of the actual
Operating Expenses for such calendar year is less than the aggregate of the
projected Operating Expenses installments actually collected by Landlord from
Tenant, Landlord shall pay to Tenant within thirty (30) days after Tenant's
receipt of the statement, the amount of the overpayment of the projected
Operating Expenses installments. If the expiration or termination of this Lease
occurs other than on the last day of a calendar year, the amount to be paid by
Tenant or reimbursed to Tenant hereunder shall be a pro rata amount based on
the ratio of the number of days of the term of this lease in such last calendar
year to 365 days.

        5.4  The obligation of Tenant for the payment of Base Rent and
Additional Rent shall survive the termination of this Lease. Failure or delay
of Landlord in connection with this paragraph shall not constitute a waiver or
renunciation of its rights therein.

OPERATING EXPENSES.

        6.1  For the purpose of this Lease, Operating Expenses shall mean the
total amounts incurred or paid by Landlord in connection with the ownership,
management, maintenance, repair, replacement and operation of the Building.
Such expenses shall include, but shall not be limited to: janitorial and
cleaning contracts; cleaning supplies and equipment; all management costs;
heating and air conditioning; electricity (other than additional electricity
supplied to and paid by individual tenants); maintenance or repair of the
exterior and interior of the Building including the roof and parking surface;
insurance premiums; landscaping services; leasing or amortization of capital
improvements made to the Building after the date of the execution of this Lease
that reduce the operating or energy expenses, improve life safety or security
systems, or are required under any governmental law or regulation that was not
applicable at the time the Building was constructed, such cost to be amortized
over such reasonable period as determined at Landlord's sole discretion,
together with interest on the unamortized balance at a rate equal to twelve
percent (12%) per annum at the time such capital improvement is put into
service; and taxes. Taxes, for the purposes of this paragraph, shall mean:
personal property taxes on property and equipment used in the operation and
maintenance of the Building; all real estate taxes including state equalization
factor, if any, payable (adjusted after protest or litigation, if any) for any
part of the term of this Lease, exclusive of penalties or discounts, on the
property; any taxes which shall be levied in lieu of any such taxes on the
gross rentals of the Building; any special assessments against the Property
which shall be required to be paid during the calendar year in respect to which
taxes are being determined; and expense of contesting the amount or validity of
any such taxes, charges, or assessments, including tax consultant fees, such
expense to be applicable to the period of the item contested.

SECURITY FOR PERFORMANCE OF LEASE.

        7.1  On the date of the execution of this Lease, Tenant has deposited
with Landlord the sum of Sixteen thousand six hundred eighty and 63/100's
Dollars ($16,680.63), and will deposit with this Lease an additional Twelve
thousand eight hundred ten and 13/100's Dollars ($12,810.13) for a total of
Twenty nine thousand four hundred ninety and 76/100 Dollars ($29,490.76) as
security for the full and faithful performance by Tenant of the Terms of this
Lease. Landlord may use, apply, or retain the whole or any part of said
security to the extent required for the payment of any rent as to which Tenant
is in default, or for any sum which Landlord may expend or may be required to
expend by reason of Tenant's default in respect of any of the terms of this
Lease. Any sums so used or applied by Landlord from said security deposit shall
immediately be repaid by Tenant to Landlord after notice. Upon termination of
this Lease, Landlord shall return to Tenant within thirty (30) days the
security deposit hereinabove provided for, less any sums used or applied upon
any default and not reimbursed. In the event of a bona fide sale subject to
this Lease, Landlord shall have the right to transfer the security deposit to
the purchaser, and upon such transfer Landlord shall be released by tenant from
all liability for the return of such security.

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        7.2  Intentionally omitted.

IMPROVEMENTS AND FINISH.

        8.1  Landlord shall construct and finish the interior of the Premises
pursuant to the tenant finish allowance, attached hereto as Exhibit "B", and the
plans and specifications mutually approved in writing by Landlord and Tenant,
attached hereto as Exhibit "C". Any work in addition to any of the items
specifically enumerated in the plans and specifications shall be performed by
Tenant at Tenant's cost and expense. Any equipment or work other than those
items specifically enumerated in the plans and specifications which Landlord
installs or constructs on the Premises on Premises on Tenant's behalf shall be
paid for by Tenant within fifteen (15) days after receipt of a statement
thereof at cost. Any additional work requested by Tenant shall be commenced
only if approved by written change orders signed by both Landlord and Tenant.

POSSESSION.

        9.1  If Landlord, for any reason whatsoever, cannot deliver possession
of the Premises to Tenant on or before the commencement date set forth in
Article 2, this Lease shall not be void or voidable, nor shall Landlord be
liable to Tenant for any loss or damage resulting therefrom. In such event, the
rent as set forth herein shall not commence until possession of the Premises is
made available to Tenant. If the Premises are ready for occupancy prior to the
commencement date set forth in Article 2, and Tenant takes early occupancy, the
term of the lease shall commence on such occupancy date and shall continue
through the ending date set forth in Article 2, and Tenant shall pay rental for
such early period of occupancy at a rate proportionate to the rental reserved
herein during the first year of the Lease.

        9.2  Possession of the Premises shall be deemed delivered when tendered
for occupancy and the tenant improvements agreed to between Landlord and Tenant
have been substantially and reasonably approved by Tenant completed. Tenant
agrees to take possession upon substantial completion. If only minor or
unsubstantial details of construction, decoration, or mechanical adjustments
remain to be completed on the Premises, then the commencement of the term of the
Lease shall not be delayed and the payment of rent under the Lease will
commence on the commencement date set forth in the Lease regardless of any
contrary provisions of the Lease. If a delay in substantial completion shall be
due to special work, changes, alterations, or additions to the Premises
required by or made by Tenant; or if such delay is due to Tenant's delay or
default in submitting plans, supplying information, approving plans or
specifications, or authorizing changes or otherwise; or if such delay is caused
by any other delay or default of Tenant, then the Premises shall be deemed
substantially complete and ready for occupancy on the commencement date.

ACCEPTANCE OF PREMISES. 

        10.1 By occupying the Premises, Tenant accepts the same and
acknowledges that the Premises are in the condition called for hereunder,
unless Tenant furnishes Landlord with a notice in writing specifying any defect
in the Premises within ten (10) days after taking possession thereof.

USE.

