EXHIBIT 99.2
===============================================================================



                               PRODUCTION PAYMENT
                           PURCHASE AND SALE AGREEMENT


                                     between


                       PIONEER NATURAL RESOURCES USA, INC.
                                       AND
                     PIONEER NATURAL RESOURCES PROPERTIES LP


                                   as Seller,


                                       and


                        ROYALTY ACQUISITION COMPANY, LLC

                                    as Buyer




- -------------------------------------------------------------------------------



                          Dated as of January 26, 2005

===============================================================================






                                TABLE OF CONTENTS

                                                                          Page



ARTICLE I     DEFINITIONS AND REFERENCES...................................1

    SECTION 1.01.    Definitions...........................................1

    SECTION 1.02.    References, Gender, Number............................5

ARTICLE II    SALE AND PURCHASE............................................5

ARTICLE III   CONSIDERATION AND PAYMENT....................................6

    SECTION 3.01.    Consideration and Purchase Price......................6

    SECTION 3.02.    Payment Instructions..................................6

ARTICLE IV    REPRESENTATIONS AND WARRANTIES...............................6

    SECTION 4.01.    Representations and Warranties of Seller..............6

    SECTION 4.02.    Representations and Warranties of Buyer..............11

ARTICLE V     LETTER OF CREDIT............................................12

    SECTION 5.01.    Letter of Credit.....................................12

ARTICLE VI    ADJUSTMENT OF SCHEDULED QUANTITIES..........................13

    SECTION 6.01.    Additional Definitions...............................13

    SECTION 6.02.    Covenant to Amend Conveyance.........................13

ARTICLE VII   COVENANTS OF SELLER AND BUYER...............................15

    SECTION 7.01.    Public Announcements.................................15

    SECTION 7.02.    Buyer's Mortgage.....................................16

    SECTION 7.03.    Survival Past Closing................................16

    SECTION 7.04.    Reasonable Cooperation...............................16

    SECTION 7.05.    Preferential Purchase Rights.........................16

ARTICLE VIII  CLOSING CONDITIONS..........................................17

    SECTION 8.01.    Seller's Closing Conditions..........................17

    SECTION 8.02.    Buyer's Closing Conditions...........................18

ARTICLE IX    CLOSING.....................................................19

    SECTION 9.01.    Closing..............................................19

    SECTION 9.02.    Seller's Closing Obligations.........................19

    SECTION 9.03.    Buyer's Closing Obligations..........................20

ARTICLE X     ASSUMPTION AND INDEMNIFICATION..............................20

    SECTION 10.01.   Covered Liabilities..................................20


                                       i




                                TABLE OF CONTENTS
                                   (continued)

                                                                         Page


    SECTION 10.02.   Indemnification by Seller............................21

    SECTION 10.03.   Third Party Claims...................................21

ARTICLE XI    MISCELLANEOUS...............................................22

    SECTION 11.01.   Counterparts.........................................22

    SECTION 11.02.   Governing Law; Consent to Jurisdiction...............22

    SECTION 11.03.   WAIVER OF JURY TRIAL.................................23

    SECTION 11.04.   Entire Agreement.....................................23

    SECTION 11.05.   Excluded Taxes and Expenses..........................23

    SECTION 11.06.   Notices..............................................24

    SECTION 11.07.   Successors and Assigns...............................24

    SECTION 11.08.   Headings.............................................24

    SECTION 11.09.   Amendments and Waivers...............................24

    SECTION 11.10.   Schedules and Exhibits...............................25

    SECTION 11.11.   Interpretation.......................................25

    SECTION 11.12.   Agreement for the Parties' Benefit Only..............25

    SECTION 11.13.   Severability.........................................26

    SECTION 11.14.   No Retained Liens....................................26

    SECTION 11.15.   Confidentiality......................................26

    SECTION 11.16.   Limitations on Damages...............................26

    SECTION 11.17.   Tax Treatment........................................26

    SECTION 11.18.   No Recourse..........................................26




                                       -ii-






                                TABLE OF CONTENTS




                                    SCHEDULES


Schedule 3.02       -    Payment Transfer Instructions
Schedule 4          -    Disclosures
Schedule 8.02D(1)   -    Seller's Opinion of Counsel
Schedule 8.02D(2)   -    Seller's Opinion of Special Counsel
                         [Thompson & Knight LLP]
Schedule 8.02D(3)   -    Seller's Opinion of Special Counsel
Schedule 8.02E      -    Affidavit of Non-Foreign Status
Schedule 8.02F      -    Insurance



                                    EXHIBITS
                                    --------


Exhibit A           -    Form of Novation Agreement
Exhibit B           -    Form of Marketing Agreement
Exhibit C           -    Form of Pioneer Guaranty
Exhibit D           -    Form of Letter of Credit Demand Certificate
Exhibit E           -    Form of Conveyance of Term Overriding Royalty Interest


                                       i








                 PRODUCTION PAYMENT PURCHASE AND SALE AGREEMENT

     THIS PRODUCTION  PAYMENT PURCHASE AND SALE AGREEMENT (herein referred to as
this "Agreement"),  dated as of January 26, 2005, by and between Pioneer Natural
Resources  USA,  Inc.,  a Delaware  corporation  and Pioneer  Natural  Resources
Properties  LP, a Delaware  limited  partnership  (herein,  together  with their
successors and permitted assigns, each individually and collectively referred to
as "Seller"), and Royalty Acquisition Company, LLC, a Delaware limited liability
company (herein, together with its successors and permitted assigns, referred to
as "Buyer"),

                                   WITNESSETH:

     WHEREAS,  Seller  intends to sell to Buyer,  and Buyer  intends to purchase
from the Seller, a Production  Payment  consisting of a term overriding  royalty
interest in certain  mineral  properties  described  herein,  upon the terms and
subject to the conditions described herein; and

     WHEREAS,  the purchase price payable  hereunder for the Production  Payment
takes into account the estimated  present value of Buyer's future  severance and
ad  valorem  tax   obligations  in  respect  of  the  Production   Payment,   in
consideration  of  Seller's  promise to pay such taxes as they become due in the
future; and

     WHEREAS,  the performance of each  obligation of each Seller  hereunder and
under the Related  Agreements  shall be guaranteed by Pioneer Natural  Resources
Company;

     NOW,  THEREFORE,  in  consideration  of the mutual covenants and agreements
hereinafter set forth, the parties hereto agree as follows:

                                   ARTICLE I
                           DEFINITIONS AND REFERENCES

SECTION 1.01.     Definitions.

     Unless the context otherwise  requires,  each defined term shall be equally
applicable  both to the  singular  and the plural  forms of the term so defined.
When used in this Agreement, the following terms have the following meanings:

     "Action"  shall  mean  any  action,  claim,  suit,  arbitration,   inquiry,
proceeding, investigation, condemnation or audit by or before any court or other
Governmental Authority or any arbitrator or panel of arbitrators.

     "Affiliate" shall have the meaning given to such term in the Conveyance.

     "Approved  Investment  Grade" shall have the meaning  given to such term in
the Conveyance.

     "Business" shall mean the ownership, maintenance, development and operation
of the Subject Interests and the gathering,  delivery,  and sale of Hydrocarbons
produced therefrom.







     "Buyer Party" means Buyer, its owners,  investors and lenders, any provider
of commodity or interest rate hedging  products to Buyer,  and their  respective
successors and permitted assigns.

     "Cash Purchase Price" shall be as defined in Section 3.01.

     "Closing"  shall be the  consummation  of the  transaction  contemplated by
Article IX.

     "Closing  Date" shall mean (a) January 26, 2005,  or (b) such other date as
may be mutually agreed to by Seller and Buyer in writing.

     "Code" shall mean the Internal  Revenue Code of 1986,  as amended,  and any
successor thereto, together with all regulations promulgated thereunder.

     "Conveyance" shall be as defined in Section 8.01.

     "Covered Liabilities" shall be as defined in Section 10.01.

     "Defensible  Title" shall mean such title as enables  Seller to  correctly,
accurately  and  truthfully  make  the  representations  in  Section  6.3 of the
Conveyance.

     "Environmental Laws" shall mean all Laws that relate to (a) the prevention,
abatement or elimination of pollution,  or the protection of the  environment or
natural resources, (b) the generation,  handling,  treatment, storage, disposal,
release or  transportation  of waste materials or hazardous or toxic substances,
or (c) the  regulation  of or exposure to hazardous,  toxic or other  substances
alleged to be  harmful,  including  the  Comprehensive  Environmental  Response,
Compensation  and  Liability  Act, 42 U.S.C.  ss.  9601,  et seq.;  the Resource
Conservation  and Recovery  Act, 42 U.S.C.  ss. 6901 et seq.;  the Federal Water
Pollution  Control Act (Clean Water Act), 33 U.S.C. ss. 1251, et seq.; the Clean
Air Act, 42 U.S.C.  ss. 7401, et seq.;  the Hazardous  Materials  Transportation
Act, 49 U.S.C.  ss. 1471, et seq.; the Toxic  Substances  Control Act, 15 U.S.C.
ss.  2601,  et seq.;  the Oil  Pollution  Act, 33 U.S.C.  ss. 2701 et seq.;  the
Emergency  Planning and Community  Right-to-Know  Act, 42 U.S.C.  ss. 11001,  et
seq.; the Safe Drinking Water Act, 42 U.S.C.  ss.ss.  300f through 300j; and the
Endangered Species Act, 16 U.S.C. ss. 1531, et seq.; and all similar Laws of any
Governmental Authority having jurisdiction over the property in question.

     "Fee  Letter"  shall mean the fee letter  dated the  Closing  Date  between
Pioneer Natural Resources USA, Inc. and Wachovia Capital Markets LLC.

     "Gas" shall have the meaning given to such term in the Conveyance.

     "Governmental  Authority"  shall have the meaning given to such term in the
Conveyance.

     "Guarantor" means Pioneer,  its permitted  successors and assigns under the
Pioneer Guaranty.


                                       2







     "Hazardous  Materials"  shall mean (a) any  substance  or material  that is
listed,  defined or  otherwise  designated  as a "toxic  substance,"  "hazardous
substance" or "hazardous waste" under any Environmental  Law,  including Section
101(14) of the Comprehensive Environmental Response,  Compensation and Liability
Act, (b) any radioactive material, asbestos or polychlorinated biphenyls and (c)
any other chemical, substance or waste that is regulated under any Environmental
Law.

