<PAGE>

                                       LEASE

                    THE PRUDENTIAL INSURANCE COMPANY OF AMERICA,
                              A NEW JERSEY CORPORATION
                                   (AS LANDLORD)

                                         AND

                           FIRSTWORLD COMMUNICATIONS, INC.,
                               A DELAWARE CORPORATION
                                    (AS TENANT)

<PAGE>


                                       LEASE

                    THE PRUDENTIAL INSURANCE COMPANY OF AMERICA,
                              a New Jersey Corporation
                                   (as Landlord)

                                         and

                           FIRSTWORLD COMMUNICATIONS, INC.,
                               a Delaware Corporation
                                    (as Tenant)

<TABLE>
<S>                                                                      <C>
  1.    PREMISES . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
  2.    TERM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
  3.    RENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
  4.    COMPLETION OR REMODELING OF THE PREMISES . . . . . . . . . . . . .2
  5.    OPERATING EXPENSES AND TAXES . . . . . . . . . . . . . . . . . . .2
  6.    SERVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
  7.    QUIET ENJOYMENT  . . . . . . . . . . . . . . . . . . . . . . . . 11
  8.    DEPOSIT  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
  9.    CHARACTER OF OCCUPANCY . . . . . . . . . . . . . . . . . . . . . 11
  10.   MAINTENANCE, ALTERATIONS AND REENTRY BY LANDLORD . . . . . . . . 12
  11.   ALTERATIONS AND REPAIRS BY TENANT  . . . . . . . . . . . . . . . 12
  12.   MECHANICS' LIENS . . . . . . . . . . . . . . . . . . . . . . . . 14
  13.   SUBLETTING AND ASSIGNMENT  . . . . . . . . . . . . . . . . . . . 14
  14.   DAMAGE TO PROPERTY . . . . . . . . . . . . . . . . . . . . . . . 17
  15.   INDEMNITY TO LANDLORD  . . . . . . . . . . . . . . . . . . . . . 17
  16.   SURRENDER AND NOTICE . . . . . . . . . . . . . . . . . . . . . . 18
  17.   INSURANCE, CASUALTY, AND RESTORATION OF PREMISES . . . . . . . . 18
  18.   CONDEMNATION . . . . . . . . . . . . . . . . . . . . . . . . . . 19
  19.   DEFAULT BY TENANT  . . . . . . . . . . . . . . . . . . . . . . . 20
  20.   DEFAULT BY LANDLORD  . . . . . . . . . . . . . . . . . . . . . . 24

</TABLE>

<PAGE>

<TABLE>
<S>                                                                      <C>
  21.   SUBORDINATION AND ATTORNMENT . . . . . . . . . . . . . . . . . . 24
  22.   REMOVAL OF TENANT'S PROPERTY . . . . . . . . . . . . . . . . . . 25
  23.   HOLDING OVER: TENANCY MONTH-TO-MONTH . . . . . . . . . . . . . . 25
  24.   PAYMENTS AFTER TERMINATION . . . . . . . . . . . . . . . . . . . 25
  25.   STATEMENT OF PERFORMANCE . . . . . . . . . . . . . . . . . . . . 26
  26.   MISCELLANEOUS  . . . . . . . . . . . . . . . . . . . . . . . . . 26
  27.   AUTHORITIES FOR ACTION AND NOTICE  . . . . . . . . . . . . . . . 29
  28.   RULES AND REGULATIONS  . . . . . . . . . . . . . . . . . . . . . 30
  29.   PARKING  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
  30.   SUBSTITUTE PREMISES  . . . . . . . . . . . . . . . . . . . . . . 30
  31.   BROKERAGE  . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
  32.   TIME OF ESSENCE  . . . . . . . . . . . . . . . . . . . . . . . . 30
  33.   OPTION TO EXTEND . . . . . . . . . . . . . . . . . . . . . . . . 30
  34.   SIGNAGE  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
  35.   RIGHT OF FIRST REFUSAL . . . . . . . . . . . . . . . . . . . . . 31
  EXHIBIT A FLOOR PLAN . . . . . . . . . . . . . . . . . . . . . . . . . 34
  EXHIBIT B LEGAL DESCRIPTION  . . . . . . . . . . . . . . . . . . . . . 35
  EXHIBIT C COMMENCEMENT CERTIFICATE . . . . . . . . . . . . . . . . . . 36
  EXHIBIT D RULES AND REGULATIONS  . . . . . . . . . . . . . . . . . . . 37

</TABLE>

                                         -ii-

<PAGE>

                                OFFICE BUILDING LEASE

     THIS LEASE is made this 1st day of December, 1998 by and between THE
PRUDENTIAL INSURANCE COMPANY OF AMERICA, a New Jersey corporation
("Landlord") and FIRSTWORLD COMMUNICATIONS, INC., a Delaware corporation
("Tenant").

                               W I T N E S S E T H:

     1.   PREMISES. In consideration of the payment of rent and the keeping and
performance of the covenants and agreements by Tenant, as hereinafter set forth,
Landlord hereby leases and demises unto Tenant the premises located on the
second floor of the Building known as Suite 208, comprised of approximately
7,108 rentable square feet (hereinafter referred to as the "Premises"), as
depicted on the plat hereto attached as Exhibit A, and being a part of the
building known as Paragon Building, located at 7100 East Belleview Avenue,
Englewood, Colorado (the "Building"), together with a non-exclusive right,
subject to the provisions hereof, to use all appurtenances thereto, including,
but not limited to, any plazas, common areas, or other areas on the real
property (described more particularly on Exhibit B "Real Property") designated
by Landlord for the exclusive or non-exclusive use of the tenants of the
Building. The Building, Real Property, plazas, common areas, other areas, and
appurtenances are hereinafter collectively sometimes called the "Building
Complex."

     2.   TERM. The term of the Lease shall commence at 12:01 a.m. on the
earlier of (i) the 1st day of December, 1998 or (ii) such date as Landlord
delivers possession of the Premises to Tenant and shall terminate at 12:00
midnight on the 30th day of November, 1999 (said term is referred to herein as
the "Primary Lease Term"). The term of the Lease may be extended pursuant to
Paragraph 33 hereof and, if so extended, any references in this Lease to the
"Term" shall include the Extension Term.

     3.   RENT. Tenant shall pay the annual rental (the "Base Rent") for the
Primary Lease Term, payable in monthly installments due on the first day of each
month during the term hereof, as follows:

<TABLE>
<CAPTION>

             TERM            MONTHLY         ANNUAL
             ----            RENTAL          RENTAL
                             ------          ------
        <S>                 <C>            <C>
        December 1, 1998 -  $11,254.33     $135,051.96
        November 30, 1999

</TABLE>

     The Base Rent for the Extension Term shall be as set forth in Paragraph 33
hereof. If the initial or final month of the term of this Lease is less than a
calendar month, Base Rent for such partial month shall be prorated at the rate
of one-thirtieth of the monthly Base Rent for each day. All rents shall be paid
in advance, without notice, set off, abatement, or diminution, at the office

<PAGE>

of Landlord in Englewood, Colorado, or at such place as Landlord from time to
time designates in writing.

     4.   COMPLETION OR REMODELING OF THE PREMISES.

          A. Landlord shall have no obligation for the completion or remodeling
of the Premises, and Tenant shall accept the Premises in their "as is" condition
on the date the Primary Lease Term commences. If Landlord is delayed in
delivering the Premises to Tenant due to the failure of a prior occupant to
vacate the same, then the obligation for the payment of rent and the
commencement of the Primary Lease Term hereof shall be postponed until Landlord
delivers the Premises to Tenant whereupon all of the covenants, conditions, and
agreements contained herein shall be in full force and effect. The postponement
of Tenant's obligation to pay rent and other sums hereunder shall be in full
settlement of all claims which Tenant may otherwise have by reason of such delay
of delivery.

          B. If the commencement of the Primary Lease Term is delayed pursuant
to subparagraph A above, and such commencement date would otherwise occur on
other than the first day of the month, the commencement date of the Primary
Lease Term shall be further delayed until the first day of the following month
and Tenant shall pay proportionate rent at the same monthly rate set forth
herein (also in advance) for such partial month. In the event said commencement
date is so delayed, the expiration of the term hereof shall be extended so that
the Primary Lease Term will continue for the full period set forth in Paragraph
2 hereof. As soon as the Primary Lease Term commences, Landlord and Tenant shall
execute a commencement certificate in the form attached hereto as EXHIBIT C,
which may be requested by either party, setting forth the exact date on which
the Primary Lease Term commenced and the expiration date of the Primary Lease
Term.

          C. Taking possession of the Premises by Tenant shall be conclusive
evidence as against Tenant that the Premises were in the condition agreed upon
between Landlord and Tenant and acknowledgment of satisfactory completion of any
fix-up or remodeling, as the case may be, which Landlord has agreed in writing
to perform.

     5.   OPERATING EXPENSES AND TAXES.

          In addition to Base Rent, Tenant shall reimburse Landlord for certain
of the Taxes and Operating Expenses of the Building Complex, such reimbursement
to be in the manner, at the times, and in the amounts set forth in this Section
5.

          A. TAXES. If the amount of Taxes billed for any calendar year
beginning with the calendar year 2000 and falling partly or wholly within the
Term of this Lease shall be in excess of the Taxes for the calendar year 1999
(the "Tax Base Amount"), then the Rent payable by Tenant for such year shall be
increased by Tenant's pro rata share ("Pro Rata Share") of such difference, such
Pro Rata Share being 4.2 percent and such share calculated on the basis that the
rentable area of floor space in the Premises (approximately 7,108 rentable
square feet) bears to the total rentable area of floor space in the Building as
of the date hereof (approximately 169,757

                                      -2-

<PAGE>

square feet). If there is a change in the total Building rentable area as a
result of an addition to the Building, partial destruction, modification or
similar cause, which event causes a reduction or increase on a permanent basis,
Landlord shall cause adjustments in the computations as shall be necessary to
provide for any such changes. Landlord's system for measurement applied to all
tenants shall be used to determine rentable area. In determining the amount of
Taxes for any calendar year, the amount of special assessments to be included
shall be limited to the amount of the installment (plus any interest payable
thereon) of such special assessment which would have been required to have been
paid during such calendar year if Landlord had elected to have such special
assessment paid over the maximum period of time permitted by law, if such
election is available to Landlord. Except as provided in the second sentence of
Subsection 5.C.(1) hereof, all reference to Taxes "for" and "billed for" a
particular calendar year shall be deemed to refer to Taxes levied, assessed,
billed or otherwise imposed for such calendar year, without regard to the dates
when any such Taxes are due and payable.

               As used in this Lease, the term "Taxes" means any and all general
and special taxes and impositions of every kind and nature whatsoever levied,
assessed, or imposed upon, or with respect to, the Building Complex, any
leasehold improvements, fixtures, installations, additions, and equipment
whether owed by Landlord or Tenant, or either because of or in connection with
the Landlord's ownership, leasing, and operation of the Building and the
Property, including, without limitation, real estate taxes, personal property
taxes, sewer rents, water rents, general or special assessments, and duties or
levies charged or levied upon or assessed against the Building and the Property
and personal property, transit taxes, all costs and expenses (including legal
fees and court costs) charged for the protest or reduction of property taxes or
assessments in connection with the Property and the Building, or any tax or
excise on rent or any other tax (however described) on account of rental
received for use and occupancy of any or all of the Building, and the Property,
whether any such taxes are imposed by the United States, the State of Colorado,
the County of Denver, or any local governmental municipality, authority, or
agency or any political subdivision of any thereof. Taxes shall not include any
net income, capital stock, succession, transfer, franchise, gift, estate, and
inheritance taxes; provided, however, if at any time during the Term hereof, a
tax or excise on rents or income or other tax, however described (herein called
"Rent Tax"), is levied or assessed by the State of Colorado or any political
subdivision thereof, on account of the Rent hereunder or the interest of
Landlord under this Lease, such Rent Tax shall constitute Taxes; provided,
further, in no event shall Tenant be obligated (i) to pay for any calendar year
any greater amount by way of such Rent Tax than would have been payable by
Tenant had the rentals paid to Landlord under all Building leases (being the
rentals upon which such Rent Tax is imposed) had been the sole taxable income of
Landlord for the calendar year in question, or (ii) to pay or to reimburse
Landlord for any tax of any kind assessed against Landlord on account of any
such Rent Tax having been reimbursed to Landlord.