        11.1 Tenant will occupy the Premises for general office use and for no
other purpose. Tenant will not use or permit in the premises anything that will
increase the rate of fire insurance thereon or which would prevent Landlord
from obtaining reduced rates for long term insurance policies, or maintain
anything that may be dangerous to life or limb, or in any manner, deface,
injure or commit waste in, on, or about said Building or any portion thereof, or
overload the floors, or permit any objectionable noise or odor to escape or be
emitted from said Premises, or permit anything to be done upon the Premises in
any way tending to create a nuisance or to disturb any other tenants of the
Building, or to injure the reputation of the Building or to use or permit the
use of the Premises for lodging or sleeping purposes, or for any immoral or
illegal purposes. Tenant will comply, at Tenant's own cost and expense, with all

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orders, notices, regulations, or requirements of any municipality, state or
other governmental authority respecting the use of the Premises.

SERVICES.

        12.1 Landlord shall furnish elevator service, adequate water, climate
control and janitorial services during normal business hours as set forth in
the rules and regulations attached hereto as Exhibit "D". Such climate control
shall be furnished in accordance with said rules and regulations. The business
hours may be changed to other reasonable hours as solely prescribed by any
applicable policies or regulations adopted by any utility or governmental
agency. In no event shall hours be less than 8 a.m. to 6 p.m. daily Monday
through Friday excluding holidays, weekends and other times upon reasonable
notice by Tenant. Landlord shall not be liable for the stoppage or interruption
of any said services or utilities caused by riots, strikes, labor disputes,
accidents, necessary repairs or any conditions beyond Landlord's control.
Landlord shall reasonably determine as to the amount and kind of services and
utilities to be provided under the provisions hereof, and any additional
services or utilities required by Tenant shall be at Tenant's sole cost and
expense. Tenant agrees not to connect to or alter any utilities or equipment
provided by Landlord without obtaining Landlord's prior written consent.

USE OF ELECTRICITY.

        13.1 Tenant's use of electricity in the Premises shall be for the
operation of building standard lighting, electrical fixtures, typewriters,
personal computers and other small office machines and lamps and shall not at
any time exceed the capacity of any of the electrical conductors and equipment
in or serving the Premises.

        13.2 In order to ensure that such capacity is not exceeded and to avert
possible adverse effect on the Building's electrical service, Tenant shall not,
without Landlord's prior written consent in each instance, connect any
additional fixtures, appliance or equipment (other than normal office
electrical fixtures and copying machinery, lamps, typewriters, and similar
small office machines) to the Building's electric system of the Premises
existing at the commencement of the term hereof. If Landlord grants such
consent, the cost of all additional risers and other equipment required
therefore shall be paid as additional rent by Tenant to Landlord upon demand.
Furthermore, Tenant shall pay on demand as additional rent to Landlord the cost
of any electric current or other energy used and consumed by Tenant for any
other purpose, including, without limitation, the operation of heavy duty
accounting equipment, copy equipment and computer equipment.

        13.3 Tenant shall pay as additional rent, on demand, the cost of any
metering which may be required by Landlord to measure any excess usage of
electricity, water or other utility or energy.

ALTERATIONS.

        14.1 Tenant will make no alterations in, or additions to, the Premises
without obtaining the prior written consent of Landlord. Landlord may impose
such conditions on its consent as Landlord deems appropriate.

TENANT REPAIR.

        15.1 If any of the elevators, or other apparatus, or elements of the
Building used for the purpose of climate control or operating the elevators, or
if the water pipes, drainage pipes, electric lighting or the room or outside
walls of the Building or parking facilities of Landlord become damaged or
destroyed through the negligence, carelessness or misuse of Tenant, its agents,
employees, or anyone permitted by Tenant to be in the Building, then the cost
of the necessary repairs, replacements or alterations shall be borne by Tenant,
who shall pay the same on demand to Landlord as Additional Rent.

        15.2 Tenant shall keep the Premises in as good order, condition and
repair as when they were entered upon, loss by fire (unless caused by the
negligence of Tenant, its agents, employees or invitees), accident or ordinary
wear and tear excepted. If Tenant fails to keep the Premises in such good
order, condition and repair as required hereunder to the reasonable
satisfaction of Landlord, as soon as reasonably possible after written demand,
Landlord may restore the Premises to such good order and condition and make
such repairs without liability to Landlord and upon completion thereof, Tenant
shall pay to Landlord, as additional rent, upon demand, the cost of restoring
the Premises to such good order and condition as the making of such repairs.

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TRADE AND OTHER FIXTURES.

        16.1 Any and all installations, alterations, changes, additions,
partitions, fixtures, or improvements to the Premises, other than Tenant's
trade fixtures, including, but not limiting the generality of the foregoing,
all fixtures, lighting fixtures, cooling equipment, built-ins, partitions, wall
coverings, tile, linoleum and power wiring shall be the property of the
Landlord upon any termination of this Lease. Notwithstanding anything herein
contained, Landlord shall be under no obligation to repair, maintain, or insure
such installation, changes, alterations, additions, partitions, fixtures, or
improvements made or installed by or on behalf of Tenant. Upon termination of
the Lease, or within thirty (30) days thereof, Landlord, at its sole
discretion, may remove all installations or alterations made by or on behalf of
Tenant pursuant to this Article and Landlord may elect to have the Premises
restored to their original condition, ordinary wear and tear expected. Tenant
agrees to pay to Landlord all costs and expenses of such removal and
restorations within five (5) days of receipt from Landlord of notice of said
expenses or costs incurred. The obligation to pay such expenses or costs shall
survive the termination of the Lease.

LIEN PROTECTION.

        17.1 Tenant agrees that at no time during the term of this Lease will
Tenant permit a lien or encumbrance of any kind or nature to come into
existence against the Premises or the Building. If at any time a lien or
encumbrance is filed against the Premises, Tenant agrees it will deposit with
Landlord in cash an amount equal to one hundred fifty percent (150%) of the
amount of the lien and shall leave the same on deposit with Landlord until said
lien is discharged. Landlord shall have the option, but not the responsibility,
to satisfy any such lien or encumbrance, and if Landlord pays any such lien or
encumbrance, Tenant shall pay to Landlord as Additional Rent, the amount of
such payment on the next following day when monthly installments of rent are
due hereunder. If Landlord satisfies any such lien or encumbrance, it may make
such payment without inquiry into the accuracy of the amount of such lien or
encumbrance or the validity of the lien or encumbrance.

INSURANCE.

        18.1 In addition to Tenant's obligation to pay its Pro Rata Share of
the cost of insurance pursuant to Article 6 hereof, Tenant shall pay all
premiums due in connection with the insurance Tenant is required to carry under
the terms of this Lease and shall furnish Landlord with copies of Certificate
of Insurance evidencing the payment thereof. All such policies shall be written
with companies satisfactory to Landlord and authorized to do business in the
State of Colorado. Landlord shall not unreasonably withhold its consent to the
placement of insurance with companies proposed by Tenant, so long as the
proposed companies have a rating of at least B XIII in the "Best's Key Rating
Guide". 

