SUBLEASE


      THIS   SUBLEASE  is  made  and  entered  into  as  of  May  1,  1996  (the
"Commencement  Date"),  by  and  between  SNYDER  OIL  CORPORATION,  a  Delaware
corporation  ("Sublandlord"),  and  PATINA  OIL & GAS  CORPORATION,  a  Delaware
corporation ("Subtenant").

                                   RECITALS

      A. Sublandlord,  as Tenant,  has entered into a Lease of Office Space (the
"Lease  Agreement")  dated June 5,  1991,  with  Brookfield  Minnesota  Inc.,  a
Colorado  corporation  (now  known  as  Brookfield  Denver  Inc.),  as  Landlord
(hereinafter, "Lessor"), for the lease of certain premises in an office building
(the "Building") located at 1625 Broadway,  Denver, Colorado, being a portion of
the World Trade Center, more particularly  defined in the Lease Agreement as the
"Project."

      B. The Lease Agreement has been amended and supplemented by various leases
of additional space,  surrenders of leases and space and amendments of which the
following  remain  effective:  (1) Lease of Additional  Office Space dated as of
September 9, 1992;  (2) Second Lease of  Additional  Office Space dated June 17,
1993;  (3) Amended and Restated  Second Lease of  Additional  Office Space dated
September  13,  1993;  (4)  Sixth  Lease of  Additional  Office  Space and First
Amendment and Extension of Lease dated June 2, 1994; (5) First Partial Surrender
of Lease dated  September 8, 1994; (6) Second  Amendment of Lease dated February
22,  1995;  (7) Third  Amendment  of Lease dated June 27,  1995;  and (8) Second
Partial   Surrender  and  Fourth  Amendment  of  Lease  dated  April  18,  1996,
(collectively, the "Lease Amendments").

      C. The Lease Agreement,  as amended by the Lease Amendments,  all of which
are attached  hereto as Exhibit A, are hereinafter  collectively  referred to as
the "Master Lease." The entire  premises leased to Sublandlord  under the Master
Lease is hereinafter referred to as the "Premises."

      D. Sublandlord desires to sublease to Subtenant,  and Subtenant desires to
sublease from  Sublandlord a portion of the Premises (the "Subleased  Premises,"
as further  defined in this  Sublease) on the terms and  conditions set forth in
this Sublease.

      For and in  consideration of the foregoing  Recitals,  the mutual promises
and  covenants of the parties,  and other good and valuable  consideration,  the
receipt  and  sufficiency  of which are  hereby  acknowledged,  Sublandlord  and
Subtenant hereby agree as follows:

     1. Sublease. Sublandlord hereby leases the Subleased Premises to Subtenant,
and Subtenant  leases the Subleased  Premises from  Sublandlord on the terms and
conditions set forth in this Sublease.



Patina sub lease





     2.  Subleased  Premises.  The  "Subleased  Premises"  shall mean the 28,628
square  feet of  rentable  area,  being  all of the 19th and 20th  floors of the
Building, as depicted on Exhibit B to this Sublease.

     3. Term. The term of this Sublease will begin as of the  Commencement  Date
and will terminate on November 30, 2001.


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     4.  Condition  of  Subleased  Premises.  THE  SUBLEASED  PREMISES  SHALL BE
DELIVERED ON AN "AS IS" CONDITION,  WITHOUT ANY REPRESENTATIONS OR WARRANTIES AS
TO ITS  CONDITION  OR FITNESS  FOR A  PARTICULAR  USE.  Except for the  possible
payment of a Future  Expansion  Allowance and an Improvement  Allowance to which
Subtenant  may be  entitled  pursuant to the terms of Sections 20 and 21 of this
Sublease,  Sublandlord shall have no  responsibility to arrange,  effect or make
any changes, alterations,  modifications,  additions or repairs to the Subleased
Premises,  nor to bear  any  cost  or  expense  incident  to any  such  changes,
alterations, modifications, additions or repairs which may be desired, requested
or undertaken by Subtenant in the future.

     5. Annual Rent.  Subtenant  shall pay to  Sublandlord an Annual Rent in the
amount of  $1,894,067.09,  payable in the manner provided in this Section 5. For
purposes of calculating  the Annual Rent payable under this  Sublease,  17,892.5
square feet of rentable area of the Subleased  Premises  shall be referred to as
the "Pass Through Space" and the remaining 10,735.5 square feet of rentable area
shall be referred to as the "Base Year Space."