          B. OPERATING EXPENSES. If, in any calendar year falling partly or
wholly within the Term of this Lease, the Operating Expenses paid or accrued by
Landlord shall be higher than Landlord's Operating Expenses for the calendar
year 1999 (the "Operating Expense Base Amount"), then the Rent payable by Tenant
for such calendar year shall be increased by an

                                      -3-

<PAGE>

amount equal to Tenant's Pro Rata Share of such difference calculated on the
basis of the percentage set forth in Subsection 5.A. above.

               As used in this Lease, the term "Operating Expenses" means any
and all expenses, costs, and disbursements (other than Taxes) of every kind and
nature whatsoever, which are paid or accrued by Landlord in connection with the
leasing, management, maintenance, operation, or repair of the Building Complex
(including, without limitation):

               (a) Costs of supplies, including, but not limited to, the cost of
relamping all lighting installed as a part of the Building Standard work or
located in common areas of the Building Complex. "Building Standard" means the
level of tenant finish improvements or the level of Building services, as the
context may require, customarily offered from time to time by Landlord to all
tenants of the Building;

               (b) Costs incurred in connection with obtaining and providing
energy for the Building Complex, including, but not limited to, costs of
propane, butane, natural gas, steam, electricity, solar energy, fuel oils, coal
or any other energy sources;

               (c) Costs of water and sanitary and storm drainage services;

               (d) Costs of janitorial and security services;

               (e) Costs of general maintenance and repairs, including costs
under climate control and other mechanical maintenance contracts and repairs and
replacements of equipment used in connection with such maintenance and repair
work;

               (f) Costs of maintenance and replacement of landscaping;

               (g) Insurance premiums, including fire and all-risk coverage,
together with loss of rent endorsement, the part of any claim required to be
paid under the deductible portion of any insurance policies carried by Landlord
in connection with the Building Complex (where Landlord is unable to obtain
insurance without such deductible from a major insurance carrier at reasonable
rates), public liability insurance and any other insurance carried by Landlord
on the Building Complex or any component parts thereof (all such insurance shall
be in such amounts as may be required by any Mortgagee, as defined in Section 20
hereof, or as Landlord may reasonably determine);

               (h) Labor costs associated with operation and maintenance of the
Building Complex, including wages and other payments, costs to Landlord of
workmen's compensation and disability insurance, payroll taxes, welfare fringe
benefits, and all legal fees and other costs or expenses incurred in resolving
any labor dispute associated with the operation and maintenance of the Building
Complex;

                                      -4-

<PAGE>

               (i) Professional building management fees including rental for
the Manager's office space and costs of supplying the Manager with necessary
office equipment and storage space in the Building;

               (j) Legal, accounting, inspection, and other consultation fees
(including, without limitation, fees charged by consultants retained by Landlord
for services that are intended to produce a reduction in Operating Expenses,
reduce the rate of increase in Operating Expenses or to reasonably improve the
operation, maintenance or state of repair of the Building Complex) incurred in
the ordinary course of operating the Building Complex;

               (k) The costs of capital improvements and structural repairs and
replacements made in or to the Building Complex in order to conform to any
applicable laws, ordinances, rules, regulations or orders of any governmental or
quasi-governmental authority having jurisdiction over the Building Complex
(herein "Required Capital Improvements") and the costs of any capital
improvements and structural repairs and replacements designed primarily to
reduce Operating Expenses or to reduce the rate of increase in Operating
Expenses (herein "Cost Savings Improvements"). The expenditures for Required
Capital Improvements and Cost Savings Improvements shall be reimbursed to
Landlord in equal installments over the useful life of such capital improvement
or structural repair or replacement (as determined by Landlord) together with
interest on the balance of the reimbursed expenditure at the Prime Rate in
effect on the date the expenditure was incurred by Landlord, plus three percent
(3%); provided, however, that the amount to be reimbursed by Tenant for any Cost
Savings Improvement shall be limited in any year to the reduction or estimated
savings in Operating Expenses as a result thereof;

               (l)  Costs incurred by Landlord or its agents in engaging experts
or other consultants to assist them in making the computations required
hereunder; and

               (m) Rental payments or acquisition costs, allocated over the
useful life, for machinery or equipment, including vehicles, necessary to timely
and economically perform the cleaning and maintenance functions imposed on
Landlord together with the interest on such acquisition costs at the Prime Rate
in effect as of the acquisition date on the balance of the unrecovered
acquisition costs over the useful life of such machinery or equipment.

     "OPERATING EXPENSES" shall NOT include:

               (1) Costs of work, including painting and decorating and tenant
change work, which Landlord performs for any tenant or in any tenant's space in
the Building other than work of a kind a scope which Landlord would be obligated
to furnish to all tenants whose leases contain a rental adjustment provision
similar to this one;

               (2)  Costs of repairs or other work occasioned by fire, windstorm
or other insured casualty to the extent of insurance proceeds received;

                                      -5-

<PAGE>

               (3)  Leasing commissions, advertising expenses, and other costs
incurred in leasing space in the Building;

               (4)  Costs of repairs or rebuilding necessitated by condemnation;

               (5)  Any interest on borrowed money or debt amortization, except
as specifically set forth above;

               (6)  Depreciation on the Building Complex;

               (7)  Any settlement, payment or judgment incurred by Landlord or
the Building manager due to their willful misconduct or gross negligence, as
established by a court of law, which is not covered by insurance proceeds; or

               (8) Cost of any damage to the Building Complex caused directly by
Landlord's willful misconduct or gross negligence, as established by a court of
law, which is not covered by insurance proceeds.

          Notwithstanding anything contained herein to the contrary, if any
lease entered into by Landlord with any tenant in the Building is on a so-called
"net" basis, or provides for a separate basis of computation for any Operating
Expenses with respect to its leased premises, then, to the extent that Landlord,
in its sole judgment, determines that an adjustment should be made in making the
computations herein provided for to appropriately allocate the Operating
Expenses among the tenants, Landlord shall be permitted to modify the
computation of Taxes, Operating Expense Base Amount, rentable area, and/or
Operating Expenses for a particular calendar year in order to eliminate or
otherwise compensate for any such expenses which are paid for in whole or in
part by such tenant. Furthermore, in making any computations contemplated
hereby, Landlord shall also be permitted to make such adjustments and
modifications to the provisions of this Section 5 as shall be reasonably
necessary to achieve the intention of the parties hereto.

          C.   The adjustments provided for in Subsections 5.A. to Taxes shall
be made as follows:

               (1) In the case of calculations made pursuant to Subsection 5.A.
above, such calculation shall be made promptly following receipt by Landlord of
the bills (meaning in the case of annual general real estate taxes, the
statement for same) for Taxes for each calendar year in question. In the event
of a subsequent adjustment of Taxes for a previous calendar year by the taxing
authority which adjustment has resulted in a corresponding adjustment payment by
or to Landlord, the same shall constitute an adjustment to Taxes paid during the
calendar year when such adjustment payment is made. If, pursuant to such
calculations, the Tenant's Pro Rata Share of Taxes due as adjusted by the taxing
authority are more than the Tenant's Pro Rata Share of the Taxes paid by Tenant,
Tenant shall pay to Landlord, within fifteen (15) days following the furnishing
(the "upward adjustment date") of each such calculation to Tenant, Tenant's Pro
Rata Share of such difference.

                                      -6-

<PAGE>

               (2) Commencing with the first calendar month next succeeding each
upward adjustment date, Tenant shall pay to Landlord on the first day of each
calendar month until the next upward adjustment date (which period between
adjustment dates is herein called a "Tax Deposit Year") one-twelfth of the
amount of Tenant's Pro Rata Share of the excess (the "Tax Excess") of: (i) Taxes
most recently billed (as reported in the calculation furnished pursuant to
foregoing clause A(1) above over (ii) the Tax Base Amount, and shall also pay
with each such first monthly payment for a Tax Deposit Year an amount equal to
one-twelfth of Tenant's Pro Rata Share of such Tax Excess multiplied by the
number of calendar months between (y) the month preceding the month in which
Landlord received the bills for Taxes and (z) the first such monthly payment
date. Amounts paid under this Subsection (2) in any Tax Deposit Year shall be
credited against any amounts payable by Tenant under the foregoing Subsection
(1) on account of Taxes billed to Landlord for the same Tax Deposit Year, and
provided there is any surplus remaining after the credit to Tenant and provided
Tenant shall not then be in default under any of the provisions of this Lease,
Landlord shall, at Landlord's option, either refund the amount of such surplus
to Tenant within thirty (30) days following the end of such Tax Deposit Year or
apply such surplus amount against any other amounts then due from Tenant to
Landlord to the extent such surplus was actually received by Landlord from
Tenant.

          D.   The adjustments provided for in Subsections 5.B. to Operating
Expenses shall be made as follows:

               (1) In the case of calculations made pursuant to Subsection 5.B.
such calculation shall be made as promptly as practicable following each
calendar year in question, and bills therefor shall be furnished to Tenant. Any
subsequent adjustment of Operating Expenses for such calendar year which results
in a corresponding adjustment payment by or to Landlord, shall constitute an
adjustment to Operating Expenses during the calendar year when such adjustment
is made. If, pursuant to such calculations, the Operating Expenses so paid
exceed the Operating Expense Base Amount, Tenant shall pay Landlord within
thirty (30) days of furnishing (the "upward adjustment date") of such
calculation to Tenant, Tenant's Pro Rata Share of such difference, calculated on
the basis of the percentage determined in Subsection 5.A.

               (2) As soon as practicable after the close of the calendar year
in which the Commencement Date occurs, Landlord shall supply Tenant with written
notice of Landlord's estimate of the Operating Expenses that will be incurred or
accrued during such calendar year immediately following the calendar year of the
Commencement Date (the "Initial Deposit Year") in excess of the Operating Base
Cost Amount. On or before the first day of each month during such Initial
Deposit Year, Tenant shall pay to Landlord one-twelfth of Tenant's Pro Rata
Share of such estimated excess amount. If the monthly deposit amount is not
determined in time for Tenant to make the first payment on January 1 of the
Initial Deposit Year, then the first monthly payment shall be due on the first
day of the month immediately following the date Landlord supplies Tenant with
notice of the excess amount and the first monthly payment(s) shall also include
a payment equal to one-twelfth of such additional sum multiplied by the number
of calendar months which have elapsed during the Initial Deposit Year prior to
the date Tenant makes its first payment. If the total of the estimated payments
made by Tenant during the Initial

                                      -7-

<PAGE>

Deposit Year are less than Tenant's obligation under this Lease for Operating 
Expenses for such Initial Deposit Year, then Tenant, within thirty (30) days 
of the billing therefor, shall pay such deficiency to Landlord. In the event 
the total of the Tenant's estimated payments for the Initial Deposit Year 
exceed Tenant's obligation for excess Operating Expenses for such year, then 
the surplus shall be handled in the manner provided in the last sentence of 
Subsection 5.D.(3).

