LEASE

                                       FOR

                            FRONTIER CENTER ONE, LLC,
                      a Colorado limited liability company

                                  (as Landlord)

                                       and

                            FRONTIER AIRLINES, INC.,
                             a Colorado corporation

                                   (as Tenant)


<PAGE>


                                      LEASE

         This  Lease is made as of the day of , 2000,  by and  between  Frontier
Center One, LLC, a Colorado limited liability company  ("Landlord") and Frontier
Airlines, Inc., a Colorado corporation, ("Tenant").

                               W I T N E S S E T H

     1. Basic Provisions. In addition to other terms which are defined elsewhere
in this Lease or any Exhibits, the terms defined in the following subsections of
this Section 1 shall have the meaning set forth in such subsection whenever used
in this Lease.

         1.1......Building:  Approximately  * rentable  square  foot,  one story
building to be  constructed by Landlord  commonly known as Frontier  Center One,
with a street address of 7001 Tower Road, Denver, CO 80249.

         1.2......Premises:  Approximately  *  rentable  square  feet  of  space
located in the Building, including all improvements therein or to be provided by
Landlord under the terms of this Lease, commonly known as Suite 101, as outlined
on Exhibit A attached  hereto,  and  approximately * square feet of space in the
Building  services court depicted on Exhibit A-1 attached hereto and made a part
hereof,  (the "Ground  Satellite Area" described in Section 49 hereof) and a day
care play area (the "DC Play  Area"),  if  requested  by Tenant and  approved by
Landlord in accordance with Exhibit C hereof.  In addition to Tenant's rights to
use and  occupy  the  Premises  as  hereinafter  specified,  Tenant  shall  have
non-exclusive  rights to the Common  Areas (as  defined in Section 2.4 below) as
hereinafter  specified,  but shall not have any  rights to the roof  (except  as
expressly  granted in Section 49 hereof),  exterior walls or utility raceways of
the Building or to any other buildings in the Building Complex.

         1.3......Building Complex: The Premises, the Building, the Common Areas
(as defined below), the land upon which they are located,  which land is legally
described  on  Exhibit B  attached  hereto  and made a part  hereof  (the  "Real
Property").

         1.4......Parking:  *  unreserved  vehicle  parking  spaces  for  each *
rentable square feet of the Premises, excluding the Ground Satellite Area and DC
Play Area from such calculation.

         1.5......Term:  * years and * months ("Primary Lease Term")  commencing
October 1, 2000 ("Commencement Date").

         1.6......Estimated Delivery  Date:  October 1, 2000.   [This  is  a non
binding estimate of the date on which the Premises will be Ready for Delivery as
defined below.]

         1.7......Base Rent:

         .........(a)  For the  Primary  Lease Term and  commencing  on the Rent
Commencement  Date,  as defined in Section 4.1 below,  Base Rent for the first *
rentable square feet of the Premises  excluding the Ground Satellite Area and DC
Play Area shall be:


<PAGE>




                           Lease Year Per Square Foot

                            1                   $ *
                            2                   $ *
                            3                   $ *
                            4                   $ *
                            5                   $ *
                            6                   $ *
                            7                   $ *
                            8                   $ *
                            9                   $ *
                           10                   $ *
                           11                   $ *
                           12                   $ *

                  (b) In addition,  with respect to the rentable  square feet of
the Building leased by Tenant  exceeding * rentable  square feet,  excluding the
Ground Satellite Area and DC Play Area, which are part of the Premises as of the
Commencement  Date, * rentable  square feet, the Base Rent for the Primary Lease
Term shall be as follows:

                           Lease Year Per Square Foot

                             1                   $ *
                             2                   $ *
                             3                   $ *
                             4                   $ *
                             5                   $ *
                             6                   $ *
                             7                   $ *
                             8                   $ *
                             9                   $ *
                            10                   $ *
                            11                   $ *
                            12                   $ *

                  (c) In  addition,  Tenant shall pay Base Rent in the amount of
$* per month, for the Primary Lease Term for the Ground Satellite Area described
in Section 49 hereof.

         1.8 Rentable Area:  Approximately  * rentable  square feet which is all
rentable  space  available  for  lease in the  Building  ("Rentable  Area of the
Building") and  approximately * rentable square feet which is the rentable space
located  within the  Building  comprising  the  Premises,  excluding  the Ground
Satellite  Area and DC Play  Area,  ("Rentable  Area of the  Premises").  Unless
otherwise  provided  herein,  any square footage set forth in this Lease or that
may have been used in calculating the Rent and/or Common Area Operating Expenses
is an  approximation  which Landlord and Tenant agree is reasonable and the Base
Rent and Tenant's Share based thereon are not subject to revision whether or not
the actual square footage is more or less.  Notwithstanding  the  foregoing,  if
there is: (i) alteration to the Premises or the Building after the  Commencement
Date; or (ii) any change in the designated  Rentable Area of the Premises and/or
the Building after the Commencement Date, then Landlord shall have the exclusive
discretion to recalculate Tenant's Share by substituting the revised approximate
Rentable Area of the Premises and/or the Building in the  calculation  described
above.  Any change in the  approximate  Rentable Area of the Premises and/or the
Building   recalculated  by  Landlord  shall  be  effective,   for  purposes  of
calculating  Tenant's Share as of the first day of the next calendar month after
Landlord  provides to Tenant written notice of such change.  Landlord and Tenant
agree that the Rentable  Area of the Premises  shall be determined in accordance
with Paragraph 3 of the Work Agreement,  Exhibit C hereto, and the Base Rent and
Tenant's Share of Operating Expenses shall be calculated at that time.  Rentable
Area shall be calculated in  accordance  with the Standard  Method for Measuring
Floor Area in Office  Buildings  published by The  Building  Owners and Managers
Association  International  and  approved  by the  American  National  Standards
Institute, Inc., on June 7, 1996.

         1.9 Tenant's Share of Operating  Expenses:  A percentage  determined by
dividing the Rentable Area of the Premises by the Rentable Area of the Building.
Tenant shall commence paying Tenant's share of Operating  Expenses on January 1,
2001.  Landlord and Tenant acknowledge that Tenant has been granted the right to
more  parking  spaces  than  other  tenants  will  be  granted.   Therefore,  in
calculating Tenant's Share of Operating Expenses,  Tenant shall pay * percent of
all costs  associated  with the  maintenance,  repair or  replacement of parking
areas for each  percent of  Tenant's  Share of other  Operating  Expenses.  (For
example,  if Tenant's  Share is *%,  Tenant's share for parking areas is * x * =
*.)

         1.10 Security Deposit:   Initially  $*  and  thereafter   decreasing in
accordance with Section 5.3 herein.

         1.11 Permitted  Use: (i) General  office;  (ii)  telephone  reservation
center; (iii) classroom training;  (iv) flight simulator training;  (v) dispatch
center;  (vi)  cafeteria  only  for  employees;  (vii)  exercise  area  only for
employees;  and  (viii)  day care  center  and for no other  purpose;  provided,
however,  at no time during the Primary  Lease Term as it may be  extended,  may
more than * of the Rentable  Area of the Premises at any time,  be used for uses
(vi) through (viii) above.

         1.12 Applicable Laws:  Applicable zoning, municipal, county, state  and
federal laws, ordinances and regulations  and  any covenants or restrictions  of
record (collectively, "Applicable Laws").

         1.13 Business Day: Monday through Friday, legal holidays (days on which
the U.S. Post Office is closed) excepted.

         2.   Premises, Parking and Common Areas.

         2.1  Grant.  In  consideration  of the  Rent  and the  other  covenants
described in the Lease,  Landlord  hereby  leases to Tenant,  and Tenant  hereby
leases from  Landlord,  the Premises,  for the Term, at the Rent and upon all of
the terms, covenants and conditions set forth in this Lease. Tenant accepts this
Lease and the Premises upon the covenants and conditions set forth in this Lease
and subject to: (a) any encumbrances,  covenants,  conditions,  restrictions and
other matters of record as of the  Commencement  Date of the Lease;  and (b) the
Applicable Laws.  Landlord hereby  represents,  covenants and warrants to Tenant
that,  as of the  Commencement  Date it will have fee  simple  title to the Real
Property of which the Premises is a part and as of the  Commencement  Date,  the
Premises  will not be  subject to leases and  tenancies  other than this  Lease.
Furthermore,  between the date of this Lease and the Commencement Date, Landlord
agrees not to record (or voluntarily permit recording) against the Real Property
any document which would prohibit Tenant's Permitted Use.

         2.2 Landlord  Delivery.  Landlord  shall deliver the Premises to Tenant
"Ready for Delivery" as hereafter  defined  within the time frames  described in
Section 3.2 herein.  Ready for  Delivery as used herein shall mean the date that
Tenant may enter the Premises to perform  Tenant's Work (as defined in Exhibit C
hereto) including,  sufficient access to the Premises for construction vehicles.
The  certificate of the architect (or other  representative  of the Landlord) in
charge of supervising the completion of the Premises shall control  conclusively
the date upon  which the  Premises  are  Ready  for  Delivery.  On and after the
Delivery Date, Tenant and its authorized agents, contractors, subcontractors and
employees  shall be  entitled to enter the  Premises  at Tenant's  sole risk and
expense to complete  Tenant's  Work.  From the  Delivery  Date,  estimated to be
October 1, 2000,  the  provisions  of this Lease other than with  respect to the
payment of Base Rent and Tenant's  Share of Operating  Expenses  shall apply and
Tenant  shall pay for all  utilities  used by Tenant,  its agents,  contractors,
subcontractors  or employees.  Prior to entry,  Tenant shall provide to Landlord
evidence of insurance  to be provided by Tenant  pursuant to the  provisions  of
Section 9 of this Lease. Tenant acknowledges that on the Delivery Date, Landlord
will be completing  Landlord's Work (as defined in Exhibit C hereto) and Tenant,
its agents,  employees  and  contractors  shall not  interfere,  delay or hinder
Landlord,   its  agents,   contractors  or  subcontractors  in  construction  of
Landlord's  Work in  accordance  with the  provisions of this Lease and any such
delay shall be Tenant Delay as described in the Work Agreement. Tenant shall not
use the Premises for storage of  inventory  or otherwise  commence  operation of
business  until such time as Tenant has  received  and  delivered  to Landlord a
Certificate of Occupancy  (temporary or final) or an equivalent  sign-off issued
by the appropriate governmental authority permitting use of the Premises for the
Permitted Use under the Lease.

         2.3  Acceptance  of Premises.  Landlord  has advised  Tenant to satisfy
itself with respect to the condition of the Premises including,  but not limited
to, the electrical and fire sprinkler systems, security,  environmental aspects,
and  compliance  with  the  Americans  with  Disabilities  Act  ("ADA")  and the
Applicable  Laws and the  present and future  suitability  of the  Premises  for
Tenant's   intended  use.   Notwithstanding   the  foregoing,   and  subject  to
reimbursement  as set forth in Section 4.2 below,  Landlord will be  responsible
for  compliance  of the  Common  Areas of the  Building  with  Applicable  Laws;
provided,  however, Landlord shall have no obligation for non-compliance if such
non-compliance  is a  result  of  Tenant's  Permitted  Use or  occupancy  of the
Premises. The Landlord's Work (as the term is used in Exhibit C hereto), without
any interior  finish work will comply with the  requirements of the ADA required
for a commercial facility with no day care facility and excluding  noncompliance
due  to  inconsistencies   with  building  codes  or  interpretations   thereof.
Compliance with the ADA as to the Tenant's Work shall be the sole responsibility
of  Tenant  and  Tenant's  Work will  comply  with the  requirements  of the ADA
required for Tenant's  Permitted  Use,  including  the day care center if Tenant
elects to operate one.  Landlord's  Work and Tenant's Work shall be completed in
accordance  with  Exhibit C attached  hereto and made a part  hereof  (the "Work
Agreement").  Except as set forth  expressly  herein and in the Work  Agreement,
Landlord  shall have no obligation  for  completion of any  improvements  to the
Premises and Tenant  shall  accept the Premises in its "AS IS"  condition on the
Lease  Commencement  Date.  Subject to Total  Delay (as  defined in Section  3.2
hereof),  Landlord's Work will be substantially completed (excluding landscaping
and parking lot  striping  that may not be able to be  performed  due to time of
year or weather constraints) by the Rent Commencement Date.

         2.4 Common Areas.  The term "Common  Areas" is defined as all areas and
facilities  outside the Premises  and  excluding  Rentable  Area of the Building
leased to other  tenants and within the exterior  boundary  line of the Building
Complex and interior  utility raceways within the Premises that are provided and
designated by the Landlord from time to time for the general  non-exclusive  use
of  Landlord,  Tenant  and  other  tenants  of the  Building  Complex  and their
respective employees, suppliers, shippers, customers,  contractors and invitees,
including  parking areas,  loading and unloading areas,  trash areas,  roadways,
sidewalks,  walkways,  parkways, driveways and landscaped areas. Landlord hereby
grants to  Tenant,  for the  benefit  of Tenant  and its  employees,  suppliers,
shippers, contractors, customers and invitees, during the Term of this Lease the
non-exclusive  right to use,  in common with  others  entitled to such use,  the
Common Areas as they exist from time to time, subject to any rights, powers, and
privileges reserved by Landlord under the terms hereof or under the terms of any
rules and regulations or restrictions governing the use of the Building Complex.
Under no  circumstances  shall the right therein granted to use the Common Areas
be  deemed  to  include  the  right  to  store  any  property,   temporarily  or
permanently,  in the Common Areas.  Any such storage shall be permitted  only by
the prior written  consent of Landlord or  Landlord's  designated  agent,  which
consent may be revoked at any time. In the event that any  unauthorized  storage
shall occur, then Landlord shall have the right,  without notice, in addition to
such other  rights and  remedies  that it may have,  to remove the  property and
charge the cost to Tenant,  which cost shall be immediately  payable upon demand
by Landlord. Landlord or such other person(s) as Landlord may appoint shall have
the  exclusive  control and  management  of the Common  Areas and shall have the
right,  from time to time, to establish,  modify,  amend and enforce  reasonable
rules and regulations  with respect  thereto subject to any limitations  thereon
specifically set forth herein. Landlord shall have the right, in Landlord's sole
discretion,  from  time  to  time:  (i) to make  changes  to the  Common  Areas,
including,  without limitation,  changes in the location, size, shape and number
of driveways,  entrances,  parking spaces,  parking areas, loading and unloading
areas,  ingress,  egress,  direction of traffic,  landscaped areas, walkways and
utility  raceways so long as access to the Premises  remains  available and such
modifications  do not  contravene  any  specific  requirement  contained in this
Lease;  (ii) to  close  temporarily  any of the  Common  Areas  for  maintenance
purposes so long as reasonable access to the Premises remains  available;  (iii)
to designate  other land outside the boundaries of the Building  Complex to be a
part of the Common Areas;  (iv) to add additional  buildings and improvements to
the Common Areas; (v) to use the Common Areas while engaged in making additional
improvements,  repairs or  alterations to the Building  Complex,  or any portion
thereof  as long as access to the  Premises  remains  available;  (vi) to do and
perform  such other acts and make such other  changes in, to or with  respect to
the Common Areas and Building  Complex as Landlord may, in the exercise of sound
business  judgment deem to be appropriate so long as such acts or  modifications
do not contravene any specific requirement  contained in the Lease and access to
the Premises  remains  available;  and (vii) use the Common Areas for  marketing
purposes.

         2.5 Parking.  Tenant shall be entitled to use the number of  unreserved
parking  spaces  specified in Section 1.4 (which number of spaces may be reduced
if Tenant elects to place a day care center in the Premises and must install the
DC Play Area to comply with  Applicable Laws related to such day care center) on
a first  come,  first  served  basis  on  those  portions  of the  Common  Areas
designated from time to time by Landlord for parking.  Tenant shall not use more
parking spaces than said number. Said parking spaces shall be used in compliance
with the Parking License attached as Exhibit G hereto and made a part hereof for
parking by vehicles no larger than full-size passengerautomobiles, sport utility
vehicles,  passenger  vans, or pick-up  trucks,  herein called  "Permitted  Size
Vehicles."  Vehicles  other than  Permitted  Size  Vehicles  shall be parked and
loaded or unloaded as directed by Landlord in the Rules and  Regulations  issued
by Landlord. Tenant shall not permit or allow any vehicles that belong to or are
controlled  by Tenant or Tenant's  employees,  suppliers,  shippers,  customers,
contractors  or invitees to be loaded,  unloaded,  or parked in areas other than
those  designated by Landlord for such  activities.  If Tenant permits or allows
use of the prohibited areas, then Landlord shall have the right, without notice,
in addition to such other rights and remedies that it may have, to remove or tow
away the vehicle involved and charge the cost to Tenant,  or if applicable,  the
owner of the vehicle  where  Tenant has not  permitted or allowed the use of the
prohibited  area,  which  cost  shall be  immediately  payable  upon  demand  by
Landlord,  if Tenant shall be  responsible  for such costs pursuant to the terms
hereof.

         3.   Term.

         3.1  Term.  The Commencement Date,  Expiration Date  and  Primary Lease
Term of this Lease are as specified in Section 1.5.

         3.2  Delay in Possession.

                  (a) If for any reason  Landlord  cannot deliver  possession of
the Premises to Tenant in accordance with the terms of Section 2.2 hereof by the
Estimated  Delivery  Date,  Landlord  shall  not be  subject  to  any  liability
therefor,  nor shall such  failure  affect the  validity of this  Lease,  or the
obligations of Tenant  hereunder,  or extend the Term hereof;  but in such case,
Tenant shall not, except as otherwise  provided herein, be obligated to pay Base
Rent,  utility  costs or Tenant's  Share of Operating  Expenses,  or perform any
other obligation of Tenant under the terms of this Lease until Landlord delivers
the  Premises  to Tenant in the  condition  described  in  Section  2.2.  If the
Premises  are not  Ready  for  Delivery  by the  Commencement  Date set forth in
Section 1.5 hereof, and such delay is due to other than Tenant Delay (as defined
in Exhibit C hereto)  and  except  for force  majeure  events,  Tenant  shall be
entitled to * day of occupancy  of the Premises  without the payment of the Base
Rent for each day after * days (the "*-Day Period") from the  Commencement  Date
as set forth in Section 1.5 that the Premises are not Ready for Delivery. Tenant
Delay and delay due to force majeure  events may be called "Total Delay" herein.
Such *-Day  Period  shall be extended  one day for each day of Total Delay until
the Premises  are Ready for  Delivery.  The term "force  majeure" as used herein
shall mean delay due to causes  outside of Landlord's  control that could not be
avoided  by the  exercise  of due care,  including,  without  limitation,  labor
disputes,  fire,  flood,  earthquake  or  civil  disturbance,  unusual  delay in
transportation,  adverse weather conditions,  or casualties. If the Premises are
not Ready  for  Delivery  * days  after  the  Commencement  Date as set forth in
Section 1.5 hereof, and such delay is due to other than Total Delay Tenant shall
be entitled to * days of occupancy of the Premises  without  payment of the Base
Rent for each day after * days from the  Commencement  Date set forth in Section
1.5 that the  Premises  are not Ready for  Delivery.  Such * day period shall be
extended  one day for each day of Total Delay until the  Premises  are Ready for
Delivery.  If  the  Premises  are  not  Ready  for  Delivery  * days  after  the
Commencement  Date as set forth in Section 1.5 hereof,  and such delay is due to
other than Total Delay, Tenant shall have the right to terminate this Lease upon
written notice to Landlord given within * calendar days after such * day period.
If Tenant exercises its right to terminate hereunder, effective on the date such
notice is  received  by  Landlord,  this Lease  shall be null and void and of no
further  force and  effect.  If Tenant  fails to  timely  exercise  its right to
terminate,  this  Lease  shall  continue  in full force and effect and the Lease
Commencement  Date shall be the date that the Premises  are Ready for  Delivery.
The delay of the  Commencement  Date, the Rent credit and the right to terminate
the Lease as set forth herein shall be in full satisfaction of any claims Tenant
might otherwise have as a result of such delay;  provided,  however,  except for
Total Delay, if and only if after the *-Day Period, Landlord is fully capable of
performing  Landlord's  Work and  fails to  proceed  with  Landlord's  Work with
reasonable  diligence,  in addition to the Rent credit described above, Landlord
will be  liable  to Tenant in the  total  amount  of  Tenant's  actual  damages,
excluding any consequential damages, resulting from the delay in delivery of the
Premises in Ready for  Delivery  condition  arising  from  delays  which are not
Tenant Delay but are delays over which  Landlord does have control and for which
Landlord fails to proceed with reasonable  diligence.  Likewise, in the event of
Tenant Delay  exceeding * days,  Tenant shall be liable to Landlord in the total
amount of  Landlord's  actual  damages,  excluding  any  consequential  damages,
arising out of Tenant Delay in excess of * days.

                  (b)  If  in  accordance  with  the  foregoing  provision,  the
Commencement  Date would occur on other than the first day of a calendar  month,
the Commencement  Date shall be delayed until the first day of the next calendar
month and the  Primary  Lease Term shall be measured  from such date;  provided,
however, during any period of delayed commencement, all terms and provisions set
forth in this Lease  including,  but not limited to Tenant's  obligation  to pay
Base Rent and all other  charges  under the Lease shall  commence  measured from
such earlier  date.  In order to place in writing the exact  Commencement  Date,
Rent  Commencement  Date and expiration date of the Lease,  the Rentable Area of
the Premises and Building, the parties agree to execute a supplemental agreement
to become a part hereof in the form attached hereto as Exhibit E.

         3.3 Lease Year.  "Lease Year" as used in this Lease shall be defined as
each  twelve  month  period  beginning  with the Rent  Commencement  Date or any
anniversary thereof and ending on the immediately preceding day one year later.

         4.   Rent.

         4.1 Base Rent. Tenant shall pay Base Rent and other rent or charges, as
the same may be adjusted  from time to time,  to Landlord in lawful money of the
United  States,  without offset or deduction on or before the day on which it is
due under the terms of this  Lease.  Subject  to the terms of Section  3.2,  the
first  payment of Base Rent shall be due no later than * calendar  months  after
the Commencement Date (the "Rent  Commencement  Date").  Base Rent and all other
Rent and  charges for the period  during the Term hereof  which is for less than
one full month  shall be  prorated  based upon the actual  number of days of the
month involved. Payment of Base Rent and other charges shall be made to Landlord
at its address stated herein or to such other persons or at such other addresses
as Landlord may from time to time designate in writing to Tenant.

         4.2 Operating Expenses. Subject to the terms of Section 3.2, commencing
no later than * calendar months after the Commencement Date, Tenant shall pay to
Landlord  during the Term hereof,  in addition to the Base Rent,  Tenant's Share
(as specified in Section 1.8) of all Operating Expenses, as hereinafter defined,
during each  calendar  year of the Term of this Lease,  in  accordance  with the
following provisions:

                  (a)  "Operating  Expenses"  are defined,  for purposes of this
Lease, as all costs incurred by Landlord relating to the ownership and operation
of the Building Complex including, but not limited to, the following:

                    (i) The operation,  repair and maintenance,  in neat, clean,
               good order and condition of the Common Areas,  including  parking
               areas,  loading  and  unloading  areas,  trash  areas,  roadways,
               sidewalks,  walkways,  parkways,  driveways,   landscaped  areas,
               striping,  bumpers,  irrigation  systems,  Common  Area  lighting
               facilities,  fences and gates,  elevators,  roofs,  and  exterior
               walls,  including  paint;  exterior  signs,  awnings,  any tenant
               directories, and fire detection and sprinkler systems.

                    (ii)  The  cost  of  water,  sewer,  gas,   electricity  and
               telephone to service the Common Areas,  or Premises to the extent
               not separately metered.

                    (iii)  Snow,  ice  and  trash  removal   service,   property
               management   and   security   services   and  the  costs  of  any
               environmental  inspections and the heating,  air conditioning and
               ventilating maintenance contract.

                    (iv) The costs of capital  improvements,  structural repairs
               and  replacements  in or to the  Building  in order to conform to
               changes  subsequent to the  Commencement  Date in any  Applicable
               Laws,   ordinances,   rules,   regulations   or   orders  of  any
               governmental or quasi-governmental  authority having jurisdiction
               over the building  (the  "Required  Capital  Improvements");  the
               costs  of  any  capital  improvements,   structural  repairs  and
               replacements  designed primarily to reduce any Operating Expenses
               (the "Cost Savings Improvements").  The expenditures for Required
               Capital  Improvements  and  Cost  Savings  Improvements  shall be
               amortized at a market rate of return over the useful life of such
               item   as   determined   by   Landlord's   accountants.   Capital
               Improvements  shall not  include  the  initial  costs of Building
               expansions for purposes of determining Operating Expenses.

                    (v)  Real  Property  Taxes  to be paid by  Landlord  for the
               Building and the Common Areas under Section 11 hereof.