     "Hydrocarbons" shall have the meaning given to such term in the Conveyance.

     "Imbalance" means, without duplication,  the sum (expressed in Mcfs) of (a)
the  aggregate  make-up,   prepaid,   or  other  volumes  of  Methane  that  are
attributable  to or could  burden the  Production  Payment and that  Sellers are
obligated as of the Closing Date,  on account of  prepayment,  advance  payment,
take-or-pay,  gas balancing or similar obligations,  to deliver from the Subject
Interests after the Closing Date and (b), to the extent such obligations  burden
the Production  Payment or Buyer could incur any liability  therefor as a result
of the  transaction  contemplated  hereby and the same are not covered by clause
(a) above,  the  aggregate  pipeline  or  processing  plant  imbalances  or over
deliveries for which Seller is obligated to pay or deliver  Hydrocarbons or cash
to any pipeline,  gatherer,  transporter,  processor,  co-owner, or purchaser in
connection with any Hydrocarbons attributable to the Production Payment.

     "Indemnified Parties" shall be as defined in Section 10.02.

     The term  "knowledge"  when  used  with  reference  to a  particular  fact,
circumstance or condition:  (a) in the case of either Seller, shall mean (i) the
actual  knowledge of any director or officer of such Seller or any  Affiliate of
such Seller or (ii) the actual knowledge of any director, officer or employee of
either Seller or any Affiliate of such Seller  involved in the  negotiation  of,
any analysis or due diligence in connection with this Agreement;  and (b) in the
case of Buyer,  shall  mean the actual  knowledge  of any  director,  officer or
employee of Buyer or any Affiliate of Buyer involved in the  negotiation of this
Agreement.

     "Law" shall mean any applicable statute, law, ordinance,  regulation, rule,
ruling, order,  restriction,  requirement,  writ,  injunction,  decree, or other
official act of or by any Governmental Authority.

     "Marketing Agreement" shall be as defined in Section 8.01.

     "Methane"  shall have the meaning given to such term in the  Conveyance and
for  the  avoidance  of  doubt  and  for  clarification,   "Methane"  means  the
Hydrocarbons  referred  to as  natural  gas in the  Netherland  & Sewell  Report
delivered in connection with the Closing.

     "Month" shall mean the  one-month  period  beginning at 9:00 a.m.,  Central
Time,  on the first day of a calendar  month and  ending at 9:00  a.m.,  Central
Time, on the first day of the following calendar month.

     "Moody's" shall have the meaning given to such term in the Conveyance.

     "Net  Revenue  Interest"  shall have the meaning  given to such term in the
Conveyance.


                                       3






     "Novation Agreement" shall be as defined in Section 8.01.

     "Oil" shall have the meaning given to such term in the Conveyance.

     "PDNP reserves" shall mean proved, developed, non-producing reserves of Gas
or Oil as shown on the Reserve Report.

     "PDP reserves" shall mean proved,  developed,  producing reserves of Gas or
Oil as shown on the Reserve Report.

     "Permits"  shall  mean  all  licenses,   permits,   certificates,   orders,
approvals, franchises,  exemptions, variances, waivers and authorizations of any
Governmental Authority,  including applications therefor,  necessary or required
to own and operate the Subject  Interests  and conduct the  Business  (including
those required by Environmental Laws).

     "Permitted Encumbrances" shall have the meaning provided in the Conveyance.

     "Person" shall mean any  Governmental  Authority or any  individual,  firm,
partnership,  corporation, joint venture, trust, unincorporated organization, or
other entity or organization.

     "Petroleum Engineer" shall mean Netherland,  Sewell & Associates,  Inc. and
any other nationally  recognized  reserve  engineering firm that audits Sellers'
oil and gas reserves for Securities and Exchange Commission reporting purposes.

     "Pioneer" shall mean Pioneer Natural Resources Company.

     "Pioneer Guaranty" shall be as defined in Section 8.02.

     "Pioneer LP" means  Pioneer  Natural  Resources  Properties  LP, a Delaware
limited partnership.

     "Pioneer  USA"  means  Pioneer  Natural  Resources  USA,  Inc.,  a Delaware
corporation.

     "Preference  Right" shall mean any right or  agreement  that enables or may
enable any Person to purchase or acquire  any Subject  Interest or any  interest
therein or  portion  thereof as a result of the  conveyance,  sale,  assignment,
mortgage or other transfer of the Production  Payment or any interest therein or
portion thereof.

     "Production  Payment"  shall  have the  meaning  given to such  term in the
Conveyance.

     "Production  Payment  Documents"  shall mean this Agreement and the Related
Agreements.

     "Production  Purchaser"  and  "Production  Sales  Contract"  shall have the
meanings given to such terms in the Marketing Agreement.

     "PUD  reserves"  shall mean  proved,  undeveloped  reserves as shown on the
Reserve Report.


                                       4






     "Related  Agreements" shall mean the Conveyance,  the Marketing  Agreement,
the Pioneer Guaranty and the Novation Agreement.

     "Reserve  Report" shall mean the reserve report with respect to the Subject
Interests  audited or prepared by the  Petroleum  Engineer and  delivered to the
Royalty Owner concurrently herewith.

     "S&P" shall have the meaning given to such term in the Conveyance.

     "Subject  Interests"  shall  have the  meaning  given  to such  term in the
Conveyance.

     "Subject  Wells"  shall  have  the  meaning  given  to  such  term  in  the
Conveyance.

     "Taxes" shall have the meaning given to such term in the Conveyance.

     "Title Failure" shall mean a breach of any of Seller's  representations and
warranties in Section 6.3 of the Conveyance shall have occurred.

     "Transfer Requirement" shall mean any consent,  approval,  authorization or
permit of, or filing with or notification to, any Person which must be obtained,
made or complied with for or in connection with the conveyance of the Production
Payment or any portion thereof in order (a) for such conveyance to be effective,
(b) to prevent any termination,  cancellation,  default, acceleration, or change
in terms (or any right thereof from  arising)  under any terms,  conditions,  or
provisions  of  any  Subject  Interest  (or  of any  agreement,  instrument,  or
obligation  relating to or burdening  any Subject  Interest) as a result of such
conveyance,  or (c) to prevent the creation or imposition  of any lien,  charge,
penalty, restriction, security interest or encumbrance on or with respect to the
Production  Payment or the  Subject  Interests  as a result of such  conveyance;
provided, however, that a Preference Right shall not be a Transfer Requirement.

SECTION 1.02.     References, Gender, Number.

     All references in this Agreement to an "Article," "Section,"  "Subsection,"
"Exhibit,"  or  "Schedule"  shall  be to  the  specified  Article,  Section,  or
Subsection  of,  or  the  specified  Appendix,  Exhibit  or  Schedule  to,  this
Agreement,  unless the context requires otherwise.  Unless the context otherwise
requires,  the words "this  Agreement,"  "hereof,"  "hereunder,"  "herein,"  and
"hereby" and words of similar  import  shall refer to this  Agreement as a whole
and  not  to  a  particular  Article,  Section,  Subsection,  clause,  or  other
subdivision hereof.  Whenever the context requires,  the words used herein shall
include the masculine,  feminine,  and neuter  gender,  and the singular and the
plural.  Defined  terms used  herein not defined  herein  shall have the meaning
provided in the Conveyance.

                                   ARTICLE II
                                SALE AND PURCHASE

     On the terms and  conditions of this  Agreement,  Sellers agree to sell and
convey to Buyer,  and Buyer  agrees to purchase  from  Sellers,  the  Production
Payment.

                                       5







                                  ARTICLE III
                            CONSIDERATION AND PAYMENT

SECTION 3.01.     Consideration and Purchase Price.

     In consideration  for and concurrently  with the sale and conveyance of the
Production  Payment to Buyer,  Buyer shall (a) enter into the Novation Agreement
in order to assume  the  liabilities  and duties  (and  acquire  the  rights) of
Pioneer USA under the hedging transactions described therein, and (b) pay to the
Sellers  jointly  in  accordance  with the terms  hereof  the  aggregate  sum of
$275,475,680.00 (herein referred to as the "Cash Purchase Price").

SECTION 3.02.     Payment Instructions.

     At the Closing, Buyer shall wire transfer the Purchase Price in immediately
available funds to Seller, as directed in Schedule 3.02.

                                   ARTICLE IV
                         REPRESENTATIONS AND WARRANTIES

SECTION 4.01.     Representations and Warranties of Seller.

     Pioneer USA and Pioneer LP jointly and  severally  represent and warrant to
Buyer as of the date hereof and as of the Closing Date as follows:

     A. Organization and Qualification. Pioneer USA is a corporation and Pioneer
LP is a limited partnership duly formed,  validly existing, and in good standing
under the Laws of the State of  Delaware  and has the  requisite  legal power to
carry  on its  business  as it is now  being  conducted.  Each  Seller  is  duly
qualified  to do  business,  and is in good  standing,  as  applicable,  in each
jurisdiction in which it owns any Subject Interests.

     B.  Authority.  Each Seller has all requisite  legal power and authority to
execute,  deliver and perform its  obligations  under this Agreement and each of
the Related  Agreements  to which it is a party.  The  execution,  delivery  and
performance of this  Agreement and each of the Related  Agreements to which such
Seller is a party and the transactions  contemplated hereby or thereby have been
duly and validly authorized by all requisite action on the part of each Seller.

     C.  Enforceability.  This  Agreement  constitutes,  and upon  execution and
delivery  by each  Seller  of each of the  Related  Agreements  to which it is a
party,  each of such Related  Agreements  will  constitute,  a valid and binding
agreement of such Seller,  enforceable in accordance with its terms,  subject to
(i) applicable bankruptcy,  insolvency,  reorganization,  moratorium,  and other
similar Laws of general  application  with respect to creditors and (ii) general
principles  of  equity.  Upon  execution  and  delivery  by each  Seller  of the
Conveyance  and Buyer's  payment of the  Purchase  Price,  the  Conveyance  will
constitute the legal, valid and binding conveyance of the Production Payment out
of the Subject Interests and the Production  Payment will constitute an interest
in real or personal property under applicable state laws owned by Buyer (and not
by either Seller) and a "production  payment" as defined in Section  101(42A) of
the Bankruptcy  Code and referred to in Section  541(b)(4)(B)  of the Bankruptcy
Code.


