COMMERCIAL LEASE - NET
                            (Single Tenant Building)

                             Basic Lease Information


Date:  January 15, 1998

Landlord:  TriNet Essential Facilities X, Inc., a Maryland corporation

Tenant:  ICG Holdings, Inc., a Colorado corporation

Premises (section 1.1):  Address:  161 Inverness  Drive West, City of Englewood,
     County of Arapahoe, State of Colorado

Term (section  2.1):  Fifteen  (15) years plus the  partial  month  between  the
     Commencement  Date and the last day of the calendar  month during which the
     Commencement Date occurs.

Commencement Date (section 2.1):  January 20, 1998

Expiration Date (section 2.1):   January 31, 2013

Initial Base Rent (section 3.1(a)):  $395,222.00 per month.

Use  (section  6.1):  Office  purposes  and,  to the extent  permitted  by Legal
     Requirements  and  subject  to the terms of  section  6.1,  ancillary  uses
     typical of  headquarters  buildings  such as employee  cafeteria,  training
     rooms, child-care center, testing laboratories,  light assembly of products
     and storage of inventory and supplies.

Liability Insurance (section 10.3):  $5,000,000

Insuring Party for Property Insurance (section 10.4): Landlord.

Landlord's Address  (section 23.1):  Four  Embarcadero  Center,  Suite 3150, San
     Francisco, CA 94111, Attn: Mr. Mark W. Whiting.

Tenant's Address (section 23.1): 9605 East Maroon Circle,  Englewood,  CO 80112,
     Attn:  Mr.  Douglas  McKinnon;  with a copy to Tenant at the same  address,
     Attention: General Counsel.

Guarantors (section 24.1): ICG Communications, Inc., a Delaware corporation; ICG
     Holdings (Canada), Inc., a Federal Canadian corporation.

Exhibits and Addenda (section 24.3):  Exhibit A - Form of Estoppel  Certificate;
     Exhibit B - Form of Lease Guaranty.


     The foregoing Basic Lease Information is incorporated in and made a part of
the Lease to which it is attached.  If there is any  conflict  between the Basic
Lease Information and the Lease, the Lease shall control.

Landlord:                               Tenant:

TRINET ESSENTIAL FACILITIES X, INC.,    ICG HOLDINGS, INC.,
a Maryland corporation                  a Colorado corporation



By  /s/Gary P. Lyon                     By /s/ James D. Grenfell
   -----------------------------           ---------------------------
     Gary P. Lyon                            James D. Grenfell  

   Its Executive Vice President           Its Executive Vice President
                                              and Chief Financial Officer





                                TABLE OF CONTENTS

                                                                        Page

ARTICLE  1     Premises....................................................1

ARTICLE  2     Term........................................................1

ARTICLE  3     Rent........................................................2

ARTICLE  4     Payment of Operating Expenses...............................5

ARTICLE  5     Operating Expenses, Property Taxes and Other Taxes 
               Defined; Contest Rights.....................................7

ARTICLE  6     Use....................................................... 11

ARTICLE  7     Services.................................................. 12

ARTICLE  8     Maintenance and Repairs; Capital Improvements............. 13

ARTICLE  9     Alterations............................................... 14

ARTICLE 10     Insurance................................................. 16

ARTICLE 11     Compliance With Legal Requirements........................ 19

ARTICLE 12     Assignment or Sublease.................................... 20

ARTICLE 13     Entry by Landlord......................................... 21

ARTICLE 14     Events of Default and Remedies............................ 22

ARTICLE 15     Damage or Destruction..................................... 27

ARTICLE 16     Eminent Domain............................................ 29

ARTICLE 17     Subordination, Merger and Sale............................ 31

ARTICLE 18     Estoppel Certificate...................................... 32

ARTICLE 19     Holding Over.............................................. 33

ARTICLE 20     Financial Statements...................................... 33

ARTICLE 21     Hazardous Materials....................................... 34

ARTICLE 22     Waiver.................................................... 36

ARTICLE 23     Notices................................................... 36

ARTICLE 24     Guaranties; Security Deposit.............................. 36

ARTICLE 25     Miscellaneous............................................. 42

ARTICLE 26     Option to Expand the Building............................. 43



                                       1



                                      LEASE



     THIS LEASE,  made as of the date specified in the Basic Lease  Information,
by  and  between  the  landlord   specified  in  the  Basic  Lease   Information
("Landlord"),   and  the  tenant  specified  in  the  Basic  Lease   Information
("Tenant"),


                              W I T N E S S E T H:


                                    ARTICLE 1

                                    Premises

     1.1  Landlord  hereby  leases to Tenant,  and  Tenant  hereby  leases  from
Landlord,  for the term and subject to the covenants  hereinafter  set forth, to
all of which  Landlord and Tenant  hereby  agree,  the  building  located at the
address  specified in the Basic Lease  Information (the  "Building")  containing
approximately  239,749  rentable square feet of space, and the land on which the
Building  is  located  (such  land,  together  with the  Building  and the other
improvements thereon are referred to herein, collectively, as the "Premises").


                                    ARTICLE 2

                                      Term

     2.1 The term of this Lease shall be the term  specified  in the Basic Lease
Information,  which shall  commence on the  commencement  date  specified in the
Basic Lease Information (the "Commencement  Date") and, unless sooner terminated
as hereinafter provided, shall end on the expiration date specified in the Basic
Lease Information (the "Expiration Date").

     2.2 If the  Commencement  Date is not the  first day of a  calendar  month,
Tenant shall pay to Landlord,  as additional  rent,  the Base Rent payable under
section  3.1,  calculated  on  a  per  diem  basis,  for  the  period  from  the
Commencement  Date until the first day of the next full calendar  month.  Tenant
shall  pay  the  Base  Rent  in  respect  of  such  period  to  Landlord  on the
Commencement Date.

     2.3 Tenant  shall accept the  Premises  "as is" on the  Commencement  Date.
Landlord  shall have no obligation to construct or install any  improvements  in
the Premises.  Tenant  acknowledges that, prior to the Commencement Date, Tenant
occupied the  Premises.  Tenant's  possession of the Premises  shall  constitute
Tenant's  acknowledgment  that the Premises are in all respects in the condition
in which Landlord is required to deliver the Premises to Tenant under this Lease
and that Tenant has  examined  the  Premises  and is fully  informed to Tenant's
satisfaction of the physical and environmental  condition and the utility of the
Premises.  Tenant acknowledges that Landlord, its agents and employees and other
persons acting on behalf of Landlord have made no  representation or warranty of
any kind in connection with any matter relating to the physical or environmental
condition,  value,  fitness, use or zoning of the Premises upon which Tenant has
relied directly or indirectly for any purpose.

                                       2


     2.4 Provided that Tenant is not in monetary or other material default under
or breach of this Lease,  either at the time of exercising the applicable option
to renew  described  below or at the time such  renewal term  commences,  Tenant
shall have the option to renew  this Lease for two (2)  additional  terms of ten
(10) years each.  Tenant shall  exercise  each option to renew by  delivering to
Landlord written notice of Tenant's  election to renew the term of this Lease at
least  eighteen (18) months before the expiration of the  then-existing  term of
this Lease.  Landlord's failure to receive Tenant's written notice duly electing
to renew the term of this Lease shall be conclusively  deemed Tenant's  election
not to exercise its option to renew, in which event the term shall expire on the
last day of the then-existing term. If Tenant duly exercises an option to renew,
then  Tenant  shall  continue  to occupy  the  Premises  on all of the terms and
conditions  of this  Lease,  except  that:  (a) the Base Rent  payable by Tenant
during the  applicable  renewal  term shall be increased as set forth in section
3.1(a);  and (b) after the second  renewal  term,  Tenant  shall have no further
renewal  options  under this Lease.  Tenant's  rights to extend the term of this
Lease are  personal  to Tenant,  may not be  exercised  by or be assigned to any
person or entity  other than  Tenant or a  Corporate  Successor  (as  defined in
section  12.1),  and  shall  terminate  and be of no  further  effect  upon  any
assignment of this Lease or subletting of all or any part of the Premises to any
person or entity.


                                    ARTICLE 3

                                      Rent

     3.1 Tenant shall pay to Landlord the following amounts as base monthly rent
for the Premises ("Base Rent"):

     (a) During the period between the Commencement Date and the last day of the
twelfth full calendar month thereafter,  Tenant shall pay to Landlord the amount
of monthly rent  specified in the Basic Lease  Information  (the  "Initial  Base
Rent").  Commencing on the first day of the thirteenth full calendar month after
the  Commencement  Date,  and on  each  anniversary  of  that  date  thereafter,
including during all renewal terms (each, an "Adjustment  Date"),  the Base Rent
shall be increased to an amount equal to the greater of:

          (i)  the  sum  of (A)  the  Base  Rent  in  effect  during  the  month
     immediately  preceding the Adjustment Date, plus (B) the product of (1) the
     Base Rent in effect during the month  immediately  preceding the Adjustment
     Date, multiplied by (2) the lesser of (x) three percent (3.0%), and (y) the
     product of two (2),  multiplied by the percentage  increase in the Consumer
     Price Index (as defined  below)  measured from the last month for which the
     Consumer  Price Index is published  immediately  preceding  the date twelve
     (12) months prior to the Adjustment  Date in question to the last month for
     which the Consumer Price Index is published  immediately  preceding the CPI
     Adjustment Date in question; and

                                       3


          (ii) the  lesser  of (A) the  Initial  Base  Rent  increased  by three
     percent  (3%)  per  year,  compounded,  from the  Commencement  Date to the
     Adjustment Date in question,  and (B) the sum of (1) an amount equal to the
     Initial  Base  Rent,  plus (2) the  product  of (x) an amount  equal to the
     Initial Base Rent,  multiplied by (y) the product of two (2), multiplied by
     the percentage  increase in the Consumer Price Index measured from the last
     month for which the Consumer Price Index is published immediately preceding
     the Commencement  Date to the last month for which the Consumer Price Index
     is published immediately preceding the Adjustment Date in question;

provided,  however,  that in no event  shall the Base Rent after any  Adjustment
Date be less than the product of an amount  equal to the Base Rent in effect for
the month immediately  preceding such Adjustment Date, multiplied by one hundred
one and one-half percent (101.5%).

     (b) Landlord and Tenant each shall, promptly after any determination of the
Base Rent pursuant to section 3.1(a), execute and deliver to the other a written
confirmation  which sets forth the Base  Rent,  but such Base Rent shall  become
effective whether or not such confirmation is executed.

     (c) As used in this Lease,  "Consumer  Price Index" shall mean the Consumer
Price Index for All Cities,  All Urban  Consumers,  All Items,  1982-1984 equals
100,  published  by the  United  States  Department  of  Labor,  Bureau of Labor
Statistics.  If the comparison Consumer Price Index required for the calculation
specified in section 3.1(a) is not available on the Adjustment Date in question,
Tenant  shall to pay, as of such  Adjustment  Date,  one hundred  three  percent
(103%) of the Base Rent payable  during the period  immediately  preceding  such
Adjustment  Date until the Consumer  Price Index is available  and the necessary
calculation  is  made.  As  soon as  such  calculation  is  made,  Tenant  shall
immediately pay to Landlord or Landlord shall credit Tenant (as the case may be)
the  amount of any  underpayment  or  overpayment  of Base Rent for the month or
months that may have elapsed  pending the  calculation  of the Base Rent for the
Adjustment  Date in  question.  If the federal  government  revises or ceases to
publish the  Consumer  Price  Index,  this  section 3.1 shall  automatically  be
amended to provide that, as of each  Adjustment Date  thereafter,  the Base Rent
shall be one hundred  three percent  (103%) of the Base Rent payable  during the
period immediately preceding such Adjustment Date.

                                       4


     (d)  Throughout  the term of this Lease,  Tenant  shall pay, as  additional
rent,  all Other Taxes (as defined in section 5.3),  all Operating  Expenses (as
defined in section 5.1) and all other  amounts of money and charges  required to
be paid by Tenant  under this  Lease,  whether  or not such  amounts of money or
charges are designated  "additional  rent." As used in this Lease,  "rent" shall
mean and  include  all Base  Rent and  additional  rent  payable  by  Tenant  in
accordance with this Lease.

     3.2 It is the  intention  of Landlord and Tenant that the Base Rent payable
by Tenant to Landlord  during the entire term of this Lease shall be  absolutely
net of all  costs and  expenses  incurred  in  connection  with the  management,
operation,  maintenance,  repair and  replacement  of the Premises in accordance
with this Lease,  except as expressly  provided in section 8.3.  Landlord  shall
have no  obligations  or  liabilities  whatsoever  with respect to the costs and
expenses of  management,  operation,  maintenance,  repair or replacement of the
Premises during the term of this Lease,  except as expressly provided in section
8.3,  and  Tenant  shall pay all  costs  and  expenses  incurred  in  connection
therewith.  Without  limiting the  generality of the  foregoing,  throughout the
entire term of this Lease,  Tenant shall pay, as additional  rent, all Operating
Expenses (as defined in section 5.1) that accrue  during or are allocable to the
term of this Lease.

     3.3 Tenant  shall pay all Base Rent to Landlord,  in advance,  on or before
the first day of each and every  calendar  month  during the term of this Lease.
Tenant shall pay all additional  rent upon demand.  Tenant shall pay all rent to
Landlord  without notice,  demand,  deduction or offset,  in lawful money of the
United  States of America,  at the address of  Landlord  specified  in the Basic
Lease  Information,  or to such other  person or at such other place as Landlord
may from time to time designate in writing.

     3.4 Tenant acknowledges that the late payment by Tenant of any Base Rent or
additional  rent  (including  the items  described  in  section  3.2) will cause
Landlord to incur costs and  expenses,  the exact  amount of which is  extremely
difficult  and  impractical  to  fix.  Such  costs  and  expenses  will  include
administration  and collection  costs and  processing  and accounting  expenses.
Therefore,  if any Base Rent or  additional  rent is not  received  by  Landlord
within five (5) Business Days (as defined  below) after it is due,  Tenant shall
immediately  pay to  Landlord a late charge  equal to six  percent  (6%) of such
delinquent  amount. The term "Business Days" means any day other than Saturdays,
Sundays  and  days on  which  national  banks  are  permitted  to be  closed  in
accordance with Federal banking laws and regulations.  Landlord and Tenant agree
that such  late  charge  represents  a  reasonable  estimate  of such  costs and
expenses and is fair  compensation to Landlord for the loss suffered by Tenant's
failure to make timely payment.  In no event shall such late charge be deemed to
grant to Tenant a grace period or extension of time within which to pay any rent
or prevent  Landlord from exercising any right or enforcing any remedy available
to  Landlord  upon  Tenant's  failure  to pay all rent due under this Lease in a
timely  fashion,  including  the right to terminate  this Lease.  All amounts of
money payable by Tenant to Landlord hereunder,  if not paid when due, shall bear
interest from the due date until paid at a rate (the "Interest  Rate") per annum
equal to five (5)  percentage  points plus the prime or reference rate announced
from time to time by Bank of America N.T.&S.A.  (the "Reference Rate"), provided
that the Interest Rate shall at no time exceed twelve percent (12%) per annum.

                                       5



                                    ARTICLE 4

                          Payment of Operating Expenses

     4.1(a) In addition to the Base Rent payable  during the term of this Lease,
Tenant  shall pay to  Landlord,  as  additional  rent,  an  amount  equal to the
Operating Expenses paid or incurred by Landlord in any calendar year (or partial
year)  during  the term of this  Lease.  If it shall not be lawful for Tenant to
reimburse Landlord for any Operating Expenses,  as defined herein, the Base Rent
payable to Landlord  shall be  increased  to net Landlord the same net Base Rent
after payment of such Operating Expenses as would have been received by Landlord
prior to the payment of such Operating Expenses.

     (b)  During  December  of  each  calendar  year or as  soon  thereafter  as
practicable,  Landlord  shall give Tenant  notice of its estimate of the amounts
payable pursuant to section 4.1(a) above for the succeeding calendar year. On or
before the first day of each month during the succeeding  calendar year,  Tenant
shall pay to Landlord,  as additional rent, one twelfth (1/12) of such estimated
amounts. If Landlord fails to deliver such notice to Tenant in December,  Tenant
shall  continue  to pay  Operating  Expenses  on the basis of the  prior  year's
estimate  until the first day of the next  calendar  month  after such notice is
given,  provided  that on such date Tenant  shall pay to Landlord  the amount of
such estimated  adjustment  payable to Landlord for prior months during the year
in question,  less any portion thereof previously paid by Tenant. If at any time
it appears to Landlord that the amounts  payable  under this section  4.1(b) for
the current calendar year will vary from Landlord's  estimate,  Landlord may, by
giving written notice to Tenant,  revise Landlord's  estimate for such year, and
subsequent  payments  by  Tenant  for such year  shall be based on such  revised
estimate.

     (c)(i)  Within ninety (90) days after the close of each calendar year or as
soon after such ninety (90) day period as practicable, Landlord shall deliver to
Tenant a statement of the amounts  payable under  section  4.1(a) above for such
calendar year (the "annual  statement")  and such  statement  shall be final and
binding upon Landlord and Tenant, subject to the terms of section 4.1(c)(ii). If
on the  basis of such  statement  Tenant  owes an  amount  that is more than the
estimated  payments for such calendar  year  previously  made by Tenant,  Tenant
shall pay the deficiency to Landlord  within fifteen (15) days after delivery of
the statement.  If on the basis of such statement Tenant has paid to Landlord an
amount in excess of the  amounts  payable  under  section  4.1(a)  above for the
preceding  calendar year and Tenant is not in default in the  performance of any
of its covenants under this Lease,  then Landlord,  at its option,  shall either
promptly  refund such excess to Tenant or credit the amount  thereof to the Base
Rent next becoming due from Tenant until such credit has been exhausted.

                                       6


     (ii) Tenant shall have the right,  during the one hundred  eighty (180) day
period  following  delivery of an annual  statement,  at  Tenant's  sole cost to
review in Landlord's  offices  Landlord's records of Operating Expenses and Real
Property Taxes for the subject  calendar year.  Such review shall be carried out
only by regular employees of Tenant or by a "Big Six" accounting firm and not by
any other third party.  No person  conducting such an audit shall be compensated
on a "contingency" or other incentive basis. If, as of the one hundred eightieth
day after  delivery  to Tenant of an  annual  statement,  Tenant  shall not have
delivered  to Landlord an  objection  statement  (as defined  below),  then such
annual statement shall be final and binding upon Landlord and Tenant, and Tenant
shall have no further right to object to such annual  statement.  If within such
one  hundred  eighty  (180) day  period,  Tenant  delivers to Landlord a written
statement  specifying   objections  to  such  annual  statement  (an  "objection
statement"),  then  Tenant and  Landlord  shall meet to attempt to resolve  such
objection within thirty (30) days after delivery of the objection statement.  If
such objection is not resolved  within such thirty (30) day period,  then either
party shall have the right to require  that the dispute be  submitted to binding
arbitration   under  the  rules  of  the   American   Arbitration   Association.
Notwithstanding  that any  such  dispute  remains  unresolved,  Tenant  shall be
obligated to pay Landlord all amounts  payable in  accordance  with this section
4.1 (including any disputed amount).  If such dispute results in an agreement or
an  arbitrator's  determination  that Tenant is  entitled to a refund,  Landlord
shall, at its option, either pay such refund or credit the amount thereof to the
Base Rent next becoming due from Tenant.

     (d) If this Lease terminates on a day other than the last day of a calendar
year,  the amounts  payable by Tenant under section 4.1(a) above with respect to
the  calendar  year in which such  termination  occurs  shall be prorated on the
basis which the number of days from the  commencement  of such calendar year, to
and including such termination date, bears to 360. The termination of this Lease
shall not affect the  obligations  of  Landlord  and Tenant  pursuant to section
4.1(c) above to be performed after such termination.