                    (vi) The cost of the  premiums  for the  insurance  policies
               maintained by Landlord under Section 9 hereof.

                    (vii) Any deductible  portion of an insured loss  concerning
               the Building or the Common Areas.

                    (viii) Any other  services to be  provided by Landlord  that
               are stated elsewhere in this Lease to be an Operating Expense.

                    (ix) The cost of  maintenance,  repair or replacement of the
               fire protection system.

                  (b)      Operating Expenses shall not include:


                    (i) any repairs to, or  replacements of the Building roof or
               structural  elements (including  foundations,  structural columns
               and  beams  and load  bearing  walls) to the  extent  covered  by
               warranty;

                    (ii) any  latent  defect of  Landlord's  Work  (Tenant  must
               notify   Landlord  of  such   defects   within  90  days  of  the
               Commencement Date);

                    (iii) any items (including but not limited to costs incurred
               by Landlord  for repair of damage to the  Building) to the extent
               Landlord receives reimbursement from insurance proceeds or from a
               third party  however any  deductible  portion of any insured loss
               may be included in operating expenses;

                    (iv) interest or principal  payments or any other  financing
               costs of any mortgage or any indebtedness of Landlord,  except as
               expressly included in Section 4.2(a) above.

                    (v) Depreciation,  amortization, or interest payments except
               as specifically included in Operating Expenses;

                    (vi)  Landlord's  general  corporate  overhead  and  general
               administrative expenses including but not limited to, salaries of
               officers  and  executives  of Landlord  except to the extent they
               provide direct service to the Building Complex;

                    (vii) advertising and promotional  expenditures and costs of
               signs in or on the Building identifying the owner of the Building
               or its manager;

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

                    (ix) costs, fees,  penalties and other expenses arising from
               the presence,  remediation or removal of any Hazardous Substances
               on or from the  Building  or Real  Property,  not  caused  by the
               actions of Tenant;

                    (x) any item to the extent  that  Tenant's  payment  thereof
               would result in Landlord  receiving  more than 100% of Landlord's
               actual expenditure;

                    (xi) legal and accounting fees for preparation of Landlord's
               business  documents  including the preparation of any and all tax
               returns; and

                    (xii) repairs or restoration necessitated by condemnation to
               the extent  reimbursed  by the award  granted  by the  condemning
               authority.

                  (c) The inclusion of the improvements, facilities and services
set forth in Section  4.2(a)  shall not be deemed to impose an  obligation  upon
Landlord to either have said  improvements  or  facilities  or to provide  those
services unless Landlord has agreed  elsewhere in this Lease to provide the same
or some of them.

                  (d) Tenant's  Share of Operating  Expenses shall be payable by
Tenant within * days after a reasonably detailed statement of actual expenses is
presented to Tenant by Landlord. At Landlord's option, however, an amount may be
reasonably estimated by Landlord, from time to time, of Tenant's Share of annual
Operating  Expenses  and the same shall be payable  monthly,  as Landlord  shall
designate,  during  each  calendar  year on the same day as the Base Rent is due
hereunder.  If during any  particular  calendar  year,  there is a change in the
information  on which  Landlord  based the  estimate  upon which  Tenant is then
making its estimated  Operating Expense payments so that such estimate furnished
to Tenant is no longer  accurate,  Landlord  shall be  permitted  to revise such
estimate,  from  time to time,  by  notifying  Tenant  and  there  shall be such
adjustments made in the monthly amount of Tenant's Share on the first day of the
month following the serving of such statement to Tenant.  Landlord shall deliver
to Tenant after the  expiration  of each  calendar  year a  reasonably  detailed
statement  showing  Tenant's  Share of the actual  Operating  Expenses  incurred
during the preceding year. If Tenant's payments under this Section 4.2(c) during
said  preceding  calendar  year  exceed  Tenant's  Share  as  indicated  on said
statement,  Tenant  shall be  credited  the amount of such  overpayment  against
Tenant's  Share of Operating  Expenses next  becoming due. If Tenant's  payments
under this Section  4.2(c)  during said  preceding  year were less than Tenant's
Share as indicated on said statement, Tenant shall pay to Landlord the amount of
the  deficiency  within * days  after  delivery  by  Landlord  to Tenant of said
statement. Landlord's failure to deliver to Tenant a statement of Tenant's Share
within * days after the end of the  applicable  calendar  year shall not relieve
Tenant of the  obligation  to pay sums  otherwise  due, but Landlord  shall make
reasonable efforts to cause such statement to be delivered to Tenant within such
period and shall deliver such statement to Tenant no later than * days after the
end of the applicable  calendar year.  Tenant's obligation to pay Tenant's Share
of  Operating  Expenses  which accrue  during the Term hereof shall  survive the
expiration or termination of the Lease.

                  (e) If  Tenant  shall  dispute  the  amount  of an  adjustment
submitted by  Landlord's  accountants  or the proposed  estimate on the basis of
which  Tenant's  Rent is to be adjusted as  provided  in  subsection  (d) above,
Tenant shall give Landlord  written notice of such objection within * days after
Landlord's  accountants or Landlord advise Tenant of such adjustment or proposed
increase or  decrease.  If Tenant does not give  Landlord  such  written  notice
within such time,  Tenant  shall have waived its right to dispute the amounts so
determined.  If Tenant timely objects, Tenant shall have the right to engage its
own certified public  accountants  ("Tenant's  Accountants")  for the purpose of
verifying the accuracy of the statement  complained of or the  reasonableness of
the estimated increase or decrease.  If Tenant's  Accountants  determine that an
error has been made,  Landlord's  accountants  and  Tenant's  Accountants  shall
endeavor to agree upon the matter,  failing  which the parties  shall settle the
dispute by  judicial  action or in such other  manner as they  agree.  All costs
incurred by Tenant in obtaining its own accountants  shall be paid for by Tenant
unless  Tenant's  Accountants  disclose  an error,  acknowledged  by  Landlord's
accountants (or found to have occurred in a judicial action),  of more than * in
the  computation  of the total amount of Operating  Expenses as set forth in the
statement  submitted by Landlord's  accountants  which is  challenged,  in which
event Landlord  shall pay the  reasonable  costs incurred by Tenant in obtaining
such audit (but  excluding  any such costs billed on a  contingency  fee basis).
Notwithstanding  the  pendency of any  dispute  over any  particular  statement,
Tenant  shall  continue  to pay  Landlord  the  amount of the  adjusted  monthly
installments of Rent determined by Landlord's  accountants  until the adjustment
has been determined to be incorrect as aforesaid. If it shall be determined that
any portion of the Operating  Expenses  were not properly  chargeable to Tenant,
then Landlord shall promptly credit or in or after the final Lease Year,  refund
the  appropriate sum to Tenant.  Delay by Landlord or Landlord's  accountants in
submitting  any  statement  contemplated  herein for any calendar year shall not
affect the  provisions  of this Section 4 or  constitute a waiver of  Landlord's
rights as set forth herein for said  calendar  year or any  subsequent  calendar
years during the Primary Lease Term and any extensions thereof.

         4.3 Rent. The Base Rent,  Tenant's  Share of Operating  Expense and all
other  amounts  due to be paid to  Landlord  under this Lease may be referred to
herein collectively as "Rent".

         4.4  Additional  Consideration.  As  Additional  Consideration  for the
Tenant's  entering the Lease for the  Premises,  Landlord will pay to Tenant the
amount of $* each calendar quarter commencing * and continuing each * thereafter
up to a total of $*; provided that on the date of each payment: (i) the Lease is
in full  force and  effect at the time of each  payment;  (ii)  Tenant has taken
possession  of the Premises and has commenced  payment of Rent;  (iii) Tenant is
not in monetary  default or material  non-monetary  default under the Lease; and
(iv) Tenant has not  assigned  the Lease or sublet any  interest in the Lease or
the  Premises  other  than to  Affiliates  of Tenant  (as  defined  below).  The
Additional  Consideration  is  personal to Tenant and may not be assigned to any
third party, nor shall it be for the benefit of any party other than Tenant.  An
"Affiliate"  as used  herein  shall  mean a company  that  controls  the  Tenant
corporation,  or is  controlled  by the Tenant  corporation  or is under  common
control with the Tenant corporation.

         5.   Security Deposit.

         5.1 The  later of the date the  Premises  are  Ready  for  Delivery  or
October 1, 2000,  Tenant shall  deposit with  Landlord the Security  Deposit set
forth in Section 1.9 as security for Tenant's  faithful  performance of Tenant's
obligations  under this Lease.  The  Security  Deposit must be delivered on such
date in good funds or by Letter of Credit as described in Section 5.2 below.  If
Tenant  provides  good  funds,  Tenant  shall  have the right at a later date to
deliver a Letter of Credit  complying with the requirements of Section 5.2 below
and after  acceptance  of such Letter of Credit,  Landlord  will return the good
funds  Security  Deposit.  If  Tenant  fails to pay Base  Rent or other  rent or
charges due hereunder, or otherwise is in default under this Lease, Landlord may
use, apply or retain all or any portion of said Security Deposit for the payment
of any amount due  Landlord  or to  reimburse  or  compensate  Landlord  for any
liability,  cost,  expense,  loss or damage  (including  attorneys'  fees) which
Landlord may suffer or incur by reason thereof.  If Landlord uses or applies all
or any  portion  of said  Security  Deposit,  Tenant  shall  within * days after
written  request  therefore  deposit monies with Landlord  sufficient to restore
said  Security  Deposit to the full amount  required  by this Lease.  If paid in
cash,  Landlord  shall  keep the  Security  Deposit  separate  from its  general
accounts in an interest  bearing account of Landlord's  choice with the interest
thereon payable to the Tenant at the expiration of the Lease;  provided  however
Landlord  shall be entitled to the interest on the Security  Deposit if Landlord
is  entitled  to the  Security  Deposit  pursuant  to the  terms of this  Lease.
Landlord shall,  within * days after the expiration of the Term hereof and after
Tenant has vacated the Premises,  return to Tenant (or, at Landlord's option, to
the last assignee,  if any, of Tenant's  interest  herein),  that portion of the
Security  Deposit,  and interest  thereon,  not used or applied by Landlord.  At
Landlord's  election,  Landlord may elect to have the  Security  Deposit held by
Landlord's  manager in a separate  security  deposit,  trust,  trustee or escrow
account  established  and  maintained  by such  manager  with respect to certain
security  deposits of tenants within the Building  Complex.  Unless Tenant is so
notified, (i) Landlord will hold the Security Deposit and be responsible for its
return;  and (ii) Tenant may request  return of the  Security  Deposit by giving
Landlord  written  notice in accordance  with the  provisions  of the Lease.  If
Landlord's  manager  holds the  Security  Deposit,  Landlord's  manager  will be
required  to agree  that in the event of a  dispute  over the  ownership  of the
Security Deposit,  the manager will not wrongfully withhold Landlord's true name
and  current  mailing  address  from  Tenant.  Landlord  may  deliver  the funds
deposited  herein by Tenant  to the  purchaser  of  Landlord's  interest  in the
Premises in the event such interest be sold,  and  thereupon,  Landlord shall be
discharged from further liability with respect to such deposit. If the claims of
Landlord exceed said deposit, Tenant shall remain liable for the balance of such
claims.

         5.2  Notwithstanding  anything to the contrary set forth in Section 5.1
above,  Tenant  has  requested  permission  to  provide  Landlord  with a clean,
unconditional,  irrevocable  letter  of  credit  on a form  and  from a  lending
institution  acceptable to Landlord in its reasonable discretion (the "Letter of
Credit") instead of a good funds Security  Deposit.  If Tenant elects to deliver
the Letter of Credit  instead of the good funds  Security  Deposit,  the initial
Letter of Credit shall be in an amount as then  required by the terms of Section
5.3. It is further understood and agreed, that no later than * days prior to the
expiration date of the initial Letter of Credit or renewal Letter of Credit,  as
the case may be, Tenant shall  present  Landlord with good funds or an extension
or renewal of the initial Letter of Credit or a substitute  Letter of Credit, in
the same  form from a  lending  institution  subject  to  Landlord's  reasonable
approval,  in the amount described herein, that shall be effective no later than
upon the  expiration of the initial  Letter of Credit and continue in effect for
at least a one-year period.  Any failure of Tenant to provide Landlord with good
funds or the extensions or renewals or substitute  Letter of Credit, as required
hereunder,  shall be deemed a default  by  Tenant  under the Lease and  Landlord
shall have the right  prior to  expiration  thereof,  to  present  any Letter of
Credit then in its possession for payment,  with the amounts received thereunder
to be held as the Security Deposit hereunder.

         5.3  Notwithstanding  the foregoing,  provided Tenant is not in default
under the  Lease,  the  Security  Deposit  shall be reduced by $* for the second
Lease Year and by $* for each succeeding  Lease Year until the Security  Deposit
has been  reduced to $*. No  earlier  than * days nor later than * days prior to
the end of the fifth Lease Year,  Tenant shall provide Landlord with a certified
statement of Tenant's net worth. If such statement  certifies Tenant's net worth
to be $* or greater, Tenant shall not be required to maintain a Security Deposit
for the remainder of the Term. If such statement certifies Tenant's net worth to
be less  than  $*,  Tenant  shall  maintain  a  Security  Deposit  of $* for the
remainder of the Term of the Lease, as it may be extended.

         6.   Use.

         6.1  Permitted Use.

                  (a)  Tenant  shall use and occupy  the  Premises  only for the
Permitted Use set forth in Section 1.11 and for no other  purpose.  Tenant shall
not use or permit the use of the Premises in a manner that is unlawful,  creates
waste,  odor,  or a nuisance,  or that disturbs  owners and/or  occupants of, or
causes damage to the Premises, Building or neighboring premises or properties.

                  (b) Landlord  hereby  agrees to not  unreasonably  withhold or
delay its  consent  to any  written  request by Tenant,  Tenant's  assignees  or
subtenants, and by prospective assignees and subtenants of Tenant, its assignees
and  subtenants,  for a  modification  of said Permitted Use so long as the same
will not impair the structural  integrity of the improvements on the Premises or
in the  Building or the  mechanical  or  electrical  systems  therein,  does not
conflict with uses by other tenants, is not significantly more burdensome to the
Premises  or the  Building  and  the  improvements  thereon,  and  is  otherwise
permissible  pursuant to  Applicable  Laws and  pursuant  to this  Section 6. If
Landlord elects to withhold such consent,  Landlord shall within * business days
after such  request  give a written  notification  of same,  which  notice shall
include an explanation of Landlord's reasonable objections to the change in use.

         7.   Hazardous Substances.

         7.1 Consent.  Tenant shall not cause or permit any Hazardous Substances
to be used, stored,  generated or disposed of on, in or about the Premises,  the
Building,  or the Building Complex by Tenant,  or any of its agents,  employees,
representatives, contractors, suppliers, customers, subtenants, concessionaires,
licensees  unless Tenant shall have received  Landlord's  prior written consent,
which  Landlord  may  withhold  or at any time  revoke  in its sole  discretion.
Landlord  warrants that to the best of Landlord's actual current knowledge as of
the date hereof,  there are no Hazardous Substances located in the Premises that
violate Hazardous Substance laws by their presence. Further, between the date of
this Lease and the Lease  Commencement  Date,  Landlord  agrees that it will not
knowingly  authorize  its  contractor  to install  into the  Premises  Hazardous
Substances that violate Hazardous Substance laws by their presence.

         7.2 Use.  Notwithstanding  the  foregoing,  Tenant may  store,  use and
dispose of de minimis amounts of office and cleaning  products which may contain
small and/or  unregulated  amounts of such  Hazardous  Substances  in the normal
course of Tenant's Permitted Use of the Premises, and Tenant covenants to comply
with all applicable laws, rules, regulations and ordinances governing same.

         7.3  Indemnification.  Tenant shall indemnify and defend Landlord,  and
hold Landlord  harmless,  from and against any and all claims,  damages,  fines,
judgments,  penalties,  costs, expenses,  liabilities, or losses relating to any
violation by Tenant of any Environmental Law (as hereinafter defined) or of this
Section 7 (including,  without limitation,  a decrease in value of the Premises,
damages caused by loss or  restriction of rentable or usable space,  and any and
all sums paid for settlement of claims,  attorneys'  fees,  consultant fees, and
expert fees) incurred by or asserted  against  Landlord  arising during or after
the Term of this  Lease  as a result  thereof.  This  indemnification  includes,
without  limitation,  any and all costs incurred because of any investigation of
the site or any cleanup,  removal,  testing or restoration mandated or conducted
by or on behalf of any federal, state, or local agency or political subdivision.
Without limitation of the foregoing, if Tenant causes or permits the presence of
any Hazardous Substance in the Premises,  the Building,  or the Building Complex
that results in any  contamination,  Tenant shall promptly,  at is sole expense,
take any and all necessary or  appropriate  actions to return the Premises,  the
Building  and the  Building  Complex  to the  condition  existing  prior  to the
presence of any such Hazardous  Substance.  Tenant shall first obtain Landlord's
written  approval  for the remedial  action  which is being  proposed by Tenant,
which approval shall not be unreasonably withheld.

         7.4 Hazardous  Substance.  Hazardous Substance means any substance that
is regulated by any local government,  the State of Colorado,  the United States
government, or any agency, authority and/or instrumentality thereof and includes
any and all  materials  or  substances  that are defined as  "hazardous  waste",
"extremely  hazardous  waste",  or  a  "hazardous  substance"  pursuant  to  any
Environmental  Law.  Hazardous  Substance  includes  but  is not  restricted  to
petroleum  and  petroleum  byproducts,  asbestos,  explosives,   polychlorinated
biphenyls ("PCBs") and infectious waste.

         7.5 Environmental Laws. Environmental Laws means all federal, state and
local laws, including statutes,  regulations, and requirements,  relating to the
discharge  of air  pollutants,  water  pollutants  or  process  waste  water  or
otherwise relating to the environment or Hazardous  Substances,  including,  but
not limited to, the Federal Clean Water Act, the Federal  Resource  Conservation
and Recovery Act of 1976, the Federal Comprehensive Environmental Responsibility
Cleanup and Liability Act of 1980,  regulations of the Environmental  Protection
Agency,  regulations of the Nuclear  Regulatory  Agency,  and regulations of any
state department of natural resources or state environmental  protection agency,
as amended or  supplemented  from time to time,  now or at any time hereafter in
effect.

         8.   Maintenance,  Repairs,  Utility Installations,  Trade Fixtures and
Alterations.

         8.1  By Tenant.

                  (a) Subject to the  provisions  of Sections  8.2,  10, and 15,
Tenant  shall,  at Tenant's  sole cost and  expense  and at all times,  keep the
Premises and every part thereof in good order,  condition and repair (whether or
not such portion of the Premises requiring repair, or the means of repairing the
same,  are  reasonably or readily  accessible to Tenant,  and whether or not the
need for such  repairs  occurs as a result of Tenant's  use,  any prior use, the
elements  or the  age of  such  portion  of the  Premises),  including,  without
limiting  the  generality  of  the   foregoing,   all  equipment  or  facilities
specifically  serving the  Premises  and located  within the  Premises,  such as
plumbing  (excluding  main utility lines serving more space than the  Premises),
electrical lighting facilities, boilers, fired or unfired pressure vessels, fire
hose  connections if within the Premises,  fixtures,  interior  walls,  interior
surfaces of exterior walls, ceilings,  floors,  windows, doors, plate glass, and
skylights,  and subject to Section 8.1 (b) below heating,  air  conditioning and
ventilating  systems,  but excluding any items which are the  responsibility  of
Landlord pursuant to Section 8.2 below.  Tenant, in keeping the Premises in good
order,  condition  and  repair,  shall  exercise  and perform  good  maintenance
practices  including,  without limitation,  providing janitorial services to the
Premises  substantially  equivalent  to those  attached  hereto  as  Exhibit  I.
Tenant's obligations shall include  restorations,  replacements or renewals when
necessary to keep the Premises and all improvements thereon or a part thereof in
good order, condition and state of repair.

                  (b) Subject to  reimbursement  under the provisions of Section
4,  Landlord  shall  procure a contract  for  maintenance  of the  heating,  air
conditioning and ventilating systems for the Building Complex.

                  (c) If Tenant fails to perform Tenant's obligations under this
Section 8.1,  Landlord may enter upon the Premises  after * days' prior  written
notice to Tenant  (except in the case of an  emergency,  in which case no notice
shall be required),  perform such  obligations on Tenant's  behalf,  and put the
Premises in good order,  condition and repair in which event  Landlord  shall be
entitled  to charge  Tenant  with  Landlord's  cost plus * due from  Tenant upon
presentation of a bill therefor.

                  (d)  Notwithstanding   the  foregoing,   Tenant  may  contract
directly  with  Landlord to perform  Tenant's  obligations  set forth under this
Section 8.1 which contract shall set forth the terms and conditions  under which
the Landlord or its manager will perform Tenant's obligations. The terms of such
performance  shall be fully included in and governed by the contract between the
parties and shall not effect  Landlord or Tenant's  rights or obligations  under
this Lease.

         8.2 By Landlord.  Subject to the  provisions  of Sections  2.2, 4.2, 6,
8.1,  9, 10,  11 and 15,  and  except  for  damage  caused by any  negligent  or
intentional  act or omission  of Tenant,  its agents,  employees,  suppliers  or
invitees, in which event Tenant shall repair the damage, Landlord, shall keep in
good order,  condition and repair the  foundations,  exterior walls,  structural
condition of interior  bearing  walls,  exterior  roof,  fire  sprinkler  and/or
standpipe  and hose (if  located in the Common  Areas) or other  automatic  fire
extinguishing  systems  including fire alarm and/or smoke detention  systems and
equipment, fire hydrants, the sewer line, utility main lines in the Common Areas
and any main  utility  lines  which are located in the  Premises  but serve more
space  than  the  Premises,   parking  lots,  walkways,   parkways,   driveways,
landscaping,  fences, signs and utility systems serving the Common Areas and all
parts of the Common Areas as well as providing the services for which there is a
Common Area  Operating  Expense  pursuant to Section 4.2.  Landlord shall not be
obligated to paint the interior surfaces of exterior walls nor shall Landlord be
obligated to maintain,  repair or replace  windows,  doors or plate glass of the
Premises. Tenant shall have no right to make repairs to the Building or Building
Complex at Landlord's expense.

         8.3  Utility Installations, Trade Fixtures, Alterations.

                  (a)   Definitions,   Consent   Required.   The  term  "Utility
Installations"  is used in this Lease to refer to all air lines,  power  panels,
electrical  distribution,  security,  fire  protection  systems,  communications
systems, lighting fixtures, heating, ventilating and air conditioning equipment,
plumbing,  and fencing in, on, or about the Premises.  The term "Trade Fixtures"
shall mean Tenant's  machinery and equipment  which can be removed without doing
material  damage  to  the  Premises.  The  term  "Alterations"  shall  mean  any
modification of the  improvements on the Premises which are provided by Landlord
under  the  terms of this  Lease,  other  than  Utility  Installations  or Trade
Fixtures. "Tenant-Owned Alterations and/or Utility Installations" are defined as
Alterations  and/or Utility  Installations made by Tenant that are not yet owned
by Landlord  pursuant to Section  8.4(a).  Tenant shall not make nor cause to be
made any  Alterations  or  Utility  Installations  in,  on,  under or about  the
Premises without  Landlord's prior written consent.  Tenant may,  however,  make
non-structural  Utility Installations to the interior of the Premises (excluding
the roof)  without  Landlord's  consent but upon notice to Landlord,  so long as
they are not visible from the outside of the Premises,  are not a water fixture,
do not involve puncturing, relocating or removing the roof or any existing walls
or changing or interfering with the fire sprinkler or fire detection  systems or
the heating,  air  conditioning  and ventilating  systems,  and the cost thereof
during the Term of this Lease as extended does not exceed * per  occurrence or a
cumulative total of *; after which Tenant must seek Landlord's  consent for such
Alterations  and/or  Utility  Installations.  Under no  circumstances  is Tenant
allowed to add water fixtures to the Premises.

                  (b) Consent.  Any  Alterations or Utility  Installations  that
Tenant shall desire to make and which require the consent of the Landlord  shall
be presented to Landlord in written form with detailed plans. All consents given
by  Landlord,  whether by virtue of  Section  8.3(a) or by  subsequent  specific
consent,  shall be deemed  conditioned upon: (i) Tenant acquiring all applicable
permits required by governmental  authorities;  (ii) the furnishing of copies of
such  permits  together  with a copy of the  plans  and  specifications  for the
Alteration or Utility Installation to Landlord prior to commencement of the work
thereon;  and (iii) the compliance by Tenant with all conditions of said permits
in a prompt and expeditious manner. Any Alterations or Utility  Installations by
Tenant  during  the  Term  of  this  Lease  shall  be  completed  in a good  and
workmanlike manner,  with good and sufficient  materials of at least the quality
of the original  installations  in the Premises,  and be in compliance  with all
Applicable Requirements,  and be performed by qualified and licensed workers who
have provided Landlord with evidence of insurance  required by Landlord.  Tenant
shall promptly upon completion  thereof furnish Landlord with as-built plans and
specifications  therefor.  Landlord  may,  (but  without  obligation  to do  so)
condition its consent to any requested  Alteration or Utility  Installation that
costs * or more upon Tenant  providing  Landlord with a lien and completion bond
in an amount equal to * times the estimated  cost of such  Alteration or Utility
Installation.