                                       6






     D. No Conflict or  Violation.  Neither the  execution  and delivery of this
Agreement or the Related Agreements nor the consummation of the transactions and
performance of the terms and conditions contemplated hereby or thereby by either
Seller or  Guarantor  will (i)  conflict  with or  result  in any  breach of any
provision  of the  articles  of  incorporation  or bylaws,  limited  partnership
agreement (or other similar governing  documents) of either Seller or Guarantor,
as applicable;  (ii) conflict in any material  respect with, or be rendered void
or  ineffective  in any way that  adversely  affects the value of the Production
Payment by, any agreement,  instrument,  or obligation to which either Seller or
Guarantor  is a party  or to  which  either  Seller,  Guarantor  or the  Subject
Interests  are subject;  (iii) subject to the  limitations  contained in Section
4.01C, violate or be rendered void or ineffective under any Law; or (iv) violate
any provision of the Public Utility Holding  Company Act of 1935 ("PUHCA"),  the
Natural Gas Act of 1935 ("NGA"),  the Natural Gas Policy Act of 1978 ("NGPA") or
any of the regulations promulgated under PUHCA, NGA or NGPA.

     E. Consents. No consent, approval,  authorization,  or permit of, or filing
with or  notification  to, any Person which,  if not obtained or made,  would be
likely to  adversely  affect  the value of the  Production  Payment  or would be
likely to adversely  affect in any material  respect the use or operation of the
Subject  Interests or would be likely to interfere in any material  respect with
the transactions  contemplated by this Agreement or the Related  Agreements,  is
required  (i) for or in  connection  with the  execution  and  delivery  of this
Agreement or any Related Agreement by either Seller or by Guarantor or for or in
connection  with the  consummation  of the  transactions  and performance of the
terms  and  conditions  contemplated  hereby  or  thereby  by  either  Seller or
Guarantor,   (ii)  in  order  to  prevent  any  change  in  terms,  termination,
cancellation, default, or acceleration (or any right thereof from arising) under
the  terms,  conditions,  or  provisions  of  any  Subject  Interest  (or of any
agreement,  instrument,  or  obligation  relating  to or  burdening  any Subject
Interest) as a result of such execution, delivery, consummation, or performance,
or (iii) in order to prevent the  creation or  imposition  of any lien,  charge,
penalty,  restriction,  security interest,  or encumbrance on or with respect to
any Subject  Interest or the Production  Payment as a result of such  execution,
delivery, consummation, or performance.

     F.  Preference  Rights and  Transfer  Requirements.  Except as disclosed in
Schedule 4, the Subject  Interests and the  Production  Payment are not and will
not be subject  to, and neither  Seller nor any  Affiliate  of either  Seller is
bound by, any  Preference  Rights or  Transfer  Requirements  which apply to the
Conveyance  of the  Production  Payment  to Buyer and  which,  if not  waived or
satisfied,  would be  likely to  adversely  affect  the value of the  Production
Payment or would be likely to adversely  affect in any material  respect the use
or  operation  of the Subject  Interests  or would be likely to interfere in any
material  respect with the  transactions  contemplated  by this Agreement or the
Related Agreements.

     G.  Actions;  Orders.  Except as  disclosed in Schedule 4: (i) there are no
Actions pending or, to the knowledge of either Seller, threatened which would be
likely to  adversely  affect  the value of the  Production  Payment  or would be
likely to adversely  affect in any material  respect the use or operation of the
Subject  Interests or would be likely to interfere in any material  respect with
the transactions  contemplated by this Agreement or the Related Agreements,  and
(ii) there is no judgment or outstanding  order,  injunction,  decree,  or award
rendered  by any  Governmental  Authority,  arbitrator  or panel of  arbitrators
against  either  Seller  or the  Subject  Interests  which  would be  likely  to
adversely  affect  the  value of the  Production  Payment  or would be likely to


                                       7





adversely  affect in any  material  respect the use or  operation of the Subject
Interests  or would be likely to  interfere  in any  material  respect  with the
transactions contemplated by this Agreement or the Related Agreements.

     H. Compliance With Laws. Except as disclosed in Schedule 4: (i) the Subject
Interests and the Business are in  compliance in all material  respects with all
Laws,  (ii) neither  Seller has received any notice of any  violation or alleged
violation  (or of any fact or  circumstance  which with notice or the passage of
time or both would constitute a violation) of any Law applicable to the Business
or the Subject  Interests that would be likely to adversely  affect the value of
the  Production  Payment or would be likely to adversely  affect in any material
respect  the use or  operation  of the Subject  Interests  or would be likely to
interfere in any material  respect with the  transactions  contemplated  by this
Agreement  or the  Related  Agreements,  and (iii)  neither  Seller  nor, to the
knowledge of either  Seller,  any prior  operator of the Subject  Interests  has
entered into any currently  existing  compliance or remediation  agreements with
any  Governmental  Authority  or filed any  currently  effective  compliance  or
remediation  plans  with any  Governmental  Authority  which  would be likely to
adversely  affect  the  value of the  Production  Payment  or would be likely to
adversely  affect in any  material  respect the use or  operation of the Subject
Interests  or would be likely to  interfere  in any  material  respect  with the
transactions contemplated by this Agreement or the Related Agreements.

     I.  Permits;  Filings.  Each Seller holds all material  Permits.  Except as
disclosed in Schedule 4, to either Seller's imputed knowledge:  (i) such Permits
are in full force and effect and all fees and charges relating thereto have been
paid,  (ii) each  Seller has in all  material  respects  and in a timely  manner
complied  with,  and  operated  the Subject  Interests  and the Business (to the
extent either Seller is the operator thereof) in accordance with, the conditions
and provisions of all such Permits,  and (iii) no notices of violation have been
received by either  Seller and no  proceedings  are pending or  threatened  that
present a material  probability  of resulting in any  modification,  revocation,
termination,  or  suspension  of any such Permit or of  requiring  any  material
corrective or remediation  action with respect  thereto.  To the extent required
and to the knowledge of each such Seller,  all  applications for renewal of such
Permits have been timely filed.  (As used in this Subsection I and the following
Subsection  J, "imputed  knowledge"  means such  knowledge  that a Seller would,
acting as a prudent operator of the Subject Interests be expected to discover or
otherwise become aware of in the course of performing its duties as operator for
those Subject Interests for which it is operator.)

     J. Compliance With Contracts and Leases. Except as disclosed in Schedule 4,
with respect to all material  contracts,  agreements,  leases,  and arrangements
which are  included  in the  Subject  Interests  or by which any of the  Subject
Interests is bound (i) to each Seller's  knowledge and to each Seller's  imputed
knowledge, such material contracts,  agreements, leases, and arrangements are in
full  force  and  effect;  (ii) to the  knowledge  of each  Seller  there are no
material  violations or breaches  thereof and no existing facts or circumstances
which  upon  notice or the  passage of time or both will  constitute  a material
violation  or  breach  thereof;  (iii) no notice of the  exercise  or  attempted
exercise of premature  termination,  price  reduction,  market-out,  or material
curtailment has been received by either Seller or any Affiliate of either Seller
with respect  thereto;  (iv) no notice has been received by either Seller or any
Affiliate  of either  Seller  that any party  thereto  intends  not to honor its
obligations thereunder; and (v) no Seller is participating in any discussions or
negotiations  regarding  modification  thereof that would be likely to adversely


                                       8





affect  the value of the  Production  Payment  or would be  likely to  adversely
affect in any material respect the use or operation of the Subject  Interests or
would be likely to  interfere  in any  material  respect  with the  transactions
contemplated by this Agreement or the Related Agreements.

     K.  Brokerage  Fees and  Commissions.  Neither  Seller nor any Affiliate of
either Seller has incurred any  obligation or entered into any agreement for any
investment banking,  brokerage,  or finder's fee or commission in respect of the
transactions  contemplated by this Agreement or the Related Agreements for which
Buyer shall incur any liability other than fees and expenses  referred to in the
Fee Letter.

     L. Imbalances.  Schedule 4 lists all material Imbalances existing as of the
dates shown on such Schedule,  and such Imbalances have not increased materially
since such dates.

     M. Taxes.  Each Seller has, to its knowledge,  timely paid all Taxes levied
against the Subject Interests, or the production attributable thereto, which are
currently due and payable as required by Law, except for any such Taxes that are
being contested in good faith by appropriate proceedings.

     N. Reserve  Report.  Without  limiting any of either  Seller's  obligations
under  the  Related   Agreements,   neither   Seller   makes  any   warranty  or
representation  as to quantity,  quality,  or  recoverability of the Hydrocarbon
reserves attributable to the Subject Interests, except that each Seller warrants
and  represents  that (i) the  production  history  data  and data on  operating
history that either  Seller  provided to the  Petroleum  Engineer to prepare the
Reserve Report are true and correct in all material  respects,  and in providing
the same such Seller did not omit any  material  information  necessary  to make
such data not  misleading in the context in which they were  provided,  (ii) the
aggregated  net revenue  interests  that either  Seller  provided the  Petroleum
Engineer with respect to the Subject Interests as a whole correctly represent in
all  material  respects  Sellers' Net Revenue  Interests in the various  Subject
Interests,  taking into account on an aggregate basis any reductions in Sellers'
interests due to either Seller's  failure to consent to proposed  operations and
any  anticipated  future  reductions  in either  Seller's  interests  due to the
achievement  of payouts and similar  events,  (iii) to each Seller's  knowledge,
substantially  all Subject  Wells which were taken into  account in such Reserve
Report were,  and  continue to be,  producing,  (iv) all such Subject  Wells are
included in or covered by the Property Exhibit  attached to the Conveyance,  and
(v) such Reserve  Report does not cover any PDP, PDNP or PUD reserves other than
the PDP, PDNP or PUD reserves attributable to the Subject Interests.

     O. Environmental Matters.

     (1) The Subject  Interests,  and the operation of the Business are, and, to
the  knowledge of each Seller,  at all times have been,  in material  compliance
with all applicable  Environmental  Laws,  other than past  violations that have
been settled or corrected and remediated in all material  respects and for which
no material  obligations  remain outstanding except those being performed in the
ordinary course of business.

     (2) To the knowledge of each Seller,  each Seller and the Subject Interests
(i) are not subject to any consent decree,  compliance  order, or administrative
order issued  pursuant to  applicable  Environmental  Laws,  and (ii) except for

                                       9






routine  matters,  have not received any currently  pending  written request for
information,   notice  of  violation,  demand  letter,  administrative  inquiry,
complaint or claim from any Governmental Authority pursuant to any Environmental
Law.