                                       7


                                    ARTICLE 5

                     Operating Expenses, Property Taxes and
                       Other Taxes Defined; Contest Rights

     5.1 "Operating  Expenses" shall mean the total costs and expenses  incurred
by Landlord in connection with the management,  operation,  maintenance,  repair
and  ownership of the Premises,  including,  without  limitation,  the following
costs:  (a)  salaries,   wages,   bonuses  and  other  compensation   (including
hospitalization,  medical, surgical,  retirement plan, pension plan, union dues,
life  insurance,  including  group  life  insurance,  welfare  and other  fringe
benefits,  and vacation,  holidays and other paid absence benefits)  relating to
employees  of  Landlord  or its  agents  engaged in the  management,  operation,
repair, or maintenance of the Premises and costs of training such employees; (b)
payroll, social security, workers' compensation,  unemployment and similar taxes
with  respect to such  employees  of  Landlord  or its  agents,  and the cost of
providing disability or other benefits imposed by law or otherwise, with respect
to such employees; (c) Property Taxes and Other Taxes (as such terms are defined
below);  (d) premiums  and other  charges  incurred by Landlord  with respect to
fire,  other  casualty,  boiler and  machinery,  theft,  rent  interruption  and
liability  insurance and any other insurance as is deemed necessary or advisable
in the  reasonable  judgment  of  Landlord,  all in  such  amounts  as  Landlord
determines to be appropriate,  and costs of repairing an insured casualty to the
extent of the deductible amount under the applicable insurance policy; (e) water
charges and sewer rents or fees;  (f) license,  permit and  inspection  fees and
charges;  (g) sales,  use and excise  taxes on goods and  services  purchased by
Landlord in connection with the operation, maintenance or repair of the Premises
and  building  systems  and  equipment;  (h)  telephone,   telegraph,   postage,
stationery   supplies  and  other  expenses  incurred  in  connection  with  the
operation,  maintenance,  or repair of the Premises;  (i) reasonable  management
fees  and  expenses  (including  fees and  expenses  for  accounting,  financial
management,  data  processing  and  information  services);  (j)  repairs to and
physical   maintenance  of  the  Premises,   including   building   systems  and
appurtenances  thereto and normal repair and replacement of worn-out  equipment,
facilities and  installations,  but excluding the  replacement of major building
systems  (except  to the  extent  otherwise  included  as an  Operating  Expense
pursuant  to  this  section  5.1);  (k)  janitorial,   window  cleaning,  guard,
extermination, water treatment, rubbish removal, plumbing and other services and
inspection or service contracts for elevator, electrical,  mechanical, sanitary,
heating,  ventilation  and air  conditioning,  and other building  equipment and
systems  or as may  otherwise  be  necessary  or  proper  for the  operation  or
maintenance of the Premises;  (l) supplies,  tools, materials and equipment used
in connection  with the operation,  maintenance  or repair of the Premises;  (m)
accounting,  legal  and  other  professional,  consulting  or  service  fees and
expenses;  (n) painting  the exterior or the interior  areas of the Premises and
the cost of maintaining  the sidewalks,  landscaping  and other outdoor areas of
the Premises;  (o) all costs and expenses for  electricity,  chilled water,  air

                                       8


conditioning,  water for heating, gas, fuel, steam, heat, lights, sewer service,
communications  service,  power and other energy related  utilities  required in
connection with the operation,  maintenance and repair of the Premises;  (p) the
cost of any capital  improvements  made by  Landlord to the  Premises or capital
assets acquired by Landlord required under any governmental  law,  regulation or
insurance  requirement with which the Premises was not required to comply on the
Commencement  Date,  such cost or  allocable  portion to be  amortized  over the
useful life thereof, together with interest on the unamortized balance at a rate
per annum equal to the Reference Rate (as defined in section 3.4 hereof) charged
at the time such  capital  improvements  or capital  assets are  constructed  or
acquired or such higher rate as may have been paid by Landlord on funds borrowed
for the purpose of  constructing  or  acquiring  such  capital  improvements  or
capital assets; (q) the cost of any capital improvements made by Landlord to the
Building or capital assets acquired by Landlord for the protection of the health
and safety of the  occupants  of the  Premises  (provided  that,  as to any such
improvements  or assets which would be considered  unnecessary  or  unreasonably
expensive by a reasonable owner of a comparable  building,  Landlord shall first
have obtained Tenant's reasonable approval) or that are designed to reduce other
Operating Expenses,  such cost or allocable portion thereof to be amortized over
the useful life  thereof  (except  that  Landlord  may  include as an  Operating
Expense in any calendar year a portion of the cost of such a capital improvement
or capital asset equal to Landlord's  estimate of the amount of the reduction of
other Operating Expenses in such year resulting from such capital improvement or
capital asset),  together with interest on the unamortized balance at a rate per
annum equal to the Reference Rate charged at the time such capital  improvements
or capital  assets are  constructed  or acquired or such higher rate as may have
been paid by  Landlord on funds  borrowed  for the  purpose of  constructing  or
acquiring  such  capital  improvements  or  capital  assets;  (r)  the  cost  of
furniture,  window  coverings,  carpeting,  decorations,  landscaping  and other
customary and ordinary items of personal  property  provided by Landlord for use
in common areas of the  Premises or in the  Building  office (to the extent that
such  Building  office is  dedicated  to the  operation  and  management  of the
Premises), such costs to be amortized over the useful life thereof; (s) the cost
of any capital  improvements  made by Landlord to the Premises or capital assets
acquired  by Landlord  to the extent  that the cost of any such  improvement  or
asset is less than fifty thousand dollars ($50,000); (t) the cost of any capital
improvements  made by Landlord to the  Premises  or capital  assets  acquired by
Landlord  after the Base Year which have a useful life of five (5) years or less
(and the cost of which is not otherwise  included in Operating Costs pursuant to
this  section  5.1),  such cost to be  amortized  over the useful life  thereof,
together with interest on the  unamortized  balance at a rate per annum equal to
the  Reference  Rate  charged at the time such capital  improvements  or capital
assets are  constructed or acquired or such higher rate as may have been paid by
Landlord on funds  borrowed for the purpose of  constructing  or acquiring  such
capital  improvements  or  capital  assets;  (u) any  such  expenses  and  costs

                                       9


resulting from substitution of work, labor,  material or services in lieu of any
of the above itemizations,  or for any such additional work, labor,  services or
material   resulting  from  compliance  with  any  governmental   laws,   rules,
regulations  or orders  applicable  to the  Premises  or any part  thereof;  (v)
property  management office rent or rental value; (w) cost of operation,  repair
and  maintenance  of the parking areas on the Premises,  including  resurfacing,
restriping  and  cleaning;   and  (x)   appropriate   reserves  to  provide  for
maintenance,  repair and  replacement of  improvements  (specifically  including
roofs,  structural  components and building  systems),  fixtures,  equipment and
personal property,  as determined by Landlord consistent with prudent accounting
practices.

     To the  extent  costs  and  expenses  described  above  relate  to both the
Premises and other  property,  such costs and expenses shall, in determining the
amount of Operating Expenses,  be allocated as Landlord may reasonably determine
to be appropriate.

     Prior to the beginning of each calendar year during the term of this Lease,
or as soon  thereafter  as  practicable,  Landlord  shall  deliver  to Tenant an
operating and capital budget for such year setting forth the estimated Operating
Expenses.  The operating and capital budget shall be consistent  with reasonable
and prudent property management practices.

     Operating Expenses shall not include the following: (i) depreciation on the
Building;  (ii) debt service; (iii) rental under any ground or underlying lease;
(iv) interest (except as expressly provided in this section 5.1); (v) attorneys'
fees  and  expenses   incurred  in  connection  with  lease   negotiations  with
prospective  tenants;  (vi) the cost of any improvements or equipment (except to
the extent such costs are  included in amounts  payable by Tenant as reserves as
set forth in clause (x) above)  which  would be properly  classified  as capital
expenditures  (except  for  any  capital  expenditures   expressly  included  in
Operating  Expenses  pursuant to this section 5.1); (vii)  advertising  expenses
relating  to vacant  space;  or (viii) real  estate  brokers'  or other  leasing
commissions.

     Landlord  may,  but shall not be  obligated  to,  cause  some or all of its
duties under this agreement to be performed by a property  management company on
such terms as Landlord may deem  appropriate.  The property  management  company
shall be  subject  to the  approval  of  Tenant,  which  approval  shall  not be
unreasonably withheld.

     5.2 "Property Taxes" shall mean all taxes,  assessments,  excises,  levies,
fees and charges (and any tax,  assessment,  excise,  levy, fee or charge levied
wholly or partly in lieu thereof or as a  substitute  therefor or as an addition
thereto)  of  every  kind and  description,  general  or  special,  ordinary  or
extraordinary,  foreseen or unforeseen, secured or unsecured, whether or not now
customary or within the  contemplation of Landlord and Tenant,  that are levied,
assessed, charged, confirmed or imposed by any public or government authority on
or against,  or  otherwise  with respect to, the Premises or any part thereof or
any personal property used in connection with the Premises. Property Taxes shall
not include net income  (measured by the income of Landlord  from all sources or
from sources other than solely rent),  franchise,  inheritance  or capital stock
taxes of Landlord,  unless  levied or assessed  against  Landlord in whole or in
part in lieu of, as a substitute for, or as an addition to any Property Taxes.

                                       10


     5.3  "Other  Taxes"  shall mean all taxes,  assessments,  excises,  levies,
owner's  association  dues or similar charges,  fees and charges,  including all
payments related to the cost of providing facilities or services, whether or not
now  customary  or within the  contemplation  of Landlord  and Tenant,  that are
levied,  assessed,  charged,  confirmed  or imposed by any public or  government
authority upon, or measured by, or reasonably  attributable to (a) the Premises,
(b) the cost or value of  Tenant's  equipment,  furniture,  fixtures  and  other
personal  property located in the Premises or the cost or value of any leasehold
improvements made in or to the Premises by or for Tenant,  regardless of whether
title to such improvements is vested in Tenant or Landlord, (c) any rent payable
under this Lease,  including any gross  receipts tax or excise tax levied by any
public or government authority with respect to the receipt of any such rent, (d)
the possession, leasing, operation, management, maintenance, alteration, repair,
replacement, use or occupancy by Tenant of the Premises, or (e) this transaction
or any document to which Tenant is a party creating or  transferring an interest
or an estate in the  Premises.  Other Taxes  shall not include net income  taxes
(measured by the income of Landlord  from all sources or from sources other than
solely rent), franchise,  inheritance or capital stock taxes of Landlord, unless
levied  or  assessed  against  Landlord  in whole  or in part in lieu  of,  as a
substitute for, or as an addition to any Other Taxes.

     5.4 In the event that  Tenant  reasonably  and in good faith  disputes  the
validity or amount of any Property Taxes or Other Taxes,  then Tenant shall have
the right to defer  payment  thereof,  provided that (a) Tenant shall have given
Landlord  written notice of such contest and the nature thereof and Tenant shall
thereafter  diligently and continuously  prosecute such contest to completion or
compromise,  (b) no such  deferral  of  payment  shall  result  in any  fines or
penalties being assessed  against  Tenant,  Landlord or the Premises or any lien
foreclosure  rights  against the  Premises  being  commenced,  (c) Tenant  shall
promptly pay any amounts  (including any interest,  fines or penalties)  finally
determined to be owing, and (d) at Landlord's  reasonable request,  Tenant shall
provide such bond or other security as may be necessary to protect  Landlord and
the Premises against any loss or liability.

                                       11



                                    ARTICLE 6

                                       Use

     6.1 The Premises shall be used only for the purpose  specified in the Basic
Lease Information and no other purpose without Landlord's prior written consent,
which consent shall not be unreasonably withheld or delayed; provided,  however,
Landlord's  withholding of consent shall be conclusively  presumed reasonable if
the proposed use would  materially  increase the wear and tear on or the risk of
damage to the Premises above levels or risks  resulting from Tenant's use of the
Premises  exclusively  for  office  purposes  or if the  proposed  use is for an
illegal,  immoral or disreputable purpose; and provided,  further, that only the
Tenant originally named herein, and no subtenant, assignee or other successor to
such  original  Tenant,  shall  have the right to use the  Premises  or any part
thereof for any purpose other than office use.  Notwithstanding  anything to the
contrary in the Basic Lease Information,  (a) Tenant's right to use the Premises
or any part  thereof for any use other than  general  office use (whether or not
such  other use is listed in the Basic  Lease  Information)  is  subject  to the
following conditions:  (i) such ancillary  (non-office) uses shall be limited to
areas  comprising  less than thirty percent (30%) of the total  rentable  square
footage  of the  building  in the  aggregate,  and (ii) all such  uses  shall be
consistent with Tenant's  obligations  under Articles 11 and 21 hereof;  and (b)
any  subtenant  or assignee of the  original  Tenant  named herein shall use the
Premises  exclusively  for office  purposes and no other use shall be permitted,
except that the  original  Tenant  named herein may sublease the portions of the
Premises  to be used as an  employee  cafeteria  or  child  care  center  to the
operators of those  facilities.  Tenant shall not do or permit to be done in, on
or about  the  Premises,  nor  bring or keep or  permit  to be  brought  or kept
therein,  anything  which is  prohibited by or will in any way conflict with any
law, ordinance, rule, regulation or order now in force or which may hereafter be
enacted,  or which is prohibited by any  insurance  policy for the Premises,  or
will in any way increase the existing  rate of, or cause a  cancellation  of, or
affect any insurance for the Premises. Tenant shall not do or permit anything to
be done in, on or about the Premises which will in any way obstruct or interfere
with the rights of  Landlord.  Tenant  shall not maintain or permit any nuisance
in, on or about the Premises or commit or suffer to be  committed  any waste in,
on or about the Premises.

                                       12



                                    ARTICLE 7

                                    Services

     7.1 Landlord shall, at Tenant's sole cost and expense,  supply the Premises
with electricity, heating, ventilating and air conditioning, water, natural gas,
lighting  replacement  for all lights,  restroom  supplies,  telephone  service,
window washing, security service, janitor,  scavenger and disposal services, and
such other services as Landlord determines to furnish to the Premises.  Landlord
shall not be in default  hereunder or be liable for any damage or loss  directly
or indirectly  resulting from, nor shall the rent be abated or a constructive or
other eviction be deemed to have occurred by reason of, the installation, use or
interruption of use of any equipment in connection with the furnishing of any of
the foregoing  services,  any failure to furnish or delay in furnishing any such
services,  whether such failure or delay is caused by accident or any  condition
beyond  the  control  of  Landlord  or Tenant or by the  making  of  repairs  or
improvements  to the  Premises,  or any  limitation,  curtailment,  rationing or
restriction on use of water, electricity,  gas or any form of energy serving the
Premises,  whether such  results  from  mandatory  governmental  restriction  or
voluntary  compliance with  governmental  guidelines.  Tenant shall pay the full
cost of all of the  foregoing  services as additional  rent in  accordance  with
Article 4.

                                       13



                                    ARTICLE 8

                  Maintenance and Repairs; Capital Improvements

     8.1  Landlord  shall,  at all times  during  the term of this  Lease and at
Tenant's  sole cost and expense  (except as otherwise  provided in section 8.3),
maintain,  repair  and  replace  the  Premises  and every part  thereof  and all
grounds, landscaping, parking areas, lighting, roof, walls, floors, foundations,
signs,  heating,  ventilating  and  air  conditioning,  mechanical,  electrical,
plumbing, sprinkler and life safety systems, equipment,  fixtures,  alterations,
additions  and  improvements  therein or thereon  and keep all of the  foregoing
clean and in good order and operating condition (including painting the exterior
of the Premises as often as  reasonably  needed to keep such exterior in a good,
well painted condition, cleaning interior and exterior doors, windows and glass,
and  repairing  and  replacing  any  exterior  windows and glass that is broken,
cracked  or  damaged).   Landlord  shall  engage  a  duly  licensed  independent
contractor  to perform  all  maintenance  and repair  services  on all  heating,
ventilating and air conditioning,  mechanical,  electrical,  plumbing, sprinkler
and life safety systems and equipment in the Premises that is to be performed by
Landlord in accordance with this section 8.1. Tenant hereby waives all rights to
make  repairs  at the  expense  of  Landlord  or in lieu  thereof  to vacate the
Premises.  Subject to section 9.2,  Tenant shall, at the end of the term of this
Lease,  surrender  to Landlord  the  Premises  and all  alterations,  additions,
fixtures  and  improvements  therein or thereto  in the same  condition  as when
received,  ordinary wear and tear and damage  thereto by fire or other  casualty
excepted.

     8.2 In the event  Landlord  fails to  perform  any  maintenance  and repair
obligation  under section 8.1 within fifteen (15) days after Tenant  delivers to
Landlord  notice  specifying  such  obligation  (or such longer period as may be
reasonably required due to the nature of such obligation), then Tenant may, upon
a further ten (10) days'  notice to  Landlord,  perform at Tenant's  own expense
such obligation  (unless  Landlord cures its  nonperformance  within such 10-day
period).  Notwithstanding  the foregoing,  in the event that (a)  maintenance or
repairs  are,  in  Tenant's  reasonable  judgment,  urgently  required  to avoid
material  disruption of or interference  with the operation of Tenant's business
on the  Premises  or to avoid  imminent  danger  to health  or  safety,  and (b)
Landlord,  having  received  notice  thereof,  does not, in Tenant's  reasonable
judgment,  commence  with  appropriate  promptness  and pursue with  appropriate
diligence  the  required  maintenance  or repairs,  then Tenant may perform such
maintenance  or repairs  without  waiting for the time  periods set forth in the
preceding sentence.

     8.3 To the extent included within the definition of "Operating Expenses" in
section 5.1, the costs incurred by Landlord in performing its obligations  under
section  8.1 shall be  recoverable  from  Tenant  pursuant  to Article 4. To the
extent such costs are excluded from the definition of "Operating Expenses," such
costs shall be Landlord's responsibility, subject to Landlord's right to collect
reserves for  anticipated  capital  repairs,  improvements  and  replacements in
accordance  with the definition of "Operating  Expenses".  In the event that the
cost of any such  capital  repairs,  improvements  or  replacements  exceeds the
amount that Landlord has specified to be reserved therefor,  Landlord shall bear
such cost to the extent of such excess.

                                       14



                                    ARTICLE 9

                                   Alterations

     9.1 Tenant shall not make any alterations,  additions or improvements in or
to the  Premises  or any part  thereof,  or attach  any  fixtures  or  equipment
thereto,  without  Landlord's prior written consent,  which consent shall not be
unreasonably withheld.  Notwithstanding the preceding sentence,  Tenant may make
such alterations,  additions or improvements  without Landlord's consent only if
the total cost of such alterations,  additions or improvements is fifty thousand
dollars ($50,000) or less and such  alterations,  additions or improvements will
not affect in any way the structural,  exterior or roof elements of the Premises
or  mechanical,  electrical,  plumbing,  utility or life  safety  systems of the
Premises,  but Tenant shall give prior written  notice of any such  alterations,
additions or improvements to Landlord.  In no event shall Tenant be permitted to
install  underground storage tanks (excepting a single 20,000 gallon water tank)
or  fuel  systems  on  the  Premises.  Landlord's  refusal  to  consent  to  the
installation  of an  underground  tank  or fuel  system  shall  be  conclusively
presumed to be reasonable. All alterations,  additions and improvements in or to
the Premises to which Landlord consents shall be made by Tenant at Tenant's sole
cost and expense as follows:

     (a) Tenant shall  submit to  Landlord,  for  Landlord's  written  approval,
complete plans and specifications for all work to be done by Tenant.  Such plans
and  specifications   shall  be  prepared  by  the  licensed   architect(s)  and
engineer(s), shall comply with all applicable codes, laws, ordinances, rules and
regulations, shall not adversely affect the structural elements of the Premises,
shall  be in a  form  sufficient  to  secure  the  approval  of  all  government
authorities  with  jurisdiction  over  the  Premises,  and  shall  be  otherwise
satisfactory to Landlord in Landlord's reasonable discretion.