                  (c) Lien  Protection.  Excluding  lien  claims  arising out of
Landlord's  Work,  Tenant  shall pay when due all claims for labor or  materials
furnished  to or for Tenant at or for use on the  Premises,  which claims are or
may be secured by any mechanic's or  materialmen's  lien against the Premises or
any interest  therein.  Tenant shall give  Landlord not less than * days' notice
prior to the  commencement  of any work in,  on,  or  about  the  Premises,  and
Landlord shall have the right to post notices of non-responsibility in or on the
Premises  as  provided  by law.  If Tenant  shall,  in good  faith,  contest the
validity  of any such lien,  claim or demand,  then  Tenant  shall,  at its sole
expense,  defend and protect itself,  Landlord and the Premises against the same
and shall pay and satisfy any such adverse judgment that may be rendered thereon
before the enforcement thereof against the Landlord or the Premises. If Landlord
shall require,  Tenant shall furnish to Landlord a surety bond  satisfactory  to
Landlord in an amount  equal to * the amount of such  contested  lien,  claim or
demand, indemnifying Landlord against liability for the same, as required by law
for the holding of the  Premises  free from the effect of such lien or claim or,
in the alternative,  if approved by Landlord's  lender,  if necessary,  a surety
bond  which  complies  with the then  applicable  requirements  of the  Colorado
statutes governing mechanic's liens. In addition, Landlord may require Tenant to
pay  Landlord's  attorneys'  fees and costs in  participating  in such action if
Landlord  shall  decide it is to its best  interest  to do so, if Tenant has not
caused the Premises to be released from the lien in the manner  required by then
applicable Colorado statutes governing mechanic's liens.

         8.4  Ownership, Removal, Surrender, and Restoration.

                  (a)  Ownership.  Subject to Landlord's  right to require their
removal and to cause Tenant to become the owner thereof as hereinafter  provided
in this Section 8.4, all Tenant-Owned Alterations and Utility Installations made
to the  Premises by Tenant  shall be the  property  of and owned by Tenant,  but
considered a part of the Premises.  Landlord may, at any time and at its option,
elect in a writing  delivered to Tenant to be the owner of all or any  specified
part of the Tenant-Owned Alterations and Utility Installations. Unless otherwise
instructed per Section 8.4(b) hereof,  all Tenant-Owned  Alterations and Utility
Installations  shall,  at the  expiration or earlier  termination of this Lease,
become the property of Landlord and remain upon the Premises and be  surrendered
with the Premises by Tenant.

                  (b) Removal. Unless otherwise agreed in writing,  Landlord may
require that any or all  Tenant-Owned  Alterations or Utility  Installations  be
removed by the expiration or earlier termination of this Lease,  notwithstanding
that their  installation  may have been  consented to by Landlord.  Landlord may
require  the  removal  at  any  time  of all or  any  part  of any  Tenant-Owned
Alterations  or Utility  Installations  made  without  the  required  consent of
Landlord. Tenant shall be obligated to repair all damage caused by such removal.
If Tenant  desires  Landlord  to decide at the time Tenant  requests  Landlord's
consent to a Tenant-Owned  Alteration or Utility  whether or not Tenant shall be
obligated to remove same upon  expiration or  termination  of the Lease,  Tenant
shall  specifically  request in writing  that  Landlord  make such  decision and
Landlord will promptly respond to Tenant with its decision.

                  (c) Surrender/Restoration. Tenant shall surrender the Premises
by the end of the last day of the Lease Term or any  earlier  termination  date,
clean and free of debris and in good  operating  order,  condition  and state of
repair,  ordinary  wear and tear  excepted.  Ordinary  wear and tear  shall  not
include  any damage or  deterioration  that would  have been  prevented  by good
maintenance  practice or by Tenant  performing all of its obligations under this
Lease.  Except as  otherwise  agreed  or  specified  herein,  the  Premises,  as
surrendered,  shall  include  the  Alterations  and Utility  Installations.  The
obligation  of Tenant shall  include the repair of any damage  occasioned by the
installation,  maintenance or removal of Tenant's Trade  Fixtures,  furnishings,
equipment,  and  Tenant-Owned  Alterations  and Utility  Installations,  and the
removal,  replacement,  or  remediation  of any soil,  material or ground  water
contaminated by Tenant, all as may then be required by Applicable  Requirements.
Tenant's Trade Fixtures shall remain the property of Tenant and shall be removed
by Tenant  subject to its obligation to repair and restore the Premises per this
Lease. Any Trade Fixtures, Tenant-Owned Alterations and/or Utility Installations
not removed upon the expiration of this Lease shall be deemed  abandoned and may
be disposed of by  Landlord,  as Landlord  may  determine  appropriate,  without
further  notice to Tenant.  Tenant shall pay  Landlord all expenses  incurred in
connection with such items including, but not limited to, the costs of repairing
any damage to the Premises caused by removal of such items.  Tenant's obligation
hereunder shall survive the expiration or other termination of the Lease.

         9.   Insurance; Indemnity.

         9.1 Payment of Premiums.  The cost of the  premiums  for the  insurance
policies  maintained  by  Landlord  under this  Section 9 shall be an  Operating
Expense pursuant to Section 4.2 hereof.  Premiums for policy periods  commencing
prior to, or  extending  beyond,  the Term of this Lease  shall be  prorated  to
coincide with the corresponding Commencement Date or Expiration Date.

         9.2  Liability Insurance.

                  (a) Carried by Tenant.  Tenant  shall obtain and keep in force
during the Term of this Lease a Commercial General Liability policy of insurance
protecting Tenant,  Landlord and any Lender(s) whose names have been provided to
Tenant in writing (as  additional  insureds)  against  claims for bodily injury,
personal injury and property damage based upon,  involving or arising out of the
ownership,  use,  occupancy  or  maintenance  of  the  Premises  and  all  areas
appurtenant  thereto.  Such insurance shall be on an occurrence  basis providing
single  limit  coverage  in an  amount  not less than * per  occurrence  with an
"Additional  Insured-Managers or Landlords of Premises" endorsement.  The policy
shall not contain any  intra-insured  exclusions as between  insured  persons or
organizations, but shall include coverage for liability assumed under this Lease
as an "insured contract" for the performance of Tenant's  indemnity  obligations
under this  Lease.  The limits of said  insurance  required  by this Lease or as
carried by Tenant shall not, however,  limit the liability of Tenant nor relieve
Tenant of any obligation hereunder.  All insurance to be carried by Tenant shall
be  primary  to and not  contributory  with any  similar  insurance  carried  by
Landlord,  whose  insurance  shall  be  considered  excess  insurance  only.  In
addition,  Tenant shall maintain workers' compensation  insurance as is required
by state law.

                  (b) Carried By Landlord.  Subject to reimbursement of premiums
as described in Section 9.1,  Landlord shall also maintain  liability  insurance
described in Section  9.2(a) above in such amounts,  from such  companies and on
such terms and  conditions as Landlord deems  appropriate  from time to time, in
addition  to and not in lieu of, the  insurance  required  to be  maintained  by
Tenant. Tenant shall not be named as an additional insured therein.

         9.3  Property  Insurance.  Subject  to  reimbursement  of  premiums  as
described in Section 9.1,  Landlord shall maintain  property damage insurance on
such  portions  of the  Building  and the  Common  Areas from time to time which
Landlord  has the  obligation  to maintain  and repair  under this Lease,  above
foundation  walls,  insuring  against  loss or damage by fire or other  casualty
covered  by a  so-called  "special  form"  policy,  in such  amounts,  and  from
companies and on such terms and  conditions as Landlord deems  appropriate  from
time to time. Tenant-Owned Alterations and Utility Installations, Trade Fixtures
and Tenant's  personal  property shall be insured by Tenant  pursuant to Section
9.4.  Landlord may also obtain and keep in force during the Term of this Lease a
policy or policies in the name of  Landlord,  with loss  payable to Landlord and
any Lender(s), insuring the loss of the full rental and other charges payable by
all  tenants  of the  Building  to  Landlord  for one year  (including  all Real
Property Taxes, insurance costs, all Operating Expenses and any scheduled rental
increases).  Tenant  shall pay for any increase in the premiums for the property
insurance of the Building and for the Common Areas if said increase is caused by
Tenant's acts, omissions, use or occupancy of the Premises.

         9.4 Tenant's Property Insurance. Subject to the requirements of Section
9.5,  Tenant at its cost shall either by separate policy or, by endorsement to a
policy already carried,  maintain insurance coverage on all of Tenant's personal
property,  Trade Fixtures and Tenant-Owned Alterations and Utility Installations
in, on, or about the Premises similar in coverage to that carried by Landlord as
the Insuring Party under Section 9.3. Such insurance  shall be full  replacement
cost coverage.  The proceeds from any such insurance shall be used by Tenant for
the  replacement of personal  property and the restoration of Trade Fixtures and
Tenant-Owned Alterations and Utility Installations.  Upon request from Landlord,
Tenant shall provide  Landlord with written  evidence that such  insurance is in
force.  Insurance  required  of  Tenant  hereunder  shall be in  companies  duly
licensed to transact  business in the state where the Premises are located,  and
maintaining during the policy term a "General  Policyholders Rating" of at least
B+, V, or such other rating as may be required by a Lender,  as set forth in the
most current issue of "Best's Insurance Guide." Tenant shall not do or permit to
be done anything which shall  invalidate the insurance  policies  referred to in
this Section 9. Tenant shall cause to be delivered to Landlord, within seven (7)
days after the  Delivery  Date  evidence  of the  existence  and amounts of, the
insurance  required  under  Section  9.2(a)  and 9.4.  No such  policy  shall be
cancelable  or subject to  modification  except  after  thirty  (30) days' prior
written  notice to Landlord.  Tenant shall at least ten (10) Business Days prior
to the expiration of such policies,  furnish  Landlord with evidence of renewals
or "insurance  binders"  evidencing renewal thereof,  or Landlord may order such
insurance  and charge the cost thereof to Tenant,  which amount shall be payable
by Tenant to Landlord upon demand.

         9.5 Waiver.  Tenant and  Landlord  each hereby  release and relieve the
other  (but not their  contractors),  and waive  their  entire  right to recover
damages  (whether in contract or in tort) against the other,  for loss or damage
to their property or for any business interruption arising out of or incident to
the  perils  to the  extent  such loss or damage  or  business  interruption  is
coverable  by a standard  or special  form  policy  regardless  of whether  such
insurance is carried or not, or if so carried,  payable to or protects  Landlord
or Tenant or both.  The  effect of such  releases  and  waivers  of the right to
recover  damages  shall not be  limited by the  amount of  insurance  carried or
required, or by any deductibles applicable thereto. Landlord and Tenant agree to
have their  respective  insurance  companies  issuing  property damage insurance
waive any right to subrogation  that such companies may have against Landlord or
Tenant, as the case may be, so long as the insurance is not invalidated thereby.

         9.6  Indemnity.

                  (a)  Subject  to Section  9.5 above and except for  Landlord's
willful  misconduct,  or that of Landlord's  agents or  employees,  Tenant shall
indemnify,  protect,  defend and hold  harmless the  Premises,  Landlord and its
agents,  employees,  Landlord's  master or ground lessor  members,  partners and
Lenders,  from and  against any and all claims,  loss of rents  and/or  damages,
costs, liens, judgments, penalties, loss of permits, attorneys' and consultants'
fees,  expenses and/or liabilities  arising out of, involving,  or in connection
with, the occupancy of the Premises by Tenant, the conduct of Tenant's business,
any act, omission or neglect of Tenant,  its agents,  contractors,  employees or
invitees,  and out of any  Default or breach by Tenant in the  performance  in a
timely  manner of any  obligation  on Tenant's  part to be performed  under this
Lease.  The  foregoing  shall  include,  but not be limited  to, the  defense or
pursuit of any claim or any action or proceeding  involved therein,  and whether
or not (in the case of claims made against Landlord) litigated and/or reduced to
judgment. In case any action or proceeding be brought against Landlord by reason
of any of the foregoing  matters,  Tenant upon notice from Landlord shall defend
the same at  Tenant's  expense by counsel  selected  by Tenant  and/or  Tenant's
insurer, which counsel is reasonably satisfactory to Landlord and Landlord shall
cooperate  with Tenant in such  defense.  Landlord  need not have first paid any
such claim in order to be so  indemnified.  The provisions of this Section shall
survive the expiration or termination of this Lease.

                  (b) Subject to Section  9.5 above and  Section 9.7 below,  and
except  for  Tenant's,  its  agents  or  employees  negligence,  Landlord  shall
indemnify  and save Tenant,  its agents and  employees  harmless of and from all
liabilities,  losses,  damages,  costs or expenses,  including  attorneys  fees,
fines,  penalties,  judgments  or  obligations  that the Tenant  may  sustain on
account of bodily  injuries to third parties  lawfully on the Common Areas where
the injuries  are caused by the wilful  misconduct  of  Landlord,  its agents or
employees.  The  provisions  of this Section  shall  survive the  expiration  or
termination of this Lease.

         9.7 Exemption of Landlord from Liability.  Landlord shall not be liable
for injury or damage to the  goods,  wares,  merchandise  or other  property  of
Tenant,  Tenant's  employees,  contractors,  invitees,  customers,  or any other
person in or about the Premises,  excluding  bodily injury claims,  whether such
damage or injury is caused by or results  from fire,  steam,  electricity,  gas,
water or rain or from the  breakage,  leakage,  obstruction  or other defects of
pipes,  fire  sprinklers,  wires,  appliances,  plumbing,  air  conditioning  or
lighting  fixtures,  or from any other cause,  excluding  bodily injury  claims,
whether said injury or damage results from conditions  arising upon the Premises
or upon other  portions of the Building of which the  Premises are a part,  from
other sources or places,  and  regardless of whether the cause of such damage or
injury or the means of repairing the same is accessible or not.  Landlord  shall
not be liable  for any  damages  arising  from any act or  neglect  of any other
tenant of Landlord nor from the failure by Landlord to enforce the provisions of
any other lease in the Building. Notwithstanding Landlord's negligence or breach
of this Lease,  Landlord  shall under no  circumstances  be liable for injury to
Tenant's  business  or for any loss of income or  profit  therefrom,  or for any
consequential  damages  of  Tenant.  Notwithstanding  anything  to the  contrary
contained herein,  Landlord's liability under this Lease shall be limited to its
interest in the Building.

         10.  Casualty and Restoration of Premises.

         10.1  Damage  Before the  Commencement  Date.  If the  Premises  or the
Building  shall be damaged by fire or other casualty after the Delivery Date but
before the Landlord has substantially completed Landlord's Work, the Lease shall
not be terminated and Landlord shall cause the same to be repaired to the extent
of  Landlord's  Work set forth in  Exhibit C hereof  and  Tenant  shall,  at its
expense, replace or fully repair Tenant's Work.

         10.2 Total  Damage.  If, after the date of  substantial  completion  of
Landlord's  Work,  the Premises or the  Building  shall be so damaged by fire or
other  casualty  so as to render the  Premises  wholly  unuseable  by Tenant (in
Landlord's  reasonable  discretion)  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 * days of said casualty that the Premises,
with the exercise of reasonable diligence,  cannot be repaired to the extent the
Premises  are  useable by Tenant for  general  office use and the repairs to the
Building,  to the extent of Landlord's Work, have been  substantially  completed
within * days from the date of the casualty (subject to delays beyond Landlord's
reasonable control),  then this Lease shall cease and terminate from the date of
occurrence of such damage and Tenant shall,  within * days after notice thereof,
surrender to Landlord the Premises and all interest  therein under this Lease or
otherwise  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 so long as Tenant  surrendered the Premises to
Landlord  within  said * days;  failing  which  Tenant  shall  pay Rent from the
expiration  of said * day  period  until  the  date  of  Tenant's  vacation  and
surrender  of the  Premises.  If,  however,  the damage  shall be such that said
architect  shall certify  within said * day period that the Premises can be made
tenantable  within  said * day  period  (subject  to  delays  beyond  Landlord's
reasonable control), then, except as hereinafter provided, Landlord shall repair
the damage so done with all  reasonable  speed (to the extent of the  Landlord's
Work set forth in Exhibit C hereof).

         10.3 Partial  Damage.  If, after the date of substantial  completion of
Landlord's  Work,  the  Premises  shall  be  slightly  damaged  by fire or other
casualty,  but not so as to render  the same  wholly  unuseable  by  Tenant  (in
Landlord's  reasonable  discretion)or  to require a repair period in excess of *
days (subject to delays beyond Landlord's  reasonable control),  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
damage so done (to the  extent  of the  Landlord's  Work set forth in  Exhibit C
hereof) with  reasonable  promptness.  If the estimated  repair period exceeds *
days  (subject  to  delays  beyond  Landlord's  reasonable  control),  then  the
provisions  of Section  10.2  shall  control  notwithstanding  the fact that the
Premises are not wholly unuseable.

         10.4  Building  Damage.  In case the  Building  throughout  shall be so
injured or damaged after the date of substantial  completion of Landlord's Work,
whether by fire or otherwise  (though said  Premises may not be affected,  or if
affected),  that can be repaired  within said * days  (subject to delays  beyond
Landlord's reasonable control),  that, within * 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 * days,  Tenant
shall within * days after notice  thereof,  surrender  the Premises to Landlord,
pay the Rent,  properly  apportioned up to the time of such  termination of this
Lease so long as Tenant  surrenders the Premises to Landlord within said * days;
failing  which  Tenant shall pay Rent from the  expiration  of said * day period
until the date of Tenant's  vacation and surrender of the  Premises.  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.

         10.5 Rent  Abatement.  Provided  that the  casualty is not the fault of
Tenant, Tenant's agents,  servants, or employees,  Tenant's Rent (Base Rent plus
Tenants  Share of  Operating  Expenses)  shall  abate  during any such period of
Landlord's  repair or  restoration,  in the same proportion that the part of the
Premises rendered unuseable to the Tenant (in Landlord's reasonable  discretion)
bears to the whole.

         10.6  Tenant's  Obligation.  In the event the Lease is not  terminated,
Tenant shall, at its expense, replace or fully repair Tenant's personal property
and Tenant's Work, Alterations and Utilities installed by Tenant in the Premises
existing  on the date of the  occurrence  of the  casualty.  Tenant  shall fully
cooperate with Landlord in removing  Tenant's  personal  property and any debris
from the Premises to facilitate making of repairs.

         10.7 Late Term Damage. Notwithstanding anything set forth herein to the
contrary,  if at any time the Premises are damaged by fire or other  casualty in
excess of * of the floor area and there is less than one (1) year  remaining  on
the then  current  Term of the Lease  (including  any Options to Extend that had
been  exercised in accordance  with Section 50 below),  then either  Landlord or
Tenant  shall have the right to  terminate  this  Lease.  If either  Landlord or
Tenant elect to terminate  the Lease  pursuant to this  Section  10.7,  it shall
advise the other party in writing within * days of said casualty of its election
to terminate and within  fourteen (14) days after notice  thereof,  Tenant shall
surrender  the Premises to Landlord,  pay the Rent properly  apportioned  to the
date of the  casualty  so long as Tenant  surrenders  the  Premises  to Landlord
within said fourteen (14) days period;  failing which Tenant shall pay rent from
the  expiration  of said * day period  until the date of Tenant's  vacation  and
surrender of the Premises.  If Landlord  terminates the Lease in accordance with
this  Section,  but  Tenant has an Option to Extend the Term of the Lease at the
end of the  then-current  Term in accordance with Section 50 below (which Option
has not yet been  exercised  nor waived in accordance  with Section 50),  Tenant
shall have the right to give notice to  Landlord  that Tenant is willing to (and
by such notice does) exercise its Option,  in which event the Lease shall not be
terminated  under this  Section and this Lease shall  continue in full force and
effect (unless  otherwise  terminated in accordance  with other Sections of this
Article 10) and Landlord and Tenant shall repair the Premises as may be required
by this Article 10.

         11.  Real Property Taxes.

         11.1 Payment of Taxes.  Landlord shall pay the Real Property  Taxes, as
defined in Section  11.2,  applicable  to the  Building  Complex,  and except as
otherwise  provided in Section  11.3,  any such amounts shall be included in the
calculation of Common Area Operating  Expenses in accordance with the provisions
of Section 4.2.

         11.2 Real  Property  Tax  Definition.  As used  herein,  the term "Real
Property  Taxes"  shall  include  any  form of real  estate  tax or  assessment,
general,  special,  ordinary or extraordinary,  and any license fee,  commercial
rental tax,  improvement  bond or bonds,  levy or tax (other  than  inheritance,
personal  income or estate  taxes)  imposed  upon the  Building  Complex  by any
authority having the direct or indirect power to tax,  including any city, state
or federal  government,  or any school,  agricultural,  sanitary,  fire, street,
drainage,  or other improvement  district  thereof,  levied against any legal or
equitable  interest of Landlord in the Building  Complex or any portion thereof,
Landlord's right to rent or other income therefrom,  and/or Landlord's  business
of leasing the Premises  (other than  Landlord's  income  taxes,  excess  profit
taxes, estate tax, inheritance tax or similar taxes on Landlord's business). The
term "Real Property Taxes" shall also include any tax, fee, levy,  assessment or
charge,  or any  increase  therein,  imposed by reason of events  occurring,  or
changes  in  Applicable  Law  taking  effect,  during  the  Term of this  Lease,
including but not limited to a change in the  ownership of the Building  Complex
or  in  the  improvements   thereon,   the  execution  of  this  Lease,  or  any
modification,  amendment or transfer thereof, and whether or not contemplated by
the Landlord or Tenant.  In  calculating  Real  Property  Taxes for any calendar
year,  the Real Property Taxes for any real estate tax year shall be included in
the  calculation  of Real  Property  Taxes for such calendar year based upon the
number of days which such calendar year and tax year have in common.

         11.3 Additional Improvements. Operating Expenses shall not include Real
Property Taxes specified in the tax assessor's  records and work sheets as being
caused by  additional  improvements  placed upon the  Building  Complex by other
tenants or by  Landlord  for the  exclusive  enjoyment  of such  other  tenants.
Notwithstanding  Section 11.1 hereof,  Tenant shall, however, pay to Landlord at
the time  Operating  Expenses are payable under Section 4.2, the entirety of any
increase in Real  Property  Taxes if assessed  solely by reason of  Alterations,
Trade Fixtures or Utility Installations placed upon the Premises by Tenant or at
Tenant's request.

         11.4 Tenant's  Taxes.  Tenant shall pay prior to delinquency  all taxes
assessed   against  and  levied  upon   Tenant-Owned   Alterations  and  Utility
Installations,  Trade Fixtures, furnishings, equipment and all personal property
of  Tenant  contained  in the  Premises  or stored  within  the  Building.  When
possible,   Tenant  shall  cause  its   Tenant-Owned   Alterations  and  Utility
Installations,  Trade  Fixtures,  furnishings,  equipment and all other personal
property  to be  assessed  and  billed  separately  from  the real  property  of
Landlord.  If any of Tenant's  said property  shall be assessed with  Landlord's
real  property,  Tenant shall pay Landlord  the taxes  attributable  to Tenant's
property  within * days after receipt of a written  statement  setting forth the
taxes applicable to Tenant's property. In addition,  Tenant shall pay all taxes,
including,  without  limitation,  workers'  compensation,   general  license  or
franchise taxes and rent taxes, if any, which may be required for the conduct of
Tenant's business.

         12.  Utilities.Tenant shall pay directly for all utilities and services
supplied to the Premises,  including but not limited to electricity,  telephone,
security,  gas and  cleaning of the Premises as described in Section 8.1 herein,
together  with any taxes  thereon.  If any such  utilities  or services  are not
separately metered to the Premises or separately billed to the Premises,  Tenant
shall pay to Landlord a reasonable  proportion  to be  determined by Landlord of
all such charges  jointly metered or billed with other premises in the Building,
in the  manner  and within the time  periods  set forth in  Section  4.2(c).  In
addition,  Tenant shall reimburse  Landlord for the reasonable costs incurred by
Landlord in  providing  services  which are shared by more than one tenant after
ordinary business hours, including, without limitation, the costs for materials,
additional  wear and tear on  equipment,  utility  charges and labor  (including
fringe  benefits and  overhead  costs).  Computation  for  Landlord's  costs for
providing  such  services  will be made by  Landlord's  engineer  or  Landlord's
representative, based on such engineer's survey of Tenant's excess usage.