            (a)  Pass  Through  Space  Annual  Rent.   Subtenant  shall  pay  to
      Sublandlord  as  Annual  Rent  for  the  Pass  Through  Space  the  sum of
      $1,110,080.60,  payable in  advance,  without  notice,  demand,  offset or
      counterclaim, in monthly installments according to the following schedule:

                  (i) The sum of $80,516.28 for the period from the Commencement
            Date  through  October 31,  1996,  calculated  at $9.00 per rentable
            square  foot  per  annum,   payable  in  monthly   installments   of
            $13,419.38,  on the first day of each  calendar  month  during  this
            period;

                  (ii) The sum of  $357,850.08  for the period from  November 1,
            1996  through  October 31, 1998,  calculated  at $10.00 per rentable
            square foot per annum, payable in monthly installments of $14,910.42
            on the first day of each calendar month during this period;

                  (iii) The sum of  $205,763.76  for the period from November 1,
            1998  through  October 31, 1999,  calculated  at $11.50 per rentable
            square foot per annum, payable in monthly installments of $17,146.98
            on the first day of each calendar month during this period; and

                  (iv) The sum of  $465,950.50  for the period from  November 1,
            1999 through  November 30, 2001,  calculated  at $12.50 per rentable
            square foot per annum, payable in monthly installments of $18,638.02
            on the first day of each calendar month during this period.

            (b) Base Year Space Annual Rent.  Subtenant shall pay to Sublandlord
      as Annual  Rent for the Base Year  Space  the sum of  $783,986.49  for the
      period from  September 1, 1996 through  November 30, 2001,  calculated  at
      $13.91 per  rentable  square foot per annum,  payable in advance,  without
      notice,  demand,  offset  or  counterclaim,  in  monthly  installments  of
      $12,444.23 on the first day of each calendar month during this period.

          (c) General.  If the Commencement  Date is other than the first day of
     the month or if the term ends on other than the last day of the month, rent
     shall be appropriately prorated, and the

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Annual  Rent for such  partial  first  month  shall be payable in advance on the
Commencement  Date.  All  Rent  payable  under  this  Sublease  shall be paid to
Sublandlord at Sublandlord's address as set forth in this Sublease.

      6. Additional Rent. During the term of this Sublease,  Subtenant shall pay
to Sublandlord, in addition to the Annual Rent, as and when due under the Master
Lease,  all other Rent which may be due and payable pursuant to the Master Lease
which is attributable to the Subleased Premises including, but not limited to:

            (a)  Any  Occupancy  Costs  which  Sublandlord  is  required  to pay
      pursuant  to Article 4 of the Master  Lease which is  attributable  to the
      Pass Through Space;

            (b)  Any  Occupancy  Costs  which  Sublandlord  is  required  to pay
      pursuant  to Article 4 of the Master  Lease which is  attributable  to the
      Base Year Space in excess of $6.75 per rentable square foot per annum;

            (c) Any other rent or other sums  payable as  additional  rent under
      the Master Lease  attributable  to the Subleased  Premises or  Subtenant's
      activities; and

            (d) Any Rent and other payments which Sublandlord is required to pay
      under Article  13.00 of the Master Lease by reason of Subtenant  remaining
      in possession of the Subleased  Premises  after the expiration of the term
      of the Master Lease or this Sublease.

If the term of this  Sublease  commences  after the  beginning of or  terminates
before the end of a Fiscal Year,  any amount  payable by Subtenant for Occupancy
Costs shall be adjusted proportionately.

          7.  Parking.  Subtenant  shall  have  the  option  of  subleasing  the
     following parking spaces from Sublandlord,  all of which spaces shall be at
     the rates set by Lessor from time to time:

            (a) Three (3) parking  spaces  underneath  the  Project,  one (1) of
      which is currently a reserved  space but may be converted to an unreserved
      space at any time by Lessor; and

            (b) Nineteen (19)  unreserved  parking spaces at the Tremont Parking
      Center,  located at 15th and Tremont  Streets,  representing one space for
      each 1,500 square feet of rentable area within the Subleased Premises.