               (3) Commencing with the calendar year following the Initial 
Deposit Year and during each calendar year of the Term of this Lease, Tenant 
shall pay to Landlord on the first day of each month of each calendar year 
(hereinafter sometimes called an "Expense Deposit Year") one-twelfth of the 
amount, if any, of Tenant's Pro Rata Share of the excess of Operating 
Expenses paid during the preceding calendar year over the Operating Expense 
Base Amount. In the event the monthly amount so payable by Tenant during any 
calendar year is not determined until after January 1 of such calendar year, 
then until such monthly amount is determined, Tenant shall continue to pay a 
monthly amount equal to the monthly payments required of Tenant with respect 
to adjusted (estimated in the case of the Initial Deposit Year) Operating 
Expenses for the preceding calendar year, and when such current calendar 
year's monthly amount is so determined, Tenant shall, upon being advised 
thereof, pay any deficiency between the monthly payments theretofore made 
during such period and the current monthly payment; provided that in the 
first calendar year in which Tenant is required to pay additional sums for 
Operating Expenses under this subsection (3), the first monthly payment shall 
also include a payment equal to one-twelfth of such additional sum multiplied 
by the number of calendar months which have elapsed during such calendar year 
prior to the first monthly payment due date(s) for such additional sum. If 
the advice shows a surplusage rather than a deficiency between the amount 
paid and the amount due, and provided Tenant is not then in default under any 
of the provisions of this Lease, Landlord shall, at Landlord's option, either 
refund the amount of such surplusage to the Tenant within thirty (30) days 
following such advice, or apply such amount against any other amounts then 
due from Tenant to Landlord to the extent actually received by Landlord from 
Tenant.

          E.   AUDIT AND ADJUSTMENT PROCEDURES.

               (1) The annual determination and statement of Taxes and 
Operating Expenses shall be prepared in accordance with generally accepted 
accounting principles. In the event of any dispute as to any Rent due 
hereunder, Tenant shall have the right to inspect Landlord's accounting 
records relative to Taxes and Operating Expenses at the office in which 
Landlord maintains its records during normal business hours at any time 
within fifteen (15) days following the furnishing by Landlord to Tenant of 
such statement. Unless Tenant shall take written exception of any item in any 
such statement within such fifteen (15) day period, such statement shall be 
considered as accepted by Tenant. If Tenant makes such timely written 
exception, a certification as to the proper amount of Rent shall be made by a 
Certified Public Accountant designated by Landlord (which certification shall 
be final and conclusive). Tenant agrees to pay the cost of such certification 
unless it is determined that Landlord's original determination of both Taxes 
and Operating Expenses was in error by more than three percent (3%) over 
Tenant's actual obligation.



                                      -8-
<PAGE>

               (2) In the event of the termination of this Lease by 
expiration of the stated Term or for any other cause or reason prior to the 
determination of an adjustment to Rent permitted by this Lease, Tenant's 
agreement to pay its Pro Rata Share of increases in Taxes and Operating 
Expenses up to the time of termination shall survive termination of this 
Lease, and Tenant shall pay all amounts due to Landlord within fifteen (15) 
days after being billed therefor. In the event of termination of this Lease 
by expiration of the stated Term or for any other cause or reason whatsoever, 
except default by Tenant of any of the terms or provisions of this Lease, 
prior to the determination of adjustments as hereinabove set forth in Section 
5, Landlord's agreement to refund any excess Rent paid by Tenant up to the 
time of termination shall survive termination of the Lease, and Landlord 
shall pay the amount due, adjusted by the amounts of any applicable offsets, 
to Tenant within fifteen (15) days of Landlord's determination of such 
amount. This covenant shall survive the expiration or termination of this 
Lease.

               (3)  All calculations to be made under this Section 5 shall be 
made, furnished, handled, and (where applicable) billed separately.

               (4) Subject to the rights of Landlord hereunder, any refund to 
which Tenant may be entitled under the provisions of any of subsections 
5.C.(1), 5.C.(2), 5.D.(1), 5.D.(2) and 5.D.(3) may not be used by Tenant to 
offset any payments of Base Rent or other payments then due or that become 
due Landlord under this Lease.

               (5) If the Term of this Lease commences on any day other than 
the first day of January, or if the Term of this Lease ends on any day other 
than the last day of December, any payment due to Landlord by reason of an 
increase in Taxes or Operating Expenses shall be prorated on the basis by 
which the number of days in such partial year bears to 365.

               (6) All sums which Tenant is required to pay or discharge 
pursuant to this Section 5 of this Lease in addition to Base Rent, together 
with any interest or other sums which may be added for late payment thereof, 
shall constitute "Rent" hereunder.

     6.   SERVICES.

          A. Subject to the provisions of subparagraph D below, Landlord, 
without charge, except as provided herein, and in accordance with standards 
from time to time prevailing for the Building, agrees: (1) to furnish running 
water at those points of supply for general use of tenants of the Building; 
(2) to furnish to public areas of the Building Complex heated or cooled air 
(as applicable), electrical current, janitorial services, and maintenance to 
the extent Landlord deems necessary; (3) to furnish, during Ordinary Business 
Hours, as hereinafter defined, such heated or cooled air to the Premises as 
may, in the judgment of Landlord, be reasonably required for the comfortable 
use and occupancy of the Premises, provided that the recommendations of 
Landlord's engineer regarding occupancy and use of the Premises are complied 
with by Tenant and, with respect to cooled air, provided the same is used 
only for standard office use; (4) to furnish, subject to availability and 
capacity of building systems, unfiltered treated cooling tower water for use 
in Tenants' packaged HVAC systems, provided that such systems are equipped



                                      -9-
<PAGE>

with Landlord-approved strainers, pumping systems and controls, and that 
such systems are connected only after approval of Landlord's engineer; (5) to 
provide, during Ordinary Business Hours, the general use of passenger 
elevators for ingress and egress to and from the Premises (at least one such 
elevator shall be available at all times, except in the case of emergencies 
or repair); (6) to provide janitorial services for the Premises to the extent 
of the Building Standard tenant finish work items contained therein 
(including such window washing of the outside of exterior windows as may, in 
the judgment of Landlord, be reasonably required), but unless and until the 
Building Standard changes, such janitorial services shall be provided after 
Ordinary Business Hours on Monday through Thursday and Sunday only, except 
for Legal Holidays; and (7) to cause electric current to be supplied to the 
Premises for all of Tenant's Standard Electrical Usage, as hereinafter 
defined. "Tenant's Standard Electrical Usage", as used herein, shall mean and 
refer to weekly electrical consumption in an amount equal to multiplying 
three and one-half (3.5) watts/square foot by fifty-nine (59) hours and by 
then multiplying the product thereof by the number of rentable square feet in 
the Premises. "Ordinary Business Hours" as used herein shall mean and refer 
to 7:00 a.m. to 6:00 p.m. Monday through Friday and 9:00 a.m. to 12:00 p.m. 
on Saturdays, Legal Holidays excepted. "Legal Holidays," as used herein, 
shall mean New Year's Day, Martin Luther King Day, Presidents' Day, Memorial 
Day, Independence Day, Labor Day, Thanksgiving Day, Christmas Day, and such 
other national holidays as may be hereafter established by the United States 
Government.

          B. "Excess Usage" shall be defined as any usage of electricity (1) 
during other than Ordinary Business Hours; or (2) in an amount in excess of 
Tenant's Standard Electrical Usage; or (3) for "Special Equipment"; or (4) 
for any requirement for standard HVAC services during other than Ordinary 
Business Hours. "Special Equipment," as used herein, shall mean (a) any 
equipment consuming more than 0.5 kilowatts at rated capacity, (b) any 
equipment requiring a voltage other than 120 volts, single phase, or (c)
equipment that requires the use of self-contained HVAC units. Tenant shall 
reimburse Landlord for reasonable costs incurred by Landlord in providing 
services for Excess Usage, which costs are subject to change from time to 
time. Such reasonable costs will include Landlord's costs for materials, 
additional wear and tear on equipment, utilities, and labor (including fringe 
and overhead costs). Computation of Landlord's cost for providing such 
services will be made by Landlord's engineer, based on his engineering survey 
of Tenant's Excess Usage. Tenant shall also reimburse Landlord for all costs 
of supplementing the Building HVAC System and/or extending or supplementing 
any electrical service, as Landlord may determine is necessary, as a result 
of Tenant's Excess Usage. Prior to installation or use by Tenant of any 
equipment which will result in Excess Usage or operation of the Premises for 
extended hours on an ongoing basis, Tenant shall notify Landlord of such 
intended installation or use and obtain Landlord's consent therefor. In 
addition to the foregoing, Tenant, at Tenant's option, upon such notice or at 
any time thereafter, may request Landlord, at Tenant's sole cost and expense, 
to install a check meter and/or flow meter to assist in determining the cost 
to Landlord of Tenant's Excess Usage. If Tenant desires electric current 
and/or heated or cooled air to the Premises during periods other than 
Ordinary Business Hours, Landlord will use reasonable efforts to supply the 
same, but at the expense of Tenant, at Landlord's standard rate as 
established by it, from time to time, for such services. Not less than 
forty-eight (48) hours' prior notice shall be given by Tenant to Landlord of 
Tenant's desire for such services. It is also

                                      -10-
<PAGE>

understood and agreed that Tenant shall pay the cost of replacing light bulbs 
and/or tubes and ballast used in all lighting in the Premises other than 
Building Standard lighting.

          C. If Tenant requires janitorial services other than those required 
to be provided to other tenants of the Building Complex generally, Tenant 
shall separately pay for such services monthly upon billings by Landlord, or 
Tenant shall, at Landlord's option, separately contract for such services 
with the same company furnishing janitorial services to Landlord. 
Notwithstanding the foregoing, Tenant shall have the right, subject to 
Landlord's prior written consent and such rules, regulations and requirements 
as Landlord may impose (including but not limited to the requirement that 
such janitors belong to a trade union), to employ janitors, other than those 
employed by Landlord, to perform such additional services.

          D. Tenant agrees that Landlord shall not be liable for failure to 
supply any such heating, air conditioning, elevator, electrical, janitorial, 
lighting or other services, or during any period Landlord is required to 
reduce or curtail such services pursuant to any applicable laws, rules, or 
regulations, including regulations of any utility now or hereafter in force 
or effect, it being understood that Landlord may discontinue, reduce, or 
curtail such services, or any of them (either temporarily or permanently), at 
such times as it may be necessary by reason of accident, repairs, 
alterations, improvements, strikes, lockouts, riots, acts of God, application 
of applicable laws, statutes, or rules and regulations or due to any other 
happening beyond the control of Landlord. In the event of any interruption, 
reduction, or discontinuance of Landlord's services (either temporary or 
permanent), Landlord shall not be liable for damages to person or property as 
a result thereof nor shall the occurrence of any such event in any way be 
construed as an eviction of Tenant; or cause or permit an abatement, 
reduction or setoff of rent; or operate to release Tenant from any of 
Tenant's obligations hereunder.

          E. Tenant agrees to notify promptly the Landlord or its 
representative of any accidents or defects in the Building of which Tenant 
becomes aware including defects in pipes, electrical wiring, and HVAC 
equipment. In addition, Tenant shall provide Landlord with prompt 
notification of any matter or condition which may cause injury or damage to 
the Building or any person or property therein.

     7.   QUIET ENJOYMENT. So long as Tenant is not in default under this 
Lease, Tenant shall be entitled to the quiet enjoyment and peaceful 
possession of the Premises, subject to the terms and provisions of the Lease.

     8.   DEPOSIT. Waived.

     9.   CHARACTER OF OCCUPANCY. Tenant covenants and agrees to occupy the 
Premises as general offices (the "Permitted Use") and for no other purpose, 
and to use them in a careful, safe, and proper manner; to pay on demand for 
any damage to the Premises caused by misuse or abuse thereof by Tenant, 
Tenant's agents or employees, or of any other person entering upon the 
Premises under express or implied invitation of Tenant. Tenant, at Tenant's 
expense, shall comply with all laws, codes, rules, and regulations of the 
United States, the State of Colorado, and of the County of Arapahoe 
("APPLICABLE LAWS"), now in effect, or which may



                                      -11-
<PAGE>

hereafter be in effect, which shall impose any duty upon Landlord or Tenant 
with respect to the occupation or alteration of the Premises. Tenant shall 
not commit waste or suffer or permit waste to be committed or permit any 
nuisance on or in the Premises. Tenant agrees that it will not store, keep, 
use, sell, dispose of or offer for sale in, upon or from the Premises any 
article or substance which may be prohibited by any insurance policy in force 
from time to time covering the Building nor shall Tenant keep, store, produce 
or dispose of on, in or from the Premises or the Building any substance which 
may be deemed a hazardous substance or infectious waste under any state, 
local or federal rule, statute, law, regulation or ordinance as may be 
promulgated or amended from time to time.