         13.  Assignment and Subletting.

         13.1  Landlord's  Consent.  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 * of the Premises,  will not be unreasonably  withheld  provided that:
(i) Tenant has complied with the applicable provisions of Section 13.3 below and
Landlord  has  declined to exercise  its rights  thereunder;  (ii) 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;  (iii)
the proposed  subtenant or assignee has reasonable  financial  worth in light of
the  responsibilities  involved and Tenant  shall have  provided  Landlord  with
reasonable evidence thereof;  (iv) Tenant is not in monetary default or material
non-monetary  default  hereunder  at the  time it  makes  its  request  for such
consent;  (v) the  proposed  subtenant  or  assignee  is not a  governmental  or
quasi-governmental  agency;  (vi) the  proposed  subtenant  or assignee is not a
tenant  under,  or is not  currently  negotiating,  a lease with Landlord in any
Building  owned by  Landlord  in the Denver  metropolitan  area  (including  the
Building);  or (vii) 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 *% 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.  Subject  to  Section  13.7  below,  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 * or more of the stock in a corporate tenant whose
stock  is not  publicly  traded;  or  transfer  of * or more  of the  beneficial
ownership  interests  in a  tenant  shall  constitute  an  assignment  hereunder
requiring Landlord's prior written consent.

         13.2 Terms and  Conditions.  If this Lease is  assigned,  Landlord  may
collect the rent from the  assignee  and apply the net amount  collected  to the
Rent herein  reserved.  If the Premises or any part hereof is sublet or occupied
by anybody  other than Tenant (other than an  assignee),  Landlord may,  after a
default by Tenant, collect the rent from the subtenant or occupant and apply the
net  amount  collected  to  the  Rent  herein  reserved.   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.  Consent by Landlord to any one  assignment or sublease  shall not in
anyway be  construed  as  relieving  Tenant from  obtaining  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  Share of  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  Landlord or
Tenant  collects  any rental or other  amounts  from an assignee or subtenant in
excess of the Base Rent and the  Tenant's  Share of  Operating  Expenses for any
monthly  period,  Landlord shall be entitled to * of such excess after deducting
actual  payments  by Tenant for  brokerage  commissions  and tenant  improvement
costs,  and Tenant shall pay to Landlord on a monthly basis,  as and when Tenant
receives the same, all such excess amounts received by Tenant.

         13.3  Landlord's  Rights.  Notwithstanding  anything  contained in this
Article 13 to the contrary,  in the event Tenant requests  Landlord's consent to
sublet all or a portion of the Premises or to assign its interest in this Lease,
Landlord  shall have the right to: (i) consent to such sublease or assignment in
its sole  discretion  (except if covered by Section 13.1 above);  (ii) refuse to
grant such  consent such in  Landlord's  sole  discretion  (except if covered by
Section 13.1 above);  or (iii) 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 this Lease as to such portion of the Premises,  Tenant shall
have the right within * 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 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 * days following such notice.

         13.4  Tenant  Notice.  Tenant  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,  Tenant  shall  notify  Landlord in writing not less than *
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 * days  following  receipt of Tenant's  Notice
within which to exercise Landlord's rights pursuant to Sections 13.1 and/or 13.3
above. If Landlord consents to such sublease or assignment and if for any reason
Tenant is unable to sublet said portion of the Premises or assign the applicable
portion of its interest in this Lease on the terms and  conditions  contained in
Tenant's Notice within * days following its original notice to Landlord,  Tenant
agrees to re-offer the Premises to Landlord in  accordance  with the  provisions
hereof prior to leasing or assigning the same to any third party.

         13.5  Documents.  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.

         13.6 Bankruptcy.  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 of
this Lease.  For  purposes of any such  assumption  or  assignment,  the parties
hereto  agree  that the term  "Adequate  Assurance"  shall  include at lease the
following:

                  (a) 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 *, 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.

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

         13.7 Permitted  Transfers.  Notwithstanding  anything set forth in this
Article 13 to the  contrary,  Tenant shall have the right to make the  following
types of assignments or subleases on the following conditions without Landlord's
prior written consent: (i) to any corporation into which Tenant may be merged or
consolidated or which purchases all or substantially  all of the stock or assets
of Tenant; provided that the entity resulting from such merger, consolidation or
purchase  has a net  worth at least  equivalent  to that of  Tenant  immediately
preceding  such  merger,  consolidation  or  purchase  and Tenant  has  provided
Landlord with evidence thereof; (ii) to a subsidiary of Tenant,  provided Tenant
owns a  controlling  interest  in  such  subsidiary;  or  (iii)  to  any  parent
corporation of Tenant or a sister corporation of Tenant wholly owned by the same
parent  corporation  as Tenant;  provided that in the event (i),  (ii), or (iii)
above  that (a) the  assignee  or  subtenant  shall  assume  and be bound by all
obligations  of Tenant for the payment of all amounts of Rent and other  charges
under the Lease and the performance of all covenants required by Tenant pursuant
to the Lease;  and such  assignee or  subtenant  has executed a document to that
effect  which has been  transmitted  to the  Landlord;  (b) Tenant  continues to
remain liable on its obligations set forth in the Lease; (c) at the time of such
assignment or sublease there shall not be an existing Event of Default under the
Lease; (d) the Premises shall continue to be used for the Permitted Use; and (e)
within * days after the effective date of such assignment or subletting,  Tenant
provides  Landlord  with a copy  of the  assignment  or  sublease  document  and
substantiation  that such assignment or sublease meets the criteria set forth in
this  subparagraph.  Landlord  has the  right in its  discretion  to  require  a
Security  Deposit  from such  assignee  or  subtenant  of the greater of (x) the
Security  Deposit amount then required of Tenant or (y) * if a transfer  meeting
the  requirements  of (i) above does not result in an entity with a net worth of
at least *.

         14.  Default; Remedies.

         14.1 Default. A "Default" or "Event of Default" by Tenant is defined as
a  failure  by Tenant to  observe,  comply  with or  perform  any of the  terms,
covenants,  conditions  or rules  applicable  to Tenant under this Lease,  which
failure shall remain uncured for any  applicable  cure periods  allowed  herein.
Each one of the following shall be an Event of Default:

                  (a) The  vacating of the  Premises  without the  intention  to
reoccupy same, or the abandonment of the Premises; provided, however, Tenant may
vacate the Premises in whole or in part provided the Tenant:  (i) gives Landlord
* days prior written notice of its intent to vacate;  and (ii) complies with all
other terms of the Lease,  including  payment of all Rent and any other monetary
sums required to be paid hereunder.

                  (b) Except as expressly  otherwise provided in this Lease, the
failure by Tenant to make any payment of Base Rent,  Tenant's Share of Operating
Expenses,  or any other monetary payment required to be made by Tenant hereunder
as and when due;  provided,  however,  the  Tenant  may cure an Event of Default
under this provision  within * calendar days after Landlord gives written notice
thereof to Tenant.  Tenant  shall not be entitled to more than two such  written
notices  within  any *  consecutive  months.  The  failure  by Tenant to provide
Landlord with  reasonable  evidence of insurance or surety bond  required  under
this Lease, or the failure of Tenant to fulfill any obligation  under this Lease
which endangers or threatens life or property.

                  (c) Except as expressly  otherwise provided in this Lease, the
failure by Tenant to provide Landlord with reasonable  written evidence (in duly
executed  original form, if applicable) of (i) the rescission of an unauthorized
assignment  or subletting  per Section 13; (ii) a Tenancy  Statement per Section
17; (iii) the subordination or  non-subordination  of this Lease per Section 31;
(iv) the execution of any document  requested under Section 41  (easements);  or
(v) any other documentation or information which Landlord may reasonably require
of Tenant under the terms of this Lease,  where any such failure continues for a
period of * days following written notice thereof by or on behalf of Landlord to
Tenant.

                  (d) A Default by Tenant as to the terms, covenants, conditions
or  provisions  of this Lease,  or of the rules  adopted under Section 39 hereof
that are to be observed,  complied with or performed by Tenant, other than those
described  in  Subparagraphs  14.1(a),  (b) or (c)  above,  where  such  Default
continues for a period of * days after written notice thereof by or on behalf of
Landlord to Tenant; provided, however, that if the nature of Tenant's Default is
such that more than * days are reasonably  required for its cure,  then it shall
not be deemed to be a breach of this  Lease by Tenant if Tenant  commences  such
cure within said * day period and thereafter  diligently prosecutes such cure to
completion.

                  (e) The  occurrence  of any of the following  events:  (i) the
making by Tenant of any general  arrangement  or  assignment  for the benefit of
creditors;  (ii) Tenant's becoming a "debtor" as defined in 11 U.S. Code Section
101 or any successor  statute thereto  (unless,  in the case of a petition filed
against Tenant, the same is dismissed within * days); (iii) the appointment of a
trustee or receiver to take possession of  substantially  all of Tenant's assets
located at the Premises or of Tenant's interest in this Lease,  where possession
is not restored to Tenant  within * days; or (iv) the  attachment,  execution or
other judicial  seizure of  substantially  all of Tenant's assets located at the
Premises  or of  Tenant's  interest  in this  Lease,  where such  seizure is not
discharged within * days; provided,  however, in the event that any provision of
this  subparagraph  14.1(e) is contrary to any  applicable  law, such  provision
shall be of no force or  effect,  and  shall  not  affect  the  validity  of the
remaining provisions.

                  (f) The discovery by Landlord that any financial statement  of
Tenant, given to Landlord by Tenant, was materially false.

         14.2     Remedies.

                  (a) If any one or more Events of Default shall occur and shall
remain uncured by Tenant during the applicable cure periods set forth in Section
14.1 above or as otherwise specified in this Lease, 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  possession  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 absolute  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;  provided, however, Landlord shall use
reasonable  efforts to relet the Premises.  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.

(1)(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)
the Base Rent and Tenant's Share of Operating Expenses, 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, reasonable attorney's 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)(a) 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 Base Rent and  Tenant's  Share of  Operating  Expenses  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 Base Rent and Tenant's
Share of Operating  Expenses 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 present value (calculated using the Treasury Rate for the
period remaining) of 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  reasonable  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.

                  (b) 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 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.

                  (c)  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 Default thereof and no acceptance of full
or partial Rent during the  continuance  of any such Default shall  constitute a
waiver of any such Default 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 Default  thereof  shall be waived,  altered,  or modified,
except by written  instrument  executed  by  Landlord.  No waiver of any Default
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  Default  thereof.   Notwithstanding   any
termination of this Lease, the same shall continue in force and effect as to any
provisions  which  specifically  by their  terms  provide  that such  provisions
survive the  termination of this Lease and require  observance or performance by
Landlord or Tenant subsequent to such termination.

                  (d)  Nothing  contained  in this  Section  14  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 Section.  Notwithstanding  anything contained in this Section
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.

                  (e) Pursue  any other  remedy now or  hereafter  available  to
Landlord under the laws or judicial  decisions of the state wherein the Premises
are located.

                  (f) The  expiration  or  termination  of this Lease and/or the
termination  of  Tenant's  right to  possession  shall not  relieve  Tenant from
liability under any indemnity  provisions of this Lease as to matters  occurring
or accruing  during the Term hereof or by reason of  Tenant's  occupancy  of the
Premises.

         14.3  Inducement  Recapture  in  Event of  Default.  Any  agreement  by
Landlord for free or abated Rent or other charges applicable to the Premises, or
for the  giving  or  paying by  Landlord  to or for  Tenant of any cash or other
bonus,  inducement or consideration  for Tenant's  entering into this Lease, but
excluding  Tenant's  right to occupy  the  Premises  without  payment of Rent as
described in Section 3.2 herein, and excluding any equity Tenant may have in the
Landlord entity, if any, all of which concessions are hereinafter referred to as
"Inducement  Provisions"  shall be deemed  conditioned  upon  Tenant's  full and
faithful performance of all of the terms, covenants and conditions of this Lease
to be performed or observed by Tenant  during the Term hereof as the same may be
extended.  Upon the occurrence of a Default (as defined in Section 14.1) of this
Lease by Tenant, not cured within an applicable cure period, any such Inducement
Provision  shall  automatically  be deemed  deleted  from  this  Lease and of no
further  force or effect,  and any Rent,  other  charge,  bonus,  inducement  or
consideration  theretofore  abated,  given  or paid by  Landlord  under  such an
Inducement Provision shall be immediately due and payable by Tenant to Landlord,
and  recoverable  by  Landlord,   as  Additional  Rent  due  under  this  Lease,
notwithstanding any subsequent cure of said Default by Tenant. The acceptance by
Landlord of Rent or the cure of the Default  which  initiated  the  operation of
this Section 14.3 shall not be deemed a waiver by Landlord of the  provisions of
this  Section 14.3 unless  specifically  so stated in writing by Landlord at the
time of such  acceptance.  Notwithstanding  the foregoing,  for the first full *
Lease  Years of the Lease  Term,  Tenant  shall be  obligated  to repay any such
charge, bonus,  inducement or consideration  theretofore abated given or paid by
Landlord.  During the * Lease Year,  Tenant must repay  one-half of such charge,
bonus  inducement  or  consideration.  During Lease Years * through *,  Tenant's
obligation to repay such charge,  bonus,  inducement or  consideration  shall be
further reduced by * of the full amount of any such charge,  bonus inducement or
consideration  each  Lease  Year until  such time as  Tenant's  obligations  are
reduced to zero.

         14.4 Late  Charges.  Tenant  hereby  acknowledges  that late payment by
Tenant to Landlord of Rent and other sums due hereunder  will cause  Landlord to
incur costs not  contemplated  by this Lease,  the exact amount of which will be
extremely  difficult to ascertain.  Such costs include,  but are not limited to,
processing  and accounting  charges,  and late charges which may be imposed upon
Landlord by the terms of any ground  lease,  mortgage or deed of trust  covering
the Premises. Accordingly, if any installment of Base Rent and Tenant's Share of
Operating  Expenses  or other  sum due from  Tenant  shall  not be  received  by
Landlord or  Landlord's  designee  within * days after such amount shall be due,
then, without any requirement for notice to Tenant, Tenant shall pay to Landlord
a late charge equal to * of such overdue  amount.  The parties hereby agree that
such late charge represents a fair and reasonable estimate of the costs Landlord
will incur by reason of late payment by Tenant.  Acceptance  of such late charge
by  Landlord  shall in no event  constitute  a waiver of Tenant's  Default  with
respect to such overdue amount,  nor prevent Landlord from exercising any of the
other rights and remedies granted hereunder.  In the event that a late charge is
payable  hereunder,  whether or not collected for * consecutive  installments of
Base Rent and Tenant's Share of Operating Expenses, then notwithstanding Section
4.1 or any other provision of this Lease to the contrary, Base Rent and Tenant's
Share of Operating Expenses shall, at Landlord's option,  become due and payable
quarterly in advance.

         14.5  Default by Landlord.  Landlord  shall not be deemed in default of
this Lease unless Landlord fails within a reasonable time and with due diligence
to proceed  promptly  to perform  an  obligation  required  to be  performed  by
Landlord. For purposes of this Section 14.5, a reasonable time shall in no event
be less than * days after receipt by Landlord,  and by any Lender(s)  whose name
and address shall have been furnished to Tenant in writing for such purpose,  of
written  notice  specifying  wherein  such  obligation  of Landlord has not been
performed;  provided,  however,  that if the nature of Landlord's  obligation is
such that more than * days after such  notice are  reasonably  required  for its
performance,  then Landlord  shall not be in breach of this Lease if performance
is  commenced  within  such * day period and  thereafter  diligently  pursued to
completion.  In the  event  of  Landlord's  default,  and  after  expiration  of
Landlord's  right to cure such default,  Tenant will be entitled to exercise any
right or  remedy  available  to  Tenant  at law or in  equity  by reason of such
default,  except to the extent  expressly waived or limited by the terms of this
Lease and provided that Tenant gave Landlord  written  notice of the  obligation
required to be performed by Landlord under the Lease.

15.  Condemnation.  If the  Premises or any portion  thereof are taken under the
power of eminent  domain or sold under the threat of the  exercise of said power
(all of which are herein called  "condemnation"),  this Lease shall terminate as
to the part so taken as of the date  the  condemning  authority  takes  title or
possession  whichever  first  occurs.  If more than * of the  floor  area of the
Premises  or more than * of the  portion  of the  Common  Areas  designated  for
parking  is taken  by  condemnation,  Tenant  may,  at  Tenant's  option,  to be
exercised  in writing  within * days  after  Landlord  shall  have given  Tenant
written  notice of such taking (or in the absence of such notice,  within * days
after the condemning authority shall have taken possession) terminate this Lease
as of the date the condemning  authority takes such  possession.  If Tenant does
not terminate  this Lease in  accordance  with the  foregoing,  this Lease shall
remain in full force and effect as to the  portion  of the  Premises  remaining,
except that the Base Rent and  Tenant's  Share of  Operating  Expenses  shall be
reduced in the same  proportion as the rentable floor area of the Premises taken
bears to the total  Rentable  Area of the  Premises.  No  reduction of Base Rent
shall occur if the  condemnation  does not apply to any portion of the Premises.
In the event a portion of the Common  Area  designated  for  parking is taken by
condemnation,  Landlord  will retain the ratio of Tenant's  parking based on the
square  feet  remaining  of the  Premises  to the ratio of parking  spaces  made
available for other tenants in the Building.  Any award for the taking of all or
any part of the Premises  under the power of eminent  domain or any payment made
under  threat of the  exercise of such power shall be the  property of Landlord,
whether such award shall be made as compensation  for diminution of value of the
leasehold  or for the  taking of the fee,  or as  severance  damages;  provided,
however,  that Tenant shall be entitled to any compensation,  separately awarded
to Tenant for Tenant's relocation  expenses,  taking of Tenant's chattels and/or
loss of Tenant's Trade Fixtures in the condemnation.

16.  Brokers.  Tenant and Landlord each  represent and warrant to the other that
(i) it has had no dealings  with any person,  firm,  broker or finder other than
Coldwell  Banker  Commercial,  Moore and Company who acted as Tenant's  agent in
connection  with the  negotiation of this Lease and/or the  consummation  of the
transaction  contemplated  hereby;  and (ii) no broker or other person,  firm or
entity other than said named Broker(s) is entitled to any commission or finder's
fee in  connection  with said  transaction.  Landlord  shall  pay a real  estate
commission to such Broker pursuant to a separate written agreement between them.
Tenant and Landlord do each hereby agree to indemnify,  protect, defend and hold
the other harmless from and against  liability for compensation or charges which
may be claimed by any such  unnamed  broker,  finder or other  similar  party by
reason of any  dealings  or actions of the  indemnifying  Party,  including  any
costs,  expenses,  and/or  attorneys'  fees  reasonably  incurred  with  respect
thereto.

         17.  Statements.

         17.1 Estoppel. Each party shall within * days after written notice from
the other party  execute,  acknowledge,  and deliver to the  requesting  party 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 the requesting
party may request.  It is intended that any such statement delivered pursuant to
this  Section  may be relied  upon by any  prospective  purchaser  of all or any
portion of Landlord's  interest  herein or any 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) the Lease
has not been  canceled or  terminated  and 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 (iii) not more than one month's Base Rent and
Tenant's Share of Operating Expenses has been paid in advance; and (iv) that the
current  amounts of the Base Rent are as represented by Landlord;  and (v) there
have been no subleases or assignments of the Leases.  Further, with * days after
Landlord's  request,  Tenant will supply  Landlord a  corporate  or  partnership
resolution,  as the case may be,  or a  certificate  executed  by the  Corporate
secretary of Tenant  certifying  that the party signing said statement of Tenant
is properly authorized to do so.

         17.2 Financial Statement. If Landlord desires to finance, refinance, or
sell the Premises or the Building  Complex,  or any part  thereof,  Tenant shall
deliver  to any  potential  lender or  purchaser  designated  by  Landlord  such
financial statements of Tenant and such Guarantors as may be reasonably required
by such lender or  purchaser,  including  but not limited to Tenant's  financial
statements for the past three (3) years. All such financial  statements shall be
received by Landlord  and such lender or purchaser  in  confidence  and shall be
used only for the purposes herein set forth.

         18.  Landlord's Liability. The term  Landlord"  as  used  herein  shall
mean the owner or owners at the time  in  question  of  the  fee  title  to  the
Premises.  In the event of a transfer  of  Landlord's  title or  interest in the
Premises or in this Lease during the Term hereof,  Landlord shall deliver to the
transferee or assignee (in cash or by credit) any unused  Security  Deposit held
by Landlord at the time of such  transfer or  assignment.  Upon such transfer or
assignment and delivery of the Security Deposit, as aforesaid,  and notification
of Tenant  thereof,  the prior  Landlord shall be relieved of all liability with
respect to the obligations  and/or  covenants under this Lease  thereafter to be
performed by the Landlord.  Subject to the  foregoing,  the  obligations  and/or
covenants in this Lease to be  performed  by the Landlord  shall be binding only
upon  the  Landlord  as  hereinabove  defined.  Notwithstanding  the  foregoing,
Landlord (or Landlord's  transferee or assignee)  shall be liable for the actual
costs  incurred  by Tenant  in  obtaining  a  transfer  of the  letter of credit
referenced in Section 5.1 hereof,  if any, upon the transfer of Landlord's title
or  interest in the  Premises up to a maximum  amount of * of the then letter of
credit amount, if any held by Landlord as a Security Deposit.

         19.  Severability.  The invalidity of any provision of this  Lease,  as
determined  by a court of  competent  jurisdiction,  shall in no way  affect the
validity of any other provision hereof.

         20.  Interest on Past-Due Obligations.Any monetary payment due Landlord
hereunder,  other than late charges,  not received by Landlord within * days for
the  first  two lat  payments  (and * days  after  the  first  two of such  late
payments)  following the date on which it was due,  shall bear interest from the
date due at an annual of interest equal to the lesser of (i) the Prime Rate plus
* (* after  the  first  two of such late  payments);  or (ii) the  highest  rate
permitted by applicable  usury law,  until paid. For purposes  hereof,  the term
"Prime Rate" shall mean the rate  published  by The Western  Edition of The Wall
Street  Journal under "Money  Rates".  If, for any reason,  the Prime Rate is no
longer  published  in The Wall Street  Journal  then the  Landlord  shall select
another financial publication and reasonably announced rate as the Prime Rate.

         21.  Time of Essence.   Time  is  of  the  essence  with respect to the
performance of all  obligations to be performed or observed by the parties under
this Lease.

         22.  Rent.   All  monetary obligations  of Tenant to Landlord under the
terms of this Lease are deemed to be Rent.

         23.  No Prior or Other Agreements.  This Lease contains all  agreements
between the parties with respect to any matter  mentioned  herein,  and no other
prior or contemporaneous agreement or understanding shall be effective.

         24.  Notices.

         24.1 Notice  Requirements.  All notices  required or  permitted by this
Lease  shall  be in  writing  and may be  delivered  in  person  (by  hand or by
messenger or courier  service) or may be sent by certified or registered mail or
U.S.  Postal Service  Express Mail,  with postage  prepaid,  and shall be deemed
sufficiently  given if served in a manner  specified  in this  Section  24.  The
addresses  noted below shall be that party's  address for delivery or mailing of
notice  purposes.  Either  party may by  written  notice to the other  specify a
different  address  for  notice  purposes,  except  that  upon  Tenant's  taking
possession of the Premises,  the Premises shall constitute  Tenant's address for
the purpose of mailing or  delivering  notices to Tenant.  A copy of all notices
required or permitted to be given to Landlord  hereunder  shall be  concurrently
transmitted to such party or parties at such addresses as Landlord may from time
to time hereafter designate by written notice to Tenant.

If to Landlord:            Shea Homes Lim. Partnership
                           300 W. Plaza Drive
                           Highlands Ranch, CO  80126
                           Attn:  Mr. David Goldberg

with a copy to:            L.C. Fulenwider, Inc.
                           1125 17th Street, Ste. 2500
                           Denver, CO  80202
                           Attn.:  Mr. William K. Prather

with a copy to:            The Krovitz Law Firm, P.C.
                           5290 DTC Parkway, Suite 150
                           Englewood, CO  80111-2764
                           Attn:  R. G. (Shelley) Krovitz, Esq.

If to Tenant (prior to     Frontier Airlines, Inc.
the Delivery Date):        12015 E. 46th Ave., #200
                           Denver, CO  80239-3116
                           Attn.:  General Counsel

If to Tenant (after the    The Premises
Delivery Date):

With a copy to:            Randall G. Alt, Esq.
                           Otten, Johnson, Robinson, Neff & Ragonetti, P.C.
                           950 17th Street, Suite 1600
                           Denver, CO  80202

                           and

                           Douglas R. Wright, Esq.
                           Faegre & Benson LLP
                           370 17th Street, Suite 2500
                           Denver, CO  80202

         24.2 Date of Notice.  Any notice sent by registered or certified  mail,
return receipt  requested,  shall be deemed given and received * hours after the
same is addressed as required  herein and mailed with postage  prepaid.  Notices
delivered by United  States  Express Mail or overnight  courier that  guarantees
next day delivery  shall be deemed given and received * hours after  delivery of
the same to the United States Postal  Service or courier.  If notice is received
on a Saturday or a Sunday or a legal holiday, it shall be deemed received on the
next business day.