     (b) Landlord  shall notify Tenant in writing,  within fifteen (15) Business
Days after Landlord's receipt of such plans and specifications, whether Landlord
approves  or  disapproves  such  plans  and  specifications   and,  if  Landlord
disapproves such plans and  specifications,  Landlord shall describe the reasons
for disapproval.  Tenant may submit to Landlord revised plans and specifications
for Landlord's prior written approval. Tenant shall pay all costs, including the
fees and expenses of the licensed  architect(s)  and  engineer(s),  in preparing
such plans and specifications.

                                       15


     (c) All changes in the plans and specifications  approved by Landlord shall
be subject to Landlord's  prior written  approval.  If Tenant wishes to make any
such change in such approved  plans and  specifications,  Tenant shall have such
architect(s) and engineer(s)  prepare plans and  specifications  for such change
and submit them to Landlord for  Landlord's  written  approval.  Landlord  shall
notify Tenant in writing promptly whether Landlord  approves or disapproves such
change and, if Landlord  disapproves  such change,  Landlord  shall describe the
reasons  for  disapproval.  Tenant  may  submit to  Landlord  revised  plans and
specifications for such change for Landlord's written approval. After Landlord's
written approval of such change,  such change shall become part of the plans and
specifications approved by Landlord.

     (d) Tenant  shall  obtain and comply  with all  building  permits and other
governmental  permits and approvals required in connection with the work. Tenant
shall, through Tenant's licensed  contractor,  perform the work substantially in
accordance  with  (i) the  plans  and  specifications  approved  in  writing  by
Landlord,  (ii) the permits obtained by Tenant,  and (iii) all applicable codes,
laws, ordinances,  rules and regulations.  Tenant shall pay, as additional rent,
the entire cost of all work (including the cost of all utilities, permits, fees,
taxes, and property and liability  insurance  premiums in connection  therewith)
required  to  make  the  alterations,   additions  and  improvements.  Under  no
circumstances  shall Landlord be liable to Tenant for any damage,  loss, cost or
expense  incurred  by  Tenant  on  account  of  any  plans  and  specifications,
contractors or subcontractors,  design of any work, construction of any work, or
delay in completion of any work.

     (e)  Tenant  shall give  written  notice to  Landlord  of the date on which
construction  of any work will be commenced at least ten (10) days prior to such
date. Tenant shall keep the Premises free from mechanics', materialmen's and all
other  liens  arising  out of any  work  performed,  labor  supplied,  materials
furnished or other  obligations  incurred by Tenant.  Tenant shall  promptly and
fully pay and  discharge all claims on which any such lien could be based or, in
the event Tenant  reasonably  disputes the validity or amount of any such claim,
Tenant may bond over such lien to Landlord's reasonable  satisfaction.  Landlord
shall have the right to post and keep posted on the  Premises  any notices  that
may be  provided  by law or  which  Landlord  may  deem  to be  proper  for  the
protection of Landlord and the Premises  from such liens,  and to take any other
action  Landlord deems necessary to remove or discharge liens or encumbrances at
the expense of Tenant.

     9.2  All  alterations,   additions,  fixtures  and  improvements,   whether
temporary or permanent in  character,  made in or to the Premises by Landlord or
Tenant,  shall become part of the Premises and  Landlord's  property  excluding,
however,  underground  tanks which shall remain the property of Tenant and shall
be  registered  in the name of Tenant so long as this  Lease  remains in effect.
Upon  termination of this Lease,  Landlord  shall have the right,  at Landlord's
option, by giving written notice to Tenant at any time before or within ten (10)
days after such termination, to retain all such alterations, additions, fixtures
and improvements in the Premises,  without  compensation to Tenant, or to remove
all such  alterations,  additions,  fixtures and improvements from the Premises,
repair all damage  caused by any such  removal,  and restore the Premises to the

                                       16


condition  in which the Premises  existed  before such  alterations,  additions,
fixtures and improvements  were made, and in the latter case Tenant shall pay to
Landlord,  upon  billing  by  Landlord,  the cost of such  removal,  repair  and
restoration   (including  a  reasonable  charge  for  Landlord's  oversight  and
administration  of  such  work).  Notwithstanding  the  foregoing,  all  movable
furniture,  equipment,  trade fixtures (including the video screen walls, visual
systems,  projectors  and  related  equipment  in Tenant's  service  reliability
center) and other personal  property  shall remain the property of Tenant.  Upon
termination of this Lease,  Tenant shall, at Tenant's  expense,  remove all such
movable  furniture,  equipment,  trade fixtures other personal property from the
Premises and repair all damage caused by any such removal.  Termination  of this
Lease shall not affect the obligations of Tenant pursuant to this section 9.2 to
be performed after such termination.


                                   ARTICLE 10

                                    Insurance

     10.1  Landlord  shall not be liable to Tenant  for any damage to or loss or
theft of any property or for any bodily or personal injury,  illness or death of
any person in, on or about the  Premises  arising at any time and from any cause
whatsoever,  except to the  extent  caused by the gross  negligence  or  willful
misconduct of Landlord.  Tenant waives all claims against  Landlord arising from
any liability described in this section 10.1, except to the extent caused by the
gross negligence or willful misconduct of Landlord.

     10.2 Tenant shall indemnify and defend  Landlord  against and hold Landlord
harmless  from all claims,  demands,  liabilities,  damages,  losses,  costs and
expenses,  including reasonable attorneys' fees and disbursements,  arising from
or related to any use or  occupancy  of the  Premises,  or any  condition of the
Premises,  or any default in the  performance  of Tenant's  obligations,  or any
damage to any property  (including property of employees and invitees of Tenant)
or any bodily or  personal  injury,  illness  or death of any person  (including
employees and invitees of Tenant)  occurring in, on or about the Premises or any
part  thereof or any part of the  building or the land  containing  the Premises
arising at any time and from any cause  whatsoever  (except to the extent caused
by the gross negligence or willful  misconduct of Landlord) or occurring outside
the Premises when such damage,  bodily or personal  injury,  illness or death is
caused by any act or  omission  of Tenant or its  agents,  officers,  employees,
contractors,  invitees  or  licensees.  This  section  10.2  shall  survive  the
termination of this Lease with respect to any damage, bodily or personal injury,
illness or death occurring prior to such termination.

                                       17


     10.3  Tenant  shall,  at all  times  during  the term of this  Lease and at
Tenant's  sole cost and  expense,  obtain and keep in force  commercial  general
liability insurance, including contractual liability (specifically covering this
Lease), cross liability,  fire legal liability, and premises operations,  all on
an "occurrence"  policy form, with a minimum combined single limit in the amount
specified in the Basic Lease  Information  per occurrence for bodily or personal
injury to, illness of, or death of persons and damage to property  occurring in,
on or about the Premises,  such insurance  shall name the Landlord and any other
parties designated by Landlord,  or any other party with an insurable  interest,
as  additional  insureds.  Tenant shall,  at Tenant's sole cost and expense,  be
responsible for insuring Tenant's  furniture,  equipment,  fixtures,  computers,
office machines and personal property.

     10.4  Tenant  shall,  at all  times  during  the term of this  Lease and at
Tenant's sole cost and expense,  obtain and keep in force worker's  compensation
and employer's  liability  insurance in all states in which the Premises and any
other  operations  of the Tenant are  located  and any other  state in which the
Tenant or its contractors or  subcontractors  may be subject to any statutory or
other  liability  arising in any manner  whatsoever out of the actual or alleged
employment  of others.  The total limits of the  employer's  liability  coverage
required hereunder shall not be less than the amounts specified in section 10.3.

     10.5 The insuring party for property insurance specified in the Basic Lease
Information  shall,  at all times during the term of this Lease, at such party's
sole cost and expense,  obtain and keep in force (a)  insurance  against loss or
damage to the  Premises by fire and all other risks of physical  loss covered by
insurance  of the type now known as "all risk," with  difference  in  conditions
coverage,  in an amount not less than the full  replacement cost of the Premises
(without deduction for depreciation),  including the cost of debris removal, and
such endorsements as Landlord may reasonably require, including the "Replacement
Cost Endorsement"; (b) boiler and machinery insurance covering pressure vessels,
air tanks, boilers,  machinery,  pressure piping,  heating,  ventilation and air
conditioning  equipment,  and elevator  and  escalator  equipment,  provided the
Premises  contain  equipment  of  such  nature  and  insurance  against  loss of
occupancy or use arising from any  breakdown of any such items,  in such amounts
as Landlord  may  reasonably  determine;  and (c) plate glass  insurance in such
amounts as Landlord  may  reasonably  determine if the  Premises  contain  plate
glass. In addition to the insurance  specifically  described above, Tenant shall
obtain and keep in force such other insurance (or the above-described  insurance
at increased limits) as Landlord may reasonably require from time to time.

     10.6 All  insurance  required to be maintained by Tenant under this Article
10 and all renewals  thereof shall be issued by good and  responsible  companies
qualified  to do and doing  business in the state where the Premises are located
and having a rating in Best's  Insurance  Guide of at least A-XI. All deductible
amounts under each such  insurance  policy shall be subject to Landlord's  prior


                                       18


written approval. Each policy to be maintained by Tenant shall expressly provide
that the policy shall not be canceled or altered  without sixty (60) days' prior
written notice to Landlord and shall remain in effect  notwithstanding  any such
cancellation  or alteration  until such notice shall have been given to Landlord
and such period of sixty (60) days shall have expired.  All insurance under this
Article 10 to be  maintained by Tenant shall name Landlord and any other parties
designated  by Landlord,  or any other party with an insurable  interest,  as an
additional insured or loss payee, shall be primary and noncontributing  with any
insurance which may be carried by Landlord, shall afford coverage for all claims
based on any act,  omission,  event or condition  that occurred or arose (or the
onset of which occurred or arose) during the policy period,  and shall expressly
provide  that  Landlord,   although  named  as  an  additional  insured,   shall
nevertheless  be  entitled to recover  under the policy for any loss,  injury or
damage to Landlord.  Upon the issuance of each such policy to be  maintained  by
Tenant,  Tenant  shall  deliver  each  such  policy  or a  certified  copy and a
certificate  thereof to Landlord for  retention by Landlord.  If Tenant fails to
insure or fails to furnish  to  Landlord  upon  notice to do so any policy to be
maintained  by Tenant or  certified  copy and  certificate  thereof as required,
Landlord shall have the right from time to time to effect such insurance for the
benefit of Tenant or Landlord or both of them and all premiums  paid by Landlord
shall be payable by Tenant as  additional  rent on demand.  Tenant  shall pay to
Landlord,  immediately upon demand all costs incurred by Landlord as a result of
Tenant's  failure to obtain and  maintain in effect the  policies  of  insurance
required under this Article 10.

     10.7  Tenant  waives on  behalf  of all  insurers  under  all  policies  of
property, liability and other insurance (excluding workers' compensation) now or
hereafter carried by Tenant insuring or covering the Premises, or any portion or
any contents thereof, or any operations therein, all rights of subrogation which
any insurer might  otherwise,  if at all,  have to any claims of Tenant  against
Landlord.  Landlord  waives on  behalf of all  insurers  under all  policies  of
property, liability and other insurance (excluding workers' compensation) now or
hereafter  carried by Landlord  insuring or covering the Premises or any portion
or any contents thereof,  or any operations  therein,  all rights of subrogation
which any insurer  might  otherwise,  if at all,  have to any claims of Landlord
against  Tenant.  Tenant shall,  prior to or immediately  after the date of this
Lease,  procure  from each of the  insurers  under  all  policies  of  property,
liability and other insurance (excluding workers' compensation) now or hereafter
carried by Tenant  insuring  or  covering  the  Premises,  or any portion or any
contents  thereof,  or  any  operations  therein,  a  waiver  of all  rights  of
subrogation which the insurer might otherwise,  if at all, have to any claims of
Tenant against Landlord as required by this section 10.6.

                                       19



                                   ARTICLE 11

                       Compliance With Legal Requirements

     11.1 Tenant shall, at Tenant's sole cost and expense,  promptly comply with
all of the following  (collectively,  "Legal  Requirements")  laws,  ordinances,
rules,  regulations,  orders and other  requirements of any government or public
authority now in force or which may hereafter be in force, with all requirements
of any  board of fire  underwriters  or  other  similar  body  now or  hereafter
constituted,  with all directions and  certificates of occupancy issued pursuant
to any  law by  any  governmental  agency  or  officer  and  with  all  recorded
covenants,  conditions or restrictions,  insofar as any thereof relate to or are
required by the  condition,  use or occupancy of the Premises or the  operation,
use or maintenance of any personal property, fixtures,  machinery,  equipment or
improvements in the Premises. Tenant's obligations under this section 11.1 shall
include the obligation to make  alterations or  improvements  to the Premises if
required to comply with any Legal Requirements.


                                       20


                                   ARTICLE 12

                             Assignment or Sublease

     12.1 Tenant shall not,  directly or  indirectly,  without the prior written
consent of Landlord (which consent shall not be unreasonably  withheld),  assign
this Lease or any interest  herein or sublease the Premises or any part thereof,
or permit the use or  occupancy  of the  Premises by any person or entity  other
than Tenant;  provided,  however,  Landlord's  withholding  of consent  shall be
conclusively presumed reasonable if: (a) the financial condition of the proposed
transferee  is not  suitable  to perform  the  obligations  being  assumed by it
hereunder;  or  (b)  the  proposed  use  of the  Premises  (i) is not  permitted
hereunder  or under any Legal  Requirements,  or (ii) is other  than  office use
(except in the case of a sublease of the portions of the Premises to be used for
an  employee  cafeteria  and  child  care  center  to  the  operators  of  those
facilities).  This Lease shall not, nor shall any interest herein, be assignable
as to the  interest of Tenant  involuntarily  or by operation of law without the
prior written consent of Landlord.  Any of the foregoing acts without such prior
written  consent of Landlord shall be void and shall, at the option of Landlord,
constitute  a  default  that   entitles   Landlord  to  terminate   this  Lease.
Notwithstanding  the  foregoing,  Landlord  hereby  consents to any  sublease or
assignment to any direct or indirect wholly-owned subsidiary of either Tenant or
ICG Communications, Inc., a Delaware corporation or to any surviving corporation
resulting  from a  merger  with  Tenant,  or to any  corporation  as part of the
acquisition  of all or  substantially  all of the assets and  business of Tenant
(collectively,  a "Corporate  Successor"),  provided such sublease or assignment
otherwise complies with this Article 12, and provided further that Landlord does
not  approve any such  sublease or  assignment  in  connection  with a merger or
acquisition if the net worth or  creditworthiness  of such subtenant or assignee
is, in Landlord's  reasonable  judgment,  less than that of Tenant prior to such
merger or  acquisition  transaction.  Tenant agrees that the instrument by which
any  assignment or sublease to which  Landlord  consents is  accomplished  shall
expressly  provide  that the  assignee  or  subtenant  will  perform  all of the
covenants to be performed by Tenant under this Lease (in the case of a sublease,
only insofar as such covenants  relate to the portion of the Premises subject to
such  sublease) as and when  performance  is due after the effective date of the
assignment  or sublease  and that  Landlord  will have the right to enforce such
covenants directly against such assignee or subtenant.  Any purported assignment
or sublease without an instrument  containing the foregoing  provisions shall be
void.  Tenant  shall in all  cases  remain  liable  for the  performance  by any
assignee or subtenant of all such covenants.

     12.2 If Landlord  consents in writing,  Tenant may  complete  the  intended
assignment or sublease subject to the following covenants:  (a) no assignment or
sublease  shall be valid and no assignee or subtenant  shall take  possession of
the Premises or any part thereof  until an executed  duplicate  original of such
assignment or sublease,  in compliance  with section 12.1, has been delivered to
Landlord,  (b) no assignee or subtenant  shall have a right further to assign or
sublease.

                                       21


     12.3 No  assignment  or  sublease  whatsoever  shall  release  Tenant  from
Tenant's  obligations  and  liabilities  under this  Lease or alter the  primary
liability  of Tenant to pay all rent and to perform all  obligations  to be paid
and  performed  by Tenant.  The  acceptance  of rent by Landlord  from any other
person or entity shall not be deemed to be a waiver by Landlord of any provision
of this Lease. Consent to one assignment or sublease shall not be deemed consent
to any  subsequent  assignment  or  sublease.  If  any  assignee,  subtenant  or
successor  of  Tenant  defaults  in  the  performance  of any  obligation  to be
performed by Tenant  under this Lease,  Landlord  may proceed  directly  against
Tenant  without the  necessity of  exhausting  remedies  against such  assignee,
subtenant  or  successor.  Landlord  may consent to  subsequent  assignments  or
subleases  or  amendments  or   modifications  to  this  Lease  with  assignees,
subtenants or successors of Tenant, without notifying Tenant or any successor of
Tenant and without obtaining any consent thereto from Tenant or any successor of
Tenant,  and such action  shall not release  Tenant  from  liability  under this
Lease.

     12.4 Upon  Tenant's  entering into any agreement to sell or transfer all or
substantially  all of its  assets  (whether  or not  the  assets  to be  sold or
transferred  include this Lease),  Tenant shall within three (3) days thereafter
notify  Landlord of the essential  terms of such  agreement.  If Tenant sells or
transfers  substantially  all of its assets but does not  expressly  assign this
Lease to the transferee,  then at Landlord's option,  this Lease shall be deemed
to have been assigned to such transferee and such transferee  shall be deemed to
have assumed all of Tenant's  obligations  under this Lease.  If such transferee
does not expressly assume such obligations in writing within ten (10) days after
demand  delivered to Tenant,  the  Stipulated  Difference (as defined in section
14.2(c)) shall be increased by five million dollars ($5,000,000).


                                   ARTICLE 13

                                Entry by Landlord

     13.1 Landlord  shall have the right,  upon not less than  twenty-four  (24)
hours prior notice (except in cases of emergency),  to enter the Premises at any
time to (a)  inspect the  Premises,  (b)  exhibit  the  Premises to  prospective
purchasers,  lenders  or  (during  the last  eighteen  (18)  months of the term)
tenants, (c) determine whether Tenant is performing all of Tenant's obligations,
(d) perform any  obligations of Tenant in accordance with section 14.5, (e) post
notices of nonresponsibility in and about the Premises,  (f) make any repairs to
the  Premises  and (g)  investigate  and  perform  tests to  determine  Tenant's
compliance  with Article 21. In connection  with any such entry,  Landlord shall
use reasonable  efforts to avoid any  unnecessary  disruption of or interference
with Tenant's business  operation.  Tenant waives all claims for damages for any
injury or inconvenience to or interference with Tenant's  business,  any loss of
occupancy or quiet  enjoyment of the  Premises or any other loss  occasioned  by
such entry.  If  Landlord  removes any  existing  underground  tanks and fueling
system from the Premises,  Landlord  shall have no obligation to replace them or
provide alternate tanks or a fueling system.  Landlord shall at all times have a
key to unlock  all such doors and  Landlord  shall have the right to use any and
all means which  Landlord  may deem proper to open such doors in an emergency to
obtain entry to the Premises.  Any entry to the Premises obtained by Landlord by
any of such means shall not under any circumstances be construed or deemed to be
a forcible or unlawful  entry into or a detainer of the Premises or an eviction,
actual or constructive, of Tenant from the Premises or any portion thereof.