Subtenant shall exercise such options by executing and delivering to Sublandlord
a written notice of exercise.  Payment of charges for parking  spaces  subleased
hereunder  shall be deemed  additional  rent due and  payable  in advance on the
first day of each calendar month during the term of this Sublease.  If Subtenant
fails to pay for any parking charges in a timely manner,  Sublandlord  shall not
be required to advance any amounts for Subtenant,  Subtenant shall be in default
and, in addition to any other rights  Sublandlord  may have,  Sublandlord  shall
have the right to cancel the  sublease of the parking  spaces for which  payment
was not received.

     As of the date of this Sublease, Sublandlord is subleasing to third parties
some or all of the parking  spaces  which are to be made  available to Subtenant
hereunder. Sublandlord has the right to terminate the existing subleases upon 30
days' notice to the parties subleasing those spaces. Upon Subtenant exercising

                                   - 4 -

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its options hereunder,  Sublandlord will give termination notices to the parties
subleasing those spaces, and will make the spaces available to Subtenant as soon
as reasonably  practicable  hereunder.  Sublandlord  shall have no liability for
delays in delivering such spaces to Subtenant.  Subtenant's sole remedy shall be
delay in paying for such spaces until they are made available to Subtenant.

      If  Subtenant  no longer  desires to  sublease  some or all of the parking
spaces,  Subtenant  may cancel its sublease of any or all of the parking  spaces
from time to time by giving  written  notice to  Sublandlord.  Unless  otherwise
agreed to in writing by Sublandlord,  such cancellation  shall be effective only
at the end of a  calendar  month and no sooner  than the last day of the  second
full  calendar  month  after  the  notice  of   cancellation   is  delivered  to
Sublandlord.

      If  Subtenant's  sublease of any parking space is  cancelled,  such spaces
shall no longer be deemed available to Subtenant, and Sublandlord shall be under
no obligation to provide those spaces to Subtenant.  If Subtenant seeks to again
sublease  all or a portion of the parking  spaces so  relinquished,  Sublandlord
shall use reasonable efforts  re-sublease such parking spaces to Subtenant,  but
in no event will  Sublandlord be obligated to re-sublease such parking spaces if
they are not available from the Lessor or if Sublandlord has other uses for such
spaces  (including  but not limited to use of such spaces by  Sublandlord or the
sublease  or  license  of such  spaces to other  users).  Subtenant's  rights to
parking  under  the  Sublease  shall at all  times be  subject  to the terms and
availability of such parking under the Master Lease.

      8. Services. Sublandlord shall not be obligated to provide any services to
Subtenant or repairs or maintenance to the Subleased  Premises,  the Building or
the Project. Subtenant's sole source of services shall be the Lessor pursuant to
the terms of the Master Lease; provided, however, upon the reasonable request of
Subtenant,  Sublandlord  will  provide  commercially  reasonable  assistance  to
Subtenant in enforcing  the terms of the Master  Lease which  require  Lessor to
provide  services,  repairs or  maintenance  to the  Subleased  Premises  or the
Building.  Sublandlord shall not be required to incur any out-of-pocket expenses
in providing such  assistance,  and Sublandlord may condition its providing such
assistance upon any such expenses being paid by Subtenant as they become due. In
the event that  Sublandlord  and Subtenant  are both involved in enforcing  such
terms  of the  Master  Lease,  Subtenant  shall  only  be  responsible  for  its
proportionate  share of such expenses  allocated to the Subleased  Premises.  If
there is any reduction or  discontinuance  of service as required to be provided
to the  Subleased  Premises by Lessor  under the Master Lease and as a result of
same Sublandlord is entitled to abatement of Rent or other sums, if any, payable
under the Master Lease, with respect to the Subleased  Premises,  then Subtenant
shall be entitled to an abatement of Rent and other sums, if any,  payable under
this  Sublease,  but only to the extent the  abatement  afforded to  Sublandlord
relates to the Subleased Premises.  Subtenant shall reimburse Sublandlord for an
equitable portion of Sublandlord's  out-of-pocket  cost incurred in enforcing an
abatement  of Rent  affecting  the  Subleased  Premises.  Sublandlord  makes  no
representations  or warranties as to the  availability  or adequacy of services.
Except as provided herein, Subtenant's covenants to pay Rent under this Sublease
are  separate and  independent  from any  covenant of  Sublandlord  or Lessor to
provide services or other amenities hereunder.

