EXHIBIT 10.30H












                       PIONEER NATURAL RESOURCES USA, INC.

                            401(k) AND MATCHING PLAN

             (Amended and Restated Effective as of January 1, 2002)
              ----------------------------------------------------







                       PIONEER NATURAL RESOURCES USA, INC.
                            401(k) AND MATCHING PLAN

             (Amended and Restated Effective as of January 1, 2002)
              ----------------------------------------------------


                                TABLE OF CONTENTS

                                                                           Page

PREAMBLE      .............................................................  1

ARTICLE I.    DEFINITIONS AND CONSTRUCTION.................................  1
              Section 1.1   Definitions  ..................................  1
              Section 1.2   Construction ..................................  9

ARTICLE II.   ELIGIBILITY AND PARTICIPATION................................  9
              Section 2.1   Eligibility  ..................................  9
              Section 2.2   Participation..................................  9

ARTICLE III.  CONTRIBUTIONS, LIMITATIONS AND FORFEITURES................... 10
              Section 3.1   Pre-Tax and Pre-Tax Bonus Contributions........ 10
              Section 3.2   Matching Contributions......................... 11
              Section 3.3   Catch-Up Contributions......................... 11
              Section 3.4   After-Tax Contributions........................ 12
              Section 3.5   Payment of Contributions....................... 12
              Section 3.6   Return of Employer Contributions............... 12
              Section 3.7   Nondiscrimination Testing...................... 13
              Section 3.8   Application of Forfeitures..................... 17
              Section 3.9   Rollover Contributions......................... 17

ARTICLE IV.   TRUST FUND................................................... 18
              Section 4.1   Trust and Trustee.............................. 18
              Section 4.2   Trust Investment Options....................... 18
              Section 4.3   Valuation and Adjustment of Accounts........... 19

ARTICLE V.    VESTING...................................................... 19
              Section 5.1   Fully Vested Accounts.......................... 19
              Section 5.2   Vesting of Employer Account.................... 19
              Section 5.3   Special Vesting Provisions..................... 20

ARTICLE VI.   VALUATIONS, DISTRIBUTIONS.................................... 21
              Section 6.1   Time of Distribution........................... 21
              Section 6.2   Distribution of Retirement and Disability
                            Benefits....................................... 22



                                         (i)





              Section 6.3   Distribution of Death Benefit.................. 24
              Section 6.4   Distribution of Separation from
                            Employment Benefit............................. 25
              Section 6.5   Forfeitures  .................................. 26
              Section 6.6   In-Service Withdrawals......................... 28
              Section 6.7   Distributions to Minors and Persons Under
                            Legal Disability............................... 29
              Section 6.8   Benefits Payable to Missing Participant or
                            Beneficiary.................................... 29
              Section 6.9   Plan Loans   .................................. 30
              Section 6.10  Qualified Domestic Relations Orders............ 30
              Section 6.11  Transfer of Eligible Rollover Distribution..... 31

ARTICLE VII.  PLAN ADMINISTRATION.......................................... 32
              Section 7.1   401(k) and Matching Plan Committee............. 32
              Section 7.2   Powers, Duties and Liabilities of
                            the Committee.................................. 33
              Section 7.3   Rules, Records and Reports..................... 33
              Section 7.4   Administration Expenses and Taxes.............. 33

ARTICLE VIII. AMENDMENT AND TERMINATION.................................... 34
              Section 8.1   Amendment    .................................. 34
              Section 8.2   Termination  .................................. 34
              Section 8.3   Benefit Plan Design Committee.................. 34

ARTICLE IX.   TOP-HEAVY PROVISIONS......................................... 35
              Section 9.1   Top-Heavy Definitions.......................... 35
              Section 9.2   Minimum Contribution Requirement............... 36
              Section 9.3   Minimum Vesting Schedule....................... 36

ARTICLE X.    MISCELLANEOUS GENERAL PROVISIONS............................. 37
              Section 10.1  Spendthrift Provision.......................... 37
              Section 10.2  Claims Procedure............................... 37
              Section 10.3  Maximum Contribution Limitation................ 37
              Section 10.4  Employment Noncontractual...................... 38
              Section 10.5  Limitations on Responsibility.................. 38
              Section 10.6  Merger or Consolidation........................ 38
              Section 10.7  Applicable Law................................. 39
              Section 10.8  USERRA Compliance.............................. 39


                                      (ii)





                       PIONEER NATURAL RESOURCES USA, INC.
                            401(k) AND MATCHING PLAN

             (Amended and Restated Effective as of January 1, 2002)
              ----------------------------------------------------

         THIS 401(k) AND MATCHING PLAN, a profit sharing plan, made and executed
by PIONEER NATURAL RESOURCES USA, INC., a Delaware corporation (the "Company"),

                          W I T N E S S E T H T H A T :