     10.  MAINTENANCE, ALTERATIONS AND REENTRY BY LANDLORD.

          A. Unless otherwise expressly provided herein, Landlord shall not 
be required to make any improvements or repairs of any kind or character to 
the Premises during the Primary Lease Term, or any extension thereof, except: 
(i) such repairs to HVAC, mechanical, life safety and electrical systems in 
the Premises (to the extent such systems are Building Standard) as may be 
deemed necessary by Landlord for normal maintenance operations of the 
Building Complex; and (ii) upkeep, maintenance, and repairs to all Common 
Areas in the Building Complex so long as the need for any such repair is not 
the result of Tenant's negligence.

          B. Tenant covenants and agrees to permit Landlord at any time to 
enter the Premises to examine and inspect the same or, if Landlord so elects, 
to perform any obligations of Tenant hereunder which Tenant shall fail to 
perform or to perform such cleaning, maintenance, janitorial services, 
repairs, additions, or alterations as Landlord may deem necessary or proper 
for the safety, improvement, or preservation of the Premises or of other 
portions of the Building Complex or as may be required by governmental 
authorities through any code, rule, regulation, ordinance, and/or law. Any 
such reentry shall not constitute an eviction or entitle Tenant to abatement 
of rent. Furthermore, Landlord shall at all times have the right at 
Landlord's election to make such alterations or changes in other portions of 
the Building Complex as Landlord may from time to time deem necessary and 
desirable as long as such alterations and changes do not unreasonably 
interfere with Tenant's use and occupancy of the Premises. Landlord may use 
one or more of the street entrances to the Building Complex and such public 
areas thereof as may be necessary, in Landlord's determination to complete 
such alterations or changes.

     11.  ALTERATIONS AND REPAIRS BY TENANT.

          A. Tenant covenants and agrees not to make any Alterations in or 
additions to the Premises, including installation of any equipment or 
machinery therein which requires modification of or additions to any existing 
electrical outlet or which would increase Tenant's usage of electricity 
beyond the Tenant's Standard Electrical Usage (all such alterations are 
referred to herein collectively as "Alterations") without in each such 
instance first obtaining the written consent of Landlord. Landlord's consent 
to any Alterations by Tenant or Landlord's approval of the plans, 
specifications and working drawings for Tenant's Alterations shall create no 
responsibility or liability on the part of Landlord for their completeness, 
design sufficiency, or compliance with all laws, rules and regulations of 
governmental agencies or authorities now in



                                      -12-
<PAGE>

effect or which may hereafter be in effect. Tenant, at its expense, shall pay 
all engineering and design costs incurred by Landlord attributable to the 
Alterations and obtain all necessary governmental permits and certificates 
required for any Alterations to which Landlord has consented and shall cause 
such alterations to be completed in compliance therewith and with all 
applicable laws and requirements of public authorities and all applicable 
requirements of Landlord's insurance carriers. All Alterations which Tenant 
is permitted to make shall be performed in a good and workmanlike manner, 
using new materials and equipment at least equal in quality to the original 
installations in the Premises. All repair and maintenance work required to be 
performed by Tenant pursuant to the provisions of subparagraph B below and 
any Alterations permitted by Landlord pursuant to the provisions hereof, 
including, but not limited to, any installations desired by Tenant for 
Tenant's telegraphic, telephonic or electrical connections, shall be done at 
Tenant's expense by Landlord's employees or, with Landlord's consent, by 
persons requested by Tenant and authorized in writing by Landlord; provided, 
however if such work is performed by persons who are not employees of 
Landlord, Tenant shall pay to Landlord, upon receipt of billing therefor, the 
costs for supervision and control of such persons as Landlord may determine 
to be necessary. If Landlord authorizes persons requested by Tenant to 
perform such work, prior to the commencement of any such work, on request, 
Tenant shall deliver to Landlord certificates issued by insurance companies 
qualified to do business in the State of Colorado, evidencing that workmen's 
compensation, public liability insurance, and property damage insurance, all 
in the amounts, with companies and on forms satisfactory to Landlord, are in 
force and effect and maintained by all contractors and subcontractors engaged 
by Tenant to perform such work. All such policies shall name Landlord and any 
Mortgagee (as defined in Paragraph 20) as an additional insured. Each such 
certificate shall provide that the same may not be canceled or modified 
without ten (10) days' prior written notice to Landlord and such Mortgagee. 
Further, Landlord and such Mortgagee shall have the right to post notices in 
the Premises in locations which will be visible by parties performing any 
work on the Premises stating that Landlord is not responsible for the payment 
for such work and setting forth such other information as Landlord may deem 
necessary. Alterations, repair, and maintenance work shall be performed in a 
manner which will not unreasonably interfere with, delay, or impose any 
additional expense upon Landlord in the maintenance or operation of the 
Building or upon other tenants' use of their premises.

          B. Tenant shall keep the Premises in as good order, condition, and 
repair and in an orderly state, as when they were entered upon, loss by fire 
or other casualty or ordinary wear excepted. Subject to Landlord's obligation 
to make repairs in the event of certain casualties, as set forth in Paragraph 
18 below, Landlord shall have no obligation for the repair or replacement of 
any portion of the interior of the Premises which is damaged or wears out 
during the term hereof regardless of the cause therefor, including but not 
limited to carpeting, draperies, window coverings, wall coverings, painting 
or any of Tenant's property or betterments in the Premises.

          C. All Alterations and permanent fixtures installed in the 
Premises, including, by way of illustration and not by limitation, all 
partitions, paneling, carpeting, drapes or other window coverings, and light 
fixtures (but not including movable office furniture not attached to the 
Building), shall be deemed a part of the real estate and the property of 
Landlord and shall



                                      -13-
<PAGE>

remain upon and be surrendered with the Premises as a part thereof without 
molestation, disturbance, or injury at the end of the Primary Lease Term, or 
any extension thereof, whether by lapse of time or otherwise, unless Landlord 
by notice given to Tenant no later than fifteen (15) days prior to the end of 
the term shall elect to have Tenant remove all or any of the Alterations, and 
in such event, Tenant shall promptly remove at Tenant's expense the 
Alterations specified by Landlord and restore the Premises to their condition 
prior to the making of the same, reasonable wear and tear excepted.

     12. MECHANICS' LIENS. Tenant shall pay or cause to be paid all costs for 
work done by Tenant or caused to be done by Tenant on the Premises (including 
work performed by Landlord or its contractor at Tenant's request following 
the commencement of the Primary Lease Term) of a character which will or may 
result in liens on Landlord's interest therein and Tenant will keep the 
Premises free and clear of all mechanics' liens, and other liens on account 
of work done for Tenant or persons claiming under it. Tenant hereby agrees to 
indemnify, defend, and save Landlord harmless of and from all liability, 
loss, damage, costs, or expenses, including attorneys' fees, on account of 
any claims of any nature whatsoever including claims or liens of laborers or 
materialmen or others for work performed for or materials or supplies 
furnished to Tenant or persons claiming under Tenant. Should any liens be 
filed or recorded against the Premises or any action affecting the title 
thereto be commenced as a result of such work (which term includes the 
supplying of materials), Tenant shall cause such liens to be removed of 
record within five (5) days after notice from Landlord. If Tenant desires to 
contest any claim of lien, Tenant shall furnish to Landlord adequate security 
of at least one hundred fifty percent (150%) of the amount of the claim, plus 
estimated costs and interest and, if a final judgment establishing the 
validity or existence of any lien for any amount is entered, Tenant shall pay 
and satisfy the same at once. If Tenant shall be in default in paying any 
charge for which a mechanic's lien or suit to foreclose the lien has been 
recorded or filed and shall not have given Landlord security as aforesaid, 
Landlord may (but without being required to do so) pay such lien or claim and 
any costs, and the amount so paid, together with reasonable attorney's fees 
incurred in connection therewith, shall be immediately due from Tenant to 
Landlord.

     13.  SUBLETTING AND ASSIGNMENT.

          A. Tenant shall neither sublet any part of the Premises nor assign 
this Lease or any interest herein without the written consent of Landlord 
first being obtained, which consent, as to any subletting of less than 
twenty-five percent (25%) of the Premises, will not be unreasonably withheld 
provided that: (1) Tenant has complied with the provision of subparagraph D 
below and Landlord has declined to exercise its rights thereunder; (2) the 
proposed subtenant or assignee is engaged in a business and the Premises will 
be used in a manner which is in keeping with the then standards of the 
Building and does not conflict with any exclusive use rights granted to any 
other tenant; (3) the proposed subtenant or assignee has a reputation and 
standing in the business community consistent with the image of tenants in a 
first-class office building and has reasonable financial worth in light of 
the responsibilities involved and Tenant shall have provided Landlord with 
reasonable proof thereof; (4) Tenant is not in default hereunder at the time 
it makes its request for such consent; (5) the proposed subtenant or assignee 
is not a governmental or quasi-governmental agency; (6) the proposed 
subtenant or

                                      -14-
<PAGE>

assignee is not a tenant under, or is not currently negotiating, a lease 
with Landlord in any Building owned by Landlord in the southeast Denver 
metropolitan area (including the Building); or (7) the rent under such 
sublease or assignment is not less than the rent to be paid by Tenant for 
such space under the Lease and is not less than 85% of the rental rate then 
being offered by Landlord for similar space in the Building. Notwithstanding 
anything contained herein to the contrary, Tenant acknowledges that if the 
use of the Premises by any proposed subtenant or assignee would require 
compliance by Landlord and the Building with any current or future laws to a 
greater extent than that required prior to the proposed occupancy by such 
subtenant or assignee, Landlord, at its sole option, may refuse to grant such 
consent, unless, as an express condition thereof, Tenant and/or such assignee 
or subtenant bears the entire cost of such greater compliance.

          B. If this Lease is assigned, or if the Premises or any part 
thereof is sublet or occupied by anybody other than Tenant, Landlord may, 
after default by Tenant, collect the rent from the assignee, subtenant, or 
occupant and apply the net amount collected to the rent herein reserved, but 
no such assignment, subletting, occupancy, or collection shall be deemed an 
acceptance of the assignee, subtenant, or occupant as the Tenant hereof or a 
release of Tenant from further performance by Tenant of covenants on the part 
of Tenant herein contained. A sale by Tenant of all or substantially all of 
its assets or all or substantially all of its stock if Tenant is a publicly 
traded corporation, a merger of Tenant with another corporation, the transfer 
of twenty-five percent (25%) or more of the stock in a corporate tenant whose 
stock is not publicly traded, or transfer of twenty-five percent (25%) or 
more of the beneficial ownership interests in a partnership tenant shall 
constitute a prohibited assignment hereunder. Consent by Landlord to any one 
Assignment or sublease shall not in any way be construed as relieving Tenant 
from obtaining the Landlord's express written consent to any further 
Assignment or sublease. Notwithstanding the consent of Landlord to any 
sublease or Assignment, Tenant shall not be relieved from its primary 
obligations hereunder to Landlord, including, but not limited to the payment 
of all Base Rent and Tenant's Pro Rata Share of increases in Operating 
Expenses. Landlord's consent to any requested sublease or Assignment shall 
not waive Landlord's right to refuse to consent to any other such request or 
to terminate this Lease if such request is made, all as provided herein. If 
Tenant collects any rental or other amounts from a subtenant or assignee in 
excess of the Base Rent and Tenant's Pro Rata Share of increases in Operating 
Expenses for any monthly period, Tenant shall pay to Landlord on a monthly 
basis, as and when Tenant receives the same, all such excess amounts received 
by Tenant.