      Subtenant  shall not request any  additional  services from Lessor without
Sublandlord's prior approval, which approval shall not be unreasonably withheld,
provided  Subtenant is not then in default.  Subtenant shall promptly pay Lessor
directly for such services and provide Sublandlord with evidence of payment.

     9.  Signage.   Sublandlord   shall   cooperate  with  Subtenant  in  having
Subtenant's name and location of its office placed on the Building  directory in
the lobby of the Building, its name placed near the

                                   - 5 -

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elevator on the floor on which the Subleased  Premises are located and otherwise
in placing a placard designating Subtenant's name, either on the entrance to the
Subleased  Premises or immediately  adjacent thereto.  All such signage shall be
standard signage for the Building and subject to the approval of Lessor.

      10. Master Lease.  This Sublease is subject and  subordinate to the Master
Lease. The provisions of the Master Lease are incorporated into this Sublease as
the agreement of  Sublandlord  and Subtenant and are applicable to this Sublease
with the same  force and effect as though  Sublandlord  was  landlord  under the
Master Lease, and Subtenant was tenant under the Master Lease. Subtenant assumes
and agrees to make all payments  with respect to the  Subleased  Premises and to
perform and be bound by all of Sublandlord's covenants and obligations contained
in the Master Lease with respect to the Subleased Premises.  In the event of any
conflict between the terms and provisions of the Master Lease and this Sublease,
the terms and provisions of the Master Lease shall prevail and control.

      11. Default by Subtenant.  Subtenant shall not cause or allow to be caused
any default under the Master Lease,  nor shall  Subtenant  permit anything to be
done which would cause the Master Lease to be  terminated or forfeited by reason
of any right of termination or forfeiture reserved or vested in Lessor under the
Master Lease.  In the event of any breach by Subtenant under the Master Lease or
this Sublease,  Sublandlord shall have all the rights against Subtenant as would
be available  to the landlord  against the tenant under the Master Lease if such
breach were by the tenant thereunder including, but not limited to, the right to
terminate  Subtenant's  right to possession  of the  Subleased  Premises and any
options  granted  under this  Sublease and all other  rights and  remedies  upon
default as set forth in the Master Lease.

      12. Subtenant Indemnification. In addition to all other obligations it may
have under this Sublease, Subtenant shall indemnify, defend and hold Sublandlord
harmless from and against any losses, liabilities,  obligations,  damages, costs
and expenses (including reasonable attorneys' fees and costs) arising out of any
default under the Sublease or the Master Lease caused solely by Subtenant or its
employees,  agents or contractors;  provided,  however,  Subtenant shall have no
obligation  to  indemnify  Sublandlord  for matters  arising out of the default,
negligence or willful  misconduct of  Sublandlord  or its  employees,  agents or
contractors.

      13. Lessor Consent.  This Sublease is contingent upon Lessor consenting to
this Sublease and Lessor not  exercising its rights of first offer under Section
11.03 of the Master Lease.  Sublandlord shall submit this Sublease to Lessor for
its approval  promptly  after  execution  of this  Sublease by  Sublandlord  and
Subtenant.  Subtenant shall cooperate with  Sublandlord in providing  Lessor any
and all  information  concerning  Subtenant as Lessor may request in  connection
with  its  review  of this  Sublease  and  Subtenant.  If  Lessor's  consent  is
conditioned  and Subtenant and  Sublandlord  accept the consent  notwithstanding
such  conditions,  this Sublease  shall be subject to the conditions of Lessor's
consent.

      14. Future Assignment or Sublease. Subtenant shall not assign or otherwise
transfer,  mortgage,  pledge,  hypothecate  or  encumber  this  Sublease  or the
Subleased Premises,  or any interest therein, and shall not sublet the Subleased
Premises or any part thereof, or any right or privilege  appurtenant thereof, or
permit any other party to occupy the Subleased Premises, or any portion thereof,
without the written consent of Lessor and  Sublandlord,  which consent shall not
be  unreasonably   withheld  by  Sublandlord.   Sublandlord's   consent  to  any
assignment, transfer or subletting by Subtenant shall not relieve Subtenant from
any of its obligations under this Sublease.