         25.  Waivers. No waiver by Landlord of the Default of any term,covenan
or  condition  hereof  by Tenant  shall be  deemed a waiver  of any  other  form
covenant or condition hereof or of any subsequent  Default by Tenant of the same
or any other  term,  covenant  or  condition  hereof.  Landlord's  consent to or
approval of any such act shall not be deemed to render unnecessary the obtaining
of Landlord's  consent to or approval of any subsequent or similar act by Tenant
or be  construed  as the  basis of an  estoppel  to  enforce  the  provision  or
provisions  of this Lease  requiring  such  consent.  Regardless  of  Landlord's
knowledge of a Default at the time of accepting  Rent, the acceptance of Rent by
Landlord  shall not be a waiver of any  Default  by  Landlord  of any  provision
hereof.  Any  payment  given  Landlord  by Tenant may be accepted by Landlord on
account  of moneys or  damages  due  Landlord,  notwithstanding  any  qualifying
statements or  conditions  made by Tenant in  connection  therewith,  which such
statements  and/or  conditions shall be of no force or effect  whatsoever unless
specifically  agreed to in writing by  Landlord at or before the time of deposit
of such payment.

         26. Recording.  Tenant  shall  not  record  this  Lease or a memorandum
hereof.  In the event that Tenant violates this  provision,  this Lease shall be
null, void and of no further force and effect, at Landlord's option, except that
Tenant shall be liable to Landlord as liquidated  damages,  in the amount of the
remaining Rent to be paid hereunder.

         27.  Holdover. Tenant has no right to retain possession of the Premises
or any part thereof beyond the expiration or earlier  termination of this Lease.
In the event that Tenant  holds over in  violation  of this  Section 27 with the
consent of  Landlord,  then the Base Rent payable from and after the time of the
expiration or earlier  termination  of this Lease shall be increased to * of the
Base Rent applicable during the month  immediately  preceding such expiration or
earlier termination. Nothing contained herein shall be construed as a consent by
Landlord to any holding over by Tenant.

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

         29.  Covenants  and  Conditions.   All  provisions  of this Lease to be
observed  or  performed  by either  Landlord  or Tenant are both  covenants  and
conditions.

         30.  Binding Effect:  Choice of Law.  This Lease shall be  binding upon
the  parties,  their  personal  representatives,  successors  and assigns and be
governed  by the laws of the  State of  Colorado.  Any  litigation  between  the
parties hereto  concerning  this Lease shall be initiated in the county in which
the Premises are located.

         31.  Subordination; Attornment; Non-Disturbance.

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

         31.2 Superior. If any Mortgagee shall elect to have this Lease superior
to the lien of the applicable mortgage, deed of trust or ground lease, and shall
give written notice thereof to Tenant,  this Lease shall be deemed prior to such
mortgage,  deed of trust or ground  lease,  whether this Lease is dated prior or
subsequent  to the date of said  mortgage,  deed of trust or ground lease or the
date of recording thereof.

         31.3  Documentation.  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 any  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 or any ground
lease,  as the case may be, and failing to do so within  fifteen  (15)  Business
Days after  written  demand,  Tenant shall be in default under the Lease without
the necessity of further  notice.  Tenant's  subordination  and  attornment to a
future mortgage,  deed of trust or other  encumbrance on the Building and/or the
Real Property,  shall be contingent upon Tenant's  receipt from such lender of a
non-disturbance  agreement  prepared on the lender's  standard  form;  provided,
however,  receipt of such  non-disturbance  agreement shall be conditioned  upon
Tenant not being in default  under this Lease.  Such  non-disturbance  agreement
will provide in substance  that so long as Tenant fully complies with the terms,
covenants  and  conditions  of this Lease,  the party  succeeding  to Landlord's
interest will recognize this Lease.

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

         32.  Attorneys' Fees.  If  any  party brings an action or proceeding to
enforce the terms hereof or declare rights  hereunder,  the Prevailing Party (as
hereafter defined) in any such proceeding,  action, or appear thereon,  shall be
entitled to  reasonable  attorneys'  fees.  Such fees may be awarded in the same
suit or recovered in a separate  suit,  whether or not such action or proceeding
is pursued or decision or judgment.  The term "Prevailing  Party" shall include,
without  limitation,  a party who  substantially  obtains or defeats  the relief
sought, as the case may be, whether by compromise,  settlement,  judgment or the
abandonment by the other party of its claim or defense. The attorneys' fee award
shall not be computed in accordance  with any court fee  schedule,  but shall be
such as to fully reimburse all attorneys' fees reasonably incurred.

         33.  Right of Entry. Landlord  and  Landlord's  agents  shall  have the
right to enter  the  Premises  at any  time,  in the case of an  emergency,  and
otherwise at reasonable  times during normal  business hours for (i) the purpose
of showing the same to prospective  purchasers,  lenders,  or tenants,  and (ii)
making such alterations,  repairs,  improvements or additions to the Premises or
to the Building,  as Landlord may reasonably  deem  necessary;  provided that in
doing so, Landlord shall not unreasonably disturb or interfere with Tenant's use
of the Premises beyond what may be reasonably necessary under the circumstances.
Landlord may at any time place on or about the Premises or Building any ordinary
"For Sale" signs and Landlord may at any time during the last * days of the Term
hereof place on or about the Premises any ordinary "For Lease"  signs.  All such
activities  of  Landlord  shall be without  abatement  of Rent or  liability  to
Tenant; provided,  however, subject to Section 9.5 herein and excluding Tenant's
personal  property,  Trade  Fixtures,  and  Tenant-Owed  Alterations and Utility
Installations in, on or about the Premises,  Landlord shall repair damage to the
Premises caused by Landlord exercising its rights under (ii) above.

         34.  Auctions.  Tenant shall not  conduct,  nor permit to be conducted,
either voluntarily or involuntarily, any auction upon the Premises without first
having obtained  Landlord's prior written consent.  Notwithstanding  anything to
the  contrary in this Lease,  Landlord  shall not be  obligated  to exercise any
standard of reasonableness in determining whether to grant such consent.

         35.  Signage.  Tenant shall not place any sign upon the exterior of the
Premises  or the  Building,  except  in  conformance  with the  Landlord's  sign
criteria attached hereto as Exhibit D, and made a part hereof.  The installation
of any sign on the Premises by or for Tenant shall be subject to the  provisions
of Section 7 (Maintenance,  Repairs,  Utility Installations,  Trade Fixtures and
Alterations).  Unless otherwise  expressly agreed herein,  Landlord reserves all
rights  to the  use of the  roof  of the  Building,  and the  right  to  install
advertising signs on the Building, excluding the roof, which do not unreasonably
interfere  with the  conduct of Tenant's  business  and  further  provided  such
signage does not advertise a scheduled  passenger  airline  (provided,  however,
such  exclusion  shall  not  apply if any  such  competitor  is a tenant  in the
Building  Complex).  Landlord  shall  be  entitled  to all  revenues  from  such
advertising  signs,  if any.  Notwithstanding  the  foregoing,  Tenant  shall be
entitled to exterior  signage on the Building  provided that the size,  location
and design shall be subject to Landlord's  prior written approval which approval
will not be  unreasonably  withheld.  Tenant's right to the exterior  signage is
personal to the Tenant  corporation,  is not  assignable and may not be used for
any other name than Tenant's  corporate  name unless the Tenant changes its name
by  corporate  action,  but such  action  shall  not  include  a name  change by
assignment  or  sublease as  described  in Section 13 above.  All such  exterior
signage  rights  shall be of no  further  force and  effect if the named  Tenant
corporation  is not occupying at least * square feet of space in the Building at
any time during the Lease Term as it may be  extended.  Tenant  shall obtain all
approvals  necessary for all signage including,  approval pursuant to the Denver
International   Business  Center  protective   covenants  and  all  governmental
entities, at its cost and expense and such signage shall comply with all codes.

         36.  Termination;  Merger.  Unless  specifically   stated  otherwise in
writing by Landlord,  the voluntary or other  surrender of this Lease by Tenant,
the mutual  termination  or  cancellation  hereof,  or a  termination  hereof by
Landlord for Default by Tenant,  shall  automatically  terminate any sublease or
lesser estate in the Premises;  provided,  however, Landlord shall, in the event
of any such surrender,  termination or cancellation, have the option to continue
any one or all of any existing  subtenancies.  Landlord's  failure within * days
following  any such event to make a written  election to the contrary by written
notice to the holder of any such lesser interest,  shall  constitute  Landlord's
election to have such event constitute the termination of such interest.

         37.  Guarantor.   [Intentionally Deleted]

         38.  Quiet  Possession.   Upon  payment  by  Tenant of the Rent for the
Premises and the performance of all of the covenants,  conditions and provisions
on Tenant's  part to be observed and  performed  under this Lease and subject to
the provisions of this Lease, Tenant shall not be disturbed in its possession of
the Premises for the entire Term hereof by Landlord or any other person lawfully
claiming through or under Landlord.

         39.  Rules and  Regulations.  Tenant  agrees that it will abide by, and
keep and  observe  all rules and  regulations  ("Rules  and  Regulations)  which
Landlord  may make  from  time to time for the  management,  safety,  care,  and
cleanliness  of the  grounds,  the parking  and  unloading  of vehicles  and the
preservation of good order, as well as for the convenience of other occupants or
tenants of the Building and their  invitees.  The current Rules and  Regulations
are attached hereto as Exhibit F and made a part hereof. Any modification to the
current Rules and  Regulations  shall be effective  only upon delivery of a copy
thereof to Tenant at the  Premises.  Landlord  shall use  reasonable  efforts to
secure  compliance  by all tenants with the Rules and  Regulations  from time to
time in effect,  but shall not be  responsible to Tenant or any other person for
failure of any person to comply with such Rules and Regulations. Notwithstanding
the  foregoing,  the terms and  conditions  set forth in the body of this  Lease
shall control over any inconsistent Rules and Regulations.

         40.  Security.  Tenant  hereby  acknowledges  that the Rent  payable to
Landlord  hereunder does not include the cost of guard service or other security
measures, and that Landlord shall have no obligation whatsoever to provide same.
Tenant assumes all  responsibility  for the protection of the Premises,  Tenant,
its agents  and  invitees  and their  property  from the acts of third  parties.
Notwithstanding  the  foregoing,  Landlord  may elect to provide a concierge  or
security guard for more  efficient  operation of the Building  Complex,  and the
cost thereof shall be included as a Common Area Operating  Expense.  Landlord is
not obligated to provide such security services at any time or for any length of
time. Tenant expressly  acknowledges that Landlord has not represented to Tenant
that the Building  Complex is secure and Landlord shall not be  responsible  for
the quality of any  security  services  which may be provided  hereunder  or for
damage or injury to Tenant,  its  agents,  employees,  invitees or others or its
betterments  contained  in  the  Building  Complex  or the  Premises  due to the
failure, action or inaction of such persons providing the security services.

         41.  Reservations.  Landlord  reserves the right, from time to time, to
grant, without the consent or joinder of Tenant, such easements,  rights of way,
utility  raceways,  and dedications that Landlord deems necessary,  and to cause
the  recordation  of parcel maps and  restrictions,  so long as such  easements,
rights of way,  utility  raceways,  dedications,  maps and  restrictions  do not
unreasonably  interfere with the use of the Premises by Tenant. Tenant agrees to
sign any  documents  reasonably  requested  by Landlord to  effectuate  any such
easement rights, dedication, maps or restrictions.

         42.  Authority.  If either party hereto is a  corporation,  trust,   or
general or limited  partnership,  each individual executing this Lease on behalf
of such entity  represents  and warrants  that he or she is duly  authorized  to
execute and deliver this Lease on its behalf. If Tenant is a corporation,  trust
or  partnership,  Tenant shall within * days after written  request by Landlord,
deliver to Landlord evidence satisfactory to Landlord of such authority.

         43.  Conflict.  Any conflict between the  printed  provisions  of  this
Lease and any typewritten or handwritten  provisions  shall be controlled by the
typewritten or handwritten provisions.

         44.  Offer.  Preparation of this Lease by either Landlord or Tenant  or
Landlord's  agent or Tenant's agent and submission of same to Tenant or Landlord
shall not be deemed an offer to lease.  This Lease is not intended to be binding
until executed and delivered by all parties hereto.

         45.  Amendments.  This  Lease may be  modified  only in writing, signed
by the parties in interest at the time of the  modification.  The parties  shall
amend this Lease from time to time to reflect any  adjustments  that are made to
the Base Rent or other rent  payable  under this  Lease.  As long as they do not
materially or unreasonably change Tenant's obligations hereunder,  Tenant agrees
to make  such  reasonable  non-monetary  modifications  to this  Lease as may be
reasonably required by an institutional insurance company or pension plan lender
in connection with the obtaining of normal  financing or refinancing of the Real
Property of which the Premises are a part.

         46.  Multiple  Parties.  Except as otherwise expressly provided herein,
if more than one person or entity is named herein as either  Landlord or Tenant,
the  obligations  of such  multiple  parties  shall  be the  joint  and  several
responsibility  of all  persons or  entities  named  herein as such  Landlord or
Tenant.

         47.  Building Name. As of the date hereof,  the name of the Building is
and shall continue to be "Frontier Center One".  Notwithstanding  the foregoing,
if at any time during the Lease Term,  as it may be  extended,  the named Tenant
Corporation  is  occupying  less  than *  rentable  square  feet of space in the
Building  under the name "Frontier  Airlines,"  this Paragraph 47 shall be of no
further  force and effect and  Landlord  shall be free to rename the Building in
its sole discretion.

         48.  Confidentiality. All information contained in this Lease Agreement
is hereby deemed  confidential  and shall not be divulged to anyone  without the
express written consent of Landlord except as otherwise  specified in Section 17
of this Lease  Agreement to their  professional  consultants  and advisors,  the
Broker  identified in Section 16 or as otherwise  required by judicial action or
governmental law, rules and regulations.

         49.  Satellite. Landlord hereby grants Tenant a nonexclusive  right  to
install one ground  satellite  dish in the Ground  Satellite  Area (the  "Ground
Satellite")  and (ii) other  reasonable  telecommunications  equipment  of which
Landlord has received prior written notice and has exercised Landlord's right to
approve the  height,  weight,  load  factor,  design,  placement  and  screening
thereof,  and has given Landlord's prior written consent thereto, on the roof of
the Building (the "Roof Satellite")  during the Term of this Lease in accordance
with the following provisions:

         49.1 The Ground Satellite dish and all equipment  associated  therewith
shall be  installed in the Ground  Satellite  Area which shall be located as set
forth on Exhibit A-1 and shall be secured by Tenant.  The  requirements  for the
Ground  Satellite Area enclosure shall be subject to Landlord's  approval at the
time  Landlord  approves  the  plans  and  specifications  for the  Premises  as
described in Exhibit C hereto.  Landlord shall not unreasonably withhold consent
of the design of Tenant's Ground Satellite Area enclosure.  The Tenant must keep
the Ground Satellite Area in a clean and orderly  condition at its sole cost and
expense.  The Roof  Satellite  and other  equipment  required  for same shall be
mounted on a self-mounting/supporting pedestal that does not require penetration
of the roof  membrane  and one  antenna  of two (2) inch  diameter  that may not
extend  higher  than  sixteen  (16) feet from the  primary  roof  surface in one
location over the dispatch  center to be located near the center of the Premises
and the  remainder  not to exceed eight (8) feet from the primary roof  surface.
All  satellite  dishes  shall be  connected  to the  Premises  through  lines in
appropriate  utility  raceways  in  the  Building  (the  dishes,  pedestals  and
connecting equipment are hereinafter referred to as the "Equipment").  Equipment
in the  Building  (but not the  Ground  Satellite  Area and not in a part of the
Premises) shall be in locations designated by Landlord;  it being understood and
agreed that the exact  location may be  designated by Landlord and is subject to
change from time to time by Landlord, at Landlord's cost and expense;  provided,
however, that such changed location shall permit satellite reception.

         49.2 Tenant  shall be  responsible  at its sole cost for  construction,
installation,  relocation and maintenance of the Equipment;  provided,  however,
that Landlord shall install any necessary conduit from the Ground Satellite Area
through the  appropriate  utility  raceways in the  Building to the  Premises at
Tenant's sole cost and expense and the connecting  Equipment  shall be installed
in the  conduit  by Tenant at  Tenant's  sole cost and  expense.  The  Allowance
described on Exhibit C hereto may be used to pay for the Equipment  installation
costs.  All  installations  shall be subject to the requirements set forth under
Section 9 of the Lease. Tenant agrees not to install the Equipment without first
submitting plans and  specifications  and obtaining the written approval thereof
by Landlord,  such approval or consent not being unreasonably  withheld.  Tenant
agrees not to make any  subsequent  alterations in or additions to the Equipment
without in each instance  obtaining the prior written consent of Landlord,  such
approval or consent not being unreasonably withheld. Tenant at its expense shall
obtain all necessary  governmental  permits and  certificates  required for such
construction,   installation,  authorization  and  use,  as  well  as  approvals
necessary under any declaration of covenants or any maintenance  and/or easement
agreements  affecting  the Real  Property or the  Building  Complex,  including,
without limitation,  required consent of the architectural  control committee of
the  Denver  International  Business  Center.  All  construction,  installation,
alterations,  repair and  maintenance  work shall be performed in a manner which
will not unreasonably  interfere with, delay, or impose any additional  expenses
upon Landlord in the  maintenance  or operation of the Building  Complex or upon
other tenants' use of their premises.

         49.3 Tenant shall maintain the Equipment and keep it in good repair and
keep the  Ground  Satellite  Area and the roof free from all  trash,  debris and
waste resulting from the use thereof by Tenant.  Tenant shall pay or cause to be
paid all costs for work done by Tenant or caused to be done by Tenant related to
the  Equipment  of a character  which will or may result in liens on  Landlord's
interest therein,  in accordance with the provisions of the Lease. The Equipment
shall  be   operated   in   strict   compliance   with  all   governmental   and
quasi-governmental  laws, codes, rules or regulations.  Tenant shall have access
to the rooftop  Equipment;  provided,  however,  that Tenant shall give Landlord
reasonable  prior notice of the need for access and such access shall be subject
to such reasonable rules as Landlord may adopt,  including,  but not limited to,
the  requirement  that an agent of Landlord  accompany  persons during such roof
access.

         49.4  Tenant  hereby  agrees to  indemnify,  defend  and save  Landlord
harmless of and from all liability,  loss, damage, costs or expenses,  including
reasonable  attorneys' fees, on account of any claims of any nature  whatsoever,
including  work  performed,  materials  or  supplies  furnished,  damage  to the
property or injury to persons  caused by  negligence  or  misconduct  of Tenant,
Tenant's agents,  servants,  or employees or any other persons entering upon the
roof under  express or implied  invitation of Tenant or where such injury is the
result of the  violation of the  provisions  of this Lease by any such person or
caused  by the  construction,  installation,  alteration,  repair  or use of the
Equipment.

         49.5 Tenant shall have the right to install the Equipment in the Ground
Satellite Area and/or roof throughout the Term; provided,  however, the terms of
the Option granted in Section 50 hereof may include a requirement  for Tenant to
pay for such rights if applicable pursuant to the terms of such Section 50. Upon
the  expiration  or other  termination  of the Term of this Lease,  Tenant shall
remove its Equipment and all other  improvements or alterations  related thereto
and restore the  Building,  the roof and Ground  Satellite  Area to its original
condition, to the extent of any damages or changes caused by the installation or
use of the  Equipment.  In the event  Tenant fails to vacate the roof space on a
timely basis as required,  Tenant shall be responsible to Landlord for all costs
and expenses  incurred by Landlord as a result of such failure,  including,  but
not  limited  to,  any  amounts  required  to be paid to  third  parties,  which
obligation shall survive the termination of the Lease.

         49.6 Tenant  acknowledges  that the Equipment shall be of such type and
frequencies,  and  operated  in a manner that will not cause  interference  with
other  tenants'  business  in  the  Building  Complex,  including  operation  of
transmitting and receiving devices.  Landlord will advise other tenants or users
desiring  receiving and transmitting  equipment who must obtain Landlord's prior
approval that their use is subject to that of Tenant's Equipment then installed;
provided,  however,  Tenant will make  reasonable  efforts to accommodate  other
users  receiving  and  transmitting  satellite  needs  about  which  it has been
notified in writing. Landlord and Tenant agree that Landlord shall arbitrate any
disputes  between Tenant and other tenants  concerning  alleged  interference by
operation of the Equipment, whether claimed to be caused by Tenant or such other
tenants, and Tenant shall be bound by Landlord's determination in such disputes.
If Tenant's installation or operation of the Equipment results in an increase in
Landlord's insurance on the Building Complex at any time during the Term of this
Lease,  Tenant shall be responsible  for the payment of such increased  premiums
attributable to Tenant's installation or operation,  as reasonably determined by
Landlord.  Tenant  shall pay such  amount  upon  receipt of billing  therefor by
Landlord  together with the insurance  documentation  relied upon by Landlord in
making such determination.  Tenant shall not install or operate the Equipment in
a manner that results in cancellation or termination of Landlord's insurance.

         49.7 Tenant shall neither hold nor attempt to hold Landlord  liable for
an injury or damage either proximate or remote,  occurring  through or caused by
fire, water, steam or other repairs, alterations,  injury, accident or any other
cause to the Equipment,  or to other  personal  property of Tenant kept with the
Equipment  or in other  parts of the Real  Property,  whether  by  reason of the
negligence  or default of Landlord or any occupants of the Building or any other
person or  otherwise  and the keeping or storing of all property of Tenant shall
be the sole risk of Tenant.

         50.  Option to Extend.

         As  additional  consideration  for the  covenants of Tenant  hereunder,
Landlord  hereby grants unto Tenant an option (the  "Option") to extend the term
of this Lease for * years each (the "First" or "Second Option Term"). The Option
shall apply to all space then under the Lease at the time the respective  Option
Term would commence and shall be on the following terms and conditions:

         50.1  Written  notice of Tenant's  interest in  exercising  each Option
shall be given to Landlord not earlier than * months and not later than * months
prior to the  expiration  of the Primary  Lease Term or First Option Term as the
case may be ("Tenant's Notice").  Not later than * days after receiving Tenant's
Notice, Landlord shall give to Tenant notice of the terms, conditions and rental
rate  applicable   during  the  respective   Option  Term,  in  accordance  with
subparagraph E below ("Landlord's Notice")

         50.2 Tenant shall have * days following  Tenant's receipt of Landlord's
Notice within which to exercise the Option by delivering  written notice of such
exercise to Landlord  under the terms,  conditions  and rental rate set forth in
Landlord's Notice. If Tenant gives such Notice and provided the other conditions
to  the  extension  have  been  satisfied,  the  Term  of  the  Lease  shall  be
automatically  extended for the respective Option Term without requiring further
action by the parties; provided, however, the parties shall execute an amendment
to the Lease to confirm the terms of the extension.

         50.3 Unless  Landlord is timely  notified by Tenant in accordance  with
subparagraphs A and B above, the respective Option shall terminate and the Lease
shall expire in accordance  with its terms, at the end of the Primary Lease Term
or First Option Term, as the case may be.

         50.4 Tenant's Option to extend shall continue only if as of the date of
Tenant's Notice or as of the date of commencement of the respective Option Term,
Tenant:  (i) shall not be in default  under the Lease at the time of exercise of
the option or at the time of the commencement of the respective Option Terms; or
(ii) Tenant  shall not have sublet more than * of the  Premises nor assigned its
interest  in the  Lease  other  than an  assignment  to an  Affiliate  of Tenant
consented  to under  the  terms of  Section  13  hereof  (which  shall  not be a
violation hereof) nor vacated the Premises.

         50.5 The  Option  granted  hereunder  shall be upon the same  terms and
conditions  of this  Lease,  except  for the  rental to be paid by  Tenant,  and
except, after the Second Option Term, there shall be no further option to extend
the Lease. The Base Rent applicable  during each Option Term shall be comparable
to that for comparable space in a comparable  building complex as of the date of
Landlord's  Notice  but in no event  shall  the rate be less  than the Base Rent
which  Tenant is paying  immediately  prior to  commencement  of the  respective
Option Term.

         50.6 After  exercise of the Option as to the Second Option Term,  there
shall be no  further  rights on the part of  Tenant  to  extend  the Term of the
Lease.

         50.7 In order to have the right to the Second Option Term, Tenant shall
be required to have exercised the Option as to the First Option Term.

The parties hereto have executed this Lease to be effective on the date and year
first above written.