     (3) To the knowledge of each Seller,  the Subject Interests are not subject
to  any  liens  recorded  by  any   Governmental   Authority  under   applicable
Environmental Laws.

     P. Title.  Each Seller's  representations  and warranties in Section 6.3 of
the Conveyance are true and correct.

     Q. Subject Wells. All currently  existing  producing wells  attributable to
the  Subject  Interests  have been  drilled  and  completed  within  the  limits
permitted by lease,  contract,  pooling,  or unit  agreement  and by Law. To the
knowledge of each Seller,  all  drilling  and  completion  of such wells and all
related  development and operations  have been conducted in material  compliance
with all Laws and in accordance with industry standards.  Except as disclosed in
Schedule  4,  to the  knowledge  of each  Seller,  no such  well is  subject  to
penalties on allowables after the Closing Date because of any  overproduction or
any other violation of Law.

     R.  Status of  Seller.  Neither  Seller is a  non-resident  alien,  foreign
corporation,  foreign  partnership,  foreign  trust or foreign  estate (as those
terms are defined in the Code).  Neither Seller is an "investment  company" or a
company  "controlled"  by an  "investment  company"  within  the  meaning of the
Investment  Company Act of 1940,  as  amended,  nor is either  Seller  otherwise
subject to regulation  under or the restrictions of such act. Neither Seller nor
the  Guarantor  is a  "public  utility  company"  or a "public  utility  holding
company"  or a  subsidiary  of a "public  utility  holding  company"  within the
meaning of the Public Utility Holding Company Act of 1935, as amended.

     S.  Condition of Subject  Interests.  The  machinery,  equipment,  tangible
personal property, fixtures and improvements used in connection with the Subject
Interests  are  adequate   (except  for  ordinary   repairs,   replacement   and
maintenance)  to  produce  the net  projected  production  of PDP  reserves  (as
estimated by the Reserve Report delivered in connection with the Closing).

     T. Information True. No information, statement, or certificate with respect
to the  Subject  Interests  furnished  by  either  Seller  or  Guarantor  or any
representative,  employee,  or consultant of either Seller or Guarantor pursuant
hereto or in connection  with the  transactions  contemplated  hereby and by the
Related Agreements, when taken as a whole with all other information provided to
Buyer, contains any untrue statement of a material fact or omits a material fact
necessary to make the statements  contained  therein under the  circumstances in
which they are made not  misleading.  Neither  Seller has  knowledge of any fact
that has not been  disclosed to Buyer which would be likely to adversely  affect
the value of the  Production  Payment or would be likely to adversely  affect in
any material  respect the use or operation of the Subject  Interests or would be
likely to interfere in any material respect with the  transactions  contemplated
by this Agreement or the Related  Agreements.  The engineering  information with
respect  to the  Subject  Interests  supplied  to Buyer by or on  behalf  of the
Sellers was from the Reserve Report delivered pursuant to Section 8.02K hereof.


                                       10






     U. Bankruptcy. There are no bankruptcy, reorganization,  assignment for the
benefit  of  creditors  or  arrangement   proceedings  pending  against,   being
contemplated  by, or, to the  knowledge  of either  Seller,  threatened  against
either Seller or Guarantor or any of their respective subsidiaries.

     V.  Dedicated  Contracts and Refund  Obligations.  Other than  contracts on
Schedule  4 of this  Agreement  and other  Permitted  Encumbrances,  no  Subject
Interest  is  dedicated  or  otherwise  subject to any  contract  (other  than a
contract to which Buyer is a party or a  Production  Sale  Contract  approved by
Buyer under the Marketing  Agreement) for the sale or  transportation of Subject
Hydrocarbons  that would bind Buyer as the owner of such  Subject  Hydrocarbons.
Neither Seller nor, to the knowledge of either Seller, any of their predecessors
in  title,  has  received  prepayments  (including  payments  for Gas not  taken
pursuant to "take or pay" or similar  contracts) for any Gas to be produced from
the Subject  Interests  after the Closing Date.  Neither Seller is, and Buyer as
its successor will not be, subject to any kind of refund  obligation (other than
Imbalances  as addressed  above) with  respect to Gas produced  from the Subject
Interests prior to the Closing Date.

     W. No Material  Adverse  Change.  From  September  30, 2004, to the Closing
Date,  there  has not  been any  material  adverse  change  (other  than  normal
production,  fluctuations  in the market  prices for Gas and Oil  generally,  or
changes that have otherwise been disclosed to Buyer in Schedule 4 hereto) in the
Subject  Interests  taken as a whole,  or to the  ability  of  either  Seller or
Guarantor to perform their respective  obligations under the Related  Agreements
or the Pioneer Guaranty taken as a whole.

     X.  Effective  Conveyance of Property  Interest.  The  Conveyance  does not
constitute  an  executory  contract  or  unexpired  lease  within the meaning of
Section 365 of the United States Bankruptcy Code.

     Y. Guarantor. Guarantor is rated BBB- by S&P and Baa3 by Moody's.

     Z. The Sellers  have in full force and effect  insurance of the type and in
the amounts set forth in Schedule 8.02F.

SECTION 4.02.     Representations and Warranties of Buyer.

     Buyer  represents  and  warrants to Seller as follows as of the date hereof
and as of the Closing Date:

     A. Buyer is a limited  liability  company duly organized,  validly existing
and in good  standing  under the laws of the state of Delaware.  The  execution,
delivery and  performance by Buyer of this Agreement and the Related  Agreements
to which it is a party,  and of the  transactions  described herein and therein,
have been duly and validly  authorized  by all  necessary  action on the part of
Buyer.  Buyer is a "United  States person" within the meaning of Section 7701 of
the Internal Revenue Code.

     B. Buyer is acquiring  the  Production  Payment for its own account and not
with any  intention  to transfer  all or any part of the  Production  Payment to
others in  violation of the  Securities  Act of 1933,  as amended,  or any other
applicable securities laws.


                                       11






     C. This Agreement and the Related Agreements to which Buyer is a party have
each been duly executed and delivered by Buyer,  and each constitutes the legal,
valid and binding  obligation of Buyer  enforceable  against Buyer in accordance
with its terms,  subject,  however, to bankruptcy,  insolvency,  reorganization,
moratorium and other laws affecting  creditors'  rights generally and to general
principles of equity.

     D. Actions;  Orders.  (i) There are no Actions pending or, to the knowledge
of Buyer,  threatened  which  relate to the  transactions  contemplated  by this
Agreement or the Related Agreements and (ii) there is no judgment or outstanding
order,  injunction,  decree, or award rendered by any Governmental  Authority by
which Buyer or any Affiliate of Buyer is bound that would be likely to adversely
affect  the   transactions   contemplated  by  this  Agreement  or  the  Related
Agreements.

     E. Brokerage Fees and Commissions. Neither Buyer nor any Affiliate of Buyer
has incurred any  obligation or entered into any  agreement  for any  investment
banking, brokerage, or finder's fee or commission in respect of the transactions
contemplated by this Agreement or the Related Agreements for which either Seller
shall incur any liability.

                                   ARTICLE V
                                LETTER OF CREDIT

SECTION 5.01.     Letter of Credit.

     If (i) either Seller or Guarantor  grants liens or security  interests on a
substantial  part of its or its  Subsidiary's  property  or assets to secure its
bank debt or bonds  generally,  (ii) a Change of Control  occurs that results in
Guarantor or its successor being rated less than Approved  Investment  Grade, or
(iii)  the  unsecured  long  term  debt of the  Guarantor  shall be rated  below
Investment  Grade at any time,  then Seller  shall  deliver to Buyer within five
business  days  after  the  Royalty  Owner's  request   therefor  an  acceptable
irrevocable letter of credit in a face amount of $20,000,000 issued by an issuer
with credit  ratings of its senior  unsecured long term  Indebtedness  of A+ (or
higher) by S&P and A2 (or higher) by Moody's Investors Service or, alternatively
A (or higher) by S&P and A1 (or higher) by Moody's Investors Service and (except
to the extent such letter of credit is drawn upon) Working  Interest Owner shall
maintain  such letter of credit,  or one or more  replacement  letters of credit
meeting  such  criteria,  in effect for the benefit of Royalty  Owner until such
time as Guarantor or its successor is once again rated  Investment  Grade.  Each
such letter of credit shall have attached thereto a form of drawing  certificate
substantially  in the form of  Exhibit D hereto,  with  appropriate  insertions,
shall  require  no  documents  to be  presented  for  drawing  other  than  such
certificate  (and the letter of credit  itself),  and shall otherwise be in such
issuing bank's standard form for "clean" irrevocable standby letters of credit.

     Royalty  Owner  may  draw  upon  such  letter  of  credit  in  any  of  the
circumstances contemplated in Exhibit D, but only in such circumstances.  If any
such  drawing is made in  connection  with a failure of  performance  or payment
under the Pioneer Guaranty (or a replacement thereof),  the funds drawn shall be
used to provide a remedy to Royalty Owner for such failure.  If any such drawing
is made in connection with a notice of termination of such letter of credit,  or
a failure to provide a  replacement  letter of credit,  the funds drawn shall be


                                       12





held by Royalty Owner as cash collateral (a) until needed to provide a remedy to
Royalty Owner for a failure of performance or payment under the Pioneer Guaranty
(or a replacement  thereof),  or (b) until an acceptable  replacement  letter of
credit is in fact  provided  to Royalty  Owner,  or (c) until  Guarantor  or its
successor is once again rated  Investment  Grade.  Upon the occurrence of either
circumstance  described in the preceding  clauses (b) or (c), any remaining cash
collateral  shall be promptly  returned to Guarantor or its  successor.  As used
herein, "Change of Control" means (a) the acquisition of ownership,  directly or
indirectly,  beneficially  or of  record,  by any  Person or group  (within  the
meaning of the  Securities  Exchange Act of 1934 and the rules of the Securities
and Exchange  Commission  thereunder as in effect on the date hereof), of equity
interests  representing  more than 35% of the  aggregate  ordinary  voting power
represented by the issued and outstanding equity interests of the Guarantor;  or
(b) occupation of a majority of the seats (other than vacant seats) on the board
of directors of the  Guarantor by Persons who were neither (i)  nominated by the
board  of  directors  of the  Guarantor  nor  (ii)  appointed  by  directors  so
nominated.  For purposes  hereof,  a Person  shall be deemed  rated  "Investment
Grade" if the long-term senior unsecured obligations of such Person are rated at
or above BBB- by S&P and Baa3 by Moody's.