          C. Notwithstanding anything contained in this Paragraph 13 to the 
contrary, in the event Tenant requests Landlord's consent to sublet 
twenty-five percent (25%) or more of the Premises or to assign twenty-five 
percent (25%) or more of its interest in this Lease, Landlord shall have the 
right to: (1) consent to such sublease or Assignment in its sole discretion; 
(2) refuse to grant such consent in Landlord's sole discretion; or (3) refuse 
to grant such consent and terminate this Lease as to the portion of the 
Premises with respect to which such consent was requested; provided, however, 
if Landlord refuses to grant such consent and elects to terminate the Lease 
as to such portion of the Premises, Tenant shall have the right within 
fifteen (15) days after notice of Landlord's exercise of its right to 
terminate to withdraw Tenant's request for such consent and remain in 
possession of the Premises under the terms and conditions hereof. In the



                                      -15-
<PAGE>

event the Lease is terminated as set forth herein, such termination shall be 
effective as of the date set forth in a written notice from Landlord to 
Tenant, which date shall in no event be more than thirty (30) days following 
such notice.

          D. Tenant hereby agrees that in the event it desires to sublease 
all or any portion of the Premises or assign this Lease to any party, in 
whole or in part, (herein "Assignment"), Tenant shall notify Landlord not 
less than ninety (90) days prior to the date Tenant desires to sublease such 
portion of the Premises or assign this Lease ("Tenant's Notice"). Tenant's 
Notice shall set forth the description of the portion of the Premises to be 
so sublet or assigned and the terms and conditions on which Tenant desires to 
sublet the Premises or assign this Lease. Landlord shall have sixty (60) days 
following receipt of Tenant's Notice within which to attempt to sublet the 
Premises or assign this Lease on Tenant's behalf (or to exercise Landlord's 
rights pursuant to subparagraph C above if Tenant's Notice discloses that 
twenty-five percent (25%) or more of the Premises is involved). In the event 
that the space covered by Tenant's Notice is leased by Landlord, rent and 
other sums due from the subtenant in accordance with the sublease shall be 
paid to Tenant for Tenant's account and Landlord shall have no responsibility 
whatsoever for the observance and performance by such subtenant of its 
obligations under its sublease with Tenant. Landlord shall be under no 
obligation to find a prospective subtenant or assignee. If Landlord is 
unwilling or unable to locate a subtenant or assignee (and, if applicable, 
declines to exercise its rights pursuant to subparagraph C above), Landlord 
will notify Tenant not later than sixty (60) days after the date Landlord 
receives Tenant's Notice and Tenant shall be free to sublet the portion of 
the Premises in question or assign the applicable portion of its interest in 
this Lease to any third party on terms substantially identical to those 
described in Tenant's Notice, subject to Landlord's consent as set forth in 
subparagraph A above. If Tenant is unable to sublet said portion of the 
Premises or assign the applicable portion of its interest in this Lease on 
said terms and conditions within one hundred twenty (120) days following its 
original notice to Landlord, Tenant agrees to reoffer the Premises to 
Landlord in accordance with the provisions hereof prior to leasing or 
assigning the same to any third party.

          E. All documents utilized by Tenant to evidence any subletting or 
assignment to which Landlord has consented shall be subject to prior approval 
by Landlord or its counsel. Tenant shall pay on demand all of Landlord's 
costs and expenses, including reasonable attorneys' fees, incurred in 
determining whether or not to consent to any requested sublease or Assignment 
and in reviewing and approving such documentation.

          F. Landlord and Tenant understand that notwithstanding certain 
provisions to the contrary contained herein, a trustee or debtor in 
possession under the Bankruptcy Code of the United States may have certain 
rights to assume or assign this Lease. If a trustee in bankruptcy is entitled 
to assume control over Tenant's rights under this Lease and assigns such 
rights to any third party, the Base Rent to be paid hereunder by such party 
shall be increased to the then current Base Rent (if greater than then being 
paid for the Premises) which Landlord would charge for comparable space in 
the Building as of the date of such third party's occupancy of the Premises. 
Landlord and Tenant further understand that in any event Landlord is entitled 
under the Bankruptcy Code to Adequate Assurance of future performance of the 
terms and provisions



                                      -16-
<PAGE>

of this Lease. For purposes of any such assumption or assignment, the parties 
hereto agree that the term "ADEQUATE ASSURANCE" shall include at least the 
following:

               i. In order to assure Landlord that the proposed assignee will 
have the resources with which to pay the rent called for herein, any proposed 
assignee must have demonstrated to Landlord's satisfaction a net worth (as 
defined in accordance with generally accepted accounting principles 
consistently applied) at least as great as the net worth of Tenant on the 
date this Lease became effective increased by seven percent (7%), compounded 
annually, for each year from the Lease Commencement Date through the date of 
the proposed assignment. The financial condition and resources of Tenant were 
a material inducement to Landlord in entering into this Lease.

               ii.  Any proposed assignee of this Lease must assume and agree 
to be bound by the terms, provisions, and covenants of this Lease.

     14.  DAMAGE TO PROPERTY. Tenant shall neither hold nor attempt to hold 
Landlord liable for any injury or damage, either proximate or remote, 
occurring through or caused by fire, water, steam, or any repairs, 
alterations, injury, accident, or any other cause to the Premises, to any 
furniture, fixtures, Tenant improvements, or other personal property of 
Tenant kept or stored in the Premises, or in other parts of the Building 
Complex not herein demised, whether by reason of the negligence or default of 
the owners or occupants thereof or any other person or otherwise and the 
keeping or storing of all property of Tenant in the Building Complex and/or 
Premises shall be at the sole risk of Tenant. Tenant shall obtain and 
maintain throughout the term of this Lease "all risk" or "multi-peril" 
insurance on and for the full cost of replacement of all of Tenant's property 
and betterments in the Premises, including, without limitation all furniture, 
fixtures, personal property and all tenant finish in excess of Building 
Standard items.

     15.  INDEMNITY TO LANDLORD.

          A. Tenant hereby agrees to indemnify, defend, and save Landlord 
harmless of and from all liability, loss, damages, costs, or expenses, 
including attorneys' fees, on account of injuries to the person or property 
of Landlord or of any other tenant in the Building Complex or to any other 
person rightfully in said Building Complex for any purpose whatsoever, where 
the injuries are caused by the negligence, misconduct or breach of this Lease 
by the Tenant, Tenant's agents, servants, or employees or of any other person 
entering upon the Premises under express or implied invitation of Tenant or 
where such injuries are the result of the violation of the provisions of this 
Lease by any of such persons. This indemnity shall survive termination or 
earlier expiration of this Lease.

          B. In addition to the above, Tenant shall obtain and maintain 
throughout the term of this Lease a commercial general liability policy, 
including protection against death, personal injury and property damage, 
issued by an insurance company qualified to do business in the State of 
Colorado, with a single limit of not less than One Million Dollars 
($1,000,000.00). All such policies shall name Landlord as an additional 
insured. Each such policy shall provide that the same may not be canceled or 
modified without at least twenty (20) days' prior written





                                      -17


<PAGE>

notice to Landlord and any Mortgagee (as defined in Paragraph 20). Prior to 
occupancy of the Premises, and thereafter from time to time, Tenant shall 
deliver certificates evidencing that such insurance, as required under 
Paragraph 14 above and this Paragraph 15, is in force and effect. The limits 
of said insurance shall not, under any circumstances, limit the liability of 
Tenant hereunder.

     16.  SURRENDER AND NOTICE. Upon the expiration or other termination of 
the term of this Lease, Tenant shall promptly quit and surrender to Landlord 
the Premises broom clean, in good order and condition, ordinary wear and tear 
and loss by fire or other casualty excepted unless due to the negligence of 
Tenant, and Tenant shall remove all of its movable furniture and other 
effects and such Alterations as Landlord shall require Tenant to remove 
pursuant to Paragraph 11 hereof. In the event Tenant fails to vacate the 
Premises on a timely basis as required, Tenant shall be responsible to 
Landlord for all costs incurred by Landlord as a result of such failure, 
including, but not limited to, any amounts required to be paid to third 
parties who were to have occupied the Premises.

     17.  INSURANCE, CASUALTY, AND RESTORATION OF PREMISES.

          A. Landlord shall maintain casualty insurance on the shell and core 
of the Building, on the Premises to the extent of the base tenant finish per 
the then-current standard allowance provided by Landlord to tenants in the 
Building therein and in the Building Complex, in such amounts, from such 
companies, and on such terms and conditions, including loss of rental 
insurance for such period of time as Landlord deems appropriate, from time to 
time.

          B. If the Premises or the Building shall be so damaged by fire or 
other casualty as to render the Premises wholly untenantable and if such 
damage shall be so great that a competent architect, in good standing, 
selected by Landlord shall certify in writing to Landlord and Tenant within 
sixty (60) days of said casualty that the Premises, with the exercise of 
reasonable diligence, cannot be made fit for occupancy within one hundred 
eighty (180) working days from the happening thereof, then this Lease shall 
cease and terminate from the date of the occurrence of such damage and Tenant 
shall thereupon surrender to Landlord the Premises and all interest therein 
hereunder and Landlord may reenter and take possession of the Premises and 
remove Tenant therefrom. Tenant shall pay rent, duly apportioned, up to the 
time of such termination of this Lease. If, however, the damage shall be such 
that said architect shall certify within said sixty (60) day period that the 
Premises can be made tenantable within said one hundred eighty (180) day 
period, then, except as hereinafter provided, Landlord shall repair the 
damage so done (to the extent of the base tenant finish per the then-current 
standard allowance provided by Landlord to tenants in the Building) with all 
reasonable speed.

          C. If the Premises shall be slightly damaged by fire or other 
casualty, but not so as to render the same wholly untenantable or to require 
a repair period in excess of one hundred eighty (180) days, then, Landlord, 
after receiving notice in writing of the occurrence of the casualty, except 
as hereafter provided, shall cause the same to be repaired to the extent of 
the base tenant finish per the then-current standard allowance provided by 
Landlord to tenants in the Building with reasonable promptness. If the 
estimated repair period as established in accordance



                                      -18-
<PAGE>

with the provisions of subparagraph B above exceeds one hundred eighty (180) 
days, then the provisions of subparagraph B shall control notwithstanding the 
fact that the Premises are not wholly untenantable.

          D. In case the Building throughout shall be so injured or damaged, 
whether by fire or otherwise (though said Premises may not be affected, or if 
affected, can be repaired within said one hundred eighty (180) days), that, 
within sixty (60) days after the happening of such injury, Landlord shall 
decide not to reconstruct or rebuild said Building, then, notwithstanding 
anything contained herein to the contrary, upon notice in writing to that 
effect given by Landlord to Tenant within said sixty (60) days, Tenant shall 
pay the rent, properly apportioned up to such date, this Lease shall 
terminate from the date of delivery of said written notice, and both parties 
hereto shall be freed and discharged of all further obligations hereunder.

          E. Landlord and Tenant hereby waive any and all rights of recovery 
against the other, their officers, agents, and employees occurring out of the 
use and occupancy of the Premises for loss or damage to their respective real 
and/or personal property arising as a result of a casualty or condemnation 
contemplated by this Paragraph 17. Each of the parties shall, upon obtaining 
the policies of insurance required by this Lease, notify the insurance 
carrier that the foregoing waiver is contained in this Lease and shall 
require such carrier to include an appropriate waiver of subrogation 
provision in the policies.

          F. Provided that the casualty is not the fault of Tenant, Tenant's 
agents, servants, or employees, Tenant's rent shall abate during any such 
period of repair and restoration, but only to the extent of any recovery by 
Landlord under its rental insurance related to the Premises in the same 
proportion that the part of the Premises rendered untenantable bears to the 
whole.