                                       22



                                   ARTICLE 14

                         Events of Default and Remedies

     14.1 The  occurrence of any one or more of the following  events ("Event of
Default") shall constitute a breach of this Lease by Tenant:

     (a) Tenant  fails to pay any Base Rent  within five (5) days after the date
when such rent becomes due or fails to make the additional  deposits to the Draw
Account within the time period set forth in section 24.5; or

     (b) Tenant  fails to pay any  additional  rent or other  amount of money or
charge payable by Tenant hereunder as and when such additional rent or amount or
charge becomes due and payable and such failure continues for more than ten (10)
Business Days after Landlord  gives written notice thereof to Tenant;  provided,
however, that after the second such failure in a calendar year, only the passage
of time,  but no further  notice,  shall be  required to  establish  an Event of
Default in the same calendar year; or

     (c) Tenant fails to perform or breaches any other  agreement or covenant of
this Lease to be  performed  or  observed by Tenant as and when  performance  or
observance  is due and such failure or breach  continues  for more than ten (10)
Business Days after Landlord  gives written notice thereof to Tenant;  provided,
however,  that if, by the nature of such agreement or covenant,  such failure or
breach cannot  reasonably be cured within such period of ten (10) Business Days,
an  Event of  Default  shall  not  exist as long as  Tenant  commences  with due
diligence  and dispatch the curing of such failure or breach within a reasonable
period of time after  becoming  aware of such  failure or breach and,  having so
commenced,  thereafter  prosecutes with diligence and dispatch and completes the
curing of such failure or breach within a reasonable time; or

                                       23


     (d) Tenant or any Guarantor  (i) files,  or consents by answer or otherwise
to the  filing  against  it of, a  petition  for  relief  or  reorganization  or
arrangement  or any other  petition in bankruptcy or for  liquidation or to take
advantage of any  bankruptcy,  insolvency  or other  debtors'  relief law of any
jurisdiction,  (ii) makes an assignment for the benefit of its creditors,  (iii)
consents to the appointment of a custodian,  receiver,  trustee or other officer
with similar powers of Tenant (or any Guarantors) or of any substantial  part of
Tenant's (or any Guarantor's)  property, or (iv) takes action for the purpose of
any of the foregoing; or

     (e) Without  consent by Tenant or a Guarantor (as the case may be), a court
or government  authority  enters an order,  and such order is not vacated within
thirty (30) days, (i) appointing a custodian, receiver, trustee or other officer
with similar powers with respect to Tenant or any Guarantor,  or with respect to
any  substantial  part  of  Tenant's  or  any  Guarantor's   property,  or  (ii)
constituting  an order  for  relief  or  approving  a  petition  for  relief  or
reorganization  or  arrangement  or any  other  petition  in  bankruptcy  or for
liquidation or to take advantage of any bankruptcy, insolvency or other debtors'
relief law of any jurisdiction, or (iii) ordering the dissolution, winding-up or
liquidation of Tenant or any Guarantor; or

     (f) This Lease or any estate of Tenant  hereunder  is levied upon under any
attachment or execution and such  attachment or execution is not vacated  within
thirty (30) days; or

     (g) Tenant vacates or abandons the Premises; or

     (h) Any Lease  Guaranty  (as defined in section  24.1) ceases to be in full
force and effect; or

     (i) Tenant  merges or sells or transfers  all or  substantially  all of its
assets  (whether  or not the assets sold or  transferred  include  this  Lease),
unless Landlord consents to such transaction in accordance with section 12.1.

     14.2 If an Event of Default  occurs,  Landlord  shall have the right at any
time to give a written  termination  notice to Tenant and, on the date specified
in such notice,  Tenant's  right to  possession  shall  terminate and this Lease
shall terminate. Upon such termination, Landlord shall have the right to recover
from Tenant:

     (a) The worth at the time of award of all unpaid rent which had been earned
at the time of termination;

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

                                       24


     (c) The worth at the time of award of the amount by which all  unpaid  rent
for the  balance of the term of this Lease  after the time of award  exceeds the
amount of such rental  loss that  Tenant  proves  could be  reasonably  avoided;
provided that, in the event that, at the time of the  termination of this Lease,
the Premises or any substantial  portion of the Premises have not been relet, in
lieu of such  amount,  Landlord  shall be entitled to withdraw  the balance then
held in the Draw Account and retain such balance as  liquidated  damages for the
loss of the rents  payable  under this Lease for the balance of the term of this
Lease, in which event such  liquidated  damages would be accepted by Landlord in
full satisfaction of all damages suffered by Landlord for the loss of rents that
would have been  payable  under the Lease with  respect to the period  after the
date of termination  of the Lease.  The amount of funds from time to time in the
Draw Account  pursuant to this Article 24 (subject to section  12.4) is referred
to herein as the "Stipulated Difference." Tenant and Landlord agree that (a) the
Stipulated  Difference is a fair and  reasonable  estimate of the  difference in
value of the Premises if Tenant's covenants and obligations, as tenant under the
Leases,  are performed in all material respects and the value of the Premises if
such covenants and obligations are not performed in all material  respects,  (b)
that the  definition  of the term  "Event  of  Default"  reflects  Tenant's  and
Landlord's  negotiated  agreement as to a fair standard for determining  whether
such covenants and obligations are being performed in all material respects, and
(c) that such difference in value will not be precisely calculable since it will
involve  complex  and  intangible  factors  such as  reduced  salability  of the
Premises,  reduced  creditworthiness of Landlord and harm to Landlord's business
reputation. Said liquidated damages would not be in lieu of or otherwise replace
amounts that Landlord would be entitled to collect under sections  14.2(a),  (b)
and (d), and  Landlord  would be entitled to collect all of the same from Tenant
in addition to the liquidated damages provided for in this section 14.2(c); and

     (d)  All  other  amounts  necessary  to  compensate  Landlord  for  all the
detriment  proximately  caused by  Tenant's  failure to perform  all of Tenant's
obligations  under this Lease or which in the ordinary course of things would be
likely  to result  therefrom.  The  "worth at the time of award" of the  amounts
referred to in clauses (a) and (b) above shall be computed by allowing  interest
at the  Interest  Rate (as  defined in section  3.4).  The "worth at the time of
award" of the  amount  referred  to in clause  (c) above  shall be  computed  by
discounting such amount at the discount rate of the Federal Reserve Bank located
nearest the Premises at the time of award plus one percent (1%). For the purpose
of  determining  unpaid  rent under  clauses  (a),  (b) and (c) above,  the rent
reserved  in this Lease  shall be deemed to be the total rent  payable by Tenant
under Articles 3 and 5 hereof.

     14.3 If an Event of Default occurs,  Landlord may, without terminating this
Lease, terminate Tenant's right to possession of the Premises, in which event:

          (a) Landlord may, with or without process of law, retake possession of
     the Premises;

                                       25


          (b) Tenant's obligations under this Lease (including the obligation to
     pay rent on the dates  specified in this Lease) shall  continue  unaffected
     for the entire  term of this Lease or until such  earlier  time as Landlord
     may, at its option,  elect to terminate  this Lease which  Landlord may, at
     its option, do at any time;

          (c) Without  being  deemed to have  elected to  terminate  this Lease,
     Landlord  may relet the  Premises in  accordance  with section 14.4 for the
     account of Tenant, in the name of Landlord or in the name of Tenant on such
     terms  and  conditions  and  to  such  tenants  as  Landlord  may,  in  its
     discretion, determine. Landlord shall be entitled to remodel and repair the
     Premises,  to subdivide the  Premises,  or to combine all or any portion or
     portions of the Premises with other  premises in any manner which  Landlord
     shall deem  appropriate in order to accomplish such  reletting;  and Tenant
     shall  reimburse  Landlord,  on  demand,  for all  costs  and  expenses  in
     connection  with  such  repair  or  remodeling  and  reletting  ("Reletting
     Costs").    Notwithstanding   Landlord's   recovery   of   possession   and
     notwithstanding  any  reletting,  Tenant  shall  continue  to pay all  rent
     provided  for  herein  as and when it  comes  due,  less  the net  proceeds
     received by Landlord from any reletting;  provided that, if the proceeds of
     reletting  exceed the amount due from Tenant,  on or before the 15th day of
     each month,  Landlord  shall  refund to Tenant any amount by which the rent
     paid by  Tenant  through  such  date,  when  added to the  amount,  if any,
     recovered by Landlord  through any  reletting of the Premises  through such
     date,  reduced  by all  Reletting  Costs  for  which  Tenant  has not  paid
     Landlord,  and reduced by all amounts  Landlord has previously  refunded to
     Tenant under this  subsection,  and reduced any other  amounts  Tenant owes
     Landlord  under this Lease,  exceeds the rent due under this Lease  through
     such date.  Tenant shall  reimburse  Landlord upon demand for all Reletting
     Costs  and any  other  costs  and  expenses  which  Landlord  may  incur in
     connection with recovery of possession or repair of the Premises;

          (d) In the event Landlord  proceeds under this section 14.3,  Landlord
     may at any time terminate this Lease by notice to Tenant.  Such termination
     shall  have the effect  specified  in section  14.2 and  Landlord  shall be
     entitled to all remedies under section 14.2 upon termination.

     14.4  Landlord  shall have no duty to attempt to  mitigate  its  damages by
retaking  and  reletting  the  Premises;  provided  that,  if  Landlord  retakes
possession of the Premises under either  section 14.2 or section 14.3,  Landlord
shall use good faith  reasonable  efforts to relet the Premises,  subject to the
following terms, conditions and limitations:

                                       26


          (a) Any reletting of the Premises shall be on the terms and conditions
     determined by Landlord in its reasonable good faith  discretion and to such
     tenants as Landlord shall approve in its reasonable good faith  discretion.
     Without limiting the generality of the foregoing, Tenant acknowledges that,
     in reletting the Premises, Landlord may legitimately consider the effect of
     any such  reletting  on the  Premises  and on any other  property  owned by
     Landlord or any other person or entity controlling, controlled by, or under
     common control with Landlord,  or otherwise affiliated with Landlord (which
     parties are referred to herein collectively as "Landlord Affiliates"), and,
     therefore,  may decide not to lease the  Premises  at rates which are lower
     than Landlord is otherwise  endeavoring to maintain in the Premises,  or at
     rates  which  are  lower  than  the  rate  that  Landlord  believes  to  be
     appropriate for the Premises.

          (b)  Tenant   recognizes  that  Landlord  and  Landlord's   Affiliates
     currently and in the future may have vacant space in the Premises and other
     property  and may in the future also have vacant  space in new  projects in
     competition  with the Premises.  In no event shall Landlord be obligated to
     use any effort to relet the  Premises  in  preference  to leasing  any such
     other  vacant  space  then  available  for  leasing by  landlord  or any of
     Landlord's  Affiliates.  Landlord  shall not be  deemed  to have  failed to
     mitigate  damages  solely on account of the  leasing of other  space  which
     Landlord or Landlord's  Affiliates have available  instead of the reletting
     of the Premises.

     14.5 Whether or not Landlord  elects to terminate  this Lease on account of
any Event of Default by Tenant,  and  subject to  Landlord's  duty to attempt to
mitigate  its  damages  as  provided  herein,  Landlord  shall have the right to
terminate  any and all  subleases,  licenses,  concessions  or other  consensual
arrangements for possession entered into by Tenant and affecting the Premises or
may,  in  Landlord's  sole  discretion,  succeed to  Tenant's  interest  in such
sublease,  licenses,  concessions  or  arrangements.  In the event of Landlord's
election  to succeed  to  Tenant's  interest  in any such  subleases,  licenses,
concessions or arrangements,  Tenant shall, as of the date of notice by Landlord
of such  election,  have no further  right to or  interest  in the rent or other
consideration  receivable  thereunder,  except that amounts actually received by
Landlord  thereunder  shall be credited  against  any amounts  payable by Tenant
hereunder.

     14.6 Except as otherwise provided in section 14.2(c), the remedies provided
for in this Lease are in addition to all other remedies available to Landlord at
law or in equity by statute or otherwise.

     14.7 All  agreements  and  covenants  to be performed or observed by Tenant
under this Lease  shall be at  Tenant's  sole cost and  expense  and without any
abatement of rent.  If Tenant fails to pay any sum of money to be paid by Tenant
or to perform any other act to be performed by Tenant under this Lease, Landlord
shall  have the  right,  but shall not be  obligated,  and  without  waiving  or
releasing Tenant from any obligations of Tenant,  to make any such payment or to
perform  any such other act on behalf of Tenant in  accordance  with this Lease.
All sums so paid by Landlord and all necessary  incidental costs shall be deemed
additional  rent hereunder and shall be payable by Tenant to Landlord on demand,
together with interest on all such sums from the date of expenditure by Landlord
to the date of repayment by Tenant at the Interest Rate. Landlord shall have, in
addition  to all other  rights and  remedies  of  Landlord,  the same rights and
remedies in the event of the  nonpayment of such sums plus interest by Tenant as
in the case of default by Tenant in the payment of rent.

                                       27


     14.8 If Tenant  abandons or surrenders the Premises,  or is dispossessed by
process of law or otherwise, any movable furniture, equipment, trade fixtures or
personal  property  belonging to Tenant and left in the Premises shall be deemed
to be abandoned, at the option of Landlord, and Landlord shall have the right to
sell  or  otherwise  dispose  of  such  personal  property  in any  commercially
reasonable manner.


                                   ARTICLE 15

                              Damage or Destruction

     15.1 If the  Premises,  or any part  thereof,  is  damaged by fire or other
casualty before the Commencement  Date or during the term of this Lease,  Tenant
shall repair such damage and restore the Premises to  substantially  the same or
better  condition  as  existed  before  the  occurrence  of such  fire or  other
casualty, Tenant shall repair and replace all such movable furniture, equipment,
trade fixtures and personal property,  and this Lease shall remain in full force
and effect.  Such repair and  replacement  by Tenant shall be done in accordance
with  Article 9. In no event shall rent abate.  Provided  that Tenant shall have
unconditionally  ratified  in writing  its repair  and  restoration  obligations
pursuant to this section 15.1 with respect to such  casualty,  Tenant shall have
the right to participate  in the adjustment of any insurance  claim arising from
such casualty and shall have the right to approve any  settlement or adjustment,
which approval shall not unreasonably be withheld or delayed. Provided Tenant is
not in  default  under this Lease  (and no event has  occurred  which,  with the
passage of time, the giving of notice, or both, would constitute a default), and
provided  Tenant has (i) delivered to Landlord  plans and  specifications  and a
budget  for such  repair  and  restoration  (all of which  Landlord  shall  have
approved in its reasonable  judgment),  and (ii) deposited with Landlord cash in
the sum  equal to the  excess,  if any,  of the  total  cost  set  forth in such
approved  budget over the amount of  insurance  proceeds  received on account of
such  casualty,  then  Landlord  shall make  available  to Tenant all  insurance
proceeds  actually  received  by  Landlord  on  account  of such  casualty,  for
application to the costs of such approved repair and restoration, as follows:

                                       28


          (a) No more  frequently  than  once per  calendar  month,  Tenant  may
     request that  Landlord  reimburse  Tenant for costs  incurred by Tenant for
     work in place to repair and restore  the  Premises  during the  immediately
     preceding calendar month.  Tenant's request shall certify that all work for
     which reimbursement is requested was performed in compliance with the plans
     and  specifications  approved  by  Landlord  pursuant  to Article 9 and all
     applicable laws, and shall include reasonably  satisfactory evidence of the
     costs  incurred  by Tenant  and  unconditional  lien  releases  in form and
     substance   required  by  applicable   law  executed  by  all   mechanic's,
     materialmen,  laborers, suppliers and contractors who performed any portion
     of the repair work or supplied materials.

          (b)  Within  fifteen  (15)  days  after  receiving  Tenant's  request,
     Landlord shall approve or disapprove Tenant's request, which approval shall
     not be  unreasonably  withheld,  by written  notice to Tenant.  If Landlord
     approves all or any portion of a request and Landlord has received (and not
     previously  disbursed)  insurance proceeds,  then Landlord's approval shall
     include a check in the amount approved by Landlord. If Landlord disapproves
     all or any portion of a request,  then  Landlord's  notice  shall state the
     reasons  for that  disapproval.  Landlord's  failure  to  deliver  a notice
     approving or disapproving a request shall be conclusively deemed Landlord's
     disapproval of the request.  In addition,  Landlord shall have the right to
     impose other  conditions  upon  disbursement so long as they are consistent
     with customary  construction  loan disbursement  practices.  Landlord shall
     maintain in an  interest-bearing  account any proceeds of insurance held by
     Landlord and any sums  deposited  with Landlord by Tenant  pursuant to this
     section  15.1,  and so long as no  default  by Tenant  under this Lease has
     occurred, interest earned on such account shall be disbursed to Tenant upon
     completion  of such  repair  and  restoration,  except to the  extent  such
     interest has been applied to the costs of such repair and restoration.

     15.2 If the  Premises,  or any part  thereof,  is  damaged by fire or other
casualty and (a) such fire or other casualty  occurs during the last twelve (12)
months  of the term of this  Lease and the  repair  and  restoration  work to be
performed  by Tenant in  accordance  with section  15.1  cannot,  as  reasonably
estimated by Landlord,  be completed within four (4) months after the occurrence
of such  fire or other  casualty,  or (b) the  insurance  proceeds  received  by
Landlord and Tenant in respect of such damage are not adequate to pay the entire
cost, as reasonably estimated by Landlord, of the repair and restoration work to
be  performed  by Landlord in  accordance  with section 15.1 and Tenant does not
deposit such shortfall with  Landlord,  then, in any such event,  Landlord shall
have the right,  by giving written notice to Tenant within sixty (60) days after
the occurrence of such fire or other casualty, to terminate this Lease as of the
date of such  notice,  in which case all  insurance  proceeds on account of such
casualty  shall be paid to Landlord.  If Landlord does not exercise the right to
terminate this Lease in accordance  with this section 15.2,  Tenant shall repair
such damage and restore the  Premises in  accordance  with section 15.1 and this
Lease shall remain in full force and effect.


                                       29


                                   ARTICLE 16

                                 Eminent Domain

     16.1 If a  substantial  portion of the Premises is taken and the  remaining
portion of the Premises is not reasonably suitable for Tenant's purposes,  or if
a portion of the Premises is taken resulting in a substantial  loss of access to
and from the Premises  without  reasonable  substitute  access being  available,
Landlord and Tenant each shall have the right,  by giving  written notice to the
other within thirty (30) days after the date of such taking,  to terminate  this
Lease. If either Landlord or Tenant exercises such right to terminate this Lease
in accordance  with this section 16.1, this Lease shall terminate as of the date
of such taking. If neither Landlord nor Tenant exercises such right to terminate
this Lease in accordance  with this section 16.1,  this Lease shall terminate as
to the portion of the  Premises so taken as of the date of such taking and shall
remain in full force and effect as to the portion of the  Premises not so taken,
Tenant shall  restore the portion of the Premises not so taken to an  integrated
architectural  unit in  accordance  with  Article 9 and the Base  Rent  shall be
reduced as of the date of such taking in the  proportion  that the rentable area
of the Premises so taken bears to the total  rentable area of the  Premises.  If
all of the Premises is taken by exercise of the power of eminent  domain  before
the  Commencement  Date or  during  the term of this  Lease,  this  Lease  shall
terminate as of the date of such taking.

     16.2 If all or any part of the  Premises  is taken by exercise of the power
of eminent domain, all awards, compensation,  damages, income, rent and interest
payable in connection  with such taking shall,  except as expressly set forth in
this section  16.2,  be paid to and become the property of Landlord,  and Tenant
hereby assigns to Landlord all of the foregoing. Without limiting the generality
of the  foregoing,  Tenant  shall have no claim  against  Landlord or the entity
exercising  the power of eminent  domain for the value of the  leasehold  estate
created by this Lease or any unexpired term of this Lease. Tenant shall have the
right to claim and  receive  directly  from the entity  exercising  the power of
eminent domain only the share of any award  determined to be owing to Tenant for
the taking of improvements  installed in the portion of the Premises so taken by
Tenant at Tenant's sole cost and expense based on the unamortized  cost actually
paid by  Tenant  for such  improvements,  for the  taking  of  Tenant's  movable
furniture,  equipment,  trade  fixtures  and  personal  property,  for  loss  of
goodwill,  for interference  with or interruption of Tenant's  business,  or for
removal and relocation expenses.