        18.2 During the term of this Lease, Tenant shall keep the Premises
insured for the protection of Landlord and Landlord's assignees who shall be so
named as additional insured in any such policies, by maintaining bodily injury
and property damage insurance including blanket contractual liability broad
form property damage, personal injury, completed operations products commercial
general liability form. Such insurance shall be written on a combined single
limit basis in an amount of not less than One Million Dollars ($1,000,000.00)
and such higher limits as the Landlord may reasonably require from time to
time. Tenant shall maintain, at its sole cost and expense, any other form or
forms of insurance in amounts and for such risks as Landlord may reasonably
require from time to time including but not limited to, insurance for the full
replacement cost of Tenant's personal property and fixtures located on the
Premises on an open perils basis insuring against "all risks of direct physical
loss." Workman's Compensation Insurance as required by statute including
employer's liability insurance in the limits of $100,000/$500,000/$100,000. All
policies of insurance required shall name Landlord as additional insured and
Tenant as insureds and provide that the proceeds of such insurance shall be
payable to Landlord and Tenant, as their interests may appear. Tenant shall
deliver to Landlord not more than thirty (30) days after execution of this
Lease and thereafter at least thirty (30) days prior to expiration of such
policy, Certificates of Insurance evidencing the above coverage which shall
expressly provide that at least thirty (30) days prior written notice shall be
given to Landlord in the event of a material alteration or cancellation of the
coverage.

        18.3 If Tenant shall at any time fail, neglect, or refuse to provide
and maintain such insurance, Landlord shall have the option, but shall not be
required, to pay for such insurance and any amounts paid therefore by Landlord
shall be deemed additional rent due Landlord and shall be paid by Tenant to
Landlord at the next rental payment date after any such payment, with interest
thereon at the rate of eighteen percent (18%) per annum at the time that such
insurance is obtained.

        18.4 Tenant agrees to pay any increase in premiums of insurance carried
by Landlord if, in the reasonable determination of Landlord, such increase is
reasonably and directly related or caused by Tenant's use of the Premises.

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WAIVER OF SUBROGATION.

        19.1 The parties shall obtain from their respective property insurance
carriers Waivers of Subrogation against the other party, agents, employees,
and, as to Tenant, invitees. Neither party shall be liable to the other for any
loss or damage caused by fire or any of the risks enumerated in the standard
fire insurance policy with an extended coverage endorsement if such insurance
was obtainable at the time of such loss or damage.

CASUALTY DAMAGE.

        20.1 In the event of fire or other casualty, against which Landlord is
insured, and which is not caused by the negligence of Tenant, Base Rent shall
abate in the proportion that the unusable portion of the Premises as reasonably
determined by Landlord is to the total area of the Premises until the Premises
are rebuilt, and upon receipt by Landlord of such insurance proceeds, Landlord
agrees that it will with reasonable diligence repair the Premises, unless
Tenant is obligated to repair under the terms hereof, or unless this Lease is
terminated as hereinafter provided, subject to the provisions of Article 20.2
and 20.3.

        20.2 If the Premises are damaged or destroyed by any cause whatsoever,
and if, in the reasonable opinion of Landlord, the Premises cannot be rebuilt
or made fit for the purposes of Tenant within one hundred twenty (120) days of
the damage or destruction, Tenant at its option may terminate this Lease upon
30 days notice, or Landlord, instead of rebuilding or making the Premises fit
for Tenant, may at its option terminate this Lease by giving Tenant within
sixty (60) days after such damage and destruction, notice of termination, and
thereupon rent and any other payments for which Tenant is liable under this
Lease shall be apportioned and paid to the date of such damage and Tenant shall
immediately deliver up possession of the Premises to Landlord provided,
however, that those provisions of this Lease which are designated to cover
matters of terminations and thereafter, shall survive the termination hereof.

        20.3 Irrespective of whether the Premises are damaged or destroyed, in
the event that fifty percent (50%) or more of the area in the Building is
damaged or destroyed by any cause whatsoever, and if, in the reasonable opinion
of Landlord, the said area cannot be rebuilt or made fit for the purpose of the
tenants of such space within one hundred eighty (180) days after the damage or
destruction, Tenant at its option may terminate this Lease upon 30 days notice,
or Landlord may at its option terminate this Lease by giving to Tenant within
sixty (60) days after such damage, notice of termination requiring it to vacate
the Premises sixty (60) days after delivery of the notice of termination and
thereupon rent and any other payments shall be apportioned and paid to the date
on which possession is relinquished and Tenant shall deliver up possession of
the Premises to Landlord in accordance with such notice or termination.

EMINENT DOMAIN.

        21.1 If the Premises or a substantial part thereof, shall be taken in
eminent domain, or conveyed under threat of condemnation proceedings, then this
Lease shall forthwith terminate and end upon the taking hereof as if the
original term provided in said Lease expired at the time of such taking. If
only such part or portion of the Premises is taken which would not
substantially and materially interfere with or adversely affect the business of
the Tenant conducted at the Premises, then Landlord, at Landlord's option to be
exercised in writing within thirty (30) days of the taking thereof, may
repair, rebuild or restore the Premises, and this Lease shall continue in
effect. If, however, because of such taking, the Premises should be rendered
untenantable or partially untenantable, then the rent, or a portion thereof,
shall abate until the Premises shall have been restored.

        21.2 In the event that an award is made for taking of such property and
parcels of the Premises or the Building in condemnation proceedings, Landlord
shall be entitled to receive and retain the amounts awarded or paid for such
taking or conveyance; provided, however, that Tenant shall be entitled to
receive and retain such amounts as are specifically awarded to it in such
proceedings because of the taking of its furniture, or fixtures, and its
leasehold improvements which have not become a part of the realty. It is
understood and agreed that any amounts specifically awarded in any such taking
for the damage to the business of Tenant, done on the Premises and awarded to
it as a result of interference with the access to the Premises or for any
other damage to said business and trade done at the Premises shall be the
property of Tenant, provided said award does not reduce the award to Landlord.

        21.3 It is understood and agreed that in the event of the termination
of this Lease as provided under this paragraph, Tenant shall have no claim
against Landlord for the value of any unexpired term of this Lease and no right
or claim to any part of the award made on account thereof.

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INDEMNIFICATION AND WAIVER OF CERTAIN CLAIMS.