LANDLORD:                                            TENANT:

FRONTIER CENTER ONE LLC,                    FRONTIER AIRLINES, INC.,
a Colorado limited liability company        a Colorado corporation

By:
SHEA FRONTIER CENTER, LLC,
a California limited liability company,    By:     _____________________________
its Manager                                Its:    _____________________________

By:   J.F. Shea Co., Inc., a Nevada
      corporation, its Manager             ATTEST:


By:  ________________________________      By:      ____________________________
        Assistant Secretary                Title:  _____________________________


By:  ________________________________
        Assistant Secretary



<PAGE>


                                    EXHIBITS

                        Exhibit A - Depiction of Premises
                        Exhibit A-1 - Ground Satellite Area
                        Exhibit B        -    The Building Complex
                        Exhibit C        -    Work Agreement
                        Exhibit D        -    Sign Criteria
                        Exhibit E        -    Commencement Certificate
                        Exhibit F        -    Rules and Regulations
                        Exhibit G        -    Parking License
                        Exhibit G-1      -    Parking Map
                        Exhibit H        -    [Intentionally Deleted]
                        Exhibit I        -    Janitorial Requirements




<PAGE>





                                    EXHIBIT A

                              DEPICTION OF PREMISES


<PAGE>



                                   EXHIBIT A-1

                              GROUND SATELLITE AREA


<PAGE>


                                    EXHIBIT B

                              THE BUILDING COMPLEX

A PARCEL OF LAND  LOCATED IN THE  NORTHEAST  QUARTER  OF  SECTION 4,  TOWNSHIP 3
SOUTH, RANGE 66 WEST OF THE 6TH PRINCIPAL  MERIDIAN,  CITY AND COUNTY OF DENVER,
STATE OF COLORADO, MORE PARTICULARLY DESCRIBED AS FOLLOWS:

COMMENCING  AT THE  NORTHEAST  CORNER OF SAID SECTION 4, WHENCE THE EAST QUARTER
CORNER  THEREOF BEARS SOUTH 00 DEGREES 48 MINUTES 54 SECONDS WEST, A DISTANCE OF
2629.96 FEET; THENCE SOUTH 00 DEGREES 48 MINUTES 54 SECONDS WEST, ALONG THE EAST
LINE OF THE  NORTHEAST  QUARTER OF SAID  SECTION 4, A DISTANCE  OF 932.42  FEET;
THENCE NORTH 89 DEGREES 11 MINUTES 06 SECONDS  WEST, A DISTANCE OF 70.00 FEET TO
A POINT  ON THE  WEST  RIGHT-OF-WAY  LINE OF  TOWER  ROAD,  BEING  THE  POINT OF
BEGINNING;  THENCE SOUTH 00 DEGREES 48 MINUTES 54 SECONDS WEST,  ALONG SAID WEST
RIGHT-OF-WAY LINE, A DISTANCE OF 382.56 FEET; THENCE NORTH 89 DEGREES 48 MINUTES
51 SECONDS  WEST, A DISTANCE OF 315.05 FEET;  THENCE SOUTH 00 DEGREES 00 MINUTES
00 SECONDS  WEST, A DISTANCE OF 142.76 FEET;  THENCE NORTH 90 DEGREES 00 MINUTES
00 SECONDS  WEST, A DISTANCE OF 188.36 FEET;  THENCE NORTH 00 DEGREES 49 MINUTES
56 SECONDS EAST, A DISTANCE OF 30.50 FEET; THENCE NORTH 90 DEGREES 00 MINUTES 00
SECONDS  WEST,  A DISTANCE OF 51.79 FEET;  THENCE NORTH 00 DEGREES 49 MINUTES 56
SECONDS  EAST,  A DISTANCE  OF 237.73 FEET TO A POINT OF CURVE;  THENCE  ALONG A
CURVE TO THE LEFT HAVING A DELTA OF 25 DEGREES 16 MINUTES 23  SECONDS,  A RADIUS
OF 538.00  FEET AND AN ARC  LENGTH OF 237.31  FEET;  THENCE  NORTH 65 DEGREES 33
MINUTES 34 SECONDS  EAST,  A DISTANCE OF 63.38 FEET;  THENCE SOUTH 89 DEGREES 56
MINUTES 19 SECONDS EAST, A DISTANCE OF 547.19 FEET TO THE POINT OF BEGINNING.

To be known as:            Lot 3, Block 1
                           Denver International Business Center Filing No. 8
                           City and County of Denver
                           State of Colorado


<PAGE>





                                    EXHIBIT C

                                 WORK AGREEMENT

Re:      Tenant:           Frontier Airlines, Inc., a Colorado corporation
         Premises:         Approximately  *  rentable square feet of floor space
                           known as Suite 101 (the "Premises")

         Concurrently  herewith,  you as Tenant and the  undersigned as Landlord
have executed a Lease (the "Lease") covering the Premises (the provisions of the
Lease are  hereby  incorporated  by  reference  as if fully  set forth  herein).
Landlord has agreed to complete the base building items  described on Schedule 1
to this Exhibit C. All such base building  items to be completed by Landlord are
referred to herein as  "Landlord's  Work." All work that is  necessary to permit
Tenant to commence its business in the Premises , including, without limitation,
the  Tenant  Improvements  set forth on  Schedule 1 to this  Exhibit  C,  except
Landlord's Work including  installation of trade fixtures and furnishings  shall
be completed by Tenant  ("Tenant Work") at Tenant's cost and expense (other than
the Tenant Finish Allowance  described below). In consideration of the execution
of the Lease, Landlord and Tenant mutually agree as set forth below:
         A.       Landlord's Work.


1.         Landlord  shall  complete  Landlord's  Work in  accordance  with  the
           working drawings  prepared by The Neenan Company dated April 11, 2000
           (the "Approved Plan").

2.

3.                2.       Landlord's contractor shall perform  Landlord's  Work
           substantially in accordance with the Approved Plan at Landlord's cost
           and  expense.   Other  than  Landlord's  Work, Landlord shall have no
           obligation for completion or remodeling of the Premises.
4.

         B.       Tenant's Work.

                  1.  Tenant may  contract  with any  architect/designer  of its
choice.  Services  requested  by Tenant in  connection  with  design and drawing
preparation  shall be at  Tenant's  sole  cost and  expense.  Landlord  makes no
representation or guarantee with respect to fees,  services,  schedules or other
items  to  be  provided  by  the  architect/designer  and  shall  in no  way  be
responsible    for   such    architect/designer's    work   product.    Tenant's
architect/designer  shall prepare plans and  specifications for Tenant's Work to
be  completed in the Premises  (the "Plans and  Specifications").  All Plans and
Specifications  shall be subject to review and approval by Landlord,  Landlord's
architect and Landlord's  engineer prior to  commencement  of Tenant's Work. All
costs of  preparation,  review and  approval,  including  review and approval by
Landlord,  Landlord's architect,  and/or Landlord's engineer,  shall be borne by
Landlord.  Landlord shall, within * Business Days after receipt of the Plans and
Specifications  by Landlord  for its review and  approval,  submit to Tenant the
Plans and Specifications  with the required  approvals noted thereon,  or submit
comments  to  Tenant  setting  forth  changes  to  be  made  in  the  Plans  and
Specifications. If changes are required by Landlord, Tenant shall have the Plans
and  Specifications  modified and  resubmitted to Landlord for approval and such
process  shall  be  repeated  until  Landlord,   Landlord's  architect,   and/or
Landlord's  engineer have approved the Plans and Specifications for the Premises
(hereinafter referred to as "Approved Plans and Specifications"). Changes to the
Approved Plans and Specifications shall be made only upon prior written approval
of Landlord and shall be at Tenant's sole cost and expense.

                  2. Tenant shall contract  directly for the Tenant's Work to be
completed in accordance  with the Approved  Plans and  Specifications.  Tenant's
contractor  shall bill Tenant and Tenant shall be solely  responsible for paying
all  costs  for  Tenant's   Work  as  set  forth  on  the  Approved   Plans  and
Specifications. Tenant and Tenant's contractor will be required to adhere to the
requirements  set  forth in  Schedule  2  attached  hereto  in  connection  with
performance  of  Tenant's  Work and the  contract  between  Tenant and  Tenant's
contractor  shall  incorporate all of the provisions of Schedule 2. All Tenant's
Work shall (i) be  performed  pursuant  to written  contracts  with  workmen and
mechanics,  which  shall  be  acceptable  to  Landlord;  (ii)  comply  with  all
reasonable  restrictions and requirements as Landlord may impose with respect to
Tenant's Work; (iii) conform to the standards of the Building  Complex;  (iv) be
done  in  a  safe  and  lawful  manner  in  compliance  with  applicable   laws,
governmental  regulations,  and  requirements;  and  (v)  be  done  so as not to
interfere with Landlord's  completion of Landlord's Work in the Building Complex
and the Premises. Tenant shall cause such contractor to take all steps necessary
to cooperate in the  coordination  of the  performance of Tenant's Work with the
work of Landlord or  Landlord's  contractors  in the Premises or in the Building
Complex,  including,  without  limitation,   exchanging  information  about  and
coordinating their respective schedules,  attending  coordination  meetings, and
cooperating in allowing and obtaining  access to and availability of portions of
the  site  for  performance  of  Tenant's  Work  and  the  work  of  such  other
contractors.  Tenant may contract with Landlord's contractor to perform Tenant's
Work which contract must also meet the terms and  conditions of this  paragraph.
Notwithstanding  the  foregoing,  Landlord's  contractor  will  be  required  to
cooperate and coordinate to the extent possible with Tenant's contractor,  so as
not to cause any unreasonable delays in Tenant's Work,  provided,  however,  the
parties agree that because of the penalties to Landlord set forth in Section 3.2
of the Lease, if a conflict arises,  Landlord's contractor's schedule shall have
priority.

                  3.  Landlord  has  agreed to pay that  portion of the costs of
Tenant's  Work up to a maximum of $* per  rentable  square foot of the  Premises
(the "Tenant Work Allowance"). The cost of Tenant's Work payable from the Tenant
Work Allowance shall include all costs  attributable to design and  construction
of the Tenant's Work including but not limited to,  services,  fees and expenses
of the Tenant's architect and Tenant's engineers;  costs of permits and licenses
required  for  completion  of the  Tenant's  Work;  labor,  materials,  fees and
expenses of Tenant's contractor in completing the Tenant's Work. Landlord agrees
to provide up to an additional $* per rentable  square foot of the Premises,  in
addition to the Tenant Work Allowance, such amount to be applied toward costs of
Tenant's Work (the "Additional  Allowance").  Such Additional Allowance shall be
payable to Landlord by Tenant as Additional Rent in addition to the Base Rent in
an amount  calculated by amortizing  the  Additional  Allowance over the Primary
Lease Term at * per annum.  If for any reason at any time during the Lease Term,
Tenant is in default, which default is not cured with an applicable cure period,
or in the  event  the  Lease  Term is  terminated  for any  reason  prior to the
expiration of the Lease Term, the Additional  Allowance shall be immediately due
and payable upon the  occurrence of such default.  Tenant's  obligation to repay
Landlord the Additional Allowance shall survive the expiration or termination of
the Lease.  All costs  incurred in the  completion of Tenant's Work in excess of
the Tenant Work Allowance and the Additional Allowance shall be at Tenant's sole
cost and expense and shall be promptly  paid in full by Tenant to Landlord  upon
receipt of billing  therefor.  Any amount of the Tenant Work  Allowance (but not
Additional  Allowance) not utilized for Tenant's Work may be applied to next due
Base Rent under the Lease.

                  4. Tenant's Work  Allowance  (and after it has been  depleted,
the Additional  Allowance if Tenant provides Landlord written notice that Tenant
elects to use the  Additional  Allowance and wishes  Landlord to disburse it for
payments  hereunder  and Landlord and Tenant have  executed an amendment to this
Lease restating the Base Rent to include the Additional Allowance) shall be paid
to Tenant  periodically  as  portions of Tenant's  Work have been  completed  in
accordance with the Approved Plans and Specifications and the provisions hereof:

               a. Before the first application of payment, Tenant shall submit a
          schedule of values to Landlord  allocating the Tenant's Work Allowance
          to various portions of Tenant's Work.

               b.  On or  before  the  5th  day  of  each  month  following  the
          commencement  of the work,  Tenant  shall  submit to the  Landlord  an
          application  for payment on account of Tenant's Work performed  during
          the  payment  period  covered  by the  application  for  payment.  For
          purposes of this Lease,  the payment  period shall be the first day of
          each month and run through the last day of each month. On the last day
          of each  payment  period,  Tenant  shall  determine as of the date the
          percentage  of completion of the work covered by each line item of the
          approved  schedule of values.  Each  monthly  application  for payment
          shall be based upon the  percentage  of  completion  of each such line
          item  of  Tenant's  Work  and  shall  be in the  sum  of  the  amounts
          determined by multiplying the value of Tenant's Work of each line item
          as set forth in the approved  schedule of values by the  percentage of
          completion  determined  as to each  line  item on the last day of each
          payment period less the amounts  previously  paid with respect to such
          line items.

               c. Each  application  for payment  shall be  accompanied  by lien
          waivers and affidavits from Tenant's contractor and its subcontractors
          in a form  reasonably  satisfactory  to Landlord  attributable  to the
          immediately  preceding month's application for payment.  Additionally,
          Tenant's  contractor  shall  deliver an affidavit  to  accompany  each
          application  for payment  setting forth the names and addresses of the
          subcontractors'  materialmen  and  suppliers  and the dollar amount of
          liability which has been  contracted for with each such  subcontractor
          materialman  or  supplier  and the amounts  requested  by each in that
          month's application for payment.

               d. The  Landlord  will review  Tenant's  application  for payment
          within * Business  Days  after  receipt  and will pay Tenant  approved
          amounts  within * days  after  submittal  of a  complete  application.
          Notwithstanding  anything  contained  in this  Lease to the  contrary,
          Landlord  may  decline to make a payment to Tenant of all or a portion
          of any  application  for payment to the extent as may be  necessary to
          protect  Landlord  from loss  because of defective  work;  third party
          claims filed or reasonable evidence indicating probable filing of such
          claims;  failure  of the  Tenant to make  payment  to  contractors  or
          subcontractors  or  for  labor,  materials  or  equipment;  reasonable
          evidence  that the Tenant's  Work cannot be  completed  for the unpaid
          balance of the Tenant Work Allowance.  In the event Landlord withholds
          payment on account of any of the  foregoing  reasons,  Landlord  shall
          provide written notice of such reasons to Tenant. When the grounds for
          withholding of payment are removed, payment shall be made promptly for
          amounts withheld because of such grounds.  The application for payment
          shall  reflect   retainage  of  *  which  Landlord  shall  hold  until
          Landlord's final payment,  described in subparagraph e below. Landlord
          in its  reasonable  discretion  may agree to not  withhold any further
          retainage  when Tenant's Work is * complete  provided that Landlord is
          satisfied with the progress and quality of the Tenant's Work.

               e.  Landlord's  final  payment  to  Tenant of the  Tenant's  Work
          Allowance (and Additional Allowance,  if applicable) and the retainage
          shall not become due until Tenant submits to Landlord (i) an affidavit
          signed by Tenant  that upon  payment of the  remaining  portion of the
          Tenant's Work  Allowance,  all  payrolls,  bills for materials and any
          equipment and other indebtedness connected with the subject portion of
          Tenant's Work for which  Landlord or its property  might in any way be
          responsible,   have  been  paid  or  otherwise  satisfied;   (ii)  the
          certificate by Tenant's architect that the subject portion of Tenant's
          Work  is  complete  in   accordance   with  the  Approved   Plans  and
          Specification;  (iii) a Certificate of Occupancy  (temporary or final)
          or equivalent sign off has been issued by the appropriate governmental
          authority  permitting  use of the Premises for the Permitted Use under
          the  Lease  and a copy of  such  certificate  of  occupancy  has  been
          delivered to Landlord;  (iv) other data establishing the final cost of
          Tenant's  Work,  reasonable  evidence that Tenant has satisfied all of
          its construction obligations such as receipts, releases and waivers of
          liens  arising out of Tenant's  Work to the extent and in such form as
          may be reasonably designated by Landlord.

               5. Tenant and Tenant's  contractor shall indemnify  Landlord from
          any mechanic's or materialman's  lien against  Landlord's  interest in
          the  Building  Complex  or  Premises.  If a lien is  filed,  Tenant or
          Tenant's  contractor  shall,  at Tenant's  option,  remove the lien by
          paying in it full, furnish Landlord a bond sufficient to discharge the
          lien or deposit in an escrow  approved by Landlord *% of the amount of
          such lien and release the lien from the real  property  records of the
          City and County of Denver. In the event Tenant or Tenant's  contractor
          shall fail to remove the lien,  provide a bond or cash escrow,  Tenant
          shall  immediately be in default under the Lease without the necessity
          of further notice from Landlord and Landlord shall be entitled to take
          such  action at law,  in equity or under the Lease as  Landlord  deems
          appropriate  and Tenant shall be responsible  for all monies  Landlord
          may pay in  discharging  any lien  including all costs and  reasonable
          attorneys' fees incurred by Landlord in settling,  defending  against,
          appealing or in any manner dealing with lien.


         C.  Notwithstanding  the provisions of the Lease, the Rent Commencement
Date will not be  delayed  or  extended  by any Tenant  delay,  which  includes,
without limitation,  delay: (i) in the preparation,  finalization or approval of
the  working  drawings  for  Landlord's  Work  caused by  Tenant,  its agents or
employees;  (ii)  caused by  modifications,  revisions  and changes to the final
working drawings due to changes requested by Tenant,  its agents or employees or
objections from Tenant;  (iii) in the delivery or installation of any special or
non-standard  building items specified by Tenant;  or (iv) of any kind or nature
in the completion of Landlord's  Work caused by Tenant,  its agents or employees
("Tenant Delay"). Tenant shall pay all costs arising from Tenant Delay.

         D.  Tenant has designated Ms. Joan Osterman  and/or Mr. Cornelius  Baas
as its sole  representative  with  respect to the matters set forth in this Work
Agreement,  who shall have full authority and responsibility to act on behalf of
the Tenant as required in this Work  Agreement.  Tenant shall have the right, by
written notice to Landlord, to change its designated representatives.

         E.  Landlord  has  designated  Mr.  David  Goldberg  and/or  Mr.   Mark
Throckmorton as its representatives with respect to Landlord's  responsibilities
under this Work Agreement,  who shall have full authority and  responsibility to
act on behalf of the Landlord as required in this Work Agreement. Landlord shall
have  the  right,  by  written  notice  to  Tenant,  to  change  its  designated
representatives.

         F.  Any and all  notices  required  to be given  hereunder  shall be in
writing in accordance  with the terms and provisions of the Lease.  However,  in
all cases  notices  shall  also be given to those  individuals  to be  specified
pursuant to Paragraphs D and E above.

             FRONTIER CENTER ONE LLC,
             a Colorado limited liability company

             By:      SHEA FRONTIER CENTER, LLC,
                      a California limited liability company,
                      its Manager

             By:      J.F. Shea Co., Inc., a Nevada
                      corporation, its Manager

                      By:  ________________________________
                              Assistant Secretary

                      By:  ________________________________
                              Assistant Secretary

                      "Landlord"
AGREED AND ACCEPTED

this       day of                  , 2000.
     -----        -----------------

FRONTIER AIRLINES, INC.,
a Colorado corporation

By:
Title:

ATTEST:

By:
Title:


<PAGE>


                     SCHEDULE 1 TO EXHIBIT C WORK AGREEMENT


<PAGE>
<TABLE>
<S>                 <C>                                               <C>


ITEM                BASE BUILDING                                        TENANT IMPROVEMENTS

Site                a. Site to be paved, striped, and landscaped.        a.   No requirement.


Structure           a. Site cast concrete and structural steel frame.    a.   No requirement.

                    b. Site cast concrete slab on grade.

                    c. Roof deck and roofing.


Core Service Areas  a. Utility service entry provided.                   a.   Distribution by Tenant.


Lobby Improvements  a. No requirement.                                   a.   Dedicated   Tenant's  lobbies  per  Tenant
                                                                              plans.


Toilet Room         a. No requirement.                                   a.   Dedicated   toilet  rooms  to  accommodate
                                                                              Tenant's projected occupancy.


Perimeter Walls     a. Fur   and   insulate    perimeter   walls   as    a.   Gypsum  board,   paint,   wall  coverings,
                       follows:               Walls               R13         base,   and  window  sill   finishes   per
                       minimum                                                building standard.
                       Roof R19 minimum

                    b. Complete exterior finishes  including exterior    b.   Install    building     standard    window
                       window   systems   and   door   systems.   All         coverings;    optional    exercise    room
                       perimeter  window and door glass  shall have a         exterior door.
                       minimum shading coefficient of 0.56.


Interior Columns    a. Structural requirements only.                     a.   Finishes per code and Tenant plan.


Interior Partitions a. No requirement.                                   a.   Construct     interior     gypsum    board
                                                                              partitions  as required by Tenant's  space
                                                                              plan.      Construct     demising     wall
                                                                              con-sisting  of wall  framing  and  gypsum
                                                                              board finishes on Tenant side only.

                    b. No requirement.                                   b.   Finishes per Tenant plan.


Ceilings            a. No requirement.                                   b.   Furnish and install  building  standard 2'
                                                                              x 4'  acoustical  ceiling  grid  and  tile
                                                                              throughout leasable area.


Floor Covering      a. No requirement.                                   a.   Furnish and install all Tenant  areas with
                                                                              building    standard   or   better   floor
                                                                              coverings.  Building  standard  shall be a
                                                                              minimum of $*/Square Yard installed.


Doors, Frames &     a. Furnish and  install  exterior  doors,  frames    a.   Furnish,   install  and  finish   building
Hardware               and hardware  with mutually  acceptable  locks         interior   standard   doors,   frames  and
                       and closers.                                           hardware as  required  by  Tenant's  space
                                                                              plan.


HVAC                a. Furnish and  install  roof top HVAC units with    a.   Furnish  and  install   distribution  duct
                       a maximum  157.5 tons of  cooling.  Landlord's         runs   from   roof  top   HVAC   units  as
                       mechanical  engineer shall design the units in         required.  The supplemental  computer roof
                       conjunction with Tenant's mechanical engineer.         top units shall be provided by Tenant.

                    b. Landlord  will provide gas service  hookup and    b.   Furnish  and install  separate  HVAC units
                       all roof penetrations.                                 for  non-standard  loads (if any).  Tenant
                                                                              will  provide   all   electrical   service
                                                                              hookups  for HVAC units  electrical wiring
                                                                              and conduit).

                                                                         c.   Tenant  pays  cost of all HVAC  electrical
                                                                              and control related roof penetrations.


Plumbing            a. Furnish and install  waste line down center of    a.   Provide  distribution waste and vent lines
                       building per applicable code.                          as required  to  facilitate  tenant  plan.
                                                                              Tenant    shall    be    responsible   for
                                                                              maintaining flow only in  that  portion of
                                                                              the drain  line(s)  that  serves  plumbing
                                                                              fixtures  within  the  boundaries  of  its
                                                                              premises.  All  other  drain lines will be
                                                                              served by Landlord.


                    b. Furnish  and install  water  service to Tenant    b.   Extension of water  service  within Tenant
                       space,  minimum  size 1-1/2" to common  single         space as required.
                       meter  for  entire  building.   Landlord  will
                       provide  a  2"  capped  and  valved   stub  to
                       Tenant's space from riser room.

                                                                         c.   Furnish and install all plumbing  fixtures
                                                                              and  required  connections  per  code  and
                                                                              tenant finish plan.


Fire Protection and a. Furnish and install  complete fire  protection    a.   Relocate   and   add   standard   building
Sprinkler System       system per code for unimproved  base building;         sprinkler   drops  and  heads  for  proper
                       risers,  mains and  branch  lines  with  brass         coverage  as  dictated  by  the   Tenant's
                       upright  sprinkler heads for a wet pipe system         space plan and code.
                       at 1 head per 125 square feet of spacing.


Electrical          a. Furnish   and   install   electrical   service    a.   Power and lighting  distribution  per code
                       including    transformers,     to    dedicated         and Tenant specifications.
                       electrical   room  to  meet  a  minimum   load
                       requirement  of 480  volt,  3-phase,  1125 amp
                       demand load maximum for Tenant.


Fire Extinguishers  a. No requirement.                                   a.   Furnish  and  install  fire  extinguishers
                                                                              and  cabinets as required by space  layout
                                                                              and code.


Satellite Dish      a. Landlord  shall  provide  a  walled  enclosure    a.   Provide and install  including  electrical
                       sufficient   in   size  to   accommodate   the         distribution      and     any     building
                       building  transformers,  building gas metering         modi-fications.
                       system,  electrical  metering system,  and the
                       Tenant satellite dish and back up generators.