                                       30


     16.3 In the event of any taking other than a taking  referred to in section
16.1, this Lease shall continue in full force and effect,  Tenant shall continue
to pay  all of the  rent  and to  perform  all of the  covenants  of  Tenant  in
accordance  with  this  Lease  and  Tenant  shall  restore  the  Premises  to an
integrated  architectural  unit in accordance with Article 9. Provided Tenant is
not in  default  under this Lease  (and no event has  occurred  which,  with the
passage of time, the giving of notice, or both, would constitute a default), and
provided  Tenant has (i) delivered to Landlord  plans and  specifications  and a
budget  for such  repair  and  restoration  (all of which  Landlord  shall  have
approved in its reasonable  judgment),  and (ii) deposited with Landlord cash in
the sum  equal to the  excess,  if any,  of the  total  cost  set  forth in such
approved  budget  over the amount of  condemnation  award  proceeds  received on
account  of such  taking,  then  Landlord  shall  make  available  to Tenant all
condemnation  award  proceeds  actually  received by Landlord on account of such
taking, for application to the costs of such approved repair and restoration, as
follows:

          (a) No more  frequently  than  once per  calendar  month,  Tenant  may
     request that  Landlord  reimburse  Tenant for costs  incurred by Tenant for
     work in place to repair and restore  the  Premises  during the  immediately
     preceding calendar month.  Tenant's request shall certify that all work for
     which reimbursement is requested was performed in compliance with the plans
     and  specifications  approved  by  Landlord  pursuant  to Article 9 and all
     applicable laws, and shall include reasonably  satisfactory evidence of the
     costs  incurred  by Tenant  and  unconditional  lien  releases  in form and
     substance   required  by  applicable   law  executed  by  all   mechanic's,
     materialmen,  laborers, suppliers and contractors who performed any portion
     of the repair work or supplied materials.

          (b)  Within  fifteen  (15)  days  after  receiving  Tenant's  request,
     Landlord shall approve or disapprove Tenant's request, which approval shall
     not be  unreasonably  withheld,  by written  notice to Tenant.  If Landlord
     approves all or any portion of a request and Landlord has received (and not
     previously disbursed) condemnation award proceeds, then Landlord's approval
     shall  include a check in the amount  approved  by  Landlord.  If  Landlord
     disapproves all or any portion of a request,  then Landlord's  notice shall
     state the reasons  for that  disapproval.  Landlord's  failure to deliver a
     notice  approving or  disapproving a request shall be  conclusively  deemed
     Landlord's disapproval of the request. In addition, Landlord shall have the
     right to impose  other  conditions  upon  disbursement  so long as they are
     consistent  with  customary   construction  loan  disbursement   practices.
     Landlord shall  maintain in an  interest-bearing  account any  condemnation
     award held by  Landlord  and any sums  deposited  with  Landlord  by Tenant
     pursuant to this  section  16.3,  and so long as no default by Tenant under
     this Lease has occurred, interest earned on such account shall be disbursed
     to Tenant upon  completion  of such repair and  restoration,  except to the
     extent  such  interest  has been  applied  to the costs of such  repair and
     restoration.

                                       31


     16.4 As used in this Article 16, a "taking" means the acquisition of all or
part of the Premises for a public use by exercise of the power of eminent domain
(or a sale of any or all of the Premises in lieu, or under threat,  thereof) and
the taking shall be  considered  to occur as of the earlier of the date on which
possession of the Premises (or part so taken) by the entity exercising the power
of eminent domain is authorized as stated in an order for possession or the date
on which title to the Premises (or part so taken) vests in the entity exercising
the power of eminent domain.


                                   ARTICLE 17

                         Subordination, Merger and Sale

     17.1 This Lease shall be subject and  subordinate  at all times to the lien
of all mortgages and deeds of trust  securing any amount or amounts  whatsoever,
and any ground  lease or master  lease of the  Premises,  which may now exist or
hereafter  be placed on or against  the  Premises  or on or  against  Landlord's
interest  or estate  therein,  all  without  the  necessity  of  having  further
instruments executed by Tenant to effect such subordination. Notwithstanding the
foregoing,  in the event of a foreclosure  of any such mortgage or deed of trust
or of any other action or proceeding for the enforcement thereof, or of any sale
thereunder, or in the event any such ground lease or master lease is terminated,
this Lease shall not be  terminated  or  extinguished,  nor shall the rights and
possession of Tenant hereunder be disturbed,  if no Event of Default then exists
under this Lease, and Tenant shall attorn to the person who acquires  Landlord's
interest hereunder through any such mortgage or deed of trust.  Tenant agrees to
execute, acknowledge and deliver upon demand such further instruments evidencing
such  subordination of this Lease to the lien of all such mortgages and deeds of
trust or to all such  ground  leases or master  leases  of the  Premises  as may
reasonably be required by Landlord,  but Tenant's  covenant to subordinate  this
Lease to  mortgages  or deeds of  trust,  or ground  leases  or  master  leases,
hereafter  executed is  conditioned  upon each such  senior  mortgage or deed of
trust, or ground lease or master lease, or a separate  subordination  agreement,
containing the commitments specified in the preceding sentence. Without limiting
the  generality of the foregoing,  Tenant agrees to enter into a  subordination,
nondisturbance  and  attornment  agreement in the form required by the holder of
any such  mortgage or deed of trust or by any party to any such ground  lease or
master lease.

     17.2 The voluntary or other surrender of this Lease by Tenant,  or a mutual
cancellation  thereof,  shall  not work a merger  and  shall,  at the  option of
Landlord,  terminate all or any existing subleases or subtenancies or operate as
an assignment to Landlord of any or all such subleases or subtenancies.

     17.3 If the original  Landlord  hereunder,  or any  successor  owner of the
Premises,  sells or conveys the Premises, all liabilities and obligations on the
part of the  original  Landlord,  or such  successor  owner,  under  this  Lease
accruing  after  such  sale or  conveyance  shall  terminate  and  the  original
Landlord,  or such successor owner, shall  automatically be released  therefrom,
and thereupon all such liabilities and obligations shall be binding upon the new
owner. Tenant agrees to attorn to such new owner.

                                       32



                                   ARTICLE 18

                              Estoppel Certificate

     18.1(a) At any time and from time to time,  Tenant  shall,  within ten (10)
days after  written  request by Landlord,  execute,  acknowledge  and deliver to
Landlord a certificate, in the form attached as Exhibit A, or such other form as
may be  requested,  certifying:  (i) that this Lease is  unmodified  and in full
force and effect  (or, if there have been  modifications,  that this Lease is in
full  force and  effect as  modified,  and  stating  the date and nature of each
modification);  (ii) the Commencement Date and the Expiration Date determined in
accordance with Article 2 and the date, if any, to which all rent and other sums
payable  hereunder  have been paid;  (iii) that no notice has been  received  by
Tenant of any default by Tenant hereunder which has not been cured, except as to
defaults  specified in such  certificate;  (iv) that  Landlord is not in default
under this Lease,  except as to defaults specified in such certificate;  and (v)
such other matters as may be  reasonably  requested by Landlord or any actual or
prospective  purchaser or mortgage  lender.  Any such  certificate may be relied
upon by Landlord and any actual or prospective  purchaser or mortgage  lender of
the Premises or any part thereof.

     (b) At any time and from time to time, Landlord shall, within ten (10) days
after written  request by Tenant,  execute,  acknowledge and deliver to Tenant a
certificate certifying:  (i) that this Lease is unmodified and in full force and
effect (or, if there have been  modifications,  that this Lease is in full force
and effect as modified,  and stating the date and nature of each  modification);
(ii) the Commencement Date and the Expiration Date determined in accordance with
Article  2 and the  date,  if any,  to which  all rent and  other  sums  payable
hereunder have been paid;  (iii) that no notice has been received by Landlord of
any  default  by  Landlord  hereunder  which  has not been  cured,  except as to
defaults specified in such certificate; (iv) that Tenant is not in default under
this Lease,  except as to defaults  specified in such certificate;  and (v) such
other matters as may be reasonably requested by Tenant. Any such certificate may
be relied upon by Tenant and any actual or prospective lender.

                                       33



                                   ARTICLE 19

                                  Holding Over

     19.1 If,  without  objection by Landlord,  Tenant holds  possession  of the
Premises  after  expiration  of the term of this Lease,  Tenant  shall  become a
tenant from month to month upon the terms  herein  specified  but at a Base Rent
equal to one  hundred  twenty  percent  (120%) of the Base Rent in effect at the
expiration  of the term of this Lease  pursuant to Article 3, payable in advance
on or before the first day of each  month.  Such month to month  tenancy  may be
terminated  by either  Landlord or Tenant by giving  thirty  (30) days'  written
notice of termination to the other at any time.


                                   ARTICLE 20

                              Financial Statements

     20.1 On or before April 1 of each year,  Tenant  shall  deliver to Landlord
audited  consolidated  financial  statements  of  ICG  Communications,  Inc.,  a
Delaware corporation  ("ICGC"),  and its consolidated  subsidiaries  ("Financial
Statements")  for the fiscal  year of ICGC ended on the  previous  December  31,
which Financial  Statements shall include an audited  consolidated balance sheet
of ICGC and its  consolidated  subsidiaries as at the end of such fiscal year, a
consolidated  statement of operations of ICGC and its consolidated  subsidiaries
for such fiscal year,  and a  certificate  of ICGC's  auditor  (which shall be a
recognized  national  independent  accounting  firm)  to the  effect  that  such
Financial  Statements  were  prepared  in  accordance  with  generally  accepted
accounting  principals  consistently  applied and fairly  present the  financial
condition and operations of ICGC and its consolidated subsidiaries for and as at
the end of such fiscal year.

                                       34



                                   ARTICLE 21

                               Hazardous Materials

     21.1 As used herein,  the term "Hazardous  Material" means any hazardous or
toxic substance, material or waste, or any pollutant or contaminant, or words of
similar  import,  which  is or  becomes  regulated  by  any  local  governmental
authority,  the state in which the Premises are  located,  or the United  States
Government.  The term "Hazardous Material" includes,  but is not limited to, any
material  or  substance  which is, (a)  designated  as a  "hazardous  substance"
pursuant to section 311 of the Federal  Water  Pollution  Control Act (33 U.S.C.
section 1317),  (b) defined as a "hazardous  waste"  pursuant to section 1004 of
the Federal Resource  Conservation  and Recovery Act, 42 U.S.C.  section 6901 et
seq. (42 U.S.C.  section 6903), (c) defined as a "hazardous  substance" pursuant
to section 101 of the  Comprehensive  Environmental  Response  Compensation  and
Liability  Act (42 U.S.C.  section 9601 et seq.),  (d)  asbestos,  (e) petroleum
(including crude oil or any fraction thereof,  natural gas, natural gas liquids,
liquefied  natural  gas,  or  synthetic  gas  usable  for fuel,  or any  mixture
thereof),  (f)  petroleum  products,  (g)  polychlorinated  biphenyls,  (h) urea
formaldehyde,  (i) radon gas, (j) radioactive matter, (k) medical waste, and (l)
chemicals which may cause cancer or reproductive toxicity.

     21.2 As used herein, the term "Environmental  Requirements" means all laws,
ordinances, rules, regulations,  orders and other requirements of any government
or public  authority now in force or which may hereafter be in force relating to
protection  of human  health  or the  environment,  including  all  requirements
pertaining to reporting, licensing, permitting, investigation and remediation of
emissions,  discharges, storage, disposal or releases of Hazardous Materials and
all  requirements  pertaining  to the  protection  of the  health  and safety of
employees or the public.

     21.3 Tenant  shall not permit or conduct  the  handling,  use,  generation,
treatment,  storage or disposal  on, in or about the  Premises of any  Hazardous
Material (other than normal  quantities of office supplies and cleaning supplies
which Tenant shall  handle,  use,  store and dispose of in  compliance  with all
Environmental  Requirements) without prior written notice to Landlord.  Any such
notice by Tenant to Landlord  shall be in writing and shall  demonstrate  to the
reasonable satisfaction of Landlord that such Hazardous Material is necessary to
the business of Tenant and will be handled, used, generated,  treated, stored or
disposed of in a manner that complies with all Environmental  Requirements.  Any
such handling, use, generation,  treatment, storage or disposal of any Hazardous
Material  permitted  by  Landlord  hereunder  shall  be in  compliance  with all
Environmental Requirements.

                                       35


     21.4 Tenant  shall,  within five (5) days after the receipt  thereof,  give
written  notice to Landlord of any notice or other  communication  regarding any
(a) actual or alleged violation of Environmental  Requirements by Tenant or with
respect  to the  Premises,  (b)  actual or  threatened  migration  of  Hazardous
Material from the Premises,  or (c) the existence of Hazardous Material in or on
the  Premises or  regarding  any actual or  threatened  investigation,  inquiry,
lawsuit, claim, citation,  directive,  summons,  proceeding,  complaint, notice,
order, writ or injunction relating to any of the foregoing.

     21.5 Tenant shall indemnify and defend  Landlord  against and hold Landlord
harmless from all claims, demands,  liabilities,  damages, fines,  encumbrances,
liens,  losses,  costs and expenses,  including  reasonable  attorneys' fees and
disbursements, and costs and expenses of investigation,  arising from or related
to the existence on or after the Commencement  Date of Hazardous  Material in or
on  the  Premises  or  the  actual  or  threatened  migration  on or  after  the
Commencement Date of Hazardous Material from the Premises or the existence on or
after the  Commencement  Date of a violation of  Environmental  Requirements  by
Tenant or with respect to the  Premises.  The  obligations  of Tenant under this
section  21.5  shall not be  affected  by any  investigation  by or on behalf of
Landlord or by any  information  which  Landlord may have or obtain with respect
thereto. Tenant shall, to the reasonable  satisfaction of Landlord,  perform all
remedial  actions  necessary  to  remove  any  Hazardous  Material  in or on the
Premises on or after the  Commencement  Date or to remedy  actual or  threatened
migration from the Premises of any Hazardous Material or to remedy any actual or
threatened  violation of  Environmental  Requirements,  provided  such  remedial
action is required  under  Environmental  Requirements.  This section 21.5 shall
survive termination of this Lease.

     21.6 If, at any time when the term of this  Lease  (including  any  renewal
term) would expire but for the terms of this section  21.6,  Hazardous  Material
exists in, on,  about or under the  Premises,  then the term of this Lease shall
automatically  be  extended  and this  Lease  shall  remain in effect  until the
earlier of (a) the  completion  of all remedial  action  required  under section
21.5,  or (b) the date  specified  in a written  notice from  Landlord to Tenant
terminating this Lease.  During any such extension period,  Tenant shall perform
all of its  obligations  under this  Lease  including  payments  of all rent due
hereunder.

                                       36



                                   ARTICLE 22

                                     Waiver

     22.1 The waiver by Landlord or Tenant of any breach of any covenant in this
Lease shall not be deemed to be a waiver of any subsequent breach of the same or
any other  covenant  in this Lease,  nor shall any custom or practice  which may
grow up  between  Landlord  and  Tenant in the  administration  of this Lease be
construed  to waive or to lessen the right of  Landlord or Tenant to insist upon
the performance by Landlord or Tenant in strict  accordance with this Lease. The
subsequent  acceptance  of rent  hereunder by Landlord or the payment of rent by
Tenant  shall not waive any  preceding  breach by Tenant of any covenant in this
Lease, nor cure any Event of Default,  nor waive any forfeiture of this Lease or
unlawful detainer action, other than the failure of Tenant to pay the particular
rent so  accepted,  regardless  of  Landlord's  or  Tenant's  knowledge  of such
preceding breach at the time of acceptance or payment of such rent.


                                   ARTICLE 23

                                     Notices

     23.1 All requests,  approvals,  consents,  notices and other communications
given by  Landlord or Tenant  under this Lease  shall be properly  given only if
made in writing and either deposited in the United States mail, postage prepaid,
certified  with return  receipt  requested,  or  delivered by hand (which may be
through a messenger or recognized  delivery or courier service) and addressed as
follows:  To Landlord at the  address of Landlord  specified  in the Basic Lease
Information,  or at such other place as Landlord may from time to time designate
in a written notice to Tenant;  and to Tenant,  before the Commencement Date, at
the address of Tenant  specified in the Basic Lease  Information,  and after the
Commencement  Date, at the  Premises,  or at such other place as Tenant may from
time  to  time  designate  in a  written  notice  to  Landlord.  Such  requests,
approvals,  consents, notices and other communications shall be effective on the
date of receipt  (evidenced by the  certified  mail receipt) if mailed or on the
date of delivery if hand delivered.


                                   ARTICLE 24

                          Guaranties; Security Deposit

     24.1 As a condition  precedent for Landlord's  benefit to the effectiveness
of this Lease and the  Commencement  Date,  on or before the  Commencement  Date
Tenant shall cause to be delivered to Landlord  Continuing  Lease  Guaranties in
the form  attached  hereto as Exhibit B, executed by the  respective  Guarantors
specified in the Basic Lease Information (the "Lease Guaranties").

                                       37


     24.2 As a condition  precedent for Landlord's  benefit to the effectiveness
of this Lease and the  Commencement  Date,  on or before the  Commencement  Date
Tenant shall  deposit with  Landlord by wire  transfer the amount of ten million
dollars  ($10,000,000)  (the  "Security  Amount")  to be held by  Landlord  as a
security  deposit in accordance  with this Article 24. The Security Amount shall
be held in an  interest-bearing  account in Landlord's own name as secured party
with  respect  to the  security  interest  hereby  granted  by  Tenant,  as cash
collateral  (the  "Draw  Account"),  established  with a  financial  institution
selected by Landlord and reasonably  satisfactory  to Tenant.  Funds in the Draw
Account  shall  be  invested  in  such  Permitted  Investments  (as  hereinafter
defined),  as  Tenant  may from  time to time  designate  by  written  notice to
Landlord  and as approved by Landlord  in its  reasonable  discretion.  The term
"Permitted  Investments"  means money market  accounts with, or  certificates of
deposit issued by, a national bank or other depository institution which bank or
institution is  satisfactory to Landlord in its sole  discretion;  United States
Treasury  securities;  or  commercial  paper rated AAA or better by Standard and
Poors Corporation (or equivalent rating of another nationally  recognized credit
rating  agency).  Risk of loss of the amounts held in the Draw Account  shall be
borne  by  Tenant,  and  Landlord  shall  have no  liability  for any  loss,  or
diminution  in  value,  of the Draw  Account  due to any  failure  of,  or other
financial problems affecting, such financial institution. Interest earned on the
Draw Account  shall for all purposes  become part of the Draw  Account.  On each
anniversary  of the date the funds are  deposited in the Draw  Account,  amounts
held in the Draw Account in excess of the Security  Amount (as the same may have
been  adjusted  pursuant to section  24.6) shall be  disbursed  as follows:  (a)
first,  to pay all reasonable  costs to establish and maintain the Draw Account;
and (b) second, the balance, if any, to Tenant. Tenant hereby grants to Landlord
a security  interest in the Draw Account and all proceeds  thereof to secure the
full and  timely  performance  of  Tenant's  obligations  under this  Lease.  In
addition to the remedies set forth in this Lease, Landlord shall have all of the
rights and remedies of a secured  party  pursuant to the  Massachusetts  Uniform
Commercial Code. At any time upon Landlord's  request,  Tenant shall execute and
deliver to Landlord such security agreements, financing statements and other




                                       38





documents as Landlord  may  reasonably  require to further  evidence and perfect
such security interest.

     24.3 If this Lease is  terminated  and  Landlord is entitled to  liquidated
damages in  accordance  with section  14.2(c),  Landlord may withdraw all of the
funds then remaining in the Draw Account and retain the withdrawn amount.

     24.4 Landlord may, from time to time,  withdraw funds from the Draw Account
for application  against any installment of Rent not paid when due or to pay any
other amount payable by Tenant  hereunder  that is not paid when due,  including
amounts  payable by Tenant  under this Lease to  reimburse  Landlord for amounts
paid by Landlord for the account of Tenant as provided for in this Lease.

     24.5 In the event of a partial withdrawal of funds from the Draw Account in
accordance with section 24.4, Tenant shall,  within five (5) business days after
Landlord has given Tenant notice of such  withdrawal  (including  the purpose of
such withdrawal),  deposit to the Draw Account such additional funds as shall be
necessary to cause the amount of funds in the Draw Account to be returned to the
Security Amount and if Tenant fails to do so within that 5-day period,  an Event
of Default shall be deemed to have occurred and the Landlord may terminate  this
Lease and/or exercise any of its other rights and remedies, including its rights
under this Article 24.