        22.1 Tenant hereby agrees to indemnify and hold harmless Landlord, its
subsidiaries, Directors, Officers, Agents, Attorneys and Employees from and
against any and all damage, loss, liability, or expense including, but not
limited to, attorney's fees and legal costs suffered by same directly or by
reason of any claim, suit or judgement brought by or in favor of any person or
persons for damage, loss, or expense due to, but not limited to, bodily injury,
including death resulting anytime therefrom, and property damage sustained by
such person or persons which arises out of, is occasioned by, or is in any way
attributable to the use or occupancy of the Premises and adjacent areas by
Tenant, the acts or omissions of Tenant, its agents, employees or any
contractors brought onto the Premises by Tenant, except that caused by sole
negligence of Landlord or its employees and agents. Such loss or damage shall
include, but not be limited to, any injury or damage to Landlord's personnel
(including death resulting anytime therefrom) or real or personal property.
Tenant agrees that the obligations assumed herein shall survive this Lease.

        22.2 Landlord shall not be liable for any damage or injury including
business interruption, either proximate or remote, occurring through or caused
by the carelessness, negligence or improper conduct on the part of any
co-Tenant or anyone other than Landlord, or for any damage to person or
property resulting from any condition of the Premises or other cause including,
but not limited to damage occasioned by defective electric wiring, breaking or
stoppage of plumbing or sewer, whether said breakage or stoppage resulted from
freezing or otherwise, not resulting from the negligence of Landlord. Tenant
shall give Landlord prompt notice of any defects in the Premises, except that
which results from Landlord's negligence.

RIGHT OF ENTRY.

        23.1 Landlord may, upon reasonable prior notice to Tenant, exhibit the
Premises to prospective tenants during the last twelve (12) months of the term,
and to any prospective purchaser, mortgagee, or assignee of any mortgage on the
property and to others having a legitimate interest at any time in the event of
an emergency, and otherwise at reasonable times, to take any and all measures,
including inspections, repairs, alterations, additions and improvements to the
Premises or the Building, as may be necessary or desirable for the safety,
protection, or the preservation of the Premises of the Building of the
Landlord's possessive interest therein, or as may be necessary or desirable in
the operation or improvement of the Building or in order to comply with all
laws, orders, and requirements of governmental or other authority. Tenant,
pursuant to this Article 23, hereby waives any claim for damages for any injury
or inconvenience to or interference with Tenant's business, occupancy or quiet
enjoyment of the Premises.

SURRENDER OF PREMISES.

        24.1 Tenant agrees to deliver, at the expiration of the Term hereof, or
earlier termination, the Premises in good repair and in a state of broom
cleanliness, subject to ordinary wear and tear.

DEFAULT BY TENANT.

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

        25.2 Failure by Tenant to pay when due any payment of rent, taxes, or
any other sum required to be paid by Tenant hereunder and such failure to pay
continues for a period of five (5) days from the date that such sum became due
and payable;

        25.3 Vacation or abandonment of the Premises without the prior written
consent of Landlord;

        25.4 Failure of Tenant to perform any one or more of its covenants and
agreements under this Lease within ten (10) days after written notice to Tenant
specifying the duties or covenants Tenant has failed to perform; provided,
however, that Tenant shall not be deemed to be in default under this Article if
Tenant shall, within said ten-day period, commence the cure of such default and
diligently prosecute the same to completion.

        25.5 If Tenant or any guarantor of Tenant's obligations under this
Lease shall file a voluntary petition in bankruptcy or shall be adjudicated
bankrupt or insolvent; or shall take the benefit of any relevant legislation
that may be enforced for bankrupt or insolvent debtors; or shall file any
petition or answer seeking any reorganization, arrangement, composition,
readjustment, liquidation, dissolution or similar relief for statute, law, or
regulation; or if any proceeding shall be taken by Tenant or any Guarantor
hereof under and relevant bankruptcy act in force in any jurisdiction available
to Tenant or any Guarantor; or if Tenant or any Guarantor hereof shall seek,
consent, or acquiesce in the 

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appointment of any trustee, receiver or liquidator of Tenant or any Guarantor
of all or any substantial part of his properties or of the Premises, or shall
make any general assignment for the benefit of creditors; or if petition shall
be filed against Tenant or any Guarantor seeking any reorganization,
arrangement, composition, readjustment, liquidation, dissolution or similar
relief under any present or future federal, state or other statute, law or
regulation and shall remain undismissed for an aggregate of sixty (60) days; or
if any trustee, receiver, or liquidator of Tenant or any Guarantor hereof or of
all or any substantial part of its properties or of the Premises shall be
appointed without the consent of acquiescence of Tenant or any Guarantor and
such appointment shall remain unvacated for an aggregate of sixty (60) days.

REMEDIES TO LANDLORD.

        26.1 All rights and remedies of Landlord enumerated herein shall be
cumulative, and none shall exclude any other right or remedy allowed by law. In
addition to other remedies in this Lease provided, the Landlord shall be
entitled to the restraint by injunction of the violation or attempted violation
of any of the covenants, agreements, or conditions of this Lease.

        26.2 Landlord shall have the right, as its election, in the event of
default by Tenant and upon giving prior written notice if required in Article
25.3 herein, to:

             26.2.1 Institute suit against Tenant to collect each installment
of rent or other sum as it becomes due or to enforce any obligation under this 
Lease;

             26.2.2 Re-enter and take possession of the Premises and all
personal property therein and remove Tenant and Tenant's agents and employees
therefrom, and either (i) terminate this Lease and sue Tenant for damages or
breach and default under the Lease; or (ii) without terminating the Lease,
relet, assign, or sublet the Premises and personal property as the agent and
for the account of Tenant in the name of Tenant or otherwise on such terms and
conditions and for such rent as Landlord may deem best, and collect (a) the
rent therefrom, provided Landlord shall, in no way, be responsible or liable
for any failure to collect any rent due upon any such re-letting, and (b) an
amount equal to the then present value of the Base Rent and Additional Rent
provided in this Lease for the remainder of the Lease term, less the present
rental value of the Premises for the remainder of the term. In so acting,
Landlord shall not be deemed to have trespassed in any manner, nor shall
Landlord's actions be construed to be a waiver or relinquishment of any of
Landlords rights or remedies. In this event, the rents received on any such
re-letting shall be applied first to the expenses of re-letting and collecting
including, without limitation, all repossession costs, attorney's fees, court
costs, broker's commissions, alteration costs, and expenses of preparing the
Premises for re-letting, and thereafter for payment of the rent and any other
amounts payable to Tenant to Landlord. If the sum realized shall not be
sufficient to pay such rent and other charges, Tenant agrees to pay Landlord
within five (5) days after demand any such deficiency as it accrues.