                                   - 6 -

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      15.  Tenant  Alterations.  Subtenant  shall  make no  alteration,  change,
improvement,  repair,  replacement or addition to the Subleased Premises without
the prior written consent of Lessor and Sublandlord.  Sublandlord agrees that it
will not  unreasonably  withhold its consent to any of the foregoing.  Subtenant
shall  provide  to  Sublandlord  copies  of any and all  plans,  specifications,
notices and other  correspondence  delivered by Subtenant to Lessor which relate
to Subtenant's request for Lessor's approval hereunder. Notwithstanding anything
in this Sublease  that may imply to the  contrary,  Subtenant is not entitled to
and shall  not  receive  from  Sublandlord  any  Expansion  Allowance,  Painting
Allowance, Other Improvement Allowance (as those terms are defined in the Master
Lease) or any other  allowance  now or  hereafter  granted or made  available by
Lessor to  Sublandlord,  except  Subtenant  may be  entitled  to an  Improvement
Allowance  under  Section 21 and a Future  Expansion  Option under Section 20 of
this Sublease, if the terms and conditions of those Sections are satisfied.

      16.  Insurance.  Subtenant  shall  maintain,  throughout  the term of this
Sublease,  such policy or policies of insurance  with  respect to the  Subleased
Premises as  Sublandlord  is required to maintain  pursuant to the Master  Lease
including, but not limited to, the policies required pursuant to Section 9.02 of
the Master Lease.  The required  liability  policies shall name  Sublandlord and
Lessor as additional  insureds,  shall insure  performance of the indemnities of
Subtenant  contained  in this  Sublease  and shall be  primary  coverage  in the
instance of Subtenant's indemnities,  so that any insurance coverage obtained by
Lessor or Sublandlord  shall be in excess thereto.  All policies  required under
this  Sublease  shall be  endorsed  to  provide  a waiver of  subrogation  as to
Sublandlord and Lessor. Upon Sublandlord's  request from time to time, Subtenant
shall promptly deliver to Sublandlord  evidence that all premiums have been paid
and all policies are in full force and effect,  all in such form as  Sublandlord
may reasonably request.  All policies required under this Sublease shall include
an agreement  by the insurer that the policy shall not be canceled,  terminated,
modified or allowed to expire without 15 days' written notice to Sublandlord.

      17.  Hazardous  Materials.  Subtenant  shall not  (either  with or without
negligence) cause or permit the escape,  disposal or release of any biologically
or chemically active or other hazardous  substances or materials on or about the
Subleased  Premises or any other  portion of the  Project,  nor shall  Subtenant
allow  the  storage  or use of such  substances  or  materials  on or about  the
Subleased Premises or any other portion of the Project,  nor allow to be brought
into the Subleased  Premises or any portion of the Project any such materials or
substances. Without limitation, hazardous substances and materials shall include
those described in the Comprehensive  Environmental  Response,  Compensation and
Liability Act of 1980, the Resource Conservation and Recovery Act, the Superfund
Amendments and  Re-Authorization Act of 1986, the Occupational Safety and Health
Act,  the Clean Water Act,  and any  amendments  to such acts,  and any federal,
state or municipal laws, ordinances,  regulations or common law which may now or
hereafter  impose  liability on Lessor or Sublandlord  with respect to hazardous
substances.  Subtenant  shall  be  solely  responsible  for  and  shall  defend,
indemnify and hold Lessor and Sublandlord,  their agents and employees, harmless
from and against all claims,  costs and liabilities,  including attorneys' fees,
court costs and other expenses of litigation (1) arising out of or in connection
with any breach of this Section, or (2) arising out of or in any connection with
the removal,  cleanup and restoration work and materials necessary to return the
Subleased  Premises  and the Project and any other  property of whatever  nature
located  therein  to  their  condition  existing  prior to the  introduction  of
hazardous  materials in or about the Sublease Premises or Project. If any lender
or governmental  agency shall ever require  testing to ascertain  whether or not
there has been any hazardous material on or about the Subleased Premises (or, as
a result of  Subtenant's  actions,  on or about other  portions of the Project),
then the cost thereof  shall be  reimbursed  by Subtenant  to  Sublandlord  upon
demand. In addition, Subtenant shall execute affidavits, representations and the
like  from  time  to  time  at  Lessor's  or  Sublandlord's  request  concerning
Subtenant's knowledge and belief regarding the presence of

                                   - 7 -

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hazardous  substances  or  materials  on  the  Subleased  Premises.  The  within
covenants and indemnities shall survive the expiration or earlier termination of
the term of this Sublease.