     24.6 The Security  Amount shall be subject to  adjustment  on the terms and
conditions  set  forth  in this  section  24.6.  As of  April  15 of  each  year
commencing  with April 15, 2001 (each a "Reduction  Date"),  the Security Amount
shall be reduced by the Reduction  Amount (as defined below)  applicable to such
Reduction  Date,  provided that, as of such Reduction Date, all of the following
conditions (the "Reduction Conditions") are satisfied:

          (a) Either

               (i)(A)  the net  income of ICGC  during  each of the  immediately
          preceding  three  fiscal  years  shall  have been more than one dollar
          ($1.00),  and (B) the  average  annual net  income of ICGC  during the
          immediately  preceding three fiscal years shall have been more than an
          amount  equal to (1) ten (10),  multiplied  by (2) the average  annual
          Base Rent  payable  under this Lease  during  such three  fiscal  year
          period; or

               (ii)(A) during each of the immediately preceding three (3) fiscal
          years, the ratio of (1) ICGC's Net Cash Flow (as defined below) during
          such year, to (2) ICGC's Fixed Charges (as defined  below) during such
          year shall have exceeded 2.0 to 1, and (B) the average annual Net Cash
          Flow of ICGC during the  immediately  preceding three (3) fiscal years
          shall have been more than an amount equal to (1) ten (10),  multiplied
          by (2) the average  annual Base Rent  payable  under this Lease during
          such three fiscal year period; and

                                       39


          (b) ICGC's  Market  Capitalization  (as  defined  below)  exceeds  one
     billion dollars ($1,000,000,000); and

          (c) ICG  Holdings,  Inc.  occupies one hundred  percent  (100%) of the
     Premises as its headquarters and system operations center; and

          (d) no Event of Default has occurred and is continuing; and

          (e) no Reduction  Event shall have occurred  during the previous three
     hundred sixty-five (365) days; and

          (f) Tenant shall have  delivered to Landlord (i) a certificate  signed
     by the Chief Financial  Officer of ICGC and a senior  executive  officer of
     Tenant,  certifying that, as of the date of such  certificate,  each of the
     Reduction Conditions is satisfied,  and (ii) detailed  calculations,  based
     upon the Financial Statements of ICGC for the relevant years, demonstrating
     to Landlord's  reasonable  satisfaction  that the  Reduction  Condition set
     forth in clause (a) above is satisfied.

References  in this  section  24.6  to  ICGC  mean  ICGC  and  its  consolidated
subsidiaries,  on a consolidated  basis in accordance  with GAAP.  References in
this  section  24.6 to  financial  terms  refer  to  such  terms  determined  in
accordance  with GAAP.  As used herein,  the  following  terms have the meanings
indicated below:

          "Fixed Charges" means,  for any period,  all taxes,  interest  expense
     (cash and  non-cash),  rent and lease  expenses and the current  portion of
     long-term debt for such period.

          "Market  Capitalization" means, as of any date, the product of (1) the
     total  number of shares of  common  stock of ICGC  traded on a major  stock
     exchange or on the NASDAQ National Market System, multiplied by (2) the per
     share price of such common stock most  recently  quoted on such exchange or
     Market System, as published in The Wall Street Journal.

          "Net Cash Flow" means, for any period,  net income during such period,
     plus depreciation,  amortization, impairment losses [and non-cash interest]
     during such period.

          "Reduction  Amount" means the  respective  amounts set forth below for
     the respective Reduction Dates indicated:

                                       40


           Reduction Date                     Reduction Amount
          ---------------------              ------------------
           April 15, 2001                        $1,250,000
           April 15, 2002                        $1,250,000
           Each April 15
             from April 15,
             2003 to April 15,
             2007, inclusive                     $1,500,000
           Each April 15
             from April 15,
             2008 to April 15,
             2012, inclusive                     $2,000,000

Upon the occurrence of any Reduction Event,  Landlord shall deliver to Tenant an
amount  equal to the excess of the funds then held in the Draw  Account over the
adjusted Security Amount becoming effective upon such Reduction Date.

     24.7(a)  The  Security  Amount  shall be  reduced to five  million  dollars
($5,000,000)   at  any  time  that  Tenant   delivers  to  Landlord   reasonably
satisfactory evidence that:

          (i) either Tenant or ICGC shall have  obtained,  and  maintained for a
     continuous  period  of not  less  than  twelve  (12)  months  (without  any
     "CreditWatch" or downgrade consideration), ratings of its unsecured debt of
     BBB- or better from  Standard  and Poor's  Corporation  ("S&P") and Baa3 or
     better from Moody's Investors Service ("Moody's"); or

          (ii) either Tenant or ICGC shall have  obtained,  and maintained for a
     continuous  period of not less  than  eighteen  (18)  months  (without  any
     "CreditWatch" or downgrade  consideration),  a rating of its unsecured debt
     of BBB- or better from S&P or Baa3 or better from Moody's,  and a rating of
     its  unsecured  debt of BBB- or better from Duff & Phelps Credit Rating Co.
     ("Duff");

provided  that,  as of the date Tenant would be entitled to such  reduction,  no
Event of Default has occurred and is continuing. Upon the occurrence of any such
reduction,  Landlord  shall  deliver to Tenant  from the Draw  Account an amount
equal to the excess (if any) of the funds then held in the Draw Account over the
adjusted Security Amount becoming effective upon such reduction. If the Security
Amount is less than five million  dollars  ($5,000,000),  this  section  24.7(a)
shall have no effect.

     (b) Tenant's  obligations  pursuant to this Article 24 to provide  security
shall terminate,  and Landlord shall return to Tenant all funds remaining in the
Draw  Account  at  any  time  that  Tenant   delivers  to  Landlord   reasonably
satisfactory evidence that:

          (i) either Tenant or ICGC shall have  obtained,  and  maintained for a
     continuous  period of not less  than  eighteen  (18)  months  (without  any
     "CreditWatch" or downgrade consideration), ratings of its unsecured debt of
     BBB or better from S&P and Baa2 or better from Moody's; or

                                       41


          (ii) either Tenant or ICGC shall have  obtained,  and maintained for a
     continuous  period of not less than  twenty-four  (24) months  (without any
     "CreditWatch" or downgrade consideration), ratings of its unsecured debt of
     BBB- or better from S&P and Baa3 or better from Moody's; or

          (iii) either Tenant or ICGC shall have obtained,  and maintained for a
     continuous  period  of not  less  than  thirty  (30)  months  (without  any
     "CreditWatch" or downgrade  consideration),  a rating of its unsecured debt
     of BBB- or better from S&P or Baa3 or better from Moody's,  and a rating of
     its  unsecured  debt of BBB- or better from Duff & Phelps Credit Rating Co.
     ("Duff");

provided that, as of the time that Tenant  delivers to Landlord such evidence of
such ratings, no Event of Default has occurred and is continuing.

     24.8 Upon the  expiration  or sooner  termination  of this Lease,  Landlord
shall return to Tenant any funds  remaining in the Draw  Account,  provided that
Landlord  shall  have the  right to  retain  in the Draw  Account  (and  draw in
accordance with this Article 24) an amount which Landlord reasonably  determines
to be equal to the  damages  Landlord  has  suffered  arising  from any  uncured
default by Tenant.

     24.9 So long as no Event of Default has occurred and is continuing,  Tenant
shall have the right to provide Landlord,  in lieu of the security  described in
this Article 24, an  irrevocable  standby  letter of credit in the amount of the
Security Amount, in form and substance  satisfactory to Landlord and issued by a
bank satisfactory to Landlord (a "Letter of Credit"). In the event Tenant elects
to so provide a Letter of Credit,  Landlord and Tenant  shall  negotiate in good
faith an  amendment  to this Lease to set forth the rights  and  obligations  of
Landlord  and Tenant  with  respect to the Letter of Credit,  the terms of which
amendment  shall  provide  Landlord  with  comparable  security,  in  Landlord's
reasonable judgment, to that provided pursuant to this Article 24.

                                       42



                                   ARTICLE 25

                                  Miscellaneous

     25.1 The words  "Landlord"  and "Tenant" as used herein  shall  include the
plural as well as the singular.  The words "include," "includes" and "including"
shall be deemed to be followed by the phrase "without  limitation." Tenant shall
indemnify  and defend  Landlord  against  and hold  Landlord  harmless  from all
claims, demands,  liabilities,  damages,  losses, costs and expenses,  including
reasonable  attorneys' fees and disbursements,  arising out of or resulting from
any failure by Tenant to perform any of its  obligations or any breach by Tenant
of any of its  representations  or warranties in accordance  with this Lease. If
there is more than one Tenant,  the  obligations  hereunder  imposed upon Tenant
shall be joint and  several.  Time is of the  essence of this Lease and each and
all  of its  provisions.  Submission  of  this  instrument  for  examination  or
signature by Tenant does not  constitute a  reservation  of or option for lease,
and it is not effective as a lease or otherwise  until execution and delivery by
both  Landlord and Tenant.  Subject to Article 12, this Lease shall  benefit and
bind Landlord and Tenant and the personal representatives, heirs, successors and
assigns of Landlord and Tenant.  If any provision of this Lease is determined to
be  illegal  or  unenforceable,  such  determination  shall not affect any other
provision of this Lease and all such other provisions shall remain in full force
and effect. This Lease shall be governed by and construed in accordance with the
laws of the state where the Premises are located.

     25.2 If there is any legal action or proceeding between Landlord and Tenant
to enforce this Lease or to protect or establish  any right or remedy under this
Lease,  the  unsuccessful  party to such action or  proceeding  shall pay to the
prevailing party all costs and expenses,  including  reasonable  attorneys' fees
and  disbursements,  incurred  by  such  prevailing  party  in  such  action  or
proceeding and in any appeal in connection  therewith.  If such prevailing party
recovers a judgment  in any such  action,  proceeding  or  appeal,  such  costs,
expenses and  attorneys'  fees and  disbursements  shall be included in and as a
part of such judgment.

     25.3 The  exhibits  and  addenda,  if any,  specified  in the  Basic  Lease
Information are attached to and made a part of this Lease.

     25.4 Tenant  warrants and  represents  to Landlord  that Tenant and has not
authorized or employed,  or acted by implication to authorize or to employ,  any
real estate broker or salesman to act for Tenant in connection with this Lease.

     25.5  Tenant  and each  person  executing  this  Lease on  behalf of Tenant
represents  and  warrants to  Landlord  that (a) Tenant is a  corporation,  duly
organized  and validly  existing  under the laws of the State of  Colorado,  (b)
Tenant is  qualified  to do business in the state where the Premises is located,
(c) Tenant has full right,  power and  authority to enter into this Lease and to
perform all of Tenant's obligations hereunder,  and (d) each person signing this
Lease on behalf of Tenant is duly and validly authorized to do so.

                                       43


     25.6 There are no oral  agreements  between  Landlord and Tenant  affecting
this  Lease,  and  this  Lease  supersedes  and  cancels  any and  all  previous
negotiations,  arrangements,  brochures,  offers, agreements and understandings,
oral or written, if any, between Landlord and Tenant or displayed by Landlord to
Tenant with respect to the subject  matter of this Lease or the Premises.  There
are no  representations  between  Landlord and Tenant or between any real estate
broker and Tenant  other  than those  expressly  set forth in this Lease and all
reliance  with  respect to any  representations  is solely upon  representations
expressly set forth in this Lease.  This Lease may not be amended or modified in
any respect whatsoever except by an instrument in writing signed by Landlord and
Tenant.


                                   ARTICLE 26

                          Option to Expand the Building

     26.1(a)  Upon and subject to the terms and  conditions  of this Article 26,
Landlord hereby grants to Tenant the right and option (the  "Expansion  Option")
(i) to request that Landlord  construct the Expansion  Improvements  (as defined
below)  and lease the  Expansion  Improvements  to  Tenant  in  accordance  with
sections  26.2 and 26.4,  or (ii) to request that Landlord  purchase  from,  and
lease back to, Tenant the  Expansion  Improvements  upon  Tenant's  construction
thereof in accordance with sections 26.3 and 26.4, or (iii) if Landlord declines
to  construct  or  purchase  from  Tenant  the  Expansion  Improvements,  to (A)
subdivide  the  Premises  and  purchase the portion of the Premises on which the
Expansion  Improvements  are  to be  constructed  and  construct  the  Expansion
Improvements  itself in  accordance  with section  26.5,  or (B)  construct  the
Expansion  Premises itself as a leasehold  improvement  without  subdividing the
Premises in accordance with section 26.6.

     (b) The additional  improvements to be constructed if the Expansion  Option
is exercised (the "Expansion  Improvements")  shall (i) be one or more buildings
separate from the existing  Building,  of design,  nature and type substantially
similar  to the  existing  Building,  and (ii) be of a size and be  located  and
configured  per the  location and  configuration  of "Phase 2" shown in the Site
Plan  attached  hereto as  Exhibit  C,  unless  at the  request  of the  Tenant,
Landlord, in its sole and absolute discretion, shall agree to construct or allow
Tenant to construct  Expansion  Improvements  of a different  design,  nature or
type.  Landlord  shall  have the  right,  but not the  obligation,  to provide a
proposal to construct the Expansion Improvements.

                                       44


     (c) The  Expansion  Option  shall be  exercised  by Tenant,  if at all,  by
written  notice  thereof (an  "Expansion  Notice") to Landlord given not earlier
than the  Commencement  Date and not later than the tenth (10th)  anniversary of
the Commencement Date (the "Exercise Period").  The Expansion Notice may propose
either one or two buildings and shall be accompanied  by preliminary  conceptual
plans and specifications for the Expansion  Improvements  ("Preliminary Plans").
The Expansion  Notice shall specify whether Tenant (i) proposes to construct the
Expansion Improvements itself and requests that Landlord purchase and lease back
the Expansion  Improvements  in accordance  with sections 26.3 and 26.4, or (ii)
requests that Landlord  construct the Expansion  Improvements  and lease them to
Tenant in accordance  with sections 26.2 and 26.4.  The Expansion  Option may be
exercised  from time to time,  each  exercise  relating  to a single  additional
building.  No purported  exercise of the Expansion Option which fails to satisfy
the  conditions  set forth in section 26.7 and no valid  exercise which is later
rescinded  shall impair  Tenant's  right  thereafter  to exercise the  Expansion
Option during the Exercise  Period.  As of the end of the Exercise  Period,  the
Expansion  Option shall lapse and be of no further  force and effect,  except to
the extent theretofore exercised. Time is of the essence of this provision.

     26.2  If  the  Expansion  Notice  requests  that  Landlord  constructs  the
Expansion  Improvements,  then not later than sixty (60) days after  delivery of
the Expansion Notice, Landlord shall notify Tenant if it elects not to construct
the  Expansion   Improvements  (which  election  shall  be  in  Landlord's  sole
discretion),  or, in the event  Landlord  proposes to  construct  the  Expansion
Improvements,  Landlord  shall  submit  to Tenant a notice  (the  "Specification
Notice") which notice shall contain  Landlord's  best good faith estimate of (a)
the total costs (hard and soft) of constructing the Expansion Improvements,  (b)
the  projected  date for  completion  and  delivery  to Tenant of the  Expansion
Improvements,  and (c) the projected  Expansion Base Rent.  Tenant may elect, by
written notice to Landlord within sixty (60) days following  Tenant's receipt of
the Specification Notice, either to accept the terms of the Specification Notice
or to rescind its exercise of the Expansion  Option. In the event Landlord shall
have  notified  Tenant  that  Landlord  elects not to  construct  the  Expansion
Improvements,  then Tenant may elect, by written notice to Landlord within sixty
(60) days following Tenant's receipt of Landlord's notice, to either (i) rescind
its exercise of the Expansion  Option,  (ii) exercise the right (the  "Leasehold
Improvement Option") to construct the Expansion  Improvements on the Premises at
its sole cost in accordance  with section 26.6, or (iii) exercise the right (the
"Tenant  Subdivision  Option") to cause the Premises to be subdivided  such that
the site on which the proposed Expansion Improvements are to be constructed (the
"Expansion  Site") is a separate legal parcel in compliance  with all applicable
laws,  codes,  ordinances and regulations  and with the  requirements of section
26.5 and to  purchase  the  Expansion  Site  from  Landlord  and  construct  the
Expansion  Improvements  itself, all in accordance with section 26.5;  provided,
however,  that if Tenant elects to either  rescind the exercise of the Expansion
Option or to exercise the Tenant Subdivision Option or the Leasehold Improvement
Option,  Tenant shall pay to Landlord as additional rent an amount equal to 150%
of Landlord's out-of-pocket costs incurred to third parties (including,  without
limitation,  architects,  engineers and other design professionals) in preparing
the Specification  Notice, and Tenant shall, upon payment, be entitled to copies
of all plans,  specifications  and designs.  Tenant's failure to timely exercise
the Tenant  Subdivision  Option or the  Leasehold  Improvement  Option  shall be
conclusively  deemed to constitute a rescission of the exercise of the Expansion
Option. Time is of the essence of this provision.

                                       45


     26.3 If the Expansion Notice proposes that Tenant  constructs the Expansion
Improvements  and requests  that Landlord  purchase the Expansion  Improvements,
then not later  than sixty (60) days after  delivery  of the  Expansion  Notice,
Landlord  shall notify Tenant whether or not it elects to purchase the Expansion
Improvements  (which election shall be in Landlord's sole  discretion),  and the
provisions of subsection (a) or (b) of this section 26.3, as  applicable,  shall
apply.

     (a) In the event Landlord shall have notified  Tenant that Landlord  elects
to purchase the Expansion  Improvements  (the  "Purchase  Notice"),  then Tenant
shall undertake construction of the Expansion Improvements ("Tenant's Work") and
the provisions of section  26.3(a)(i) through  26.3(a)(ix)  hereinbelow shall be
applicable.

          (i) Tenant shall cause to be constructed the Expansion Improvements in
     accordance   with  all  applicable   laws  and  the  procedures  set  forth
     hereinbelow.  Upon the  Expansion  Rent  Commencement  Date (as  defined in
     section  26.4(a)),  Landlord  shall  purchase  and  Tenant  shall  sell the
     Expansion  Improvements  for a net price equal to Tenant's  Expansion Costs
     (as defined  below),  and Tenant shall execute and deliver to Landlord such
     documents and instruments as Landlord may reasonably  request in connection
     with such purchase and sale. The term "Tenant's  Expansion Costs" means all
     hard and soft  costs  incurred  by Tenant  (but  excluding  land  costs) in
     connection with the design and construction of the Expansion  Improvements,
     as said term may be further defined in the Lease Amendment described below.
     Tenant shall pay all closing  costs in  connection  with such  purchase and
     sale,  including the premium for an endorsement to Landlord's  title policy
     to increase  the  liability  amount to reflect  the price of the  Expansion
     Improvements.  From and after the Expansion Rent  Commencement Date and for
     the remainder of the term (as the same may be extended  pursuant to section
     26.4(c)),  Tenant pay Expansion  Base Rent (as defined in section  26.4(a))
     for the Expansion Improvements;  the Expansion Improvements shall be deemed
     to be a part of the Premises hereunder;  and Tenant shall pay all Operating
     Expenses for the Expansion  Improvements as set forth in section 3.1(b) and
     shall  perform all other  obligations  of Tenant under this Lease as if the
     Expansion   Improvements  were  part  of  the  original  Premises.  At  the
     conclusion of this Lease, the Expansion  Improvements shall be delivered to
     Landlord in good condition  (reasonable  wear and tear excepted).  Title to
     the  Expansion  Improvements  shall,  at all  times,  remain in the name of
     Landlord and shall not pass to Tenant.