         WHEREAS,  the Company has  heretofore maintained for the benefit of its
employees a qualified profit sharing plan known as the Pioneer Natural Resources
USA, Inc.  401(k) Plan and a  qualified money purchase pension plan known as the
Pioneer Natural Resources USA, Inc. Matching Plan; and

         WHEREAS,  effective as of  12:01 a.m. on  January 1,  2002, the Company
merged the Pioneer Natural Resources  USA, Inc.  Matching Plan with and into the
Pioneer Natural Resources, Inc. 401(k) Plan; and

         WHEREAS,  the  Company  now  desires to  restate  the  Pioneer  Natural
Resources  USA,  Inc.  401(k) Plan to  accommodate such merger,  change the plan
name, update the plan for tax compliance,  incorporate prior amendments and make
certain other changes;

         NOW, THEREFORE, in consideration of the premises and pursuant to the
authority  reserved  thereunder,  the Pioneer Natural Resources USA, Inc. 401(k)
Plan is hereby amended by  restatement in its entirety,  effective as of January
1, 2002, as the Pioneer Natural  Resources USA, Inc. 401(k) and Matching Plan to
read as follows:


                                   ARTICLE I.

                          DEFINITIONS AND CONSTRUCTION

         Section  1.1   Definitions.    Unless  the  context  clearly  indicates
otherwise, when used in this Plan:

                 (a) "Account" means a Participant's After-Tax Account, Employer
         Employer Account,  Matching Plan Account,  Mesa After-Tax Account, Mesa
         Premium Account,  Mesa Profit-Sharing Account,  Pre-Tax Account,  Prior
         Plan  Employer  Account,  Prior  Plan  Pre-Tax Account  and/or Rollover
         Account,  as the  context requires.  The  Committee  may  establish and
         maintain  separate subaccounts  within a  Participant's  Accounts if it
         deems such to be necessary for the proper administration of the Plan.


                                       -1-








                 (b) "Affiliated Company" means any corporation or organization,
         other than  an Employer,  which is a  member of a  controlled  group of
         corporations  (within the meaning of  Section 414(b) of the Code) or of
         an affiliated  service group  (within the meaning of  Section 414(m) of
         the Code) with respect  to which an Employer is also a member,  and any
         other incorporated or unincorporated trade or business which along with
         an  Employer  is  under  common  control  (within  the  meaning  of the
         regulations  from  time to time  promulgated  by the  Secretary  of the
         Treasury pursuant to  Section 414(c) of the Code);  provided,  however,
         that for the  purposes of Section 10.3 of the Plan,  Section 414(b) and
         (c) of the Code  shall be applied as  modified by Section 415(h) of the
         Code.

                 (c)  "After-Tax Account"  means  the  account  established  and
         maintained  under this  Plan by the Committee to record a Participant's
         interest under this Plan  attributable to  After-Tax Contributions made
         to this Plan.

                 (d)  "After-Tax  Contribution"  means a  contribution made by a
         Participant to this Plan pursuant to Section 3.4.

                 (e) "Basic Compensation"  means the sum of  (i) the base salary
         or wages  and any  overtime payable by an  Employer to an  Employee for
         personal services  rendered to the  Employer but  excluding any  amount
         payable pursuant to an Employer's salary continuation program, (ii) any
         contributions  made  by an  Employer on  behalf  of the  Employee  to a
         qualified cash or  deferred arrangement  (within the meaning of Section
         401(k) of the Code) maintained by such Employer, including any Catch-Up
         Contributions and  Total Pre-Tax  Contributions  made by an Employer to
         this Plan on behalf of such Employee,  (iii) any compensation reduction
         amounts elected by such  Employee for the purchase of benefits pursuant
         to a cafeteria plan  (within the meaning of Section 125(d) of the Code)
         maintained by an  Employer,  and (iv) any elective amounts that are not
         includible  in the gross  income of an  Employee by  reason of  Section
         132(f)(4) of the Code; provided, however,  that the Basic  Compensation
         of an  Employee  taken into  account  under the  Plan for any Plan Year
         shall  not  exceed  $200,000  (as  adjusted  to  take into  account any
         cost-of-living increases  authorized pursuant to  Section 401(a)(17)(B)
         of the Code).

                 (f)  "Catch-Up  Contribution" means a pre-tax contribution made
         by an Employer on behalf of a Participant pursuant to Section 3.3.

                 (g)  "Code"  means  the  Internal  Revenue  Code  of  1986,  as
         amended.

                 (h)  "Committee" means the  401(k) and  Matching Plan Committee
         appointed  by the  Board of Directors of the  Company to administer the
         Plan.

                 (i)  "Company" means  Pioneer Natural  Resources  USA,  Inc., a
         Delaware corporation, and any successor thereto.