      18.  Termination  of Master Lease.  Sublandlord  shall not do or suffer or
permit  anything to be done which would  constitute  a default  under the Master
Lease or would cause the Master Lease to be canceled, terminated or forfeited by
virtue of any rights of  cancellation,  termination  or  forfeiture  reserved or
vested in the Lessor  under the Master  Lease.  Notwithstanding  the  foregoing,
Sublandlord may  voluntarily  terminate the Master Lease during the term of this
Sublease  provided  Lessor  agrees in writing to treat  such  termination  as an
assignment of this Sublease by Sublandlord  to Lessor.  In the event of any such
termination,  Subtenant  shall be bound to Lessor for the balance of the term of
this Sublease as if Lessor were the Sublandlord  under this Sublease,  Subtenant
shall attorn to Lessor as its landlord,  Sublandlord  shall be released from any
liability with respect to such  termination and no liability or obligation shall
thereafter accrue against Sublandlord with respect to this Sublease.

      19.  Sublandlord  Indemnification.  Sublandlord  shall  perform all of its
obligations  as tenant  under the Master  Lease.  Sublandlord  shall  indemnify,
defend  and  hold  Subtenant  harmless  from  and  against  any and all  losses,
liabilities,  obligations,  damages,  costs and expenses  (including  reasonable
attorneys'  fees and costs)  arising out of any default  under the Master  Lease
caused solely by Sublandlord or its employees, agents or contractors;  provided,
however, Sublandlord shall have no obligation to indemnify Subtenant for matters
arising out of the default, negligence or willful misconduct of Subtenant or its
employees, agents or contractors.

      20.  Rights of First  Offer.  Pursuant to Articles  30.00 and 31.00 of the
Master Lease,  Sublandlord  has been granted  certain rights of first offer (the
"Rights of First Offer") to lease  additional  space in the  Building.  Provided
Subtenant is not then in default under this  Sublease and provided  further that
Sublandlord  does not intend to lease the  subject  Offer Space for its own use,
Sublandlord  will promptly  forward to Subtenant a copy of any written notice of
available  First Offer Space or Second  Offer  Space (the "Offer  Space")  which
Sublandlord  receives  from Lessor under  Article  30.00 or Article 31.00 of the
Master Lease. Upon all of the following conditions being satisfied,  Sublandlord
will exercise its right to lease the Offer Space, in which event Subtenant shall
sublease the Offer Space  specified in such notice upon the terms and conditions
herein set forth:

            (a) Subtenant shall deliver to Sublandlord an unconditional, written
      notice of  Subtenant's  exercise  of its right to lease such Offer  Space,
      which  notice must be received by  Sublandlord  at least one  business day
      prior to the date upon which  Sublandlord is required to deliver to Lessor
      its notice of exercise under Section 30.02 or 31.02 of the Master Lease;

            (b) Subtenant  shall not be in default beyond any applicable  notice
      and cure period under the Sublease at the time Lessor gives notice,  or at
      the  commencement  date of the Sublease of the Offer Space and there shall
      have  been no  material  adverse  change  in the  financial  condition  of
      Subtenant from the date of this Sublease;

            (c)  Sublandlord  does not desire to use the subject Offer Space for
      its own use, it being understood that Subtenant's  rights under the Rights
      of  First  Offer  shall at all  times  be  subordinate  to the  rights  of
      Sublandlord; and

            (d)   Lessor in fact leases such Offer Space to Sublandlord.