                                       46


          (ii) On or before ten (10) days from the date of the Purchase  Notice,
     Tenant  shall notify  Landlord of the  identity and mailing  address of the
     licensed  architect  engaged  by Tenant  for the  preparation  of plans for
     Tenant's  Work.  On or  before  forty-five  (45)  days from the date of the
     Purchase  Notice,   Tenant,  at  Tenant's  expense,  shall  cause  Tenant's
     architect  to prepare  and deliver to Landlord  for  Landlord's  reasonable
     approval five (5) sets of final plans and specifications for Tenant's Work.

          (iii) Landlord shall review said plans and  specifications  and notify
     Tenant within fifteen (15) days of receipt of said plans and specifications
     in Landlord's  office, of the matters,  if any, in said plans which fail to
     conform to Landlord's  construction  requirements or otherwise fail to meet
     with Landlord's approval which approval shall not be unreasonably withheld,
     conditioned or delayed.  Tenant shall, within ten (10) days from receipt of
     any such  notice  from  Landlord,  cause  said  plans to be revised in such
     manner as is requisite to  obtaining  Landlord's  approval and shall submit
     revised plans for Landlord's approval.  When Landlord has approved Tenant's
     plans,  Landlord  shall initial and return one (1) set of approved plans to
     Tenant, which set shall also show the date of Landlord's approval. Tenant's
     Work  shall be  carried  out  pursuant  to a fixed  price or  not-to-exceed
     construction  contract in form and  substance  reasonably  satisfactory  to
     Landlord,  and  with  a  licensed  contractor  reasonably  satisfactory  to
     Landlord.  Landlord  shall have the right to  require  that  Tenant  obtain
     payment and  completion  bonds on terms  satisfactory  to Landlord prior to
     commencing Tenant's Work. Tenant agrees not to commence Tenant's Work until
     Landlord has approved the final plans,  the contractor and the construction
     contract,  all  required  permits  have been issued and this Lease has been
     amended in accordance with section 26.8.  Tenant shall  reimburse  Landlord
     for actual costs expended for review of all plans.

          (iv)  Tenant  shall  not  deviate  from the  final  set of  plans  and
     specifications  approved  by  Landlord  without  Landlord's  prior  written
     consent,  which  consent  shall not be  unreasonably  withheld.  Landlord's
     approval of plans and specifications shall not constitute the assumption of
     any  responsibility by Landlord for any of Tenant's Work or the accuracy or
     sufficiency of Tenant's plans and specifications.

          (v) If Tenant fails to complete the Tenant's Work in  accordance  with
     such  plans  and  specifications  prior to the  Construction  Deadline  (as
     defined below),  Landlord,  at Landlord's  option, may terminate this Lease
     or, at Landlord's  option, may enter the Expansion  Improvements,  complete
     Tenant's  Work,  and Tenant  shall pay the cost  thereof to  Landlord  upon
     demand.  The term  "Construction  Deadline"  means the date  eighteen  (18)
     months after  commencement  of  construction,  plus the number of days that
     construction is delayed due to Force Majeure; provided that such date shall
     be extended an additional six (6) months so long as Tenant is  continuously
     and diligently proceeding with construction.

                                       47


          (vi) Tenant shall  comply with and shall  require its  contractors  to
     comply with all federal, state, and local laws, ordinances, regulations and
     directions  relating to the employment,  conditions of employment and hours
     of labor in connection with any construction,  alteration,  installation or
     repair work done by or for Tenant in or about the Premises.  If Landlord is
     damaged  as a result of any  breach by  Tenant of these  covenants,  Tenant
     shall pay to Landlord the amount of such damage, upon demand.

          (vii) Upon completion of  construction of the Expansion  Improvements,
     Tenant shall submit:

               (A)  Properly  notarized  final  releases of liens from  Tenant's
          general contractor and all subcontractors.

               (B)  Properly  notarized  final  releases of liens from  Tenant's
          major suppliers, architect or anyone supplying a significant amount of
          materials  or  services  for  the   construction   of  the   Expansion
          Improvements.

               (C) A certificate of occupancy and a final inspection  report (as
          applicable) from the appropriate  governing body,  indicating that the
          Expansion Improvements has no violation of local building codes.

          (viii) At all times prior to the completion of Tenant's  Work,  Tenant
     shall cause its general  contractor  and  subcontractors  to maintain  such
     insurance as Landlord  may  reasonably  require,  with  insurance  carriers
     reasonably  approved  by  Landlord,   in  amounts  reasonably  approved  by
     Landlord.

          (ix)  Tenant's  Work  shall  be  completed,  lien-free  in a good  and
     workmanlike  manner,  and shall constitute Class A office space constructed
     to the same  standards as the existing  Building.  Tenant  hereby agrees to
     indemnify,  defend and hold Landlord harmless from any and all liens and/or
     claims placed against the Premises,  arising out of, or in connection with,
     Tenant's Work; and  notwithstanding  anything to the contrary  contained in
     this Lease, no liens of any nature,  whether voluntary or involuntary,  may
     be placed or allowed by Tenant on the  Premises.  However,  Tenant may bond
     around any mechanic's  liens within thirty (30) days of recording,  without
     an Event of Default  occurring.  Landlord  shall have no  liability  of any
     kind,  and Tenant  shall be solely  responsible,  for any  defects or legal
     violations respecting the Expansion  Improvements.  Tenant hereby agrees to
     indemnify,  defend and hold  Landlord  harmless from any and all claims and
     liabilities  of any kind,  howsoever  arising,  relating  to the  Expansion
     Improvements and Tenant shall execute an indemnity, reasonably satisfactory
     to Landlord in form and content, prior to commencement of Tenant's Work.

                                       48


     (b) In the event Landlord shall have notified  Tenant that Landlord  elects
not to purchase the Expansion  Improvements,  then Tenant may elect,  by written
notice  to  Landlord  within  sixty  (60) days  following  Tenant's  receipt  of
Landlord's  notice,  to either (i) rescind its exercise of the Expansion Option,
(ii) exercise the Leasehold  Improvement  Option,  or (iii)  exercise the Tenant
Subdivision  Option.  Tenant's failure to timely exercise the Tenant Subdivision
Option or the  Leasehold  Improvement  Option  shall be  conclusively  deemed to
constitute a rescission of the exercise of the Expansion Option.  Time is of the
essence of this provision.

     26.4(a)  Base  Rent  for  the  Expansion   Improvements  if  the  Expansion
Improvements are constructed by Landlord or if Landlord  purchases the Expansion
Improvements  in  accordance  with  section  26.3(a)  ("Expansion  Base  Rent"),
calculated  as provided in section  26.4(b),  shall  commence upon the date (the
"Expansion Rent Commencement Date") the Expansion Improvements are substantially
completed, subject only to "punch list" items and other items of incomplete work
that do not  materially  interfere  with the use and  occupancy of the Expansion
Improvements (as certified to Landlord and Tenant by the supervising  architect,
or, as evidenced by the  issuance of a temporary  or  permanent  certificate  of
occupancy), and delivered to Tenant for Tenant's occupancy.  Expansion Base Rent
shall be  included  in "Base  Rent" for  purposes  of this  Lease,  and shall be
payable  concurrently  with  payments  of Base  Rent  hereunder  as set forth in
Article 3 of this Lease.  From and after the Expansion Rent  Commencement  Date,
the  Expansion  Improvements  shall  be  deemed  to be a part  of  the  Premises
hereunder,  and in  addition  to  Expansion  Base  Rent,  Tenant  shall  pay all
Operating Expenses for the Expansion Improvements as set forth in section 3.1(b)
and shall  perform all other  obligations  of Tenant  under this Lease as if the
Expansion Improvements were part of the original Premises.

     (b) If  the  Expansion  Improvements  are  constructed  by  Landlord  or if
Landlord  purchases  the  Expansion  Improvements  in  accordance  with  section
26.3(a),  Expansion  Base Rent shall be: (i) for the first  twelve  (12)  months
after the Expansion  Rent  Commencement  Date,  an amount  calculated to provide
Landlord with an annual return on Landlord's investment of Total Expansion Costs
(as defined below) equal to the Rent Yield (as defined below), and (ii) for each
successive twelve (12) month period  thereafter,  an amount equal to one hundred
three percent  (103%) of the Expansion  Base Rent in effect during the preceding
12-month period.  The term "Total Expansion Costs" means all hard and soft costs
incurred by Landlord (including a reasonable development fee payable to Landlord


                                       49


and financing  charges,  but excluding land costs) in connection with the design
and  construction  of the  Expansion  Improvements,  as said term may be further
defined in the Lease Amendment  described below. In the event Landlord purchases
the Expansion Improvements in accordance with section 26.3(a),  "Total Expansion
Costs"  shall mean  Tenant's  Expansion  Costs.  The term "Rent  Yield"  means a
percentage  equal to Landlord's  Spread (as defined below) plus the Assumed Loan
Constant (as defined below).  The term  "Landlord's  Spread" means (x) if, as of
the  Expansion  Rent  Commencement  Date,  Tenant shall have  satisfied the debt
rating conditions set forth in section 24.7, seventy-five (75) basis points; and
(y) if,  as of the  Expansion  Rent  Commencement  Date,  Tenant  shall not have
satisfied  the debt rating  conditions  set forth in section  24.7,  one hundred
twenty-five  (125)  basis  points.  The term  "Assumed  Loan  Constant"  means a
percentage equal to the percentage of Total Expansion Costs which Landlord would
be required to pay  annually  as debt  service on a secured  loan in a principal
amount equal to Total  Expansion  Costs,  with  amortization of principal over a
term which ends five (5) years  after the term of this Lease (as the same may be
extended  pursuant to section  26.4(c)) and interest at the then prevailing rate
(determined  with reference to loan terms being proposed by major life insurance
company  lenders  such as  Principal  Mutual,  Metropolitan  Life  and  Teachers
Insurance) for fully amortizing mortgage loans of like tenor secured by property
comparable to the Premises. Effective upon the Expansion Rent Commencement Date,
the Security  Amount  shall be  increased  by an amount equal to twenty  percent
(20%) of the Total Expansion Costs,  provided that the Security Amount shall not
be required  to exceed ten million  dollars  ($10,000,000).  Effective  upon the
Expansion Rent Commencement  Date, section 24.6 shall be amended to provide that
the first Reduction Date shall occur on the fourth (4th) April 15 to occur after
the Expansion Rent Commencement Date, and subsequent Reduction Dates shall occur
annually  thereafter  (but the Reduction  Amounts  applicable on the  successive
Reduction Dates shall remain as set forth in section 24.6).

     (c) In the event the  Expansion  Commencement  Date  occurs  later than the
third (3rd)  anniversary of the Commencement  Date, the term of this Lease shall
automatically be extended such that the Expiration Date shall be the date twelve
(12) years after the  Expansion  Commencement  Date.  If Landlord  constructs or
purchases the Expansion  Improvements,  Base Rent for the extended term shall be
calculated  in accordance  with section 3.1 based upon the Base Rent  (including
Expansion Base Rent).

     26.5 In the event that Landlord elects not to undertake construction of the
Expansion  Improvements  or elects not to purchase  the  Expansion  Improvements
pursuant to section 26.3(a),  and Tenant exercises the Tenant Subdivision Option
and elects to undertake  construction of the Expansion  Improvements  ("Tenant's
Work"),  the provisions of section 26.5(a) through 26.5(f)  hereinbelow shall be
applicable.

                                       50


     (a) Tenant shall,  at its sole cost and expense and upon and subject to the
terms of this section 26.5 and the other  applicable  provisions of this Article
26, (i) cause the  Premises to be  subdivided  so that the  Expansion  Site is a
separate legal parcel, (ii) purchase the Expansion Site from Landlord, and (iii)
cause to be  constructed  the  Expansion  Improvements  in  accordance  with all
applicable laws and the procedures set forth  hereinbelow.  For the remainder of
the term of this Lease, the Expansion Site and the Expansion  Improvements shall
not be a part of the Premises hereunder.

     (b) On or before  forty-five (45) days after the date of Tenant's  exercise
of the Tenant Subdivision Option, Tenant, at Tenant's expense, shall (i) cause a
registered  surveyor  or civil  engineer  to prepare  and  deliver to Landlord a
proposed  subdivision  map (the "Proposed  Subdivision  Map"),  complying in all
respects with all laws, statutes, codes and ordinances,  to legally separate the
Expansion Site and the remainder of the Premises (the  "Remaining  Parcel") such
that each parcel complies with all applicable laws, statutes,  codes, ordinances
and covenants,  conditions and restrictions  ("Legal  Requirements"),  and (iii)
cause  Tenant's  architect  to prepare and deliver to  Landlord  for  Landlord's
approval  five (5) sets of final  plans and  specifications  for  Tenant's  Work
including a detailed depiction of all proposed improvements (the "Final Plans").
The Proposed  Subdivision  Map shall be subject to  Landlord's  approval,  which
shall not be unreasonably withheld. Without limiting the foregoing, Landlord may
disapprove  the Proposed  Subdivision  Map if (A) Landlord  would be required to
expend any sums to improve the Remaining  Parcel to cause it to be in compliance
with any Legal  Requirements,  (B) the  Remaining  Parcel  would,  in Landlord's
reasonable  judgment,  be of less value than the value prior to the  subdivision
minus  the  Site  Price  (as  defined  below),  or (C) the  expense  of  owning,
operating,  managing or maintaining  the Remaining  Parcel would be increased by
the subdivision.  Landlord shall review the Proposed  Subdivision Map and notify
Tenant within fifteen (15) days of receipt of the matters, if any, which fail to
conform to Landlord's reasonable requirements.

     (c) Landlord  shall review the Final Plans and notify Tenant within fifteen
(15) days of receipt of said plans and  specifications in Landlord's  office, of
the matters,  if any, in said plans which fail to meet with Landlord's  approval
which  approval  shall not be  unreasonably  withheld,  conditioned  or delayed.
Tenant  shall,  within  ten (10)  days  from  receipt  of any such  notice  from
Landlord, cause the Proposed Subdivision Map and/or the Final Plans, as the case
may be, to be revised in such manner as is  requisite  to  obtaining  Landlord's
approval and shall submit a revised Proposed  Subdivision Map and/or Final Plans
for Landlord's approval. The Proposed Subdivision Map as approved by Landlord is
referred  to  herein  as  the  "Subdivision  Map."  As  promptly  as  reasonably
practicable  after  Landlord's  approval  of the  Subdivision  Map and the Final
Plans,  Tenant shall cause the Subdivision Map to be recorded and shall take all
other steps necessary to cause the Premises to be subdivided.  Tenant agrees not
to commence  Tenant's Work until Landlord has approved the  Subdivision  Map and
the Final Plans, the Premises has been legally subdivided in accordance with the
approved  Subdivision Map, Tenant has purchased the Expansion Site in accordance
with this section 26.5, all required permits have been issued and this Lease has
been amended in accordance with section 26.8.  Tenant shall  reimburse  Landlord
for actual  costs  expended  for review of all maps and plans.  Tenant shall not
materially  deviate from the Final Plans approved by Landlord without Landlord's
prior written  consent,  which shall not be  unreasonably  withheld.  Landlord's
approval of plans and specifications  shall not constitute the assumption of any
responsibility  by  Landlord  for  any  of  Tenant's  Work  or the  accuracy  or
sufficiency of Tenant's plans and specifications.

                                       51


     (d) Immediately  upon  recordation of the Subdivision Map and completion of
all  procedures  necessary  to legally  subdivide  the  Premises,  Tenant  shall
purchase the Expansion Site from Landlord for a price (the "Site Price"), net to
Landlord,  equal to the  product of (i) the number of gross  square feet of land
area in the Expansion Site, multiplied by (ii) the Square Foot Price (as defined
below) in effect as of the date of the sale.  The term "Square Foot Price" means
(A) during the twelve (12) month period  commencing  on the  Commencement  Date,
seven and one-half  dollars ($7.50) (the "Initial  Price"),  and (B) during each
successive twelve (12) month period, the Initial Price increased by five percent
(5%) per year on a compounded  basis.  Tenant shall bear all costs and expenses,
and shall reimburse Landlord for all costs and expenses incurred by Landlord, in
connection with such purchase, including the subdivision of the Premises and the
Lease  Amendment.  After  the  recordation  of  the  Subdivision  Map  and  upon
completion of the sale of the Expansion Site to Tenant,  Tenant shall be subject
to no further  restriction  on encumbrance of the Expansion Site with a mortgage
or deed of trust.

     (e) If Tenant fails to commence  construction  of Tenant's work within nine
(9) months  after  delivery of the  Expansion  Notice or fails to  complete  the
Tenant's  Work in  accordance  with the Final  Plans  prior to the  Construction
Deadline,  Landlord, at Landlord's option, may rescind the sale of the Expansion
Site in which case the sale of the Expansion Site shall be reversed (with Tenant
conveying  the  Expansion  Site to  Landlord  at a net  price  equal to the Site
Price), and Tenant shall be deemed to have elected not to exercise the Expansion
Option.

     (f) Landlord and Tenant  acknowledge  that the  subdivision of the Premises
and  construction  of the Expansion  Improvements  will require  modification of
and/or additions to the parking facilities on the Premises.  Landlord and Tenant
shall include in the Final Plans provisions for parking  facilities serving both
the existing Building and the Expansion  Improvements.  Such parking  facilities
shall be designed and constructed at Tenant's sole cost and expense. If adequate
parking  facilities are not constructed on each respective  parcel sufficient to
serve that  parcel and it is  necessary  or  appropriate  to  construct  parking
facilities  on one of the  parcels to provide  parking  for both  parcels,  then
Landlord and Tenant shall enter into an appropriate perpetual access and parking
easement simultaneously with Tenant's purchase of the Expansion Site.

                                       52


     26.6 In the event that Landlord elects not to undertake construction of the
Expansion  Improvements  or elects not to purchase  the  Expansion  Improvements
pursuant to section  26.3(a),  and Tenant  exercises the  Leasehold  Improvement
Option  and  elects to  undertake  construction  of the  Expansion  Improvements
("Tenant's Work"), the provisions of section 26.6(a) through 26.6(c) hereinbelow
shall be applicable.

     (a) Tenant shall cause to be  constructed  the  Expansion  Improvements  in
accordance  with all applicable  laws and the procedures set forth  hereinbelow.
Landlord  shall have no obligation to purchase the Expansion  Improvements,  and
Tenant shall,  for the remainder of the term, pay no Expansion Base Rent for the
Expansion  Improvements,  but the Expansion Improvements shall be deemed to be a
part of the Premises hereunder,  and Tenant shall pay all Operating Expenses for
the Expansion  Improvements as set forth in section 3.1(b) and shall perform all
other  obligations  of Tenant under this Lease as if the Expansion  Improvements
were  part of the  original  Premises.  At the  conclusion  of this  Lease,  the
Expansion  Improvements  shall  be  delivered  to  Landlord  in  good  condition
(reasonable wear and tear excepted).  Title to the Expansion Improvements shall,
at all  times,  remain in the name of  Landlord  and  shall not pass to  Tenant.
Landlord  shall  have no  liability  of any  kind,  and  Tenant  shall be solely
responsible,  for any  defects  or legal  violations  respecting  the  Expansion
Improvements in the event Tenant performs Tenant's Work. Tenant hereby agrees to
indemnify,  defend  and  hold  Landlord  harmless  from any and all  claims  and
liabilities  of  any  kind,   howsoever  arising,   relating  to  the  Expansion
Improvements and Tenant shall execute an indemnity,  reasonably  satisfactory to
Landlord in form and content, prior to commencement of Tenant's Work.

     (b) The design and  construction  of the  Expansion  Improvements  shall be
carried  out in  accordance  with the  terms  of  sections  26.3(a)(ii)  through
26.3(a)(ix),  all of which shall be applicable to Tenant's Work pursuant to this
section 26.6.

     (c)  Notwithstanding  that  Tenant  may  pay for  the  construction  of the
Expansion Improvements, if an Event of Default occurs, Landlord shall retain all
rights in law and equity against  Tenant,  including,  without  limitation,  the
right to dispossess Tenant from the Expansion  Improvements without compensation
for the cost thereof.