                                   ARTICLE VI
                       ADJUSTMENT OF SCHEDULED QUANTITIES

SECTION 6.01.     Additional Definitions

     As used in  this  Article  VI,  the  following  terms  have  the  following
meanings:

     "Adjustment  Quantity"  shall  have the  meaning  given to such term in the
Conveyance.

     "PDP Reserves" means proved  developed  producing  reserves of Methane,  as
determined in accordance with the  definitions and standards  promulgated by the
Society of Petroleum Engineers.  Each calculation of PDP Reserves shall be based
on the then most recent reserve engineering report provided under Section 4.4 of
the Conveyance.

     "Remaining Reserves" means, as of the date of any determination, all of the
PDP Reserves  projected to be  attributable  to the Subject  Interests  (whether
attributable to the Production  Payment or to Working  Interest Owner's retained
interests) after such date for the remaining expected productive life thereof.

     "Tail  Ratio"  means  the  ratio  of the  Tail  Reserves  to the  Remaining
Reserves.

     "Tail Reserves" means, as of the date of any  determination,  the Remaining
Reserves  projected to be attributable to the Subject Interests after the Target
Termination Time.

     "Target  Termination  Time" means  January 1, 2010 (or,  if any  Adjustment
Quantity is expected to exist at such time,  after the first date  thereafter on
which no Adjustment Quantity is expected to exist).

SECTION 6.02.     Covenant to Amend Conveyance

     A. Option to Adjust Scheduled Quantities.


                                       13






     If for any reason at any time, or from time to time,  both of the following
conditions exist:

     (1)   the Tail Ratio is less than fifty percent (50%), and

     (2)   the production of  Subject Hydrocarbons  for any period of  January 1
           through June 30 or any period  of July 1 through  December 31 exceeds
           120% of the projected production of Subject Hydrocarbons attributable
           to the Subject Wells  for such period as set forth in the most recent
           Reserve Report,  (assuming equal  semi-annual production  during each
           year for which  such  projected  production  is set  forth only  on a
           yearly basis),

then  Royalty  Owner  shall  have the  option to cause the  remaining  Scheduled
Quantities to be adjusted as provided in Subsection B of this Section.

     B. Procedure to Adjust Scheduled Quantities.

     Upon  Royalty  Owner's  election  to  exercise  the  option  set  forth  in
Subsection A of this section,  Working Interest Owner shall in good faith adjust
the  Scheduled  Quantities by preparing a revised  Schedule 1 to the  Conveyance
that results,  at the time of Royalty Owner's exercise of the option,  in a Tail
Ratio as of the Target  Termination  Time that is greater  than,  but as near as
reasonably possible to fifty percent (50%); provided,  however, that (i) Working
Interest Owner shall not increase Scheduled Quantities in any Month to more than
95% of the Methane  projected in the relevant  Reserve Report to be produced and
saved in such Month,  (ii)  Working  Interest  Owner shall  consult with Royalty
Owner about  adjustments to Scheduled  Quantities that will minimize costs under
Subsection D below, and (iii) in no event shall any adjustments to the Scheduled
Quantities extend the Termination Time or decrease  Scheduled  Quantities in any
earlier  Month if any later Month is  increased or changed or if any Month has a
smaller  proportional  decrease.  In addition,  any  adjustment to the Scheduled
Quantities  under  this  Section  shall  result  in a net  present  value of the
adjusted  Scheduled  Quantities  equal to the net present value of the Scheduled
Quantities  prior to such  adjustment.  The net present  value of the  Scheduled
Quantities  prior to such  adjustment  shall be equal to the net  present  value
(before deduction of federal income taxes) of each Month's Scheduled  Quantities
as of the date of determination, assuming that such Scheduled Quantities will be
sold at a price  whose index  component  is the net fixed price to be paid under
Royalty Owner's commodity and basis swaps as then in effect with respect to such
Scheduled  Quantity  (in  this  Section,   the  "Related  Commodity  Swap")  and
discounting  the assumed sales  proceeds at a discount  rate of 4.625%.  The net
present  value of the adjusted  Scheduled  Quantities  shall be equal to the net
present  value  (before  deduction  of  federal  income  taxes) of each  Month's
adjusted Scheduled Quantities as of the date of determination, assuming that the
unchanged  Scheduled  Quantities  will be sold at the prices provided for in the
preceding sentence and any increased Scheduled  Quantities for any month will be
sold at a price then  available  under an  achievable  market  swap whose  index
component is the net fixed price to be paid under Royalty Owner's  commodity and
basis swaps to be entered into with respect to such increased Scheduled Quantity
(in this Section,  the "Related  Adjusted  Commodity  Swap") and discounting the
assumed sales  proceeds at a discount rate equal to the sum of an achievable one
month LIBOR rate under a swap plus 87.5 basis points and taking into account the
costs (less the  benefits) to Royalty  Owner of adjusting  (both  unwinding  for
reductions in Scheduled  Quantities and adding or supplementing for increases in

                                       14






Scheduled  Quantities) the Related Adjusted Commodity Swap to reflect the change
in the Scheduled  Quantities and similarly  adjusting the interest rate swaps of
Royalty  Owner.  To the extent  that,  after doing the  foregoing,  any such net
unwind costs still result in a present  value of adjusted  Scheduled  Quantities
that is less than the present  value of the Scheduled  Quantities  prior to such
adjustment,  Working Interest Owner shall make further  adjustments to Scheduled
Quantities  to  eliminate  such  shortfall  and,  if  necessary,  to extend  the
Termination Time.  Within 20 days of Royalty Owner's election,  Working Interest
Owner shall  present the revised  Schedule 1 to Royalty  Owner for  verification
that the revised Schedule complies with the foregoing  requirements.  If Royalty
Owner agrees with the revised  Schedule 1, Working Interest Owner shall promptly
prepare a supplement to the Conveyance incorporating the revised Schedule 1 into
the Conveyance,  Working Interest Owner and Royalty Owner shall promptly execute
and  acknowledge  such  supplement,  and Working  Interest  Owner shall,  at its
expense,  cause such  amendment to be filed promptly in all  appropriate  county
records.

     C. Determination by Petroleum Engineer.

     If Working  Interest  Owner and  Royalty  Owner do not agree  upon  Working
Interest  Owner's revised Schedule 1 and execute and acknowledge a supplement to
the Conveyance pursuant to Subsection B above, then the Petroleum Engineer shall
within 30 days  determine  the revisions to be made to Schedule 1 to achieve the
result  set out in the  first  sentence  of  Subsection  B  above.  The fees and
expenses of the Petroleum  Engineer  shall be borne equally by Working  Interest
Owner and Royalty Owner. The  determination  of the Petroleum  Engineer shall be
binding  upon  Working   Interest   Owner  and  Royalty   Owner  and,  upon  the
determination by the Petroleum  Engineer of the contents of the revised Schedule
1, Working  Interest Owner shall promptly prepare a supplement to the Conveyance
incorporating the revised Schedule 1 into the Conveyance, Working Interest Owner
and Royalty Owner shall promptly execute and acknowledge  such  supplement,  and
Working  Interest Owner shall, at its expense,  cause such amendment to be filed
promptly in all appropriate county records.

     D.       Ancillary Costs.

     All costs and expenses  resulting from any exercise of the option  provided
in Subsection B above shall, to the extent not included in the net present value
calculation  described  in  Subsection  B above,  be paid  promptly  by  Working
Interest Owner.  Among such costs and expenses are (a) any costs and expenses of
adjusting and unwinding the Production  Sales  Contracts to match or approximate
the new Scheduled Quantities,  and (b) if the Production Sales Contracts are not
amended, any penalties, extra charges, or reductions in purchase price resulting
from  Scheduled  Quantities  that  are  more  or less  than  the  quantities  of
Hydrocarbons specified in the Production Sales Contracts.

                                  ARTICLE VII
                          COVENANTS OF SELLER AND BUYER

SECTION 7.01.     Public Announcements.

     Section  8.10  of the  Conveyance  and  Section  11.15  hereof  set out the
obligations  of  the  parties  hereto  with  respect  to  certain   confidential
information.  The parties acknowledge and agree,  however, that such obligations

                                       15






shall not restrict  Royalty  Owner,  Working  Interest  Owner or Guarantor  from
filing this Agreement or the Related  Agreements  with the  Securities  Exchange
Commission  or  any  other  Governmental   Authority  or  from  describing  this
Agreement,  the Related Agreements,  or the transactions  contemplated herein or
therein in any press  release  or other  public  statement  or any  earnings  or
analyst  conference  calls.  Section 8.10 of the  Conveyance  and Section  11.15
hereof shall not be deemed to prevent the filing and recording of the Conveyance
or any  mortgage,  financing  statement  or similar  agreement by any lender (or
trustee or agent on any  lender's  behalf) to Buyer in the public deed  records.
Buyer's  lenders  and  their  Affiliates,   including  Wachovia  Bank,  National
Association  may  also  publish  customary  "tombstone"  announcements  in  such
publications  as they deem  appropriate  following  the  Closing  Date,  and the
parties hereto and their respective  counsel may from time to time refer to such
"tombstones" and repeat the content thereof to third parties.

SECTION 7.02.     Buyer's Mortgage.

     As  provided in Section  7.1 of the  Conveyance,  Buyer may grant liens and
security  interests in, to and covering the Production  Payment and also Buyer's
rights under this Agreement.

SECTION 7.03.     Survival Past Closing.

     All of the representations,  warranties, covenants and agreements contained
in this  Agreement  shall survive the Closing and the delivery of the Conveyance
and continue until the termination of the Production  Payment as provided in the
Conveyance.

SECTION 7.04.     Reasonable Cooperation.

     From and after the date hereof,  the each Seller and their Affiliates shall
reasonably  cooperate  with the Buyer and its  counsel  in  connection  with the
offering  and  sale of  loans,  certificates  of  ownership  interest,  or other
instruments secured by, payable from or representing  ownership interests in the
Production Payment (such instruments,  "VPP  Instruments"),  provided,  however,
that  such  reasonable  cooperation  shall be at  Buyer's  expense  and shall be
limited to the following: (i) providing  non-confidential  information available
to either Seller that the Buyer and/or its counsel deems reasonably necessary in
connection  with the  offering  and  sale of VPP  Instruments;  and (ii)  making
available to Buyer's lenders,  financiers and rating agencies, such officers and
engineers  as Buyer  may  reasonably  request  in order to  assist  Buyer in any
financing or securitization.