                                   - 8 -

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The terms of any  sublease  of the Offer Space will be exactly the same as those
on which Sublandlord  leases such space from Lessor,  the terms of which are set
forth  in  the  Master  Lease,  including  the  right  to any  Future  Expansion
Allowance,  but only to the extent  actually paid by Lessor and allocable to the
Offer  Space  which  Subtenant  subleases  hereunder.  Any  payments  of  Future
Expansion Allowance to Subtenant shall be contingent upon Sublandlord  receiving
payment from Lessor, and Sublandlord's receipt and approval of invoices and such
other  evidence that such funds have been spent for the design and  construction
of improvements  with the subject Offer Space,  as Subtenant may request.  It is
the intent of the parties  that any sublease of Offer Space be a net sublease to
Sublandlord,  and  Subtenant  shall  reimburse  Sublandlord  for any  reasonable
out-of-pocket  expenses  incurred  by  Sublandlord  in leasing  the Offer  Space
hereunder.  The  obligation  of  Subtenant  to sublease the Offer Space shall be
automatic upon satisfaction of the foregoing conditions.  Nonetheless, within 15
days of receipt from  Sublandlord,  Subtenant shall execute an amendment to this
Sublease to evidence any lease under this Section,  provided  such  amendment is
consistent  with the terms hereof.  Sublandlord  shall use good faith efforts in
providing Subtenant with notices from Lessor hereunder and otherwise  attempting
to make  available to Subtenant any Offer Space which is offered to  Sublandlord
under the Rights of First Offer.  Subtenant's remedies for Sublandlord's failure
to deliver any Offer Space in  accordance  with the  provisions of this Sublease
shall be limited to $10,000,  and  Subtenant  shall have no claim for and hereby
waives all rights to any other damages,  specific performance or any other legal
or equitable relief against Sublandlord or any other party.

      21.  Improvement  Allowance.  Sublandlord  shall  provide  an  improvement
allowance not to exceed $35,000 (the "Improvement Allowance") for the purpose of
contributing  toward the cost of any design,  engineering  and  construction  of
approved   improvements   within  the   Subleased   Premises   (the   "Leasehold
Improvements")  upon the terms and conditions  set forth herein.  Within 75 days
after  receipt  of  substantiating  invoices  and  lien  waivers  acceptable  to
Sublandlord  and  Lessor,  Sublandlord  shall pay to  Tenant an amount  equal to
invoices submitted for Leasehold Improvements, but not to exceed the Improvement
Allowance.  Any portion of the Improvement Allowance for which invoices have not
been  submitted  as of  November  1, 1999 shall be deemed  Sublandlord's  and no
longer  available to Subtenant,  and no Rent or any other amounts owed hereunder
shall be offset by such amount.  Subtenant  acknowledges that all or part of the
Improvement  Allowance will be funded by Sublandlord from allowances  granted to
Sublandlord  under the Master Lease.  Subtenant shall cooperate with Sublandlord
in  promptly   providing   to   Sublandlord   any  and  all   invoices,   plans,
specifications,  drawings and other  documentation as Sublandlord may reasonably
request, including, but not limited to, any such documents as may be required by
Lessor, in order to assure Sublandlord and Lessor that the Improvement Allowance
is properly payable hereunder.

     22.  Governing  Law.  This  Sublease  shall be governed by and construed in
accordance with the laws of the State of Colorado.

     23.  Severability.  Should any of the  provisions  of this  Sublease to any
extent be held to be invalid or  unenforceable,  the  remainder of this Sublease
shall continue in full force and effect.

     24. Entire Agreement.  This Sublease embodies the entire  understanding and
agreement  among the  parties  relative  to the matters  contained  herein,  and
supersedes  all  prior  negotiations,  understandings  or  agreements  in regard
thereto, whether written or oral.

     25.  Waiver.  No  provision of this  Sublease  may be waived,  except by an
agreement in writing signed by all of the parties  hereto.  A waiver of any term
or provision shall not be construed as a waiver of any other term or provision.

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Patina sub lease





     26.  Headings.  The subject headings used in this Sublease are included for
purposes  of  reference   only,  and  shall  not  affect  the   construction  or
interpretation of any of its provisions.

     27.  Amendment.  This  Sublease may be amended,  altered or revoked only by
written instrument executed by all of the parties.

      28. Notices.  All notices required or permitted by this Agreement shall be
in writing and shall be given by personal delivery or sent to the address of the
party set forth below by registered or certified mail,  postage prepaid,  return
receipt  requested,  or  by  reputable  overnight  courier,   prepaid,   receipt
acknowledged.  Notices  shall be deemed  received  on the earlier of the date of
actual receipt or, in the case of notice by mail or overnight courier,  the date
of receipt  marked on the  acknowledgment  of receipt.  Rejection  or refusal to
accept or the  inability  to  deliver  because  of change of address of which no
notice was given  shall be deemed to be  received as of the date such notice was
deposited in the mail or delivered to the courier.