     26.7 Anything in this Article 26 to the contrary notwithstanding,  Tenant's
notice of exercise of the Expansion Option or the Tenant  Subdivision  Option or
the Leasehold Improvement Option shall be effective, only if at the time of such
notice of exercise the following  conditions (the "Expansion  Conditions") shall
be satisfied:

          (i) Landlord shall not have notified  Tenant that Tenant is in default
     in the performance of any of the terms,  covenants or conditions  contained
     in this Lease which default has not been cured within any applicable  grace
     period or cure period.

                                       53


          (ii) This Lease  shall not have been  terminated  and shall be in full
     force and effect.

          (iii) There shall have been no assignment of Tenant's interest in this
     Lease except to a Corporate  Successor as permitted by section 12.1 hereof.
     Tenant  acknowledges  that the  Expansion  Option  and all other  rights of
     Tenant under this Article 26 are personal to Tenant, and not a right of any
     successor to the rights of Tenant under this Lease.

          (iv) There shall have been no material adverse change in the financial
     condition of Tenant or the Guarantor since the execution of this Lease, and
     Landlord shall determine,  at its sole reasonable  discretion,  that Tenant
     and Guarantor are each creditworthy in light of the obligations  undertaken
     pursuant  to this Lease and the other  existing  obligations  of Tenant and
     Guarantor.

     26.8 Notwithstanding anything to the contrary herein, promptly after Tenant
accepts the proposal in Landlord's  Specification  Notice, or Landlord elects to
purchase  the  Expansion  Improvements  pursuant to section  26.3(a),  or Tenant
exercises the Tenant Subdivision Option or the Leasehold  Improvement Option, as
the case may be, Landlord and Tenant shall enter into an amendment to this Lease
(the "Lease  Amendment")  setting  forth the terms of the expanded  lease or the
terms relating to Tenant's  Subdivision Option or Leasehold  Improvement Option,
in form and substance  mutually  agreeable to Landlord and Tenant which shall be
consistent with the applicable terms of this Article 26.

     IN WITNESS WHEREOF,  Landlord and Tenant have executed this Lease as of the
date first hereinabove written.

Landlord:                                Tenant:

TRINET ESSENTIAL FACILITIES X, INC.,     ICG HOLDINGS, INC.,
a Maryland corporation                   a Colorado corporation


By  /s/Gary P. Lyon                     By /s/ James D. Grenfell
   -----------------------------           ---------------------------
     Gary P. Lyon                            James D. Grenfell  

   Its Executive Vice President           Its Executive Vice President
                                              and Chief Financial Officer


                                       1


                                    EXHIBIT A

                           TENANT ESTOPPEL CERTIFICATE


TO:  TriNet Corporate Realty Trust, Inc. Four Embarcadero Center, Suite 3150 San
     Francisco, CA 94111 Attn: Mr. Mark S. Whiting




     Re:  Lease,  dated as of January 15, 1998,  between ICG  HOLDINGS,  INC., a
          Colorado  corporation,  as tenant (the original named tenant under the
          Lease,  together  with such  tenant's  successors  and assigns,  being
          hereinafter  referred  to  as  the  "Tenant"),  and  TRINET  ESSENTIAL
          FACILITIES X, INC., a Maryland  corporation,  as landlord  ("TriNet"),
          covering  certain  premises  known by the street address 161 Inverness
          Drive West,  in the City of  Englewood,  County of Arapahoe,  State of
          Colorado  (the  "Leased  Premises"),  as amended as noted on  attached
          Schedule A (collectively, the "Lease")


Gentlemen:

     The undersigned Tenant hereby represents,  warrants and certifies to TriNet
that:

     1. The Lease has not been  modified,  changed,  altered  or  amended in any
respect,  either orally or in writing,  except as may be indicated on Schedule A
annexed hereto,  and constitutes the entire agreement  between Tenant and TriNet
affecting  Tenant's leasing of the Leased  Premises.  A true and correct copy of
the Lease is  attached  as Schedule B. The Lease is in full force and effect and
is not subject to any contingencies or conditions not set forth in the Lease.

     2. The term of the Lease  commenced on  __________________,  1998, and will
expire on  __________________,  2013;  Tenant has two (2) successive  options to
renew the Lease term, each for an additional period of ten (10) years.

     3. Tenant has paid all fixed and  additional  rent and other sums which are
due and payable under the Lease through the date hereof, and Tenant has not made
and will  not make any  prepayments  of fixed  rent for more  than one  month in
advance.  There are no presently  unexpired rental concessions or abatements due
under the Lease except as set forth on Schedule A annexed hereto.  Tenant has no
credits, offsets, abatements,  defenses, counterclaims or deductions against any
rental or other payments due under the Lease or with respect to its  performance
of the other  terms and  conditions  of the Lease,  and has  asserted  no claims
against TriNet.

                                       2


     4.  Tenant  has  paid  to  TriNet  a  security  deposit  in the  amount  of
$___________. Tenant has not made any other the payments to TriNet as a security
deposit, advance or prepaid rent.

     5. TriNet has completed,  and, if required  under the Lease,  paid for, any
and all tenant work required  under the Lease and Tenant has accepted the Leased
Premises.  Tenant is not  entitled to any  further  payment or credit for tenant
work.

     6. To the  best  knowledge  of  Tenant,  TriNet  is not in  default  in the
performance  of any of the  terms of the  Lease,  nor is  there  now any fact or
condition  which,  with  notice  or lapse of time or both,  will  become  such a
default.  Tenant has not  delivered to TriNet any notice of default with respect
to the TriNet's obligations under the Lease.

     7. Tenant is in actual possession of the entire Leased Premises and, to the
best  knowledge  of Tenant,  is not in any  respect in default  under any of the
terms and conditions of the Lease, nor is there now any fact or condition which,
with notice or lapse of time or both, will become such a default. Tenant has not
received from TriNet any notice of default with respect to Tenant's  obligations
under the Lease.

     8. Tenant has not assigned, transferred,  mortgaged or otherwise encumbered
its interest  under the Lease,  nor  subleased any of the Leased  Premises,  nor
permitted any person or entity to use the Leased  Premises,  except as otherwise
indicated on Schedule A annexed hereto.

     9. Except as expressly provided in the Lease, Tenant

          (i) does not have any right to renew or extend the term of the Lease,

          (ii) does not have any right to cancel or surrender the Lease prior to
     the expiration of the term of the Lease,

          (iii)  does not have any  option or rights of first  refusal  or first
     offer to  purchase  or lease all or any part of the Leased  Premises or the
     real property of which the Leased Premises are a part,

          (iv) does not have any right,  title or interest  with  respect to the
     Leased Premises other than as lessee under the Lease, and

          (v) does not have any right to relocate into other  property  owned by
     TriNet or any of TriNet's affiliates.

                                       3


     10. There has not been filed by or against Tenant a petition in bankruptcy,
voluntary  or  otherwise,  any  assignment  for the  benefit of  creditors,  any
petition seeking  reorganization or arrangement under the bankruptcy laws of the
United  States,  or any state  thereof,  or any other action  brought under said
bankruptcy laws with respect to Tenant.

     11. If Tenant is required to provide  insurance  coverage  under the Lease,
Tenant has not given or received written notice that Tenant  insurance  coverage
will be canceled or will not be renewed.

     12. To the best knowledge of Tenant,  all systems,  elements and components
of the Leased  Premises are in good working order and repair and sound operating
condition.  To the best  knowledge of Tenant,  Tenant's use and occupancy of the
Leased  Premises  complies  with all  applicable  building,  zoning,  land  use,
environmental,  anti-pollution,  health, fire, safety, access accommodations for
the physically  handicapped,  subdivision,  energy and resource conservation and
similar laws, statutes,  rules,  regulations and ordinances,  and all covenants,
conditions and restrictions  applicable to the Leased  Premises.  Tenant has not
received any notice,  citation or other claim alleging any violation of any such
law, statute, rule, regulation, ordinance, covenant, condition or restriction.

     13. To the best  knowledge  of Tenant,  any and all  brokerage  and leasing
commissions relating to and/or resulting from Tenant's execution and delivery of
the Lease and occupancy of the Leased Premises have been paid in full.

     14. The individual  executing this Tenant Estoppel Certificate on behalf of
Tenant  represents  and  warrants  that __he has the power and the  authority to
execute this Tenant Estoppel Certificate on behalf of Tenant.

     Dated this ____ day of _______________, 199_.

                                     Tenant

                                     ICG HOLDINGS, INC., a Colorado corporation



                                     By:

                                        Its:




                                       4


                                   SCHEDULE A

                             TO ESTOPPEL CERTIFICATE




                                       5





                                   SCHEDULE B

                             TO ESTOPPEL CERTIFICATE



                                       1


                                    EXHIBIT B

                            CONTINUING LEASE GUARANTY


     THIS GUARANTY, made as of ___________ __, ____, by  _______________________
("Guarantor")  to TriNet  Essential  Facilities X, Inc., a Maryland  corporation
("Landlord").

                              W I T N E S S E T H:

     1. For valuable  consideration,  receipt of which is  acknowledged,  and to
satisfy  certain  requirements  under  the Lease  dated  January  15,  1998 (the
"Lease")  between  Landlord  and ICG  Holdings,  Inc.,  a  Colorado  corporation
("Tenant"),   Guarantor  hereby  absolutely,   unconditionally  and  irrevocably
guarantees to Landlord,  and agrees fully to pay, perform and discharge,  as and
when  payment,  performance  and  discharge  are  due,  all  of  the  covenants,
obligations  and  liabilities  of Tenant  under  the  Lease and all  amendments,
modifications, renewals, extensions, supplements, substitutions and replacements
of the Lease arising  during the period  beginning on the date hereof and ending
on the date this  Guaranty is terminated  (the  "Guaranteed  Obligations").  The
obligations of Guarantor  under this Guaranty  shall be absolute,  unconditional
and irrevocable and shall continue and remain in full force and effect until all
of the Guaranteed Obligations have been fully paid, performed and discharged.

     2. The  obligations of Guarantor under this Guaranty shall not be affected,
modified or impaired by the occurrence of any of the following  events,  whether
or not with notice to, or the consent of, Guarantor: (a) the waiver,  surrender,
compromise,  settlement,  release or termination of any or all of the Guaranteed
Obligations; (b) the failure to give notice to Guarantor of the occurrence of an
event of default under the Guaranteed Obligations; (c) the extension of the time
for  the  payment,  performance  or  discharge  of any or all of the  Guaranteed
Obligations;  (d) the amendment or modification  (whether material or otherwise)
of the Guaranteed Obligations in any respect; (e) any failure,  omission,  delay
or lack on the part of Landlord to enforce,  assert or exercise any right, power
or remedy  conferred  on  Landlord  under the  Guaranteed  Obligations;  (f) the
voluntary or involuntary liquidation,  dissolution, sale or other disposition of
all or substantially  all of the assets,  marshalling of assets and liabilities,
receivership,  insolvency,  bankruptcy, assignment for the benefit of creditors,
reorganization,  arrangement, composition with creditors or adjustment of debts,
or other similar proceedings  affecting Tenant or Guarantor or any of the assets
of either of them;  (g) the release or  discharge  by operation of law of Tenant
from the  payment,  performance  or  discharge  of any or all of the  Guaranteed
Obligations;  (h) the release or discharge by operation of law of Guarantor from
any or all of the  obligations  of  Guarantor  under this  Guaranty;  or (i) the
invalidity  or  unenforceability  of any or all of the  Guaranteed  Obligations.
Guarantor acknowledges that Landlord would not enter into the Lease without this
Guaranty and that Landlord is relying on this Guaranty.

                                       2


     3. The  obligations of Guarantor under this Guaranty are independent of the
Guaranteed  Obligations.  Guarantor agrees that Landlord shall have the right to
proceed  against  Guarantor  directly and  independently  of Tenant.  A separate
action may be brought and prosecuted  against Guarantor whether or not an action
is  brought  against  Tenant or Tenant is joined in any such  action.  Guarantor
authorizes  Landlord and Tenant,  without  notice to, demand of, or consent from
Guarantor and without  releasing or affecting  Guarantor's  liability under this
Guaranty,  from time to time to amend,  modify,  renew,  extend,  supplement  or
replace  the  Guaranteed  Obligations  or  otherwise  change  the  terms  of the
Guaranteed   Obligations,   to  take  and  hold  security  for  the   Guaranteed
Obligations, and to enforce, waive, surrender, impair, compromise or release any
such  security  or any or all of the  Guaranteed  Obligations  or any  person or
entity liable for any or all of the Guaranteed  Obligations.  Guarantor shall be
and remain bound under this Guaranty notwithstanding any such act or omission by
Tenant or Landlord.  Guarantor  waives the right, if any, to require Landlord to
proceed  against  Tenant,  to proceed  against or exhaust any  security  held by
Landlord, or to pursue any other remedy in Landlord's power. Landlord shall have
the right to exercise or enforce any right or remedy  Landlord  may have against
Tenant or any security held by Landlord.  Guarantor waives the right, if any, to
the benefit of, or to direct the  application of, any security held by Landlord.
Guarantor  waives (a) any defense  arising out of any alteration of the original
Guaranteed Obligations,  (b) any defense arising out of the absence,  impairment
or loss of any right of reimbursement or subrogation or other right or remedy of
Guarantor  against Tenant or any security held by Landlord,  and (c) any defense
arising by reason of any  disability  or other defense of Tenant or by reason of
the cessation or reduction from any cause  whatsoever of the liability of Tenant
other  than  full  payment,   performance   and  discharge  of  the   Guaranteed
Obligations.  The  cessation  or  reduction  of the  liability of Tenant for any
reason  whatsoever  other than full  payment,  performance  and discharge of the
Guaranteed  Obligations  shall not release or affect in any way the liability of
Guarantor under this Guaranty.

     4. If  Tenant  becomes  insolvent  or is  adjudicated  bankrupt  or files a
petition for  reorganization,  arrangement,  composition or similar relief under
any present or future  provision of the federal  Bankruptcy  Code,  or if such a
petition is filed against  Tenant,  or if Tenant makes a general  assignment for
the  benefit  of  creditors,  and  in  any  such  proceeding  any  or all of the
Guaranteed  Obligations  are  terminated  or  rejected  or  any  or  all  of the
Guaranteed  Obligations  are modified or abrogated,  then Guarantor  agrees that
Guarantor's  liability  under this  Guaranty  shall not  thereby be  affected or
modified  and such  liability  shall  continue in full force and effect as if no
such action or proceeding  had  occurred.  This  Guaranty  shall  continue to be
effective or be reinstated, as the case may be, if any payment of the Guaranteed
Obligations  must be returned by Landlord  upon the  insolvency,  bankruptcy  or
reorganization of Tenant or Guarantor,  or otherwise, as though such payment had
not been made.

                                       3


     5. Guarantor  assumes the  responsibility  for being and keeping  Guarantor
informed of the  financial  condition  of Tenant and of all other  circumstances
bearing  upon  the risk of  failure  to pay,  perform  or  discharge  any of the
Guaranteed Obligations which diligent inquiry would reveal, and Guarantor agrees
that Landlord has no duty to advise  Guarantor of information  known to Landlord
regarding such condition or any such circumstance.  Guarantor  acknowledges that
repeated and  successive  demands may be made and payments or  performance  made
hereunder  in response to such  demands as and when,  from time to time,  Tenant
defaults in the payment, performance or discharge of the Guaranteed Obligations.
Notwithstanding any such payments and performance hereunder, this Guaranty shall
remain  in full  force and  effect  and  shall  apply to any and all  subsequent
defaults  by Tenant.  It is not  necessary  for  Landlord  to  inquire  into the
capacity,  authority or powers of Tenant or the partners,  directors,  officers,
employees,  agents or  representatives  acting or purporting to act on behalf of
Tenant,  and all of the Guaranteed  Obligations made or created in reliance upon
the purported exercise of such powers shall be guaranteed under this Guaranty.

     6. If Tenant and Guarantor fail to pay, perform and discharge,  as and when
payment,  performance and discharge are due, all of the Guaranteed  Obligations,
Landlord shall have the right, but no obligation,  and without  releasing Tenant
or  Guarantor  from  any of the  Guaranteed  Obligations,  to pay,  perform  and
discharge  any or all of the  Guaranteed  Obligations  on behalf  of Tenant  and
Guarantor.  Guarantor  shall,  on demand,  pay to Landlord all sums  expended by
Landlord  in  the  payment,   performance   and  discharge  of  the   Guaranteed
Obligations,  together  with  interest  on  all  such  sums  from  the  date  of
expenditure  to the date  all such  sums are  paid by  Tenant  or  Guarantor  to
Landlord at the Interest  Rate (as defined in the Lease).  Guarantor  waives all
presentments,  demands for  performance,  notices of  nonperformance,  protests,
notices of  protest,  notices of  dishonor  and  notices of  acceptance  of this
Guaranty.  Guarantor agrees to pay all costs and expenses,  including reasonable
attorneys'  fees and  disbursements,  which  are  incurred  by  Landlord  in the
enforcement  of this  Guaranty.  If any provision of this Guaranty is held to be
invalid or unenforceable, the validity or enforceability of the other provisions
of this Guaranty shall not be affected. If there is more than one Guarantor, all
obligations  of  Guarantor  under this  Guaranty  shall be the joint and several
obligations of each  Guarantor.  This Guaranty may not be amended or modified in
any respect except by a written instrument signed by Guarantor and Landlord.  As

                                       4


used in this  Guaranty,  the singular  shall  include the plural.  This Guaranty
shall  bind and  inure to the  benefit  of  Guarantor  and  Landlord  and  their
respective transferees, personal representatives, heirs, successors and assigns.
This Guaranty shall be governed by and construed in accordance  with the laws of
the  State  where the  premises  leased by Tenant  from  Landlord  are  located.
Guarantor hereby irrevocably  consents to the non-exclusive  jurisdiction of the
courts of the States of Colorado  and  California  and any federal  court of the
United States of America  located in the City of San Francisco,  California,  or
the city of Denver,  Colorado.  Guarantor  and Landlord  each waive any right to
trial by jury in connection  herewith.  Without limiting anything else contained
herein,  the  fullest  extent it may  effectively  do so under  applicable  law,
Guarantor  irrevocably  waives and agrees not to assert,  by way of motion, as a
defense or otherwise,  any claim that it is not subject to the  jurisdiction  of
any such court, any objection that it may now or hereafter have to the laying of
the venue of any such suit,  action or proceeding  brought in any such court and
any claim that any such suit, action or proceeding brought in any such court has
been brought in an inconvenient forum.

                                       5


     7. To induce  Landlord to enter into the Lease,  Guarantor  represents  and
warrants to Landlord as follows:  Guarantor is a corporation  existing under the
laws of the ________ of  _________.  Guarantor  has full power and  authority to
enter into this Guaranty and to perform its obligations under this Guaranty. The
execution, delivery and performance of this Guaranty by Guarantor have been duly
and validly  authorized by all necessary action on the part of Guarantor and all
required  consents and  approvals  have been duly  obtained.  This Guaranty is a
legal, valid and binding obligation of Guarantor,  enforceable against Guarantor
in accordance  with its terms,  subject to the effect of applicable  bankruptcy,
insolvency,  reorganization,  arrangement,  moratorium  or  other  similar  laws
affecting the rights of creditors generally.  Neither the execution and delivery
of this Guaranty nor the  consummation of the transactions  contemplated  hereby
will conflict with, or (with or without notice or lapse of time, or both) result
in a termination,  breach, impairment or violation of, or give rise to a default
under (i) any provision of Guarantor's articles of incorporation or bylaws, (ii)
any material  instrument  or contract to which  Guarantor is a party or by which
Guarantor is bound,  or (iii) any  federal,  state,  local or foreign  judgment,
writ, decree, order, statute, rule or regulation applicable to Guarantor, or any
property of Guarantor.

     IN WITNESS  WHEREOF,  Guarantor has executed this Continuing Lease Guaranty
as of the date first hereinabove written.

                                        Guarantor:

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                                    EXHIBIT C