SECTION 7.05.     Preferential Purchase Rights.

     If a third party properly and lawfully  exercises a  preferential  right to
purchase the  Production  Payment or a portion  thereof after the Closing,  then
Buyer will reconvey the Production  Payment or such portion thereof to Seller in
order  that  Seller  may make  the  necessary  conveyance  to such  third  party
purchaser,  and Seller  and Buyer  shall  amend the  Conveyance  (including  the
"Scheduled Quantities" listed therein) accordingly. The consideration payable by
such third party purchaser upon the exercise of such preferential right shall be
paid over by Seller to Buyer in consideration of Buyer's reconveyance. Since the
entire purchase price paid hereunder by Buyer consists of both the Cash Purchase
Price and Buyer's  assumption of certain  hedging  contracts with Wachovia Bank,

                                       16






National Association pursuant to the Novation Agreement,  Seller and Buyer shall
together decide whether to request Wachovia Bank, National Association to permit
such  third  party  purchaser,  as part  of its  purchase  price,  to  assume  a
proportionate portion of the liabilities under such hedging contracts agreements
or whether to calculate the value of such liabilities as a component of the cash
purchase  price to be paid by such  third  party  purchaser.  Seller  will  also
indemnify and hold harmless Buyer for any losses and expenses  suffered by Buyer
as the result of the exercise of any such preferential right to purchase, to the
extent not compensated by the payment to Buyer of the consideration paid by such
third party purchaser.

                                  ARTICLE VIII
                               CLOSING CONDITIONS

SECTION 8.01.     Seller's Closing Conditions.

     The obligation of Seller to consummate the transactions contemplated hereby
is  subject,  at the option of Seller,  to the  satisfaction  on or prior to the
Closing Date of all of the following conditions:

     A.  Representations,  Warranties,  and Covenants.  The  representations and
warranties of Buyer contained in this Agreement shall have been true and correct
when  made on and as of the  date  of this  Agreement,  and  the  covenants  and
agreements  of Buyer to be performed on or before the Closing Date in accordance
with this Agreement shall have been duly performed.

     B. Officer's Certificate. Seller shall have received a certificate dated as
of the Closing  Date,  executed by a duly  authorized  officer of Buyer,  to the
effect that to such officer's knowledge the conditions set forth in Subsection A
of this Section 8.01 have been satisfied.

     C. Related Agreements.  Buyer shall have executed and delivered each of the
following instruments or agreements:

     (1)  Conveyance.   A  Conveyance  of  Term  Overriding   Royalty  Interest,
substantially in the form and to the effect attached hereto as Exhibit E (herein
referred to as the "Conveyance");

     (2) Marketing  Agreement.  A Marketing Agreement  substantially in the form
and to the  effect  attached  hereto as  Exhibit B  (herein  referred  to as the
"Marketing Agreement"); and

     (3) Swap Novation. A Novation Confirmation substantially in the form and to
the effect  attached  hereto as Exhibit A (herein  referred to as the  "Novation
Agreement") among Buyer, Pioneer USA and Wachovia Bank, National Association.


                                       17






SECTION 8.02.     Buyer's Closing Conditions.

     The obligation of Buyer to consummate the transactions  contemplated hereby
is  subject,  at the  option of Buyer,  to the  satisfaction  on or prior to the
Closing Date of all of the following conditions:

     A.  Representations,  Warranties,  and Covenants.  The  representations and
warranties of each Seller contained in this Agreement and of Guarantor contained
in the Pioneer  Guaranty shall have been true and correct when made on and as of
the date of this  Agreement,  and the covenants and agreements of each Seller to
be  performed on or before the Closing Date in  accordance  with this  Agreement
shall have been duly performed.  There shall have been no fraud committed by the
either Seller or Guarantor in  connection  with inducing the Buyer to enter into
this Agreement or the Related Agreements.

     B. Officer's Certificate.  Buyer shall have received a certificate dated as
of the Closing Date,  executed by a duly authorized  officer of each Seller,  to
the  effect  that to such  officer's  knowledge  the  conditions  set  forth  in
Subsection A of this Section 8.02 have been satisfied.

     C. Related  Agreements.  Each Seller shall have  executed and delivered the
Conveyance,  and Pioneer USA shall have  executed and  delivered  the  Marketing
Agreement and the Novation Agreement.

     D.  Opinion of Counsel.  Seller  shall have  delivered to Buyer the written
opinions,  dated the  Closing  Date,  of W. Marc  Dingler IV,  Senior  Attorney,
counsel  to Seller and  Guarantor,  and of  Thompson  & Knight LLP and  Foulston
Seifkin,  LLP, special counsel to Seller,  substantially in the forms and to the
effect set forth in Schedules 8.02D(1), 8.02D(2), and 8.02D(3) hereto.

     E. Affidavit of Non-foreign Status.  Buyer shall have received an Affidavit
of  Non-foreign  Status,  substantially  in the form attached as Schedule  8.02E
hereto, which has been properly executed by or on behalf of each Seller.

     F. [Intentionally Blank].

     G.  Production  Sales  Contract.  Buyer shall have  received  copies of the
executed  initial  Production  Sales  Contract  referred  to in Section 2 of the
Marketing Agreement.

     H. Pioneer  Guaranty.  Pioneer shall have executed and delivered to Buyer a
Pioneer Guaranty  substantially in the form and to the effect attached hereto as
Exhibit C (herein referred to as the "Pioneer Guaranty"); and

     I. Organizational Documents; Incumbency. Buyer shall have received:

     (1) copies of the articles or certificates of  incorporation of Pioneer USA
and the  partnership  agreement  of  Pioneer  LP and  Guarantor,  in  each  case
certified  as of a recent date by an  appropriate  officer of the such Seller or
Guarantor, as the case may be, each such certificate dated the Closing Date;


                                       18






     (2) signature and  incumbency  certificates  of the officers of each Seller
and Guarantor executing this Agreement and the Related Agreements;

     (3) resolutions of the board of directors or similar governing body of each
Seller and  Guarantor  approving and  authorizing  the  execution,  delivery and
performance  of  this  Agreement  and the  Related  Agreements,  as  applicable,
certified as of the Closing Date by its  secretary or an assistant  secretary as
being in full force and effect without modification or amendment; and

     (4) a good standing certificate from the applicable  Governmental Authority
of  Pioneer  USA's  and  Guarantor's  jurisdiction  of  incorporation,  and each
jurisdiction  in which such Seller owns Subject  Interests,  each dated a recent
date prior to the Closing Date.

     J. Buyer, in Buyer's sole  discretion,  shall be satisfied with the results
of any review of the Subject  Interests  that it  undertakes,  any due diligence
investigation   with  respect  to  the  matters   addressed  by  each   Seller's
representations and warranties in this Agreement, the Conveyance and the Related
Documents,  and with all legal matters related to the transactions  contemplated
in this  Agreement,  the  Conveyance  and the Related  Documents,  including the
status of the consents and  amendments  obtained  with respect to such  Seller's
loan agreements, mortgages, and indentures, if any.

     K. The Sellers shall have delivered the Reserve Report.

                                   ARTICLE IX
                                     CLOSING

SECTION 9.01.     Closing.

     The Closing shall be held on the Closing Date at 10:00 a.m.,  Houston time,
at the offices of Buyer's  counsel in Houston,  Texas,  or at such other time or
place as Seller  and  Buyer may  otherwise  agree.  Each of Seller  and Buyer is
obligated to the other to proceed to Closing,  to satisfy the  conditions to the
other's consummation of the transactions contemplated hereby that are set out in
Article VIII hereof,  and to deliver the  documents  (and funds,  in the case of
Buyer) that are described in the remainder of this Article IX.

SECTION 9.02.     Seller's Closing Obligations.

     At Closing,  each Seller shall execute and deliver, or cause to be executed
and delivered, to Buyer the following, against delivery of the Purchase Price:

     A. Related Agreements. The Related Agreements;

     B. Officer's  Certificate.  The  certificate of such Seller  referred to in
Section 8.02B;

     C. Legal Opinions. The legal opinions referred to in Section 8.02D;

     D. Non-foreign  Affidavit.  The Affidavit of Non-foreign Status referred to
in Section 8.02E;


                                       19






     E. Reserve Report. The Reserve Report referred to in Section 8.02K;

     F. Sale  Contract.  The Production  Sales  Contract  referred to in Section
8.02G; and

     G. Corporate Certificates.  The various certificates referred to in Section
8.02I.

SECTION 9.03.     Buyer's Closing Obligations.

     At Closing,  Buyer shall  deliver,  or cause to be  delivered  the Purchase
Price in immediately available funds to Pioneer USA and Pioneer LP in the manner
provided in Section 3.02,  and execute and deliver,  or cause to be executed and
delivered, to Seller the following:

     A.  Related  Agreements.  The  Related  Agreements  (other than the Pioneer
Guaranty); and

     B. Certificate.  The officer's  certificate of Buyer referred to in Section
8.01B.

                                   ARTICLE X
                         ASSUMPTION AND INDEMNIFICATION

SECTION 10.01.    Covered Liabilities.