     18.  CONDEMNATION. If the entire Premises or substantially all of the 
Premises or any portion of the Building Complex which shall render the 
Premises untenantable shall be taken by right of eminent domain or by 
condemnation or shall be conveyed in lieu of any such taking, then this 
Lease, at the option of either Landlord or Tenant exercised by either party 
giving notice to the other of such termination within thirty (30) days after 
such taking or conveyance, shall forthwith cease and terminate and the rent 
shall be duly apportioned as of the date of such taking or conveyance. Tenant 
thereupon shall surrender the Premises and all interest therein under this 
Lease to Landlord and Landlord may reenter and take possession of the 
Premises or remove Tenant therefrom. In the event less than all of the 
Premises shall be taken by such proceeding, Landlord shall promptly repair 
the Premises as nearly as possible to its condition immediately prior to said 
taking, unless Landlord elects not to reconstruct or rebuild as described in 
subparagraph D of Paragraph 17 above. In the event of any such taking or 
conveyance, Landlord shall receive the entire award or consideration for the 
portion of the Building so taken.



                                      -19-
<PAGE>

     19.  DEFAULT BY TENANT.

          A.   Each one of the following events is herein referred to as an 
"Event of Default":

               (1)  Any failure by Tenant to pay the rent or any other 
monetary sums required to be paid hereunder on the date such sums are due 
shall be deemed a default. Notwithstanding the foregoing, Tenant may cure a 
default under this provision at any time prior to five (5) business days 
after written notice of such default is given by Landlord exercising its 
remedies as to such default under this Lease; provided, however, Tenant shall 
not be entitled to more than two (2) notices of a delinquency in payment 
during any calendar year and, if thereafter during such calendar year any 
rent or other amounts owing hereunder are not paid when due, an Event of 
Default shall be deemed to have occurred immediately even though no notice 
thereof is given;

               (2)  Tenant shall vacate or abandon the Premises;

               (3)  This Lease or the estate of Tenant hereunder shall be 
transferred to or shall pass to or devolve upon any other person or party 
except in the manner set forth in Paragraph 13;

               (4)  This Lease or the Premises or any part thereof shall be 
taken upon execution or by other process of law directed against Tenant or 
shall be taken upon or subject to any attachment at the instance of any 
creditor of or claimant against Tenant and said attachment shall not be 
discharged or disposed of within fifteen (15) days after the levy thereof;

               (5)  The filing of any petition or the commencement of any case 
or proceeding by the Tenant under any provision or chapter of the Federal 
Bankruptcy Act, the Federal Bankruptcy Code, or any other federal or state 
law relating to insolvency, bankruptcy, or reorganization or the adjudication 
that the Tenant is insolvent or bankrupt or the entry of an order for relief 
under the Federal Bankruptcy Code with respect to Tenant;

               (6)  The filing of any petition or the commencement of any case 
or proceeding described in subparagraph (5) above against the Tenant, unless 
such petition and all proceedings initiated thereby are dismissed within 
sixty (60) days from the date of such filing; the filing of an answer by 
Tenant admitting the allegations of any such petition; the appointment of or 
taking possession by a custodian, trustee or receiver for all or any assets 
of the Tenant, unless such appointment is vacated or dismissed within sixty 
(60) days from the date of such appointment;

               (7)  The insolvency of the Tenant or the execution by the 
Tenant of an assignment for the benefit of creditors; the convening by Tenant 
of a meeting of its creditors, or any class thereof, for purposes of 
effecting a moratorium upon or extension or composition of its debts; or the 
failure of the Tenant generally to pay its debts as they mature;



                                      -20-
<PAGE>

               (8)  The admission in writing by Tenant, or any partner of 
Tenant if Tenant is a partnership, that he is unable to pay his debts as they 
mature or he is generally not paying his debts as they mature;

               (9)  Tenant shall fail to take possession of the Premises on the
date the Primary Lease Term commences;

               (10) Tenant shall fail to perform any of the other agreements, 
terms, covenants, or conditions hereof on Tenant's part to be performed and 
such non-performance shall continue for a period of thirty (30) days after 
written notice thereof by Landlord to Tenant or, if such performance cannot 
be reasonably had within such thirty (30) day period, Tenant shall not in 
good faith have commenced such performance within such thirty (30) day period 
and shall not diligently proceed therewith to completion; provided, however, 
if Tenant fails to perform any of the other agreements, covenants or 
conditions hereof repeatedly during the term of this Lease, Tenant shall no 
longer have the opportunity to cure any subsequent failure and an Event of 
Default shall be deemed to have occurred immediately upon such failure.

          B.   REMEDIES OF LANDLORD. If any one or more Event of Default 
shall happen, then Landlord shall have the right at Landlord's election, then 
or at any time thereafter, either:

               (1) (a) Without demand or notice, to reenter and take 
possession of the Premises or any part thereof and repossess the same as of 
Landlord's former estate and expel Tenant and those claiming through or under 
Tenant and remove the effects of both or either, without being deemed guilty 
of any manner of trespass and without prejudice to any remedies for arrears 
of rent or preceding breach of covenants or conditions. Should Landlord elect 
to reenter, as provided in this subparagraph (1), or should Landlord take 
possession pursuant to legal proceedings or pursuant to any notice provided 
for by law, Landlord may, from time to time, without terminating this Lease, 
relet the Premises or any part thereof, either alone or in conjunction with 
other portions of the Building of which the Premises are a part, in 
Landlord's or Tenant's name but for the account of Tenant, for such term or 
terms (which may be greater or less than the period which would otherwise 
have constituted the balance of the term of this Lease) and on such 
conditions and upon such other terms (which may include concessions of free 
rent and alteration and repair of the Premises) as Landlord in its 
uncontrolled discretion, may determine and Landlord may collect and receive 
the rents therefor. Landlord shall in no way be responsible or liable for any 
failure to relet the Premises, or any part thereof, or for any failure to 
collect any rent due upon such reletting. No such reentry or taking 
possession of the Premises by Landlord shall be construed as an election on 
Landlord's part to terminate this Lease unless a written notice of such 
intention be given to Tenant. No notice from Landlord hereunder or under a 
forcible entry and detainer statute or similar law shall constitute an 
election by Landlord to terminate this Lease unless such notice specifically 
so states. Landlord reserves the right following any such reentry and/or 
reletting to exercise its right to terminate this Lease by giving Tenant such 
written notice, in which event the Lease will terminate as specified in said 
notice.

                    (b)  If Landlord elects to take possession of the Premises
as provided in this subparagraph (1) without terminating the Lease, Tenant shall
pay to Landlord (i)



                                      -21-
<PAGE>

the rent and other sums as herein provided, which would be payable hereunder 
if such repossession had not occurred, less (ii) the net proceeds, if any, of 
any reletting of the Premises after deducting all of Landlord's expenses 
incurred in connection with such reletting, including, but without 
limitation, all repossession costs, brokerage commissions, legal expenses, 
attorneys' fees, expenses of employees, alteration, remodeling, and repair 
costs and expenses of preparation for such reletting. If, in connection with 
any reletting, the new lease term extends beyond the existing term or the 
premises covered thereby include other premises not part of the Premises, a 
fair apportionment of the rent received from such reletting and the expenses 
incurred in connection therewith, as provided aforesaid, will be made in 
determining the net proceeds received from such reletting. In addition, in 
determining the net proceeds from such reletting, any rent concessions will 
be apportioned over the term of the new lease. Tenant shall pay such amounts 
to Landlord monthly on the days on which the rent and all other amounts owing 
hereunder would have been payable if possession had not been retaken and 
Landlord shall be entitled to receive the same from Tenant on each such day; 
or

               (2) To give Tenant written notice of intention to terminate 
this Lease on the date of such given notice or on any later date specified 
therein and, on the date specified in such notice, Tenant's right to 
possession of the Premises shall cease and the Lease shall thereupon be 
terminated, except as to Tenant's liability hereunder as hereinafter 
provided, as if the expiration of the term fixed in such notice were the end 
of the term herein originally demised. In the event this Lease is terminated 
pursuant to the provisions of this subparagraph (2), Tenant shall remain 
liable to Landlord for damages in an amount equal to the rent and other sums 
which would have been owing by Tenant hereunder for the balance of the term 
had this Lease not been terminated less the net proceeds, if any, of any 
reletting of the Premises by Landlord subsequent to such termination, after 
deducting all Landlord's expenses in connection with such reletting, 
including, but without limitation, the expenses enumerated above. Landlord 
shall be entitled to collect such damages from Tenant monthly on the days on 
which the rent and other amounts would have been payable hereunder if this 
Lease had not been terminated and Landlord shall be entitled to receive the 
same from Tenant on each such day. Alternatively, at the option of Landlord, 
in the event this Lease is terminated, Landlord shall be entitled to recover 
forthwith against Tenant as damages for loss of the bargain and not as a 
penalty an amount equal to the worth at the time of termination of the 
excess, if any, of the amount of rent reserved in this Lease for the balance 
of the term hereof over the then Reasonable Rental Value of the Premises for 
the same period plus all amounts incurred by Landlord in order to obtain 
possession of the Premises and relet the same, including attorneys' fees, 
reletting expenses, alterations and repair costs, brokerage commissions and 
all other like amounts. It is agreed that the "Reasonable Rental Value" shall 
be the amount of rental which Landlord can obtain as rent for the remaining 
balance of the term.

          C.  CUMULATIVE REMEDIES. Suit or suits for the recovery of the 
rents and other amounts and damages set forth hereinabove may be brought by 
Landlord, from time to time, at Landlord's election, and nothing herein 
shall be deemed to require Landlord to await the date whereon this Lease or 
the term hereof would have expired had there been no such default by Tenant 
or no such termination, as the case may be. Each right and remedy provided 
for in this Lease shall be cumulative and shall be in addition to every other 
right or remedy provided for in



                                      -22-
<PAGE>

this Lease or now or hereafter existing at law or in equity or by statute or 
otherwise, including, but not limited to, suits for injunctive relief and 
specific performance. The exercise or beginning of the exercise by Landlord 
of any one or more of the rights or remedies provided for in this Lease or 
now or hereafter existing at law or in equity or by statute or otherwise 
shall not preclude the simultaneous or later exercise by Landlord of any or 
all other rights or remedies provided for in this Lease or now or hereafter 
existing at law or in equity or by statute or otherwise. All such rights and 
remedies shall be considered cumulative and non-exclusive. All costs incurred 
by Landlord in connection with collecting any rent or other amount and 
damages owing by Tenant pursuant to the provisions of this Lease, or to 
enforce any provision of this Lease, shall also be recoverable by Landlord 
from Tenant. Further, if an action is brought pursuant to the terms and 
provisions of the Lease, the prevailing party in such action shall be 
entitled to recover from the other party any and all reasonable attorneys' 
fees incurred by such prevailing party in connection with such action.

          D.  NO WAIVER. No failure by Landlord to insist upon the strict 
performance of any agreement, term, covenant or condition hereof or to 
exercise any right or remedy consequent upon a breach thereof and no 
acceptance of full or partial rent during the continuance of any such breach 
shall constitute a waiver of any such breach or of such agreement, term, 
covenant, or condition. No agreement, term, covenant, or condition hereof to 
be performed or complied with by Tenant and no breach thereof shall be 
waived, altered, or modified, except by written instrument executed by 
Landlord. No waiver of any breach shall affect or alter this Lease but each 
and every agreement, term, covenant, and condition hereof shall continue in 
full force and effect with respect to any other then existing or subsequent 
breach thereof. Notwithstanding any termination of this Lease, the same shall 
continue in force and effect as to any provisions which require observance or 
performance by Landlord or Tenant subsequent to such termination.

          E.  BANKRUPTCY. Nothing contained in this Paragraph 19 shall limit 
or prejudice the right of Landlord to prove and obtain as liquidated damages 
in any bankruptcy, insolvency, receivership, reorganization, or dissolution 
proceeding an amount equal to the maximum allowed by any statute or rule of 
law governing such a proceeding and in effect at the time when such damages 
are to be proved, whether or not such amount be greater, equal to, or less 
than the amounts recoverable, either as damages or rent, referred to in any 
of the preceding provisions of this Paragraph. Notwithstanding anything 
contained in this Paragraph to the contrary, any such proceeding or action 
involving bankruptcy, insolvency, reorganization, arrangement, assignment for 
the benefit of creditors, or appointment of a receiver or trustee, as set 
forth above, shall be considered to be an Event of Default only when such 
proceeding, action, or remedy shall be taken or brought by or against the 
then holder of the leasehold estate under this Lease.