Uninterrupted Power a. No requirement.                                   a.   All service provisions by Tenant.
Source and Back Up
Generation
</TABLE>


<PAGE>



                     SCHEDULE 2 TO EXHIBIT C WORK AGREEMENT

                     PROCEDURE AND SCHEDULES FOR COMPLETION

                            OF TENANT WORK BY TENANT

Tenant and Tenant's  Contractor  and the contracts  between  Tenant and Tenant's
Contractors,  to be entered into in connection  with the performance of Tenant's
Work, shall conform to the following rules, regulations, and requirements, which
shall be  incorporated  into such  contracts.  Tenant  shall  ensure that all of
Tenant's  Contractors act in conformity with the provisions set forth herein. In
the event of any  conflict  between  any other terms or  provisions  of Tenant's
contracts and the terms and provisions set forth below, the terms and provisions
set forth below shall control.

         1. Tenant shall start construction of Tenant's Work in the Premises not
later than * days from  issuance  of a  building  permit,  and shall  carry such
construction to completion with all due diligence.

         2. Tenant shall submit to Landlord, in writing, at least *days prior to
the commencement of construction, the following information:

                  A. The names and  addresses  of the  general,  mechanical  and
electrical contractors,  if any, Tenant intends to engage in the construction of
Tenant's  Work and copies of proposed  contracts  executed by Tenant.  (The term
"Contractor" as used hereinafter  shall mean Tenant's general  Contractor or, if
Tenant does not use a general Contractor,  then all Contractors with whom Tenant
contracts directly for Tenant's Work. The term  "Subcontractors"  shall mean and
refer to all  entities  contracting  with the  Contractor  to complete  Tenant's
Work.)

                  B. A proposed  schedule setting forth the commencement date of
construction  of Tenant's  Work and the date of completion  of  construction  of
Tenant's Work,  fixturing work, dates for proposed  interruption of services (if
any required) and the date of projected opening.

                  C. Copies  of  performance and/or labor and material bonds, as
required by Landlord, from the Contractor and Subcontractors.

                  D. Final itemized statement of estimated  construction  costs,
including architectural, engineering and contracting fees.

                  E. Evidence of  insurance  as called for herein.  Tenant shall
secure, pay for and maintain,  or cause its Contractor(s) to secure, pay for and
maintain,  during  the  continuance  of  and  for *  year  after  completion  of
construction and fixturing work within Tenant's  Premises,  all of the insurance
policies  required  and in the  amounts as set forth  herein.  Tenant  shall not
permit, and Tenant's contract shall prohibit its Contractor to commence any work
until all required  insurance has been obtained and certified copies of policies
have been delivered to Landlord.

         3. Insurance:  The  following  insurance requirements shall be complied
with:

                  A.  Minimum  Coverage  -  Prior  to any  Tenant's  Work  being
commenced  by  Tenant's   Contractor  or  Subcontractors,   Tenant  or  Tenant's
Contractor  (as set forth  below),  shall  obtain and  maintain  insurance  with
minimum  coverage and limits to protect  Landlord and Landlord's  managing agent
from the claims hereinafter set forth which may arise or result from performance
of any Tenant's Work, whether such work be done by Tenant's Contractor or by any
of  Subcontractors  or by anyone  directly  or  indirectly  employed by Tenant's
Contractor or Subcontractors or by anyone for whose acts Tenant's  Contractor or
Subcontractors  may be  liable  as set  forth as  follows  (such  limits  may be
provided by an appropriate "umbrella" policy):

         1. Workmen's  Compensation  insurance  at the statutory limits provided
for by the State  of Colorado;


         2. Employer's liability insurance  at  a  limit of not less than $* for
all damages arising from each accident;

         3. Comprehensive general liability insurance covering:  (i)  Operations
Premises liability;  (ii) Completed  operations;  (iii) Product liability;  (iv)
Contractual  liability;  (v) Broad form property damage endorsement and property
damage  caused by  conditions  otherwise  subject to  exclusion  for  explosion,
collapse or underground  damage;  (vi) Fire legal liability,  with the following
insurance limits: Bodily Injury: $* each occurrence; $* general aggregate and $*
products/completed operation aggregate;

         4. Comprehensive  automobile  liability  insurance  covering all owned,
hired or non-owned  vehicles  including the loading and  unloading  thereof with
limits of no less than:  $* combined  single limit each  occurrence;  Automobile
Property Damage: $* each person;

         5. Physical  damage  insurance  covering  the  completed  value  of the
Tenant's Work which shall afford coverage  against "all risks" for physical loss
or damage.

                  B.  Cancellation - All such insurance shall be carried  with a
company or companies reasonably satisfactory to Landlord and Landlord's managing
agent and the  insurance  described  in (3),  (4) and (5) above,  and shall name
Landlord  and  Landlord's  managing  agent and  their  employees  and  agents as
additional insured parties. In addition,  each policy shall provide that it will
not be  canceled  or  altered  except  after * days  advance  written  notice to
Landlord, and the certificate of insurance shall so state.

                  C.  Policy Termination -Tenant's Contractor shall maintain all
insurance  required  hereunder  during the completion of Tenant's Work and for a
period ending * year after the date of completion of all Tenant's Work.

                  D.  Policies -Either Tenant or Tenant's Contractor may provide
the insurance  required  hereunder  except that Tenant's  Contractor  shall at a
minimum provide the insurance described in (1), (2) and (3) of subparagraph 3(a)
above.  Prior to commencement of work by Tenant's  Contractor,  it shall deliver
two (2) copies of the  aforementioned  policies or  evidence  of  policies  such
insurance to Landlord. All policies shall be deemed primary over any other valid
or collectible  insurance carried by Landlord or Landlord's managing agent. Such
policies  must be  approved  by  Landlord  prior to  commencement  of said work.
Without the express written consent of the Landlord, Tenant agrees that it shall
not allow any Contractor or  subcontractor  to commence work within the Building
until such entity has obtained the insurance required above. Landlord shall have
ten (10)  Business  Days to  disapprove  such  policies  or they  will be deemed
approved.

                  E.  Waiver of Subrogation - Tenant and Tenant's Contractor and
Subcontractors shall waive all rights against each other and the subcontractors,
sub-subcontractors,  agents and employees,  each of the other for damages caused
by fire or other perils  available under the normal "All Risk" I.S.0.  insurance
policy on the work itself and the Building.

              4. As provided above, Tenant shall notify Landlord of the names of
the proposed Tenant's Work general,  mechanical and electrical contractors.  All
Contractors  and  Subcontractors  engaged by Tenant shall be bondable,  licensed
contractors,  capable of performing  quality  workmanship and working in harmony
with Landlord's  general  contractor and other  contractors on the job. All work
shall be  coordinated  with the general  project work.  Landlord  shall have the
right to require Tenant's  Contractors to provide payment and performance  bonds
for any or all  Tenant's  Work,  such bonds to be paid for out of Tenant's  Work
Allowance if such funds are available.  Any bond shall be requested and provided
prior to the commencement of Tenant's Work.

              5.  Tenant's  Contractor  and  construction  shall  comply  in all
respects  with  applicable   federal,   state,  county  and/or  local  statutes,
ordinances, regulations, laws and codes. All required building and other permits
in connection  with the  construction  and  completion of Tenant's Work shall be
obtained and paid for by Tenant out of Tenant's Work Allowance if such funds are
available. If either party observes that any Tenant's Work is at variance in any
respect with any applicable codes, ordinances,  laws, rules and regulations,  it
shall promptly notify the other party and Landlord in writing, and any necessary
changes shall be made by Tenant.  If Tenant's  Contractor  performs any Tenant's
Work  that it knows is  contrary  to such  codes,  laws,  ordinances,  rules and
regulations,  and fails to  deliver  such  notice to the  Tenant  and  Landlord,
Tenant's Contractor shall assume full responsibility therefor and shall bear all
costs  attributable  to repair,  replacement or correction.  Tenant and Tenant's
Contractor and its subcontractors shall comply with Federal, State and local tax
laws, social security acts,  unemployment  compensation acts and such other acts
and laws as are applicable to the performance of Tenant's Work.

              6. All  contracts  shall be in writing,  and no work shall be done
except pursuant to such  contracts.  Tenant'scontract  with Tenant's  Contractor
shall be subject to Landlord's prior written consent, which consent shall not be
unreasonably withheld or delayed. Any approved contracts shall not be amended or
modified without approval by Landlord,  which consents shall not be unreasonably
withheld or delayed.  The Tenant's contract shall conform with the provisions of
the Lease,  including all  provisions  herein,  and shall  obligate the Tenant's
Contractor to complete Tenant's Work in accordance with the schedule referred to
in Paragraph 2(b) above.

              7. Work which  Landlord  shall have the right to have performed on
behalf of and for the benefit of Tenant shall be limited to work which  Landlord
deems  necessary  to be  done  on an  emergency  basis  and  which  pertains  to
structural  components,  the general  utility  systems for the project,  and the
erection of temporary  barricades  and  temporary  signs,  per standard  project
details and criteria,  during  construction or Tenant's Work which in Landlord's
reasonable opinion is not being performed in compliance with this Schedule 2.

              8. Tenant's Work shall be subject to the inspection and reasonable
approval  of  Landlord,   Landlord's  architect  and  general  Contractor.  Such
inspection  shall  be for  Landlord's  sole  benefit  and  shall  in no event be
construed as any benefit to, nor may Tenant rely  thereon.  All of Tenant's Work
shall be first  quality,  new  materials  and equipment and meet or exceed those
standards or qualities (as judged by Landlord's  architect)  contemplated at the
Building Complex.

              9. Tenant shall apply and pay for all utility meters except  where
metered service is provided by Landlord or public service agency.

              10. The Tenant's contract shall include a statement  requiring the
Contractor and all Subcontractors,  laborers,  and materialmen to execute a lien
waiver for any  interim and final  payments.  A copy of the  executed  waiver or
notice of refusal is to be immediately forwarded to the Landlord.

              11.  Tenant  and  Tenant's  Contractor  shall  indemnify  and hold
harmless  Landlord,  Tenant  and their  respective  representatives,  agents and
employees from and against all claims, damages, losses, and expenses, including,
but not limited to, reasonable  attorney's fees arising out of or resulting from
the  performance  of Tenant's Work or Tenant's  Contractor's  performance of the
Tenant's contract which are: (a) caused in whole or in part by any negligence or
omission  of  Tenant's  Contractor,  any  subcontractor  or anyone  directly  or
indirectly  employed  by any of them or anyone for whose acts any of them may be
liable;  and (b) attributable to bodily injury,  sickness,  disease or death, or
the destruction of tangible personal  property,  including loss of use resulting
from any of the  foregoing  acts and all Tenant's Work  contracts  shall reflect
this  indemnity.  In any and all claims  against the  Landlord,  Tenant or their
respective representatives or any of their agents or employees or by an employee
of  Tenant's  Contractor,  any  subcontractor,  anyone  directly  or  indirectly
employed by any of them, or anyone for whose acts any of them may be liable. The
indemnification  obligation  under this Paragraph 11 shall not be limited in any
way by any limitation on the amount or type of damages, compensation or benefits
payable by or for the Tenant's Contractor or any Subcontractor under the Workers
Compensation Act, disability benefit acts, or other employee benefit acts.

              12. In the event a Subcontractor or materialman files a mechanics'
lien as a result of performing work pursuant to Tenant's  contract then Tenant's
Contractor  shall  indemnify  the Tenant and Landlord  from said lien and shall,
when  requested  by the Tenant  and/or  Landlord,  pay the amount  requested  to
release  the lien or furnish  Tenant and  Landlord  (as  Landlord  or Tenant may
specify)  either a bond sufficient to discharge the lien or deposit in an escrow
approved by Landlord  and Tenant a sum equal to 150% of the amount of such lien.
Subject to any restrictions thereon posed by any mortgagee of Landlord, Tenant's
Contractor  shall have the right and  opportunity,  in cooperation with Landlord
and Tenant,  to contest the validity of any such  mechanics'  lien by such legal
means as are  available,  including the right to prosecute any appeals which may
be permitted by law so long as during the pendency of any contest or appeal, the
Tenant's  Contractor shall  effectively stay or prevent any official or judicial
sale of any of the real property or improvements  comprising the building,  upon
execution or otherwise,  and so long as the Tenant's  Contractor  pays any final
judgment  entered  with  respect  to any such  mechanics'  lien  and  thereafter
procures and records,  within a reasonable time, record satisfaction thereof. In
the  event the  Tenant  and  Landlord  shall be a party to any such  contest  or
appeal,  or any other action resulting from or arising out of the performance of
the  work by  Tenant's  Contractor  (or any of its  subcontractors,  agents,  or
employees),  Tenant's  Contractor  shall be  responsible  for all legal fees and
other costs and  expenses  incurred by Landlord  and Tenant in any such  action.
Landlord  and Tenant  shall have the right to obtain  separate  counsel of their
choice at Tenant's  Contractor's  expense. In the event that Tenant's Contractor
fails to pay the lien or provide a bond or cash escrow,  or  otherwise  fails to
fully satisfy and obtain the release of any lien or claim in accordance with the
provisions  hereof,  Tenant's  Contractor shall be obligated to pay to Tenant or
Landlord,  as the case may be, all monies that the latter may pay in discharging
any such lien  including all costs and  reasonable  attorneys'  fees incurred by
Landlord or Tenant in  settling,  defending  against,  appealing or in any other
manner dealing with any such lien.

              13. All risk of loss to all  property of the  Tenant's  Contractor
and its  subcontractors,  including,  but not  limited to,  tools and  materials
located on the Premises,  shall be the sole and exclusive  responsibility of the
Tenant's  Contractor  and its  subcontractors,  and the  Landlord  shall have no
responsibility therefor.

              14. If Tenant or Tenant's Contractor is adjudicated a bankrupt, or
if Tenant or Tenant's  Contractor makes a general  assignment for the benefit of
its creditors, or if a receiver is appointed on account of Tenant's Contractor's
insolvency,  or if Tenant's  Contractor  persistently  or repeatedly  refuses or
fails,  except in cases  where delay is  justified,  to supply  enough  properly
skilled  workmen or proper  materials  or if  Tenant's  Contractor  persistently
disregards  laws,  ordinances,  rules,  regulations  or  orders  of  any  public
authority having jurisdiction, or otherwise is guilty of a substantial violation
of a provision of Tenant's  contract,  then the Tenant (or Landlord in the event
of Tenant's  bankruptcy,  default,  or  assignment to  creditors)  may,  without
prejudice to any right or remedy and after giving the  Tenant's  Contractor  and
its surety, if any, * business days' written notice, terminate Tenant's contract
with the Contractor and in the event of Contractor's  default take possession of
all materials,  equipment,  tools,  construction equipment and machinery thereon
owned by Tenant's Contractor and shall thereafter finish all Tenant's Work being
constructed  and previously  contracted  for by Tenant's  Contractor by whatever
method it may deem expedient.  In such case,  Tenant's  Contractor  shall not be
entitled to receive any further  payments  from Tenant until  completion  of all
Tenant's Work;  provided,  however,  that the Tenant's actions shall not release
Tenant's  Contractor from any obligations to Tenant arising from its performance
or  nonperformance  under any contracts  prior to the date of such  termination.
Following the completion of such uncompleted Tenant's Work, Tenant shall pay the
Tenant's Contractor an amount equal to the aggregate of the amounts actually due
under Tenant's contract at the time of the termination of the contract, less the
cost to Tenant of completing all the Tenant's Work. Upon termination of Tenant's
contract,  Tenant's  Contractor shall execute and deliver all documents and take
all steps,  including the legal  assignment of Tenant's  Contractor  contractual
rights as the Tenant may require for the purpose of fully  vesting in Tenant the
rights and benefits of the Tenant's  Contractor  under  Tenant's  contract,  and
arising out of it. Tenant shall also pay to the Tenant's  Contractor fair rental
for any equipment retained.

              15. Tenant's  Contractor  shall warrant and agree, at its expense,
and at no expense  whatsoever  to  Landlord  or Tenant to correct or cause to be
corrected  any  defects in the  Tenant's  Work  (including,  but not limited to,
latent  defects or defects due to defective  workmanship  or  materials  whether
supplied,  installed or performed by Tenant's Contractor or any Subcontractor or
supplier) which occur within * year after Tenant's  Contractor has substantially
completed the Tenant's Work,  including  completion of all punchlist  items, (as
evidenced by the Tenant's  acceptance of such Work) or for such longer period as
may be set forth in the Tenant's contract.  Tenant's  Contractor shall require a
similar warranty in all Subcontracts,  and shall deliver to Landlord and Tenant,
together  with  appropriate   assignments,   if  required,   all  warranties  of
subcontractors  and suppliers of materials,  components and equipment  furnished
and installed in connection with such Tenant's Work. Tenant's Contractor further
agrees that all guaranties  and warranties  relating to any Tenant's Work or any
materials  incorporated into the Tenant's Work shall be extended to and given to
both the Landlord and the Tenant, as their respective interests in such Tenant's
Work exist, as more particularly set forth in the Lease between the Landlord and
Tenant.

              16. Landlord shall have no obligation  with  respect  to  Tenant's
Contractor.

              17. Landlord and Landlord's  contractor shall have the right, from
time to time as may be required, to inspect or perform work within the Premises.
Such inspections or work shall not conflict with Tenant's  Contractor's  work in
the Premises unless it is necessary in an emergency situation. Further, Landlord
shall have the right to suspend  Tenant's  Contractor's  work in the Premises if
such work, in the reasonable opinion of Landlord or of Landlord's contractor, is
presenting  or may  present  a danger to life,  safety,  or  property,  or in an
emergency situation.

              18.  Tenant  shall give  Landlord  reasonable  prior notice to all
inspections,  punchouts and other reviews during the course of  construction  so
that  Landlord  may observe  such events.  Further,  Landlord  shall be likewise
informed of all Building Department inspections and requirements for issuance of
the  Certificate  of Occupancy for the Premises.  Landlord's  observation of any
such  events  shall,  in no event be  construed  or  interpreted  as a review or
approval  by  Landlord  of any such work nor shall it  prevent  Landlord,  if it
thereafter  discovers any  deficiency in such Work,  from  requiring  correction
thereof  as  otherwise  provided  herein.  Tenant's  Contractor  shall be solely
responsible  for  obtaining  such  Certificate  of Occupancy and shall submit to
Landlord the original  thereof  prior to Tenant's  occupancy of the Premises for
the purpose of conducting business.

              19.  Provided  the  same  is  performed  in a  reasonable  manner,
Landlord's  architect  or other  agent  shall have the option of  reviewing  all
equipment and materials to be used in the  construction of the Tenant's Work and
all such work prior to Tenant move-in.  Such review shall in no event constitute
approval by Landlord  and shall not  unreasonably  delay  Tenant's  Contractor's
progress.

              20.  Tenant's  Contractor will not store materials or supplies in,
about, or outside the Building Complex (other than within the Premises)  without
the prior approval of the Landlord and Landlord's contractor.

              21.  Tenant's  Contractor  will  provide,  at  all  times,  direct
supervision  of any and all work being  performed  for the Tenant  including the
delivery and hoisting of materials, if necessary.

              22. Tenant's Contractor will cooperate with Landlord to dispose of
refuse  resulting  from  Tenant's  Work.  This may include the use of Landlord's
dumpster and a proration of charges  associated  with such use or at  Landlord's
option and Tenant's sole cost and expense the  placement of Tenant  Contractor's
dumpster at a location specified by Landlord.

              23. If any legal action or arbitration  proceeding is commenced in
order to enforce the provisions of Tenant's  contract or to recover damages as a
result of the alleged breach of the provisions thereof,  the prevailing party in
any such action or proceeding  shall be entitled to recover all reasonable costs
incurred in connection therewith, including reasonable attorneys' fees.


<PAGE>



         EXHIBIT D

                                  SIGN CRITERIA

         These  criteria  have been  established  for the  purpose of assuring a
quality  business  park and for the mutual  benefit of all Tenants.  Conformance
will be strictly enforced,  and any installed  nonconforming or unapproved signs
must be brought in  conformance  at the  expense of the  Tenant.  After  written
notice to Tenant of a violation and * days to cure such violation, ANY SIGN THAT
DOES NOT  CONFORM TO THESE  REGULATIONS  WILL BE  REMOVED  AND  REPLACED  WITH A
CONFORMING SIGN AT TENANT'S EXPENSE.

         It will be the sole  responsibility  of the  Tenant to  conform  to the
terms of this Sign Criteria as follows:

         1.   No later  than * days  prior to the  Delivery  Date,  Tenant  will
              provide, at its sole cost and expense, the Tenant's portion of the
              sign in conformance with the criteria below.

         2.   The sign base complete with the unit number has been  provided  on
              the Building.  The sign base is the property of the Landlord.

         3.   Tenant identification shall be restricted to the Tenant portion of
              the sign.

         4.   The  lettering/logo  and installation of the Tenant portion of the
              sign on the sign base  shall be paid for by Tenant  and remain the
              property of  Landlord.  All letters and other  scripting  shall be
              consistent  in color and style with the  lettering on the base and
              in good taste, in the opinion of Landlord.

         5.   Tenant  shall  submit to Landlord for its approval all copy and/or
              logo prior to installation of the Tenant portion of the sign.

         6.   Upon Lease termination,  Tenant  shall remove  its sign and return
              the Premises to their original condition.

         7.   No audible signs will be allowed;  provided,  however, the parties
              acknowledge   that  the  permitted   signs  may  emit  an  audible
              mechanical hum during  operation.  Landlord will allow  internally
              illuminated lighting with no moving fixtures.

         8.   Except  as  provided  herein,  no  banners,  pennants,   placards,
              freestanding  signs,  or signs affixed to  automobiles or trailers
              are  allowed  on the  Building,  in the  landscaped  areas,  or on
              streets or parking area. The restriction pertaining to automobiles
              or trailers  does not apply to magnetic or painted  identification
              signs placed on company or private  vehicles for use in the normal
              course of business.

         9.   All signs will be reviewed for conformance  with this criteria and
              overall aesthetics and design quality.  Approval or disapproval of
              sign submittals based on aesthetics shall remain the sole right of
              the Landlord.

         10.  Each Tenant  shall submit or cause to be submitted to Landlord for
              approval before fabrication at least * copies of detailed drawings
              indicating  location,  size,  layout,  design  and  color  of  the
              proposed signs, including all lettering and/or graphics.

         11.  All permits for signs and their  installation shall be obtained by
              the Tenant or their  representative  at Tenant's  cost and expense
              and will  comply  with all  appropriate  government  requirements.
              Nothing in this criteria shall imply a waiver of  requirements  by
              the local authorities.

         12.  Tenant   shall   be  responsible  for  the   fulfillment  of   all
              requirements and specifications.

         13.  All signs shall be constructed and installed at Tenant's expense.


<PAGE>


                                    EXHIBIT E

                          Commencement Date Certificate

         COMMENCEMENT DATE CERTIFICATE  ("Certificate") is executed this ___ day
of  __________________,  2000, by Frontier  Center One, LLC, a Colorado  limited
liability  company,   ("Landlord")  and  Frontier  Airlines,  Inc.,  a  Colorado
corporation,  ("Tenant")  with  respect  to and  forming a part of that  certain
Office Suite lease  ("Lease") dated  __________________,  20__, for the premises
commonly known as Suite _________________________________ ("Premises").

WITNESSETH:

         WHEREAS,  the  parties  desire to  reaffirm and/or amend and certify to
certain provisions of the Lease; and

         WHEREAS,  the  parties  desire  that the  matters  set forth  herein be
conclusive and binding on the parties.

         NOW, THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which are hereby acknowledged, the parties agree as follows:


1.       The   Lease   Commencement   Date   is   deemed   and   agreed   to  be
         _____________________,   20___,  and  the  Lease  termination  date  is
         _____________________,  20___, unless sooner terminated or extended, as
         provided therein.

2.

3.       Base Rent as set forth in Section 1.7 of the Lease is hereby  confirmed
         to be as follows:
4.

5.       Period                              Monthly Rent
         ------                              ------------
6.                                           $
         ------------------
7.                                           $
         ------------------
8.                                           $
         ------------------
9.                                           $
         ------------------
10.                                          $
         ------------------
11.

12.      Tenant's first installment of Base Rent in the amount of ______________
         Dollars ($__________) for the period of ___________________ (is due on)
         (was paid on) _______________, 20__.
13.

14.      Tenant's Share of Operating Expenses as set forth in Section 1.9 of the
         Lease is hereby confirmed to be _________%.  Tenant's first installment
         of Tenant's  Share of Operating  Expenses in an amount to be determined
         is due on _________________, 20____.

15.

16.      The Rentable Area of the Building  (as  defined in  Section 1.8  of the
         Lease) is agreed to be _________ rentable square feet.
17.

18.      The Rentable Area of the Premises (as defined in  Section  1.8  of  the
         Lease) is agreed to be __________ rentable square feet.
19.