         As used herein, "Covered Liabilities" means:

     (1) any and all liabilities,  losses,  costs,  damages,  penalties or fines
suffered by any Buyer Party as a result of either Seller's or Guarantor's breach
of any of its respective representations,  warranties,  covenants or obligations
under  this  Agreement  or any of the  Related  Agreements,  including,  without
limitation, all of each Seller's obligations under Article VI of the Conveyance,
and including, without limitation, any Title Failure,

     (2) any and all liabilities,  losses,  costs,  damages,  penalties or fines
suffered  by an  Indemnified  Party as a result of (i) any  injury to persons or
property or similar tort arising  from or  involving  activities  on the Subject
Lands,  (ii) any violation on the Subject  Lands (or in connection  with oil and
gas operations or ancillary activities on or involving the Subject Lands) of any
Environmental  Law or any other Law or legal duty  relating to public  health or
safety or the production or conservation  of Hydrocarbons or natural  resources,
(iii) the breach of any duty  imposed  under any such Law, or under any Lease or
Permitted  Encumbrance,  relating  to  oil  and  gas  operations  and  ancillary
activities (including environmental  remediation) on the Subject Lands, (iv) the
delivery  to or  receipt  by Buyer or a  designee  of Buyer of any  Hydrocarbons
produced from or  attributable  to the Subject  Interests  (including  any claim
relating to the quality or handling  thereof) or (v) oil and gas  operations and
ancillary  activities on or involving the Subject Lands, in each case regardless
of whether the foregoing  arise under,  out of, or in connection with any Action
or any claim therein,  any order or decree of any Governmental  Authority or any
arbitrator's award;

     (3) any and all liabilities,  losses,  costs,  damages,  penalties or fines
suffered by any Buyer Party (or any successor owners of the Production  Payment)
as a result of any Action set forth on Schedule 4, and


                                       20






     (4)  all  reasonable  costs  and  expenses  of  any  Indemnified  Party  in
investigating or defending  against any claims for such alleged damages,  costs,
losses,  liabilities,  penalties or fines (including,  without  limitation,  any
reasonable attorneys' fees).

SECTION 10.02.    Indemnification by Seller.

     Buyer  will be the  purchaser  of an  overriding  royalty  interest  in the
Subject  Interests  and  Buyer  will not own any  rights  to  conduct  or direct
operations  thereon or any tangible  property  interest therein or any equipment
located  thereon,  all such rights,  tangible  property  interests and equipment
being retained by either Seller. Buyer will not be responsible for the operation
or condition of any such property.

     FROM AND AFTER THE CLOSING  DATE,  EACH SELLER SHALL  JOINTLY AND SEVERALLY
INDEMNIFY  AND  HOLD  HARMLESS  EACH  BUYER  PARTY,  THEIR  PRESENT  AND  FORMER
DIRECTORS,  OFFICERS,  EMPLOYEES,  AND AGENTS, AND EACH OF THE HEIRS, EXECUTORS,
SUCCESSORS, AND ASSIGNS OF ANY OF THE FOREGOING (COLLECTIVELY HEREIN REFERRED TO
AS THE "INDEMNIFIED  PARTIES") FROM AND AGAINST ANY AND ALL COVERED LIABILITIES.
THE FOREGOING INDEMNITY SHALL APPLY WHETHER OR NOT THE COVERED LIABILITIES ARISE
OUT OF THE SOLE,  JOINT OR CONCURRENT  NEGLIGENCE,  FAULT OR STRICT LIABILITY OF
ANY  INDEMNIFIED  PARTY OR ANY OTHER PERSON  INDEMNIFIED  HEREUNDER AND APPLIES,
WITHOUT LIMITATION,  TO ANY COVERED LIABILITY IMPOSED UPON ANY INDEMNIFIED PARTY
AS A RESULT OF ANY LAW, THEORY OF STRICT  LIABILITY OR OTHERWISE,  EXCEPT TO THE
EXTENT CAUSED BY AN INDEMNIFIED PARTY'S GROSS NEGLIGENCE OR WILLFUL MISCONDUCT.

SECTION 10.03.    Third Party Claims.

     If a claim by a third  party is made  against an  Indemnified  Party and if
such Indemnified Party intends to seek indemnity with respect thereto under this
Article X, such  Indemnified  Party shall  promptly  notify  Pioneer USA of such
claim.  Pioneer USA shall have thirty (30) days after  receipt of such notice to
undertake,  conduct, and control, through counsel of its own choosing and at its
own expense,  the settlement or defense thereof, and the Indemnified Party shall
cooperate  with it in  connection  therewith;  provided  that  Pioneer USA shall
permit  the  Indemnified  Party to  participate  in such  settlement  or defense
through  counsel  chosen  by  such  Indemnified  Party  at the  expense  of such
Indemnified  Party and further provided that, to the extent that the Indemnified
Party  reasonably  appears to have  defenses  available to it that are different
from or additional to those  available to either  Seller,  the assertion of such
different  or  additional  defenses by such  counsel  shall be at the expense of
Seller. So long as the Sellers,  at their own cost and expense,  (a) have within
such thirty (30) days undertaken the defense of, and assumed full responsibility
for all Covered  Liabilities  with  respect to, such claim,  (b) are  reasonably
contesting  such claim in good faith by  appropriate  proceedings,  and (c) have
taken such action (including the posting of a bond,  deposit, or other security)
as may be  necessary  to  prevent  any  action to  foreclose  a lien  against or
attachment of the property of the  Indemnified  Party for payment of such claim,
the  Indemnified  Party shall not pay or settle any such claim.  Notwithstanding
compliance by the Sellers with the preceding  sentence,  the  Indemnified  Party

                                       21






shall  have the right to pay or settle any such  claim,  provided  that,  if the
Sellers are in material  compliance  with the preceding  sentence at the time of
such  payment  or  settlement  by the  Indemnified  Party then in such event the
Indemnified Party shall waive any right to indemnity therefor by the Sellers for
such claim.  If,  within  thirty (30) days after the receipt of the  Indemnified
Party's notice of a claim of indemnity hereunder,  the Sellers do not notify the
Indemnified  Party that they elect, at their cost and expense,  to undertake the
defense thereof and assume full  responsibility for all Covered Liabilities with
respect thereto, or gives such notice and thereafter fails to contest such claim
in good faith or to prevent action against the Indemnified Party or to foreclose
a lien against or attachment of the Indemnified Party's property as contemplated
above,  the  Indemnified  Party  shall  have the right to  contest,  settle,  or
compromise the claim but shall not thereby waive any right to indemnity therefor
pursuant to this Agreement.

                                   ARTICLE XI
                                  MISCELLANEOUS

SECTION 11.01.    Counterparts.

     This Agreement may be executed in one or more  counterparts and by separate
parties on separate  counterparts,  all of which shall be considered one and the
same agreement,  and shall become effective when one or more  counterparts  have
been signed by each of the parties and delivered to the other party.

SECTION 11.02.    Governing Law; Consent to Jurisdiction.

     THIS  AGREEMENT  SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE  WITH THE
LAWS OF THE STATE OF TEXAS  WITHOUT  GIVING EFFECT TO ANY CONFLICTS OF LAW RULES
OR PRINCIPLES  THEREOF THAT WOULD DIRECT THE  APPLICATION OF THE LAWS OF ANOTHER
JURISDICTION.

     EACH  OF  SELLER  AND  BUYER  HEREBY  IRREVOCABLY  SUBMITS  ITSELF  TO  THE
NON-EXCLUSIVE  JURISDICTION  OF THE STATE AND FEDERAL  COURTS  SITTING IN DALLAS
COUNTY,  TEXAS, AND IN THE CITY AND COUNTY OF NEW YORK, NEW YORK, AND AGREES AND
CONSENTS  THAT  SERVICE OF PROCESS  MAY BE MADE UPON IT IN ANY LEGAL  PROCEEDING
RELATING TO THIS AGREEMENT BY ANY MEANS ALLOWED UNDER TEXAS, NEW YORK OR FEDERAL
LAW. EACH OF SELLER AND BUYER HEREBY WAIVES AND AGREES NOT TO ASSERT,  BY WAY OF
MOTION, AS A DEFENSE OR OTHERWISE,  THAT ANY PROCEEDING IN EITHER OF SUCH VENUES
ARISING  OUT OF OR IN ANY  WAY  RELATED  TO  THIS  AGREEMENT  IS  BROUGHT  IN AN
INCONVENIENT  FORUM OR THAT THE VENUE  THEREOF  IS  IMPROPER,  AND EACH  FURTHER
CONSENTS TO ANY REQUESTED  TRANSFER OF ANY SUCH PROCEEDING  BROUGHT IN ANY OTHER
VENUE TO A FEDERAL COURT SITTING IN THE NORTHERN  DISTRICT OF THE STATE OF TEXAS
OR SOUTHERN DISTRICT OF THE STATE OF NEW YORK, TO THE EXTENT THAT IT HAS SUBJECT
MATTER  JURISDICTION,  AND OTHERWISE TO A STATE COURT IN DALLAS COUNTY, TEXAS OR


                                       22






IN THE CITY AND COUNTY OF NEW YORK,  NEW YORK. IN FURTHERANCE  THEREOF,  EACH OF
SELLER  AND  BUYER  HEREBY  ACKNOWLEDGES  AND  AGREES  THAT IT  WILL BE  NEITHER
INCONVENIENT NOR UNFAIR TO LITIGATE OR OTHERWISE  RESOLVE ANY DISPUTES OR CLAIMS
IN A COURT SITTING IN EITHER SUCH COUNTY AND STATE.

SECTION 11.03.    WAIVER OF JURY TRIAL.

     EACH OF THE PARTIES HERETO HEREBY AGREES TO WAIVE ITS RESPECTIVE  RIGHTS TO
A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING  HEREUNDER OR
ANY DEALINGS BETWEEN THEM RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT.  THE
SCOPE OF THIS WAIVER IS INTENDED TO BE  ALL-ENCOMPASSING OF ANY AND ALL DISPUTES
THAT MAY BE FILED IN ANY COURT AND THAT  RELATE  TO THE  SUBJECT  MATTER OF THIS
TRANSACTION,  INCLUDING CONTRACT CLAIMS, TORT CLAIMS,  BREACH OF DUTY CLAIMS AND
ALL OTHER COMMON LAW AND STATUTORY CLAIMS.  EACH PARTY HERETO  ACKNOWLEDGES THAT
THIS WAIVER IS A MATERIAL INDUCEMENT TO ENTER INTO A BUSINESS RELATIONSHIP, THAT
EACH HAS ALREADY RELIED ON THIS WAIVER IN ENTERING INTO THIS AGREEMENT, AND THAT
EACH WILL CONTINUE TO RELY ON THIS WAIVER IN ITS RELATED FUTURE  DEALINGS.  EACH
PARTY HERETO FURTHER  WARRANTS AND  REPRESENTS  THAT IT HAS REVIEWED THIS WAIVER
WITH ITS LEGAL  COUNSEL AND THAT IT KNOWINGLY  AND  VOLUNTARILY  WAIVES ITS JURY
TRIAL  RIGHTS  FOLLOWING  CONSULTATION  WITH LEGAL  COUNSEL.  THIS WAIVER MAY BE
MODIFIED  ONLY IN  WRITING,  AND  THIS  WAIVER  SHALL  APPLY  TO ANY  SUBSEQUENT
AMENDMENTS,  RENEWALS,  SUPPLEMENTS  OR  MODIFICATIONS  HERETO.  IN THE EVENT OF
LITIGATION,  THIS AGREEMENT MAY BE FILED AS A WRITTEN  CONSENT TO A TRIAL BY THE
COURT.