        26.3 In the event Landlord elects to re-enter or take possession of the
Premises, Tenant agrees to quit and peaceably surrender the Premises to
Landlord, and Landlord may enter upon and re-enter the Premises and possess and
repossess itself thereof, by force, summary proceedings, ejectment or
otherwise, and may dispossess and remove Tenant and may have, hold, and enjoy
the Premises and the right to receive all rental income of and from the same.
No such re-entry and taking of possession by Landlord shall be construed as an
election on Landlord's part to terminate or surrender this Lease unless
Landlord gives notice to Tenant specifically terminating the Lease, unless a
written notice of such intention is served on Tenant, notwithstanding the
service of Demand for the Payment of Rent and Possession, and Landlord and
Tenant expressly agree that the service of posting of such demand will not
constitute an election on the part of the Landlord to terminate this Lease.

        26.4 If Landlord elects to terminate this Lease in accordance with the
provisions herein, Landlord shall be entitled to recover as damages attorneys'
fees and costs, the cost of removing Tenant, all costs of refurbishing and
repairing the Premises for re-letting, all sums due Landlord by Tenant.

LANDLORD'S RIGHT TO CURE TENANT'S DEFAULT.

        27.1 If Tenant shall default in the performance of any covenant or
provision of this Lease to be performed on Tenant's part, Landlord may, after
fifteen (15) days written notice to Tenant, or without notice if in Landlord's
option an emergency exists, perform the same for the account and at the expense
of Tenant. If Landlord shall incur any expense, including reasonable attorney's
fees, in instituting, prosecuting, or defending any action of Tenant, Tenant
shall reimburse Landlord for the amount of such expense with interest at the 
rate of eighteen percent (18%) per annum from the date of Landlord's advance 
or advances therefore. Should Tenant, pursuant to this Lease, become obligated 
to reimburse or otherwise pay Landlord one or more sums of money pursuant to 
this Article 27, the amount thereof

                                       8
<PAGE>   9
shall by paid by Tenant to Landlord within two (2) days of Landlord's written
demand thereof, and if Tenant fails to make such payment, such failure shall be
deemed an event of default as set forth is Article 25 hereof. The provisions
hereof shall survive the termination of this Lease. The provisions hereof shall
neither impose a duty on Landlord nor excuse any failure on Tenant's part to
perform or observe any covenant or condition in this Lease contained on
Tenant's part to be performed or observed.

ASSIGNMENT AND SUBLEASE.

        28.1 Tenant shall not voluntarily or by operation of law assign,
license, transfer, mortgage or otherwise transfer or encumber all or any part
of Tenant's interest in this Lease or in the Premises, shall not sell or
otherwise transfer more than 50% or the value of the assets of Tenant, and
shall not sublet or license all or any part of the Premises, without the prior
written consent of Landlord such consent shall not be unreasonably withheld in
each instance, and any attempted assignment, sale, transfer, mortgage,
encumbrance or subletting without such consent shall be wholly void. Without in
any way limiting Landlord's right to refuse to give consent for any other
reason or reasons, Landlord reserves the right to refuse to give such consent
if in Landlord's reasonable discretion and opinion the quality of business
operation of the Building is or may be in any way adversely affected during the
term of the Lease.

        28.2 No subletting or assignment, even with the consent of Landlord,
shall relieve Tenant of its obligation to pay the Base Rent and Additional Rent
and to perform all of the 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 subletting, assignment, or other
transfer. Consent to one assignment, subletting or other transfer shall not be
deemed to constitute consent to any subsequent assignment, subletting or other
transfer. 

SUBORDINATION, ESTOPPEL LETTER AND ATTORNMENT.

        29.1 This Lease is subject and subordinate to all first mortgages or
first deeds of trust which now or hereafter may affect the Premises or the
building, and Tenant shall execute and deliver upon demand of Landlord any and
all instruments subordinating this Lease, in the manner requested by Landlord,
to any new or existing mortgage or deed of trust. In the event that Tenant's
interest is subordinated, said mortgagee shall agree that it shall not disturb
Tenant's possession, provided that Tenant is not in default under the terms and
condition of this Lease. Further, Tenant shall at any time and from time to
time, upon not less than five (5) days' prior written notice from Landlord,
execute, acknowledge, and deliver to Landlord a statement in writing certifying
that this Lease is unmodified and in full force and effect (or, if modified,
stating the nature of such modification and certifying that this Lease as so
modified, is in full force and effect) and the dates to which rent and other
charges are paid in advance, in any, and acknowledging that there are not, to
Tenant's knowledge, any uncured defaults on the part of the Landlord hereunder,
or specifying such defaults, if any are claimed, and certifying as to such
other matters Landlord may reasonably request.

        29.2 In the event that Landlord or its principal sells, conveys,
transfers or grants the Building or the Premises to any person, firm,
corporation, company, or entity during the term hereby demised, Tenant agrees
to attorn to such new owner, and Landlord and its principal shall be released
from performance hereunder.

QUIET ENJOYMENT.

        30.1 So long as the Tenant shall observe and perform the covenants and
agreements binding on it hereunder, the Tenant shall, at all times during the
term herein granted, peacefully and quietly have and enjoy possession of the
Premises without any encumbrance or hindrance by, from, or through Landlord.

        30.2 To the best of Landlord's knowledge, Suites 200 and 310 (totaling
7,992 rsf) meet building codes. Tenant warrants that the remaining Premises
(Suites 210 and 100 totaling 19,283 rsf) meet building codes. The Landlord
shall not require the Tenant to provide additional funds to meet any building
code or federal requirements other than those provided for in Paragraph 6.1.

HOLDING OVER.

        31.1 Unless otherwise agreed to in writing by Landlord and Tenant, if
Tenant retains possession of the Premises or any part thereof after the
termination of the term, such holding over shall be deemed to be tenancy from
month-to-month at a monthly rental equal to one hundred fifty percent (150%) of
the monthly installment of Base Rent due under the terms of the Lease from the
month next preceding the commencement of the holdover period, and Tenant shall
remain liable for all other payments provided for hereunder, and such holding
over shall be subject to all of the other terms and conditions of the Lease. In
addition to rent, Tenant agrees to pay the Landlord for all damages,

                                       9
<PAGE>   10
consequential as well as direct, sustained by Landlord resulting or arising
from tenant's possession. No such holding over shall be deemed to constitute a
renewal or extension of the term of the Lease.