          F.  LATE PAYMENT CHARGE. Any rents or other amounts owing hereunder 
which are not paid within five (5) days after the date they are due shall 
thereafter bear interest at the rate of three percentage points over the 
Prime Rate then being charged by Wells Fargo Bank, N.A. or its successor, to 
its most credit-worthy customers on an unsecured basis for short term loans 
(the "Prime Rate") or the highest rate permitted by applicable usury law, 
whichever is lower, until paid. Further, in the event any rents or other 
amounts owing hereunder are not paid within five



                                      -23-
<PAGE>

(5) days after written notice, Landlord and Tenant agree that Landlord will 
incur additional administrative expenses, the amount of which will be 
difficult if not impossible to determine. Accordingly, Tenant shall pay to 
Landlord an additional, one-time late charge for any such late payment in the 
amount of five percent (5%) of such payment. Any amounts paid by Landlord to 
cure any defaults of Tenant hereunder, which Landlord shall have the right 
but not the obligation to do, shall, if not repaid by Tenant within five (5) 
days of demand by Landlord, thereafter bear interest at the rate of three 
percentage points over the Prime Rate or the highest rate permitted by 
applicable usury law, whichever is lower, until paid.

          G.  WAIVER OF JURY TRIAL. TENANT AND LANDLORD HEREBY WAIVE (TO THE 
EXTENT ALLOWED BY LAW) ANY AND ALL RIGHTS TO A TRIAL BY JURY IN SUIT OR SUITS 
BROUGHT TO ENFORCE ANY PROVISION OF THIS LEASE OR ARISING OUT OF OR 
CONCERNING THE PROVISIONS OF THIS LEASE.

     20.  DEFAULT BY LANDLORD. In the event of any alleged default on the 
part of Landlord hereunder, Tenant shall give written notice to Landlord in 
the manner herein set forth and shall afford Landlord a reasonable 
opportunity to cure any such default. Notice to Landlord of any such alleged 
default shall be ineffective unless notice is simultaneously delivered to any 
holder of a Mortgage and/or Trust Deed affecting all or any portion of the 
Building Complex ("Mortgagees"), as hereafter provided. Tenant agrees to give 
all Mortgagees, by certified mail, return receipt requested, a copy of any 
notice of default served upon Landlord, provided that prior to such notice 
Tenant has been notified, in writing (by way of notice of Assignment of Rents 
and Leases, or otherwise), of the address of such Mortgagees. Tenant further 
agrees that if Landlord shall have failed to cure such default within the 
time provided for in this Lease, then the Mortgagees shall have an additional 
thirty (30) days within which to cure such default or, if such default cannot 
be cured within that time, then such additional time as may be necessary, if, 
within such thirty (30) days, any Mortgagee has commenced and is diligently 
pursuing the remedies necessary to cure such default (including, but not 
limited to, commencement of foreclosure proceedings, if necessary to effect 
such cure), in which event this Lease shall not be terminated while such 
remedies are being so diligently pursued. In no event will Landlord or any 
Mortgagee be responsible for any consequential damages incurred by Tenant as 
a result of any default, including, but not limited to, lost profits or 
interruption of business as a result of any alleged default by Landlord 
hereunder.

     21.  SUBORDINATION AND ATTORNMENT.

          A. This Lease, at Landlord's option, shall be subordinate to any 
mortgage or deed of trust (now or hereafter placed upon the Building Complex, 
or any portion thereof), including any amendment, modification, or 
restatement of any of such documents, and to any and all advances made under 
any mortgage or deed of trust and to all renewals, modifications, 
consolidations, replacements, and extensions thereof. Tenant agrees that with 
respect to any of the foregoing documents, no documentation, other than this 
Lease, shall be required to evidence such subordination.



                                      -24-
<PAGE>

          B. If any holder of a mortgage or deed of trust shall elect to have 
this Lease superior to the lien of the holder's mortgage or deed of trust and 
shall give written notice thereof to Tenant, this Lease shall be deemed prior 
to such mortgage or deed of trust, whether this Lease is dated prior or 
subsequent to the date of said mortgage or deed of trust or the date of 
recording thereof.

          C. In confirmation of such subordination or superior position, as 
the case may be, Tenant agrees to execute such documents as may be required 
by Landlord or its Mortgagee to evidence the subordination of its interest 
herein to any of the documents described above, or to evidence that this 
Lease is prior to the lien of any mortgage or deed of trust, as the case may 
be, and failing to do so within ten (10) days after written demand, Tenant 
does hereby make, constitute, and irrevocably appoint Landlord as Tenant's 
attorney-in-fact and in Tenant's name, place and stead, to do so.

          D. Tenant hereby agrees to attorn to all successor owners of the 
Building Complex, whether or not such ownership is acquired as a result of a 
sale, through foreclosure of a deed of trust or mortgage, or otherwise.

     22.  REMOVAL OF TENANT'S PROPERTY. All movable furniture and personal 
effects of Tenant not removed from the Premises upon the vacation or 
abandonment thereof or upon the termination of this Lease for any cause 
whatsoever shall conclusively be deemed to have been abandoned and may be 
appropriated, sold, stored, destroyed, or otherwise disposed of by Landlord 
without notice to Tenant or any other person and without obligation to 
account therefor and Tenant shall pay Landlord all expenses incurred in 
connection with the disposition of such property.

     23.  HOLDING OVER: TENANCY MONTH-TO-MONTH. If, after the expiration of 
this Lease, Tenant shall remain in possession of the Premises and continue to 
pay rent, and Landlord shall accept such rent, without any express written 
agreement as to such holding over, then such holding over shall be deemed and 
taken to be a holding upon a tenancy from month-to-month, subject to all the 
terms and conditions hereof on the part of Tenant to be observed and 
performed and at a monthly rent equivalent to two hundred percent (200%) of 
the monthly installments paid by Tenant immediately prior to such expiration 
or the current market rental rate for the Premises, whichever is greater. All 
such rent shall be payable in advance on the same day of each calendar month. 
Such month-to-month tenancy may be terminated by either party upon ten (10) 
days' notice prior to the end of any such monthly period. Nothing contained 
herein shall be construed as obligating Landlord to accept any rental 
tendered by Tenant after the expiration of the term hereof or as relieving 
Tenant of its liability pursuant to Paragraph 16 and any holdover without 
Landlord's consent shall be deemed a default hereunder entitling Landlord to 
all of its rights and remedies set forth in Paragraph 19 above, including, 
without limitation, its right to recover consequential damages resulting from 
said holdover.

     24.  PAYMENTS AFTER TERMINATION. No payments of money by Tenant to 
Landlord after the termination of this Lease, in any manner, or after giving 
of any notice (other



                                      -25-
<PAGE>

than a demand for payment of money) by Landlord to Tenant shall reinstate, 
continue, or extend the term of this Lease or affect any notice given to 
Tenant prior to the payment of such money, it being agreed that after the 
service of notice or the commencement of a suit or other final judgment 
granting Landlord possession of the Premises, Landlord may receive and 
collect any sums of rent due or any other sums of money due under the terms 
of this Lease or otherwise exercise Landlord's rights and remedies hereunder 
and the payment of such sums of money, whether as rent or otherwise, shall 
not waive said notice or in any manner affect any pending suit or judgment 
theretofore obtained.

     25.  STATEMENT OF PERFORMANCE. Tenant agrees at any time and from time 
to time, upon not less than ten (10) days' prior written request by Landlord, 
to execute, acknowledge, and deliver to Landlord a statement in writing 
certifying that this Lease is unmodified and in full force and effect (or, if 
there have been modifications, that the same is in full force and effect as 
modified and stating the modifications), that there have been no defaults 
thereunder by Landlord or Tenant (or, if there have been defaults, setting 
forth the nature thereof), the date to which the rent and other charges have 
been paid in advance, if any, and such other information as Landlord may 
request. It is intended that any such statement delivered pursuant to this 
Paragraph may be relied upon by any prospective purchaser of all or any 
portion of Landlord's interest herein or a holder of any mortgage or deed of 
trust encumbering the Building Complex. Tenant's failure to deliver such 
statement within such time shall be conclusive upon Tenant that: (i) this 
Lease is in full force and effect, without modification except as may be 
represented by Landlord; (ii) there are no uncured defaults in Landlord's 
performance; and (iii) not more than one (1) month's rent has been paid in 
advance. Further, upon request, Tenant will supply to Landlord a corporate or 
partnership resolution, as the case may be, certifying that the party signing 
said statement of Tenant is properly authorized to do so.

     26.  MISCELLANEOUS.

          A. The term "Landlord" as used in this Lease, so far as covenants 
or obligations on the part of Landlord are concerned, shall be limited to 
mean and include only the owner or owners of the Building Complex at the time 
in question and, in the event of any transfer or transfers of the title 
thereto, Landlord herein named (and in the case of any subsequent transfers 
or conveyances, the then grantor) shall be automatically released, from and 
after the date of such transfer or conveyance, of all liability as respects 
the performance of any covenants or obligations on the part of Landlord 
contained in this Lease thereafter to be performed, provided that any funds 
in the hands of Landlord or the then grantor at the time of such transfer in 
which Tenant has an interest shall be turned over to the grantee and any 
amount then due and payable to Tenant by Landlord or the then grantor under 
any provisions of this Lease shall be paid to Tenant.

          B. The termination or mutual cancellation of this Lease shall not 
work a merger, and such termination or mutual cancellation shall, at the 
option of Landlord, either terminate all subleases and subtenancies or 
operate as an assignment to Landlord of any or all such subleases or 
subtenancies.



                                      -26-
<PAGE>

          C. The Tenant agrees that, for the purposes of completing or making 
repairs or alterations in any portion of the Building, Landlord may use one 
or more of the street entrances, the halls, passageways, and elevators of the 
Building.

          D. This Lease shall be construed as though the covenants herein 
between Landlord and Tenant are independent and not dependent and Tenant 
shall not be entitled to any setoff of the rent or other amounts owing 
hereunder against Landlord if Landlord fails to perform its obligations set 
forth herein; provided, however, the foregoing shall in no way impair the 
right of Tenant to commence a separate action against Landlord for any 
violation by Landlord of the provisions hereof so long as notice is first 
given to Landlord and any holder of a mortgage or deed of trust covering the 
Building Complex or any portion thereof and an opportunity granted to 
Landlord and such holder to correct such violation as provided in Paragraph 
20 above.

          E. If any clause or provision of this Lease is illegal, invalid, or 
unenforceable under present or future laws effective during the term of this 
Lease, then and in that event it is the intention of the parties hereto that 
the remainder of this Lease shall not be affected thereby and it is also the 
intention of the parties to this Lease that in lieu of each clause or 
provision of this Lease that is illegal, invalid, or unenforceable there be 
added as a part of this Lease a clause or provision as similar in terms to 
such illegal, invalid, or unenforceable clause or provision as may be 
possible and be legal, valid, and enforceable.

          F. The caption of each paragraph is added as a matter of 
convenience only and shall be considered of no effect in the construction of 
any provision or provisions of this Lease.

          G. Except as herein specifically set forth, all terms, conditions, 
and covenants to be observed and performed by the parties hereto shall be 
applicable to and binding upon their respective heirs, administrators, 
executors, and assigns. The terms, conditions, and covenants hereof shall 
also be considered to be covenants running with the land to the fullest 
extent permitted by law.

          H. Tenant and the party executing this Lease on behalf of Tenant 
represent to Landlord that such party is authorized to do so by requisite 
action of the board of directors or partners, as the case may be, and agree, 
upon request, to deliver to Landlord a resolution or similar document or 
opinion of counsel to that effect.

          I. If there are more than one entity or person which or who are the 
Tenant under this Lease, the obligations imposed upon Tenant under this Lease 
shall be joint and several.