            If to Sublandlord:      Snyder Oil Corporation
                                    1625 Broadway, Suite 2200
                                    Denver, CO  80202

                                    Attn:  Rodney L. Waller

            If to Subtenant:        Patina Oil & Gas Corporation
                                    1625 Broadway, Suite 2000
                                    Denver, CO  80202

                                    Attn:  General Counsel

Any party may change its address to which notices should be sent to it by giving
the other parties  written  notice of the new address in the manner set forth in
this paragraph.

      29. Notices from Lessor.  Sublandlord  and Subtenant  shall use good faith
efforts to promptly  forward to one another copies of any notices  applicable to
this  Sublease or the Subleased  Premises  which either of them may receive from
Lessor under the Master Lease.

     30.  Construction.  All terms  used in this  Sublease  shall  have the same
meaning as assigned to them in the Master Lease  except as  otherwise  expressly
provided herein.

      31. Further Acts. Upon reasonable  request from a party hereto,  from time
to time,  each party shall  execute and deliver such  additional  documents  and
instruments  and take such other actions as may be reasonably  necessary to give
effect to the intents and purposes of this Sublease.

      32.  Attorneys'  Fees.  In the  event  of any  litigation  or  arbitration
proceedings  between the parties  hereto  concerning  the subject matter of this
Sublease,  the  prevailing  party  in such  litigation  or  proceeding  shall be
awarded,  in  addition  to the amount of any  judgment  or other  award  entered
therein, the costs and expenses,  including reasonable attorneys' fees, incurred
by the prevailing party in the litigation or proceeding.


                                   - 10 -

Patina sub lease





     33.  Binding  Effect.  This Sublease shall be binding upon and inure to the
benefit of the parties hereto and their respective successors and assigns.

      34. Brokers.  Each party  represents and warrants to the other that it has
not  dealt  with any real  estate  broker  or  finder  in  connection  with this
Sublease.  Each party shall indemnify and hold harmless the other from any loss,
claim, damage,  obligation,  cost or expense,  including  reasonable  attorneys'
fees,  arising out of any claim made by any other broker or finder  claiming by,
through or under such party.

      35. Authority.  Each party represents and warrants unto the other that (a)
it is a duly  organized and existing legal entity under the laws of the State in
which it is organized, and in good standing and authorized to do business in the
State of Colorado,  (b) it has full right and authority to execute,  deliver and
perform this Sublease,  (c) the person  executing this Sublease is authorized to
do so, and (d) upon request of Sublandlord,  such person  executing on behalf of
Subtenant will deliver satisfactory  evidence of his or her authority to execute
this Sublease on behalf of Subtenant.

      36. Effective Date.  Pursuant to the Agreement and Plan of Merger between,
among  others,  Subtenant  and  Sublandlord,  Subtenant is  responsible  for the
occupancy costs for two floors of Sublandlord's  space under the Master Lease as
of May 1, 1996. The Subleased Premises represents the two floors contemplated by
that Agreement.  As of the Commencement Date, some of Subtenant's  employees are
occupying a portion of the Premises other than the Subleased Premises,  and some
of Sublandlord's employees may be occupying a portion of the Subleased Premises.
Subtenant  and  Sublandlord  will  relocate  their  respective  employees to the
Subleased Premises and the balance of the Premises, respectively, within 15 days
following  written  notice  given  by  the  other  party.   Notwithstanding  the
foregoing, Subtenant acknowledges that it has accepted delivery of the Subleased
Premises as of the Commencement Date.

      THIS  SUBLEASE is executed by the parties  effective  as of the date first
above written, notwithstanding the actual date of execution.

                                    SUBLANDLORD:

                                    SNYDER OIL CORPORATION,
                                    a Delaware corporation


                                    By:

                                    Its:



                                   - 11 -

Patina sub lease


                                    SUBTENANT:

                                    PATINA OIL & GAS CORPORATION,
                                    a Delaware corporation


                                    By:

                                    Its:

                                   - 12 -
Patina sub lease