        32.1  Intentionally omitted.

NOTICES.

        33.1  Any notice required or permitted hereunder or which any part
elects to give shall be in writing and delivered either personally to the other
party or the other party's authorized agent set forth below (or as changed by
written notice), or by depositing such notice in the United States Certified
Mail, Return Receipt Requested, postage fully prepaid, to the person at the
address set forth below, or to such other address as either party may later
designate in writing:

        Landlord:       Sheridan Realty Partners, L.P.
                        1800 Glenarm Place, Suite 200
                        Denver, CO 80202

        Tenant:         Abacus Direct
                        8774 Yates Drive, Suite 200
                        Westminster, CO 80030

DEFINITION OF LANDLORD.

        34.1  The term "Landlord" as used in this Lease, so far as covenants or
agreements on the part of the Landlord are concerned, shall be limited to mean
and include only the owner or owners of the Landlord's interest in this Lease
at the time in question, and in the event of any transfer or transfers of such
interest, the Landlord herein named (and in case of any subsequent transfer,
then transferor) shall be automatically freed and relieved from and after the
date of such transfer of all liability as respects the performance of any
covenants or agreements on the part of the Landlord contained in this Lease
thereafter to be performed.

WAIVER.

        35.1  No waiver or any breach of any one of the agreements, terms,
conditions, or covenants of this Lease by Landlord or Tenant shall be deemed to
imply or constitute a waiver of any other agreement, term, condition, or
covenant of this Lease. The failure of either party to insist on strict
performance of any agreement, term, condition, or covenant, herein set forth,
shall not constitute or be construed as a waiver of the rights of either or of
the other thereafter to enforce any other default of such agreement, term,
condition, or covenant; neither shall such failure to insist upon strict
performance be deemed sufficient grounds to enable either party hereto to
forego or subvert or otherwise disregard any other agreement term, condition,
or covenant of the Lease.

SUCCESSOR.

        36.1  All of the agreements, terms, conditions, and covenants set forth
in this Lease shall inure to the benefit of and be binding upon the heirs legal
representatives, successors, executors, and assigns of the parties, except that
no assignment or subletting by Tenant in violation of the provisions of this
Lease shall vest any rights in the assignee or in

                                       10
<PAGE>   11
CORPORATE RESOLUTION.

        37.1 If a corporation executes this Lease as a Tenant, Tenant shall
promptly provide Landlord with certified corporate resolutions attesting to the
authority of the officers to execute this Lease on behalf of such corporation.

ENFORCEMENT OF LEASE - ATTORNEY'S FEES.

        38.1 In the event that either Landlord or Tenant commences any action
for the enforcement of or arising out of a breach of the terms of this Lease,
then the party who is awarded judgment in such action shall be awarded, in
addition to any other award made thereof, an amount to be fixed by the Court
for court costs and reasonable attorney's fees.

INVALIDITY OF PARTICULAR PROVISIONS.

        39.1 If any clause or provision of this Lease is or becomes illegal,
invalid, or unenforceable because of present or future laws or any rule,
decision, or regulation of any governmental body or entity, the intention of
the parties hereto is that the remaining parts or provisions of this Lease
shall not be affected thereby.

ARTICLE HEADINGS.

        40.1 The article headings throughout this Lease are for convenience and
reference only, and the words contained therein shall in no way be held to
explain, modify, amplify or aid in the interpretation, construction, or
meanings of the provisions of this Lease.

GOVERNING LAW.

        41.1 This Lease shall be deemed to have been made and shall be
construed in accordance with the laws of the State of Colorado.

TIME.

        42.1 Time is of the essence of this Agreement.

RECORDING OF LEASE.

        43.1 This lease shall not be recorded by either Landlord or Tenant
without the prior written consent of the other.

EXCULPATION.

        44.1 Not withstanding anything to the contrary contained herein,
Landlord's liability under this Lease shall be limited strictly to its interest
in the Building.

RULES AND REGULATIONS.

        45.1 Tenant agrees that Tenant, Tenant's employees and agents or any
other permitted by Tenant to occupy or enter the Premises shall abide by the
rules and regulations attached hereto as Exhibit "D" and made a part hereof.
Landlord shall have the right to amend, modify or change in any way the rules
and regulations provided that said amendments are not inconsistent with the
terms of this Lease, and Tenant agrees to comply with all such rules and
regulations upon notice from Landlord thereof. A breach of any of such Rules
and Regulations shall be deemed a default under the Lease and Landlord shall
have all remedies as set forth in Article 26.

PARKING.

        46.1 Tenant and its employees and invitees shall have the non-exclusive
privilege to use non-reserved parking spaces in common with other tenants of
Landlord pursuant to the rules and regulations relating to parking adopted by
Landlord from time to time. Tenant agrees not to overburden the parking
facilities and agrees to cooperate with Landlord and other tenants in its
discretion to determine whether parking facilities are becoming crowded and, in
such event, to allocate specific parking spaces among Tenant and other tenants
or to take my other steps necessary to correct such condition.

<PAGE>   12
SIGNS.

        47.1 Tenant shall not install any signs, window lettering or other
advertisement in, upon or around the Premises without the prior written
approval of Landlord. Landlord shall have absolute discretion in approving or
disapproving any proposed sign. Tenant shall have the right to the existing
line on the building lobby directory, which the landlord shall provide.

BROKERS.

        48.1 Tenant represents and warrants that it has dealt with no broker,
agent or other person in connection with this transaction and that no broker,
agent or other person brought this transaction other than Sheridan Properties,
L.L.C. and Tenant agrees to indemnify and hold Landlord harmless from and
against any claims by any broker, agent, or other person claiming a commission
or other form of compensation by virtue of having dealt with Tenant with
regards to this Leasing transaction. The provision of this Article shall
survive the termination of the Lease.

ENTIRE AGREEMENT.

        49.1 The within Lease constitutes the entire agreement of the parties
hereto. No representations, promises, terms, conditions, obligations or
warranties whatsoever referring to the subject matters hereof, other than those
expressly set forth herein, shall be of any binding legal force or effect
whatsoever. No modification, change, or alteration of this Lease shall be any
legal force or effect whatsoever unless in writing, signed by all parties 
hereto.

ATTACHMENTS.
       
        Addendum
        Exhibit A - Legal Description and Premises
        Exhibit B - Tenant Finish Allowance
        Exhibit C - Plans and Specifications
        Exhibit D - Rules and Regulations
        Exhibit E - Right of First Refusal
        Exhibit F - Option to Extend
        Exhibit G - Option to Renew
        Exhibit H - Signage

In witness whereof, the Parties hereto execute this Lease the day and year
first above written.