20.      By  execution   hereof,   Tenant   acknowledges  and  agrees  that  all
         improvements or other work required of Landlord has been satisfactorily
         performed  except for latent  defects,  and Tenant  hereby  accepts the
         Premises in full compliance with the terms and conditions of the Lease.

21.

22.      Except as may be amended herein,  all terms and conditions of the Lease
         shall continue in full force and effect and are hereby  republished and
         reaffirmed in their entirety.

23.

24.      This Certificate  shall be  binding  upon and may be relied upon by the
         parties hereto and their respective legal  representatives,  successors
         and assigns.

25.

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

                                     FRONTIER CENTER ONE LLC,
                                     a Colorado limited liability company

                                       By:    SHEA FRONTIER CENTER, LLC,
                                       a California limited liability company,
                                       its Manager

                                       By:   J.F. Shea Co., Inc., a Nevada
                                             corporation, its Manager

                                       By:  ___________________________________
                                                   Assistant Secretary

                                       By:  ___________________________________
                                               Assistant Secretary

                                                    "Landlord"


                                     FRONTIER AIRLINES, INC.,
                                     a Colorado corporation

                                       By:
                                       Title:

                                     ATTEST:

                                       By:
                                       Title:

                                                      "Tenant"


<PAGE>

                                    EXHIBIT F

                              RULES AND REGULATIONS

         The Rules and  Regulations  in this  Exhibit  F have  been  adopted  by
Landlord  for the  safety,  benefit  and  convenience  of all  tenants and other
persons in the Building  Complex.  Landlord  may,  from time to time in its sole
discretion, amend, delete from, or add to the Rules and Regulations and any such
modification shall be effective upon delivery of a copy thereof to Tenant at the
Premises.  Landlord  shall use  reasonable  efforts to secure  compliance by all
tenants  with the  Rules  and  Regulations  then in  effect,  but  shall  not be
responsible  to Tenant for the  failure of any person to comply  with such Rules
and  Regulations  nor shall any such failure relieve Tenant of its obligation to
comply with the Rules and Regulations. In these Rules and Regulations,  the Term
"Tenant"  includes the employees,  agents,  invitees and licensees of Tenant and
others permitted by Tenant to use or occupy the Premises.



1.   Tenant shall not do or permit anything to be done on the Premises, or bring
     or keep anything  therein which shall in any way obstruct or interfere with
     the rights of other  tenants,  or in any way injure or annoy them,  or with
     any insurance policy covering the Building and/or Common Areas thereof. Any
     picketing  of the  Premises  shall take place  only on  publicly  dedicated
     sidewalks and not on the Common Area or in the Premises. 2.

2.

3.   Tenant  shall not sweep or throw,  or permit to be swept or thrown from the
     Premises,  any dirt or other  substance into any of the Common Areas of the
     Building Complex.  Tenant shall not use, keep or permit to be used any foul
     or  noxious  gas or  substance  in the  Premises,  or permit or suffer  the
     Premises to be occupied or used in a manner  offensive or  objectionable to
     Landlord  or other  occupants  of the  property  by reason of noise,  odors
     and/or  vibrations.  Tenant  shall  place all refuse in proper  receptacles
     provided by Landlord (and charged as a Common Area Operating  Expense),  in
     the locations  designated by Landlord for the Building,  and shall keep the
     loading dock area outside the Premises free of all refuse. Tenant shall not
     loiter  on the  Common  Areas to smoke  except in the  Building  designated
     smoking  area.  Tenant  shall,  at its sole cost and  expense,  comply with
     recycling programs for the Building Complex established by Landlord.

4.

5.   Tenant shall not store,  nor cause to be stored,  any material,  substance,
     equipment,  supplies  or  vehicles  outside  or  adjacent  to the  Premises
     described in this Lease.

6.

7.   Tenant  and its  employees  or  vendors  shall  not go upon the roof of the
     Building without prior written consent of Landlord.

8.

9.   No animals,  birds,  reptiles or other pets may be brought in or kept in or
     about the Premises  without  Landlord's  written consent except for animals
     assisting persons with disabilities.

10.

11.  Unless escorted by an adult, children are not allowed on the Premises or in
     the Building Complex.

12.

13.  Canvassing,  soliciting  and  peddling  in the  Building  Complex or on the
     Premises are  prohibited,  and Tenant shall  cooperate to prevent the same.
     Only  persons  approved  in  writing,  from time to time by  Landlord,  may
     solicit  orders for,  sell,  serve or distribute  foods or beverages in the
     Building or Common Areas.  Except with Landlord's prior written consent and
     in  accordance  with  arrangements  approved by Landlord.  Tenant shall not
     permit  cooking  within the Premises,  except for microwave  ovens,  coffee
     makers,  etc., for the use of their employees,  agents or invitees.  Tenant
     shall be  entitled  to install  vending  machines  operated  by third party
     licensees and contract with a caterer who may serve breakfast  and/or lunch
     to Tenant,  its employees,  agents or invitees;  provided such caterer does
     not have its  personal  property or fixtures on the  Premises for more than
     the period reasonably  necessary to serve such meal(s) and such catering is
     operated  in  compliance  with the  requirements  of this Lease  including,
     without limitation, approval of Final Working Drawings showing the location
     of the eating area in which the caterer  will serve meals and  Paragraph 18
     below.  If such  caterer will occupy a portion of the Premises as evidenced
     by its personal  property or fixtures  remaining in the Premises beyond the
     meal it is  serving,  then Tenant  must  comply  with the  requirements  of
     Section 13 of the Lease for subletting a portion of the Premises.

14.  Tenant shall not use or keep on the Premises, any kerosene, gasoline or any
     inflammable,  combustible or explosive fluid, chemical or substance, or use
     any method of heating or air  conditioning  other than that  authorized  in
     writing by Landlord;  provided,  however, Tenant can store small quantities
     of paint thinner and other similar cleaning products in compliance with the
     requirements of all governmental and quasi-governmental  rules, regulations
     and laws applicable thereto and with the provisions of Section 7.

15.

16.  Tenant shall give prompt  notice to Landlord of any accidents to or defects
     in plumbing,  electrical  fixtures,  heating or cooling  apparatus or other
     utilities.

17.

18.  The toilet rooms, toilets,  urinals, wash bowls and other apparatus serving
     the  Premises  shall not be used for any purpose  other than that for which
     they were  constructed,  and no foreign  substance  of any kind  whatsoever
     shall be thrown therein.  All damage and expense  resulting from any misuse
     of the  fixtures  shall be borne by  Tenant  to the  extent  its  servants,
     employees, agents, visitors and licensees shall have caused it.

19.

20.  Tenant  shall  give  Landlord  reasonable  advance  notice of and refer all
     contractors,  contractors'  representatives  and  installation  technicians
     rendering any service to the Premises for Tenant to Landlord for Landlord's
     approval and  supervision  before  performance of any  contractual  service
     relating to the Premises  itself.  This  provision  shall apply to all work
     performed  which  may  effect  the  Building  or in the  Building  Complex,
     including  installation  of  telephones,  telegraph  equipment,  electrical
     devices and attachments and installations of any nature.  Excluded from the
     requirement of advance notice to Landlord shall be repairs and  maintenance
     of any of Tenant's own equipment or Tenant's Trade Fixtures to include, but
     not be limited to phone equipment,  security system, copiers and computers.
     Tenant  shall carry out those  activities  which are  restricted  herein in
     connection  with Tenant's  repair,  maintenance,  approved  alterations and
     improvements  in the Premises only during the times agreed to in advance by
     Landlord and in a manner which will not interfere  with the rights of other
     tenants in the Building Complex.

21.

22.  The sidewalks,  exits, entrances,  driveways and Common Areas in and around
     the Premises  shall not be  obstructed  by Tenant or used by Tenant for any
     purpose other than for ingress to and egress from the Premises.  The exits,
     entrances,  driveways,  Common  Areas,  and roof are not for the use of the
     general  public,  and  Landlord  shall,  in all cases,  retain the right to
     control and prevent  access thereto by all persons whose  presence,  in the
     judgment  of  Landlord,  shall  adversely  affect  the  safety,  character,
     reputation  and interest of the Building  and its tenants,  provided,  that
     nothing  herein  contained  shall be  construed  to prevent  such access to
     persons  with whom  Tenant  normally  deals in the  ordinary  course of its
     business  unless such persons are engaged in illegal  activities.  Landlord
     may  remove,   at  Tenant's   expense,   any  such   obstruction  or  thing
     (unauthorized by Landlord) without notice or obligation to Tenant. 23.

24.  Landlord agrees to furnish Tenant fifteen (15) keys without charge for each
     of the keyed exterior entry doors.  Additional  keys will be furnished at a
     nominal  charge.  Tenant  shall not alter any lock,  nor install any new or
     additional  locks or any bolts on any door of the Premises  without written
     consent of the Landlord.  If Landlord shall give its consent,  Tenant shall
     in each case,  furnish the  Landlord  with a key for any such lock.  Tenant
     acknowledges  that Landlord  retains a master key to all entry doors in the
     Building Complex.

25.

26.  Tenant must,  upon the  termination  of this Lease,  return to Landlord all
     keys either furnished to, or otherwise procured by Tenant; and in the event
     of the loss of any keys so furnished, Tenant shall pay to Landlord the cost
     of replacing  the same or of changing the lock or locks opened by such lost
     key if Landlord shall deem it necessary to make such change.  Landlord will
     not  permit  entrance  to the  Premises  by use of pass key  controlled  by
     Landlord,  to any  person at any time  without  the  permission  of Tenant,
     except employees,  contractors, or service personnel authorized by Landlord
     in accordance with the provisions of Section 33 herein.

27.

28.  Tenant  shall  ensure that the windows and doors of the Premises are closed
     and securely locked before leaving the Premises. Tenant must observe strict
     care and caution  that all water  faucets or other  apparatus  are entirely
     shut off before  Tenant or Tenant's  employees  leave the Premises so as to
     prevent  damage,  and  Tenant  shall be  responsible  for the costs for all
     injuries or damages  sustained by other  tenants or by Landlord as a result
     thereof.

29.

30.  Special  requests by Tenant shall be attended to only upon written approval
     by Landlord or its agent. Employees or agents of Landlord shall not perform
     any work for or do  anything  outside  of their  regular  duties for Tenant
     unless under written approval from the Landlord.

31.

32.  Landlord  will not be  responsible  for  damaged,  lost or stolen  personal
     property,  equipment, money or jewelry from Tenant's Premises or the Common
     Areas  regardless  of whether such loss occurs when area is locked  against
     entry or not.

33.

34.  Tenant, its employees,  agents or invitees shall comply with all directions
     of Landlord as posted in and for the use of the  Building  Complex  parking
     areas.

35.

36.  With regard to the employee  cafeteria or food  service  preparation  area,
     Tenant shall be obligated to comply with, at its sole cost and expense, any
     code,  ordinance,  statute,  law, rule,  regulation,  or requirement of any
     governmental agency having jurisdiction over the Premises or declaration of
     covenants  affecting the Real Property related to Tenant's  preparation and
     service of food from a portion of the  Premises and Tenant shall obtain all
     licenses  related to such  operation.  Tenant  shall  maintain any required
     grease  traps and all  plumbing and  electrical  facilities  related to the
     operation of the Cafeteria in good order, condition and repair. Tenant will
     at all times  maintain  and conduct its  business so that no odors,  fumes,
     vapors,  steam, moisture or condensation shall affect any walls, floors, or
     ceilings in the Building or emanate from the Premises. All refuse cans must
     be kept  inside the  Premises  and shall be kept as  required by the health
     codes.  Tenant shall at all times transport the refuse and garbage from the
     Premises to the refuse area in such manner as may be designated by Landlord
     from  time to time.  Tenant  shall  enter  into and keep in full  force and
     effect  throughout  the  term of this  Lease  a full  service  preventative
     extermination  contract with a licensed pest control  operator  approved in
     advance by  Landlord.  Further,  Tenant  agrees to keep the premises at all
     time free from pests attracted by the cafeteria and shall cause the same to
     be  exterminated  from time to time to the  satisfaction  of the  Landlord.
     Tenant  shall  have no right to apply  for and  obtain a  license  to serve
     liquor or wine from the Premises.

37.

38.  The Premises  shall not be used or  permitted  to be used for  residential,
     lodging or sleeping  purposes,  or for the  storage of personal  effects or
     property not required for business purposes.

39.

40.  No blinds,  drapes or other  window  coverings  shall be  detached  from or
     installed  in the Premises  without the express  prior  written  consent of
     Landlord.  In the event of  violation  of any of the  foregoing  by Tenant,
     Landlord may remove the articles  constituting  the  violation  without any
     liability and Tenant shall reimburse  Landlord for the expense  incurred in
     such  removal  and  replacement  upon demand as  additional  Rent under the
     Lease.

41.

42.  Tenant,  its  employees,  agents and  invitees  shall not bring any weapons
     and/or  explosives  into the  Premises,  Building  or Common  Areas for any
     reason;  provided,  however,  if Tenant  provides a security  guard for the
     Premises,  such guard may carry a firearm so long as such guard has a valid
     license therefor.

43.

44.  No  person  shall  enter  or  remain  within  the  Building  Complex  while
     intoxicated or under the influence of liquor or drugs.  Landlord shall have
     the right to exclude or expel from the Building  Complex any person who, in
     the sole discretion of Landlord, is under the influence of liquor or drugs.

45.

46.  Tenant shall  maintain the air  temperature  in its Premises warm enough to
     prevent the freezing of the plumbing and sprinkler system.

47.

48.  The failure of the  Landlord to seek  redress for  violation  of, or insist
     upon the strict performance of any covenants or conditions of this Lease or
     any of the Rules and  Regulations  set forth above or hereafter  adopted by
     Landlord,  shall not prevent a subsequent  act, which would have originally
     constituted  a  violation  from  having  all the  force  and  effect of any
     original  violation.  The receipt of Landlord  of any rental  payment  with
     knowledge  of the breach of any  covenant  of this Lease or breach of these
     Rules and Regulations shall not be deemed a waiver of such breach.

49.

50.  No act or thing done or omitted to be done by Landlord or Landlord's  agent
     during the term of the Lease which is necessary to enforce  these Rules and
     Regulations shall constitute an eviction by Landlord nor shall it be deemed
     a surrender or acceptance of said Premises, and no agreement to accept such
     surrender shall be valid unless in writing signed by Landlord.  No employee
     of Landlord or Landlord's  agent shall have any power to accept the keys of
     said Premises prior to the  termination of the Lease.  The delivery of keys
     to any employee of Landlord or Landlord's agent shall not be construed as a
     termination of the Lease or a surrender of the Premises.



<PAGE>




                                 PARKING LICENSE

         Landlord hereby grants a license to Tenant for the use by Tenant at the
option of Tenant on an unreserved, unassigned basis of * standard size passenger
vehicle  parking  stalls  (the  "Spaces")  on the  surface  lot  adjacent to the
Building  upon terms of the Lease and this  License.  Tenant's  Spaces  shall be
located in the area of the surface lot marked on the diagram  attached hereto as
Exhibit G-1.  Tenant shall have the right to designate  visitor parking near its
entrances at its discretion.  The right to use such spaces is non-exclusive  and
is in common  with  others on a  first-come,  first-served  basis (the  "Parking
Privileges").  In the event Tenant  elects to construct a day care center in the
Premises  and in the event an outdoor  play area may be  required  or desired in
connection  with the operation of such day care center,  Tenant's Spaces will be
reduced to provide such DC Play Area on the surface parking lot. Tenant shall be
required to obtain  Landlord's  prior written consent to the location of such DC
Play Area.


1.  Tenant's  right to the  Parking  Privileges  shall  commence  on the date of
execution  of the  Lease  and shall  continue  for the Term of the Lease  unless
sooner  terminated or extended,  or unless Tenant is in default not cured within
an  applicable  cure  period  under the  Lease.  The  Parking  Privileges  shall
automatically terminate upon the expiration or earlier termination of the Lease,
the Primary Lease Term and any extensions thereof.

2.

3.  Landlord  shall  have the right at any time to  change  the  arrangement  or
location of or to regulate the use of Spaces without  incurring any liability to
Tenant or its Designated Users as long as the number of Spaces  referenced above
area are available.  Landlord will not require parking off the Building  Complex
except for reasons beyond Landlord's control. Among other things, Landlord shall
be entitled to assign  designated areas of the surface lot for use by particular
persons  or groups of persons  and Tenant  shall  refrain  from  parking in such
Spaces as long as the number of Spaces  referenced  above are available.  Tenant
acknowledges that the Spaces will not be individually designated or reserved for
use by Tenant and that  Tenant  will use the Spaces in the surface lot in common
with all persons to whom or which  Landlord  grants the right to use the surface
lot  except  as  expressly  set  forth  herein  as long as the  number of Spaces
referenced above are available.

4.

5. In addition to the Rules and Regulations  set forth in the Lease,  the use of
the Spaces is subject to the following  rules related to Landlord's  measures to
restrict use of the Building parking facilities by unauthorized persons:

6.

7. a. Landlord will provide Tenant with written notice that Landlord  intends to
establish a system of  restricted  parking and will consult with Tenant prior to
finalizing any such system.

8.

9. b. At Landlord's  written  request,  Landlord may provide Tenant with tags or
stickers for Tenant to  distribute  to specific  individual  employees of Tenant
(the "Designated Users"). Alternatively,  Landlord may designate use of specific
spaces  to  Designated  Users;  but  Tenant  shall  remain  responsible  for all
obligations hereunder.  Within * business days after Landlord's written request,
Tenant  agrees to provide  Landlord with a listing of all vehicles or Designated
Users,  including names of vehicle owners, vehicle models, colors, license plate
numbers, and Tenant shall provide Landlord with a revised listing promptly after
any change to the listing.  Tenant shall  deliver to Tenant's  Designated  Users
parking  decals or other  identification  provided by Landlord which shall be at
all times displayed  prominently on the vehicles of Designated  Users.  Landlord
shall have the right to directly ban any Designated User from further use of any
of the  Spaces  for  violation  of the rules for the use of the  Spaces.  Anyone
parked in the Spaces  without a parking  decal may be towed by Landlord  without
notice and at the vehicle owner's expense.

10.

11. c. Tenant and Designated  Users shall park only in parking spaces and not on
ramps, corridors, approaches, or other areas designated as "no parking" areas.

12.

13. d. Tenant and  Designated  Users shall observe the special hours of opening,
closing and non-use of the surface lot when  closings are necessary for repairs,
cleaning and rehabilitation.

14. e. Tenant and  Designated  Users  shall use the Spaces  only for  automobile
parking to include Permitted Size Vehicles as defined in the Lease.

15.

16. f. Tenant and  Designated  Users shall  observe  all posted  vehicle  height
limitations.

17.

18. g. Tenant and Designated Users shall not allow unauthorized  vehicles to use
the Spaces and, except for emergencies,  shall not repair nor authorize  service
to vehicles parked in the parking structure or in surface parking area.

19.

20. If any portion of the surface lot shall be damaged by fire or other casualty
or shall be taken by right of  eminent  domain  or by  condemnation  or shall be
conveyed in lieu of any such taking, the Parking Privileges shall  automatically
cease and terminate, Tenant thereupon shall surrender to Landlord the Spaces and
all interest  therein,  and Landlord  may  re-enter and take  possession  of the
Spaces. 21.

22. Tenant shall not be permitted to assign the Spaces or any interest herein or
permit the Space or any part thereof to be used by other than  Designated  Users
without the prior written  consent of Landlord,  which consent may be granted or
withheld  in  Landlord's  sole  discretion,  except  as to  Landlord's  approved
subleases in which event consent shall be granted. Tenant shall remain primarily
liable  for  the  performance  of  the  obligations  of  the  Tenant   hereunder
notwithstanding any assignment or occupancy  arrangement  permitted or consented
to by Landlord.

23.

24. Neither  Landlord or its agents shall be liable for any damage,  fire, theft
or loss to  vehicles  or  other  properties  or  persons  while  in the  parking
facilities of the Building, whether caused by theft, collision, moving vehicles,
explosion,  fire, or any other activity or occurrence in such  Building.  Tenant
and/or  its  Designated  Users  assume the risk of such loss or damage and shall
indemnify,  defend and hold  Landlord and its agents  harmless  from any and all
claims  against and damages  incurred by Landlord  arising from  Tenant's or the
Designated Users' use of the parking facilities, including all costs, attorneys'
fees, expenses and liabilities incurred on or about any such claim or action.

25.

26.



<PAGE>




                                   EXHIBIT G-1

                                   PARKING MAP


<PAGE>




                                    EXHIBIT H

                             [INTENTIONALLY DELETED]


<PAGE>



                                    EXHIBIT I

                             JANITORIAL REQUIREMENTS

I.       GENERAL SERVICES

         A.       DAILY SERVICES

                  1.  Clean entry door glass.

                  2.  Sweep with chemically treated dust mop or vacuum all
                      floors.

                  3.  Spot clean composition floors and carpets.

                  4.  Dust desk, chairs and all other office furniture.

                  5.  Clean all ash trays and sand urns.

                  6.  Properly position furniture in offices.

                  7.  Empty all waste baskets and carry trash  to  pick up area.

                  8.  Spot clean door, door frames and counters.

                  9.  Spot clean partition and door glass.

                  10. Spot clean around wall switches.

                  11. Clean and polish drinking fountains.

                  12. Clean elevator and elevator tracks.

                  13. Leave on designated lights.

                  14. Police stairway entries.


II.      OTHER REQUIREMENTS

         A.       WEEKLY SERVICES

                  1.  Dust ledges and window sills.

                  2.  Perform low dusting.

                  3.  Dust the baseboards.

                  4.  Sweep/Vacuum stairways and dust the rails.

                  5.  Remove fingerprints from woodwork, walls and partitions.

         B.       MONTHLY SERVICES

                  1.  Perform high dusting (i.e., Door sashes and tops of
                      partitions).

                  2.  Dust picture frames.

         C.       FLOOR FINISHING SERVICES

                  1.  Clean and refinish all composition floors - Monthly.


III.     RESTROOM SERVICES

         A.       DAILY SERVICES

                  1.  Empty and wipe out all waste paper receptacles.

                  2.  Empty sanitary napkin containers and replace insert.

                  3.  Polish all metal and mirrors.

                  4.  Clean and polish all dispensers.

                  5.  Clean and disinfect wash basins, toilet bowls and urinals.

                  6.  Disinfect underside and tops of toilet seats.

                  7.  Spot clean tile walls and toilet partitions.

                  8.  Spot clean walls around wash basins.

                  9.  Clean floors with a germicidal solutions.

                  10. Refill soap, towel, tissue and seat cover dispensers.

         B.       SEMI-WEEKLY SERVICES

                  1.  Pour  clean water down floor drains to prevent sewer gases
                      from escaping.

         C.       WEEKLY SERVICES

                  1.  Wash  down  ceramic  tile  walls  and  toilet  compartment
                      partitions.

                  2.  Perform high dusting.

         D.       MONTHLY SERVICES

                  1.  Brush down vents.

                  2.  Machine scrub floors.


<PAGE>




                                TABLE OF CONTENTS

1.   Basic Provisions                                             1

2.   Premises, Parking and Common Areas                           3

3.   Term                                                         5

4.   Rent                                                         6

5.   Security Deposit                                             9

6.   Use                                                         11

7.   Hazardous Substances                                        11

8.   Maintenance, Repairs, Utility Installations,
     Trade Fixtures and Alterations                              12

9.   Insurance; Indemnity                                        15

10.  Casualty and Restoration of Premises                        17

11.  Real Property Taxes                                         18

12.  Utilities                                                   19

13.  Assignment and Subletting                                   19

14.  Default; Remedies                                           22

15.  Condemnation                                                26

16.  Brokers                                                     26

17.  Statements                                                  26

18.  Landlord's Liability                                        27

19.  Severability                                                27

20.  Interest on Past-Due Obligations                            27

21.  Time of Essence                                             27

22.  Rent                                                        27

23.  No Prior or Other Agreements                                28

24.  Notices                                                     28

25.  Waivers                                                     29

26.  Recording                                                   29

27.  Holdover                                                    29

28.  Cumulative Remedies                                         29

29.  Covenants and Conditions                                    29

30.  Binding Effect:  Choice of Law                              29

31.  Subordination; Attornment; Non-Disturbance                  29

32.  Attorneys' Fees                                             30

33.  Right of Entry                                              30

34.  Auctions                                                    30

35.  Signage                                                     30

36.  Termination; Merger                                         31

37.  Guarantor                                                   31

38.  Quiet Possession                                            31

39.  Rules and Regulations                                       31

40.  Security                                                    31

41.  Reservations                                                32

42.  Authority                                                   32

43.  Conflict                                                    32

44.  Offer                                                       32

45.  Amendments                                                  32

46.  Multiple Parties                                            32

47.  Building Name                                               32

48.  Confidentiality                                             32

49.  Satellite                                                   32

50.  Option to Extend                                            34