SECTION 11.04.    Entire Agreement.

     This  Agreement  and the Related  Agreements  contain the entire  agreement
between the parties with respect to the subject  matter  hereof and there are no
agreements,  understandings,  representations, or warranties between the parties
other than those set forth or referred to herein or therein.

SECTION 11.05.    Excluded Taxes and Expenses.

     A. The final  sentence  of the  definition  of  "Taxes"  in the  Conveyance
describes  certain taxes (in this Section,  "Excluded  Taxes") that are excluded
from the  "Taxes"  for which  Seller is  responsible  under  Section  2.3 of the
Conveyance. Buyer shall be responsible for all such Excluded Taxes.

     B.  Whether  or  not  the  transactions   hereby   contemplated   shall  be
consummated, Seller agrees to pay all reasonable costs and expenses of Buyer and
the  other  Buyer  Parties  in  connection  with the  negotiation,  preparation,
execution,  delivery,  enforcement,  filing, recording or registration,  and any

                                       23


>



refiling,  re-recording  or  re-registration,  of this  Agreement,  the  Related
Agreements,  any  amendment  or  supplement  hereto  or  thereto,  and any other
document  listed in Section 9.02 or 9.03 (and,  subject to the provisions of the
Fee Letter,  any instruments or documents executed and delivered pursuant to any
financing,  the proceeds of which are used or to be used to finance the purchase
of the Production  Payment from the Sellers)  including the reasonable  fees and
out-of-pocket  expenses  of  counsel  for Buyer and the other  Buyer  Parties in
connection  therewith,  as well as any and all  stamp and  other  similar  taxes
payable or  determined  to be payable  with  respect  thereto,  all such  costs,
expenses,  stamp and other  similar  taxes to be paid in  immediately  available
funds at the  Closing,  if then  invoiced,  and  after  the  Closing  to be paid
promptly upon receipt of an invoice therefor.  Sellers also agree to pay, and to
reimburse  Buyer for, all reasonable  costs and expenses  hereafter  incurred by
Buyer  in  connection  with  the  final  discharge  of the  Production  Payment,
including,  without limitation,  the fees and out-of-pocket  expenses of counsel
employed by Buyer in connection therewith.

SECTION 11.06.    Notices.

     All  notices  and other  communications  hereunder  shall be in writing and
shall be deemed  sufficiently  given for all purposes hereof if (a) delivered in
person,  by courier or by  registered  or  certified  United  States Mail to the
Person to be notified,  with receipt obtained, or (b) sent by telecopy,  telefax
or other  facsimile or  electronic  transmission,  with  "answer  back" or other
"evidence  of  receipt"  obtained,  in each case to the  appropriate  address or
number as set forth in Section 8.2 of the  Conveyance  (or at such other address
or number for a party as shall be specified by like  notice).  Each notice shall
be deemed  effective on receipt by the  addressee as aforesaid;  provided  that,
notice   received  by  telecopy,   telefax  or  other  facsimile  or  electronic
transmission  after 5:00 p.m. at the  location of the  addressee  of such notice
shall be deemed  received on the first  business day  following the date of such
electronic receipt.

SECTION 11.07.    Successors and Assigns.

     This  Agreement  shall be  binding  upon and  inure to the  benefit  of the
parties hereto and their respective heirs, legal representatives, successors and
assigns; provided, however, that any assignment or transfer hereof or grant of a
security  interest  herein must be made in compliance with Sections 7.1, 7.2 and
8.1 of the Conveyance.

SECTION 11.08.    Headings.

     The  headings  to  Articles,  Sections,  and  other  subdivisions  of  this
Agreement are inserted for convenience of reference only and will not affect the
meaning or interpretation of this Agreement.

SECTION 11.09.    Amendments and Waivers.

     This  Agreement  may  not be  waived,  modified  or  amended  except  by an
instrument  or   instruments  in  writing  signed  by  the  party  against  whom
enforcement of any such  modification or amendment is sought.  The waiver by any
party hereto of a breach of any term or provision of this Agreement shall not be
construed as a waiver of any subsequent breach.


                                       24






SECTION 11.10.    Schedules and Exhibits.

     All Schedules  and Exhibits  hereto which are referred to herein are hereby
made a part hereof and incorporated herein by such reference.

SECTION 11.11.    Interpretation.

     In construing this Agreement:

     A.  Examples.  Examples  shall not be construed  to limit,  expressly or by
implication, the matter they illustrate;

     B. Including.  The word "includes" and its derivatives means "includes, but
is not limited to" and corresponding derivative expressions;

     C.  Location  of  Definitions.  A  defined  term  has its  defined  meaning
throughout  this  Agreement and each Schedule to this  Agreement,  regardless of
whether it appears before or after the place where it is defined;

     D.  Controlling  Provisions.  Each Schedule to this  Agreement is a part of
this Agreement,  but if there is any conflict or inconsistency  between the main
body of this Agreement and any Schedule, the provisions of the main body of this
Agreement shall prevail; and

     E. Neutral  Interpretation.  This  Agreement is the result of  arm's-length
negotiations  from equal  bargaining  positions by all parties.  It is expressly
agreed that this  Agreement  shall not be  construed  against any party,  and no
consideration  shall be given or  presumption  made on the basis of who  drafted
this  Agreement or any particular  provision  hereof or who supplied the form of
Agreement.

SECTION 11.12.    Agreement for the Parties' Benefit Only.

     Except as provided in Section  7.02  hereof,  nothing in this  Agreement is
intended to confer upon any Person,  other than the parties and their respective
successors and permitted assigns, any rights, benefits,  remedies or obligations
hereunder; and no Person, other than the parties and their respective successors
and  permitted  assigns,  is entitled to rely on any  representation,  warranty,
covenant, or agreement contained herein; provided,  however, that, Buyer and its
successors  and  permitted  assigns  shall be  entitled  to enforce the terms of
Article X for the benefit of any Persons who are Indemnified  Parties. Any claim
for indemnification under Article X on behalf of an Indemnified Party other than
Buyer (or Buyer's  successor or permitted  assign) must be made and administered
by  Buyer or its  successors  or  permitted  assign.  For  avoidance  of  doubt,
permitted  assigns of Buyer include  Buyer's  Affiliates and managed  commercial
paper conduits and Buyer's and such Affiliate's  respective  owners,  investors,
insurers,  lenders,  and any providers of any commodity or interest rate hedging
products.


                                       25






SECTION 11.13.    Severability.

     If any term or other  provision of this Agreement is invalid,  illegal,  or
incapable  of being  enforced  by any rule of Law or  public  policy,  all other
conditions and provisions of this Agreement  shall  nevertheless  remain in full
force and effect so long as the economic or legal substance of the  transactions
contemplated  hereby is not  affected in any adverse  manner to any party.  Upon
such  determination  that any term or other  provision is invalid,  illegal,  or
incapable of being enforced, the parties hereto shall negotiate in good faith to
modify  this  Agreement  so as to effect the  original  intent of the parties as
closely as possible  in an  acceptable  manner to the end that the  transactions
contemplated hereby are fulfilled to the extent possible.

SECTION 11.14.    No Retained Liens.

     No lien or encumbrance of whatsoever nature,  express or implied,  shall be
retained by or created in favor of either  Seller in or against  the  Production
Payment as security  for payment or  performance  of the  Purchase  Price or any
other obligations of Buyer; and each Seller hereby expressly waives and releases
any such express or implied liens and encumbrances.

SECTION 11.15.    Confidentiality.

     Each party hereto shall hold in confidence any confidential  information it
has  obtained  from  another  party  hereto as provided  in Section  8.10 of the
Conveyance.

SECTION 11.16.    Limitations on Damages.

         NEITHER PARTY HERETO SHALL BE RESPONSIBLE TO THE OTHER PARTY OR TO ANY
PERMITTED BENEFICIARY HEREOF FOR CONSEQUENTIAL DAMAGES OR PUNITIVE OR EXEMPLARY
DAMAGES.

SECTION 11.17.    Tax Treatment.

     Although the Production Payment is a real property interest for purposes of
state law, the parties agree to treat the Production  Payment as a mortgage loan
for federal income tax purposes. For avoidance of doubt, the parties acknowledge
that Sellers (and not Buyer) are entitled to all tax credits  (including credits
under Section 29 of the Code)  attributable  to the  Production  Payment and the
production attributable thereto.

SECTION 11.18.    No Recourse.

     EACH PARTY HERETO HEREBY AGREES THAT THE OBLIGATIONS AND LIABILITIES OF THE
BUYER UNDER THIS AGREEMENT ARE SOLELY THE LIMITED LIABILITY COMPANY  OBLIGATIONS
AND  LIABILITIES  OF THE  BUYER,  AND NO  OFFICER,  DIRECTOR,  MEMBER,  MANAGER,
EMPLOYEE,  AGENT OR  AFFILIATE  OF THE BUYER SHALL HAVE ANY  PERSONAL  LIABILITY
THEREFOR.

              [The remainder of this page intentionally left blank]

                                       26






     IN WITNESS WHEREOF,  this Agreement has been signed by or on behalf of each
of the parties as of the day first above written.

                                  BUYER:

                                  ROYALTY ACQUISITION COMPANY, LLC,
                                  a Delaware limited liability company

                                  By:  RAC Holding Corp., Its Managing Member


                                  By:     /s/ Jill A. Gordon
                                     ------------------------------------------
                                  Name:   Jill A. Gordon
                                  Title:  Vice President





                                      S-1









                                  SELLER:

                                  PIONEER NATURAL RESOURCES USA, INC.


                                  By:    /s/ Richard P. Dealy
                                     ------------------------------------------
                                       Richard P. Dealy
                                       Executive Vice President and Chief
                                       Financial Officer




                                  PIONEER NATURAL RESOURCES PROPERTIES LP


                                  By: Westpan Properties, Inc., general partner
                                      Its General Partner

                                      By:    /s/ Richard P. Dealy
                                         --------------------------------------
                                           Richard P. Dealy
                                           Executive Vice President





                                      S-2