                                LANDLORD:

                                Sheridan Realty Partners, L.P.
                                By: Sheridan Realty Corp., General Partner

                                By:    /s/ LAURIE M. ADAMS
                                    ------------------------------------------
                                    Laurie M. Adams

                                Title:          Vice President
                        
                                Address:        1800 Glenarm Place, Suite 1200
                                                Denver, CO 80202

                                TENANT:

                                Abacus Direct

                                By:            /s/ KARL FRIEDMAN
                                   -------------------------------------------

                                Title:          Senior V.P. Finance
                                      ----------------------------------------
                                Address:        8774 Yates Drive, Suite 200
                                                Westminster, CO 80030
<PAGE>   13
                                   EXHIBIT A

                               Legal Description

Lot 4,
Block 1,
First Amended Plat of SHERIDAN PARK, Filing #4,
County of Adams,
State of Colorado.

                                      1st
                                   FLOOR PLAN


                                  [BLUEPRINT]


                                      A-1
<PAGE>   14
                                   EXHIBIT A

                               Legal Description

Lot 4,
Block 1,
First Amended Plat of SHERIDAN PARK, Filing #4,
County of Adams,
State of Colorado.

                                      2nd
                                   FLOOR PLAN


                                  [BLUEPRINT]


                                      A-2


<PAGE>   15
                                   EXHIBIT A

                               Legal Description

Lot 4,
Block 1,
First Amended Plat of SHERIDAN PARK, Filing #4,
County of Adams,
State of Colorado.

                                      3rd
                                   FLOOR PLAN


                                  [BLUEPRINT]


                                      A-3

<PAGE>   16
                                   EXHIBIT B

                            Tenant Finish Allowances

Landlord shall provide $28,000.00 towards Tenant's finish. Tenant has elected
to apply this tenant finish as a rent reduction in the first year covering the
period 1/1/91 through 9/30/97.


                                      B-1
<PAGE>   17
                                   EXHIBIT C

                            Plans and Specifications

                            Wall and door not added

                                  [BLUEPRINT]


                                      C-1
<PAGE>   18
                                   EXHIBIT D

                             Rules and Regulations



1.      The sidewalks, entrances, halls and corridors of the Building shall be
        kept clear of debris and shall not be obstructed or used for storage or
        as a waiting or lounging place by Tenant, its agents, servants,
        employees, invitees licenses and visitors.

2.      Landlord reserves the right to refuse admittance to the Building at any
        time other than between the hours of 7:00 a.m. through 6:00 p.m. Monday
        through Friday and Saturdays 8:00 a.m. through 1:00 p.m., except for
        holidays, to any person not producing both a key to the Leased Premises
        and/or a pass issued by Landlord. In case of invasion, riot, public
        excitement or other commotions, Landlord also reserves the right to
        prevent access to the Building during the continuance of same. Landlord
        shall in no case be liable for damages for the admission or exclusion of
        any person to or from the Building.

3.      Landlord will furnish to each Tenant existing new keys to each door lock
        in the Leased Premises and existing building access cards, and Landlord
        may make a reasonable charge for any additional keys and/or access cards
        requested by Tenant. Tenant shall not alter any lock, or install new or
        additional locks or bolts, on any door without the prior written consent
        of Landlord. If a lock alteration or installment is made, the new lock
        must accept the master key for the building or Tenant must provide
        Landlord with duplicate pass keys for all such locks and bolts. Each
        Tenant, upon the expiration or termination of its tenancy, shall deliver
        to Landlord all keys and access cards in any such Tenant's possession
        for all locks and bolts to the building.

4.      In order that the Building may be kept in a state of cleanliness, each
        Tenant shall during the term of each respective Lease, permit Landlord's
        employees (or Landlord's agent's employees) to take care of and clean
        the Leased Premises. No Tenant shall cause any unnecessary labor by
        reason of such Tenant's carelessness or indifference in the preservation
        of good order and cleanliness of the Leased Premises. Tenant will see
        that (a) the windows are closed, (b) the doors are securely locked, and
        (c) all water faucets and other utilities are shut off (so as to
        prevent waste or damage), each day after leaving the Leased Premises.
        In the event Tenant must dispose of crates, boxes, etc., which will not
        fit into office waste paper baskets, it will be the responsibility of
        Tenant to dispose of same.

5.      Landlord reserves the right to prescribe the date, time, method, and
        conditions that any personal property, equipment, trade fixtures,
        merchandise and other similar items shall be delivered to or removed
        from the Building. No iron safe or other heavy or bulky object shall be
        delivered to or removed from the Building, except by experienced safe
        men, movers or riggers approved in writing by Landlord. All damage done
        to the Building by the delivery or removal of such items, or by reason
        of their presence in the Building, shall be paid to Landlord, upon
        demand, by Tenant, through or under whom such damage was done. There
        shall not be used in any space or in the public halls of the Building
        either by Tenant or by jobbers or others in the delivery or receipt of
        merchandise, any hand-trucks, except those equipped with rubber tires.

6.      The walls, partitions, skylights, windows, doors and transoms that
        reflect or admit light into passageways or into any other part of the
        Building shall not be covered or obstructed by any Tenant.

7.      The toilet-rooms, toilets, urinals, wash bowls and water apparatus shall
        not be used for any purpose other than for those for which they were
        constructed or installed, and no sweeping, rubbish, chemicals or other
        unsuitable substances shall be thrown or placed therein. The expense of
        any breakage, stoppage or damage resulting from violations of this rule
        by Tenant or by Tenant's agents, servants, employees, invitees,
        licensees or visitors, shall be borne by Tenant.

8.      No sign, name, place card advertisement, or notice visible from the
        exterior of any Leased Premises, shall be inscribed, painted or affixed
        by any tenant on any part of the Building or Project without the prior
        written approval of the Landlord. A directory containing the names of
        all tenants of the Building shall be provided by Landlord at an
        appropriate place on the first floor of the Building.

                                      D-1
<PAGE>   19
9.      No signaling, telegraphic, or telephonic instruments of devices, shall
        be installed in connection with any Leased Premises without the prior
        written approval of Landlord. Such installations, and the boring or
        cutting for wires, shall be made at the sole cost and expense of Tenant
        and under the control and direction of Landlord, other than phone
        outlets normally provided by Landlord as part of the Lease. Landlord
        retains in all cases the right to require (a) the installation and use
        of such electrical projection devices that prevent the transmission of
        excessive currents of electricity into or through the  Building, (b)
        the changing of the wires and of their installation and arrangements
        underground or otherwise as Landlord may direct, and (c) compliance on
        the part of all using or seeking access to such wires with such rules
        as Landlord may establish relating thereto. All such wires used by
        Tenant must be clearly tagged at the distribution boards and junction
        boxes and elsewhere in the Building, with the number of the Leased
        Premises to which said wires lead, the purpose for which said wires are
        used, and the name of the company operating same.
        