          J. No act or thing done by Landlord or Landlord's agents during the 
term hereof, including, but not limited to, any agreement to accept surrender 
of the Premises or to amend or modify this Lease, shall be deemed to be 
binding on Landlord, unless such act or thing shall be by a partner or 
officer of Landlord, as the case may be, or a party designated in writing by 
Landlord as so authorized to act. The delivery of keys to Landlord, or 
Landlord's agents,

                                      -27-

<PAGE>

employees, or officers shall not operate as a termination of this Lease or a 
surrender of the Premises. No payment by Tenant or receipt by Landlord of a 
lesser amount than the monthly rent and all other amounts owing, as herein 
stipulated, shall be deemed to be other than on account of the earliest 
stipulated rent or other amounts nor shall any endorsement or statement on 
any check or any letter accompanying any check or payment as rent be deemed 
an accord and satisfaction and Landlord may accept such check or payment 
without prejudice to Landlord's right to recover the balance of such rent or 
pursue any other remedy available to Landlord.

          K.   Landlord shall have the right at any time to change the name 
of the Building, to increase the size of the Building Complex by adding 
additional real property thereto, to construct other buildings or 
improvements on any portion of the Building Complex or to change the location 
and/or character of or to make alterations of or additions to the Building 
Complex. In the event any such additional buildings are constructed or 
Landlord increases the size of the Building Complex, Landlord and Tenant 
shall execute an Amendment to Lease which incorporates such modifications, 
additions, and adjustments to Tenant's Pro Rata Share, if necessary. Tenant 
shall not use the Building's name for any purpose other than as a part of its 
business address. Any use of such name in the designation of Tenant's 
business shall constitute a default under this Lease.

          L.   Tenant covenants and agrees that no diminution of light, air, 
or view of or from the Building or any other building (whether or not 
constructed or owned by Landlord) shall entitle Tenant to any reduction of 
rent or other charges under this Lease, result in any liability of Landlord 
to Tenant, or in any way affect this Lease or Tenant's obligations hereunder.

          M.   Notwithstanding anything to the contrary contained herein, 
Landlord's liability under this Lease shall be limited to Landlord's interest 
in the Building Complex.

          N.   Tenant acknowledges and agrees that it has not relied upon any 
statements, representations, agreements, or warranties by Landlord, its agents 
or employees, except such as are expressed herein and that no amendment or 
modification of this Lease shall be valid or binding unless expressed in 
writing and executed by the parties hereto in the same manner as the 
execution of this Lease.

          O.   Tenant agrees to make such modifications and amendments of 
this Lease as may hereafter be required to conform to any lender's 
requirements, so long as such modifications or amendments will not increase 
Tenant's obligations hereunder or materially alter its rights as set forth 
herein.

          P.   Submission of this instrument for examination or signature by 
Tenant does not constitute a reservation of or an option for lease, and it is 
not effective as a lease or otherwise until execution and delivery by both 
Landlord and Tenant.

          Q.   Tenant represents as follows:



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<PAGE>

               (1) Neither Tenant nor any of its affiliates (within the 
meaning of Part V(c) of Prohibited Transaction Exemption 84-14, 49 Fed.Reg. 
9494 (1984), as amended ("PTE 84-14") has, or during the immediately 
preceding year, has exercised authority to:

                    (a)  appoint or terminate the Prudential Insurance 
Company of America or Prudential Real Estate Investors ("Prudential") as 
investment manager over assets of any employee benefit plan invested in 
Landlord; or

                    (b)  negotiate the terms of a management agreement with 
Prudential on behalf of any such plan;

               (2) Tenant is not a "related party" of Prudential (as defined 
in Part V(h) of PTE 84-14);

               (3) Tenant has negotiated and determined the terms of this 
Lease at arm's length, as such terms would be negotiated and determined by 
Tenant with unrelated parties; and

               (4) Tenant is not an "employee benefit plan" as defined in 
Section 3(3) of the Employees Retirement Income Security Act of 1974, as 
amended ("ERISA"), a "plan" as defined in Section 4965(e)(1) of the Internal 
Revenue Code of 1986, as amended (the "Code"), or any entity deemed to hold 
"plan assets" within the meaning of 29 C.F.R. Section 2510.3-101 of any such 
employee benefit plan or plans.

     27.  AUTHORITIES FOR ACTION AND NOTICE.

          A. Except as herein otherwise provided, Landlord may act in any 
manner provided for herein by and through Landlord's Building Manager or any 
other person who shall from time to time be designated in writing.

          B. All notices, demands, statements or communications required or 
permitted to be given to Landlord hereunder shall be in writing and shall be 
deemed duly served when delivered personally to any officer of Landlord (or a 
partner of Landlord if Landlord is a partnership or to Landlord individually 
if Landlord is a sole proprietor) or manager of Landlord whose principal 
office is in the Building, or when deposited in the United States mail, 
postage prepaid, certified or registered, return receipt requested, addressed 
to Landlord at Landlord's principal office in the Building or at the most 
recent address of which Landlord has notified Tenant in writing. All notices, 
demands, statements or communications required to be given to Tenant 
hereunder shall be in writing and shall be deemed duly served when delivered 
personally to any officer of Tenant (or a partner of Tenant if Tenant is a 
partnership or to Tenant individually if Tenant is a sole proprietor) or 
manager of Tenant whose office is in the Building, when deposited in the 
United States mail, postage prepaid, certified or registered, return receipt 
requested, addressed to Tenant at the Premises, or, prior to Tenant's taking 
possession of the Premises, to the address known to Landlord as Tenant's 
principal office address. Either party shall have the right to designate in 
writing, served as above provided, a different address to

                                      -29-
<PAGE>

which notice is to be mailed. The foregoing shall in no event prohibit notice
from being given as provided in Rule 4 of Colorado Rules of Civil Procedure, as
the same may be amended from time to time.

     28.  RULES AND REGULATIONS. It is further agreed that the rules and 
regulations set forth on EXHIBIT D attached hereto shall be and are hereby 
made a part of this Lease and Tenant agrees that Tenant's employees and 
agents or any others permitted by Tenant to occupy or enter the Premises will 
at all times abide by said rules and regulations. A breach of any of such 
rules or regulations shall be deemed an Event of Default under this Lease and 
Landlord shall have all remedies as set forth in Paragraph 19 hereof.

     29.  PARKING. Tenant shall be provided non-assigned surface parking in 
the Building parking lots at a ratio of one (1) space per three hundred (300) 
rentable square feet of office space leased. Based upon leasing 7,108 
rentable square feet, this ratio equates to twenty-four (24) spaces, all of 
which will be provided at no expense to Tenant during the Primary Lease Term.

     30.  SUBSTITUTE PREMISES. At any time during the Extension Term, 
Landlord shall have the right upon thirty (30) days' prior written notice to 
Tenant to substitute other substantially comparable space within the 
Building, including substantially comparable tenant finish, for the Premises 
(the "Substitute Premises"). Tenant shall relocate to the Substitute Premises 
on the date set forth in Landlord's notice (to occur no sooner than thirty 
(30) days after receipt by Tenant of said notice). Landlord agrees to pay all 
reasonable expenses incurred by Tenant to move its furniture, fixtures, and 
equipment to the Substitute Premises. The suite number designation and 
Exhibit A shall be deemed revised to reflect the description of the 
Substitute Premises. Except for such revisions, the terms and provisions of 
the Lease shall be applicable to the Substitute Premises and the Substitute 
Premises shall be deemed to be the Premises under the Lease.

     31.  BROKERAGE. Tenant hereby represents and warrants that Tenant has 
not employed any broker other than Frederick Ross Company in regard to this 
Lease and that Tenant has no knowledge of any other broker being instrumental 
in bringing about this Lease transaction except Cushman and 
Wakefield/Premisys Colorado, Inc., a Delaware corporation ("Cushman and 
Wakefield") which has acted as Landlord's leasing agent. Tenant shall 
indemnify Landlord against any expense incurred by Landlord as a result of 
any claim for brokerage or other commissions made by any other broker, 
finder, or agent, whether or not meritorious, employed by Tenant or claiming 
by, through, or under Tenant. Tenant acknowledges that Landlord shall not be 
liable for any representations by Cushman and Wakefield regarding the 
Premises, the Building, or this lease transaction.

     32.  TIME OF ESSENCE. Time is of the essence herein.

     33.  OPTION TO EXTEND. Provided that this Lease is in full force and 
effect and no Event of Default, or event which but for the passage of time or 
the giving of notice, or both, would constitute an Event of Default has 
occurred and is continuing, Tenant shall have one




                                      -30-
<PAGE>

option to extend the Lease for a period of one (1) year (the "Extension 
Term") beginning immediately after the Primary Lease Term upon the same terms 
and conditions provided in this Lease except that (i) Base Rent will be equal 
to the then-current market rental rate for the Premises as determined by the 
Landlord; and (ii) the option to extend stated in this Paragraph shall be 
deleted. Tenant may exercise this option by giving Landlord at least one 
hundred twenty (120) days written notice prior to the expiration of the 
Primary Lease Term.

     34.  SIGNAGE. In the event that, and at such time as, Tenant leases more 
than 10,000 square feet in the Building, for a term of at least three years, 
at Tenant's request and sole expense, Landlord will put a Building-standard 
sign with Tenant's name on it on one or both of the two exterior monument 
signs located outside the Building. Further, prior to the installation of any 
sign, Tenant shall pay to Landlord a fee in an amount to be agreed upon 
between Landlord and Tenant, which fee shall be in addition to the costs of 
design and installation of any such sign.

     35.  RIGHT OF FIRST REFUSAL. If, prior to the expiration or sooner 
termination of the Term of this Lease, (a) Landlord receives an offer to 
lease the 26,802 rentable square foot premises located on the third floor of 
the Building and shown on Exhibit A-2 hereto or (b) Landlord receives an 
offer to lease the 1,773 rentable square foot area adjacent to the Premises 
which is known as Suite 206 (either space shall be referred to as the 
"Refusal Space"), which Landlord desires to accept, and provided that Tenant 
is not in default, Landlord shall give Tenant written notice of such offer, 
setting forth the rental rate and all other terms and conditions of such 
offer, and Tenant shall have the exclusive first right and option to lease 
the Refusal Space by giving written notice to Landlord of its intention to 
lease the Refusal Space within three (3) business days after such notice, at 
the same price and on the same terms of any such offer, it being understood 
that in the event Tenant does not give notice of its intention to exercise 
said right and option to lease within said three (3) business day period, 
Landlord shall be free to lease the Refusal Space upon the same terms and 
conditions given to Tenant, and in the event the Refusal Space is not leased 
for any reason, Tenant shall have, upon the same conditions and notice, the 
continuing right and option to lease the same upon the terms of any 
subsequent offer or offers to lease. The termination of Tenant's right of 
first refusal for the Refusal Space for nonexercise, is automatic and 
self-executing, however, Tenant shall upon request, execute and deliver to 
Landlord a release of such right and option. Notwithstanding the foregoing, 
the right of first refusal with respect to Suite 206 shall be subordinate and 
subject to, the rights of any existing tenant of Suite 206, and an offer to 
lease by such tenant shall not activate a right of first refusal in favor of 
Tenant.

     IN WITNESS WHEREOF, the parties hereto have caused this Lease to be 
executed the day and year first-above written.



                                      -31-
<PAGE>

FIRSTWORLD COMMUNICATIONS, INC.,         THE PRUDENTIAL INSURANCE
a Delaware corporation                   COMPANY OF AMERICA, a New Jersey
                                         corporation

By: /s/ Scott Chase                      By: CUSHMAN AND WAKEFIELD/
   --------------------------------      PREMISYS COLORADO, INC., a
Its: Senior Vice President,              Delaware corporation, as agent for The
     Corporate & Government Affairs      Prudential Insurance Company of America
    ------------------------------- 

                                         By: /s/ Stephen M. Schwab
                                            -------------------------------
                                            Stephen M. Schwab
                                            Its: Director





                                      -32-