10.     Tenant, its agents, servants, employees, shall not (a) go upon the roof
        of the Building, (b) use any additional method of heating or air
        conditioning in the Leased Premises, (c) sweep or throw any dirt or
        other substances from the Leased Premises into any of the halls or
        corridors of the Building, (d) bring in or keep in or about the Leased
        Premises any vehicles or animals of any kind, (e) install any radio or
        television antennae or any other device or item on the roof, exterior
        walls, windows or window sills of the Building, (f) place objects
        against glass partitions, doors or window which would be unsightly from
        the interior or exterior of the building, or (g) use any portion of the
        Leased Premises: (i) for the storage of merchandise for sale to the
        general public, (ii) for lodging or sleeping, (iii) for cooking (except
        that the use by any Tenant of Underwriter's Laboratory equipment for
        brewing coffee, tea and similar beverages for the use of by Tenant of a
        similarly approved microwave oven shall be permitted, provided that such
        use is in compliance with law), or (iv) for the selling or display of
        any goods, items or merchandise, either at wholesale or retail. Tenant,
        its agents, servants and employees, invitees, licensees, or visitors
        shall not permit the operation of any musical or sound producing
        instruments or device which may be heard outside the Leased Premises,
        Building or garage facility, or which may emit electrical waives which
        will impair radio or television broadcast or reception from or into the
        Building.

11.     Tenant shall not store or use in any Leased Premises any (a) ether,
        naphtha, phosphorous, benzol, gasoline, benzine, petroleum, crude or
        refined earth or coal oils, flashlight power, kerosene or camphene, (b)
        any other flammable, combustible, explosive or illuminative fluid, gas
        or material of any kind, or (c) any other fluid, gas or material of any
        kind having an offensive odor.

12.     No canvassing, soliciting, distribution of hand bills or other written
        material, or pedaling shall be permitted in the Building, Tenant shall
        cooperate with Landlord in prevention and elimination of same.

13.     Tenant shall give Landlord prompt notice of all accidents to, or defects
        in, air conditioning equipment, plumbing, electrical facilities, or any
        part of the appurtenances of the Leased Premises.
     
14.     If the Leased Premises demised to Tenant becomes infested with vermin,
        Tenant, at its sole cost and expense, shall cause the Leased Premises to
        be exterminated from time to time to the satisfaction of Landlord and
        shall employ such exterminators as shall be approved by Landlord.

15.     The landscaped grounds adjacent to the Building shall be used for the
        enjoyment of Tenant, its agents, servants and employees, without
        restriction so long as such parties conduct themselves in a manner so as
        not to disturb, destroy, or litter said grounds. All parties using the
        grounds shall comply will all laws, ordinances, and rules and
        regulations of federal, state and local authorities.

16.     Landlord reserves the right to allocate specific parking spaces among
        Tenant and other tenants, police the parking areas, and have vehicles
        towed at the owner's expense. If Tenant, its employees, contractors or
        invitees are deemed by Landlord to be contributing to overcrowding of
        the parking areas, Landlord shall be entitled to charge the portion of
        the cost thereof to Tenant which Landlord shall reasonably determine to
        be caused by the failure of Tenant, its employees, contractors, agents
        and invitees to use the parking in compliance with the Lease and these
        Rules and Regulations.


                                      D-2
     
<PAGE>   20
        Landlord may, at its own discretion, change the location and nature of
        the reserved and non-reserved parking spaces available to Tenant, its
        employees and invitees, provided that after such change, there shall be
        available to Tenant and its employees and invitees approximately the
        same number of spaces as available before the change, which spaces shall
        be approximately located in the Building.

17.     Landlord reserves the right to make reasonable amendments,
        modifications, and additions to the rules and regulations heretofore set
        forth, and to make additional reasonable rules and regulations, as in
        Landlord's sole judgement may from time to time be needed for the
        safety, care, cleanliness, and preservation of good order of the
        Building.


                                      D-3
<PAGE>   21
                                  EXHIBIT E


                             RIGHT OF FIRST REFUSAL


Provided Tenant is not in default under any of the terms of this Lease, Tenant
will have a Right of First Refusal on any unoccupied or unleased space in
Sheridan Park 1. Should another party present an offer to lease to Landlord
that would be acceptable to Landlord, Landlord will present said offer to
Tenant. Tenant must respond to Landlord within three (3) business days of
receipt of notice of Tenant's intent to exercise said Right of First Refusal.
Should Tenant not respond within said three business days, Landlord will be
free to lease the space to that party and the Right of First Refusal will
automatically cancel if said other party signs a lease.

If Tenant doesn't exercise its Right of First Refusal at any time, it shall
retain such right for any future options on that space subject to its Right of
First Refusal, excluding renewals on existing tenants.

As of the date of this Lease, no other Right of First Refusal exists in the
Building. Tenant's Right of First Refusal with this Lease is equal to or
superior to Tenant's rights under the prior Lease dated January 20, 1992 and
those rights will not be lessened (except as in the case of Tenant's default)
during the term of this Lease and Options (if exercised).















                                      E-1
<PAGE>   22
                                  EXHIBIT F



                                OPTION TO EXTEND



Provided Tenant is not in default under any of the terms of this Lease. Tenant
shall have a two (2) year option to extend this Lease at the Base Rent of
$13.50/rsf plus an increase based on the Denver CPI increase from 6/30/96 to
6/30/99. All other terms and conditions of the Lease will remain the same.




















                                      F-1
<PAGE>   23
                                  EXHIBIT G


                                OPTION TO RENEW


Provided Tenant is not in default under any of the terms of this Lease. Tenant
shall have two (2) three (3) year Options to Renew at 90% of the then current
market rates. To exercise this option Tenant must provide written notice to
Landlord at lease six (6) months prior to the expiration of the current term.




















                                      G-1
<PAGE>   24
                                  EXHIBIT H


                                    SIGNAGE


Tenant will be allowed Building Signage with Landlord's prior written approval
at Tenant's sole cost and expense, subject to applicable Westminster codes.
Tenant shall be responsible for repairing any damage to the building if the
sign is removed.





















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