                                       -2-








                 (j)  "Compensation"  means  the  sum of  (i)  wages  within the
         meaning  of  Section  3401(a) of the  Code and  all  other  payments of
         remuneration  to  an  Employee by an  Employer  (in  the  course of the
         Employer's trade  or business)  for  which the Employer  is required to
         furnish  the  Employee a  written  statement  under  Sections  6041(d),
         6051(a)(3) and 6052  of the Code,  but determined without regard to any
         rules that limit the remuneration included in wages based on the nature
         or location of the employment or the  services  performed  (such as the
         exception  for agricultural labor in  Section 3401(a)(2)  of the Code),
         (ii) any contributions made by an Employer on behalf of the Employee to
         a qualified cash or deferred arrangement (within the meaning of Section
         401(k) of the Code) maintained by such Employer, including any Catch-Up
         Contributions and  Total Pre-Tax  Contributions made  by an Employer to
         this Plan on behalf of such Employee,  (iii) any compensation reduction
         amounts elected by such  Employee for the purchase of benefits pursuant
         to a cafeteria plan  (within the meaning of Section 125(d) of the Code)
         maintained by an Employer,  and (iv)  any elective amounts that are not
         includible  in the  gross income of an  Employee  by reason of  Section
         132(f)(4) of the Code; provided,  however,  that except for purposes of
         determining  whether an  Employee is a Highly Compensated Employee or a
         Key Employee  (within the meaning of Section 9.1(c)),  the Compensation
         of an  Employee  taken  into  account  under the Plan for any Plan Year
         shall  not  exceed  $200,000  (as adjusted  to take  into  account  any
         cost-of-living  increases authorized  pursuant to Section 401(a)(17)(B)
         of the Code).

                 (k)  "Covered  Employee"  means  any  Employee  other  than  an
         individual who is  (i) a member  of a  collective  bargaining unit with
         which an Employer negotiates and with respect to whom no coverage under
         this Plan has been provided by collective bargaining agreement,  (ii) a
         nonresident  alien with  respect to the  United States who  receives no
         earned income from  an Employer  which constitutes income  from sources
         within the United States,  (iii) a  temporary or  seasonal  Employee as
         determined in accordance with the Employer's normal personnel policies,
         (iv)  not  treated  by an  Employer at  the time of the  performance of
         services as  an  employee for federal  tax purposes,  regardless of any
         subsequent reclassification by an Employer,  any governmental agency or
         account, or (v) treated as a leased employee by an Employer.

                 (l)  "Employee" means any individual employed by an Employer.

                 (m)  "Employer"  shall  include   the  Company  and  a ny other
         incorporated or unincorporated trade or business which may subsequently
         adopt this  Plan with the  consent  of the  Board of  Directors  of the
         Company.

                 (n)  "Employer  Account"  means  the  account  established  and
         maintained under this Plan by  the Committee to record a  Participant's
         interest under this  Plan  attributable to  (i) any amounts credited to
         his or her  Employer Account under the  Superseded Plan as in effect on
         December 31, 2001, and (ii) any Matching Contributions made to the Plan
         for the Participant on or after January 1, 2002.


                                       -3-








                 (o) "Employment Date" means the date an Employee first performs
                 an Hour of Service.

                 (p) "Highly Compensated Employee" means for a Plan Year:

                           (1) any Employee who  during such Plan Year or during
                  the preceding  Plan Year was at any time a 5-percent owner (as
                  defined in  Section 416(i)(1) of  the Code)  of an Employer or
                  Affiliated Company; or

                           (2) any Employee  who during the  preceding Plan Year
                  received  Compensation  greater than  $80,000  (as adjusted to
                  take  into account  any  cost-of-living  increases  authorized
                  pursuant to  Section 414(q)(1) of the  Code) and who is in the
                  group consisting  of the top 20%  (when ranked on the basis of
                  Compensation  received  during  such  preceding  year)  of all
                  Employees, except those excluded pursuant to Section 414(q)(5)
                  of the Code.

         Solely  for  purposes  of  this  definition,  (i)  an  employee  of  an
         Affiliated Company shall be deemed to be an Employee, (ii) compensation
         received from an Affiliated Company shall be deemed to be Compensation,
         and  (iii) a  nonresident alien  who receives  no earned income from an
         Employer  or  Affiliated Company which  constitutes income from sources
         within the United States shall not be considered an Employee.

                 (q) "Hour of Service"  means an  hour for  which an Employee is
         directly   or  indirectly  compensated  or  entitled   to  compensation
         (including  back  pay,  regardless  of  mitigation  of  damages)  by an
         Employer for the  performance of  duties for an Employer or for reasons
         (such as vacation,  sickness or disability)  other than the performance
         of duties for an  Employer.  An Employee will be  credited  with  eight
         Hours of  Service per day  for any customary  work period  during which
         such Employee is on leave of absence authorized by his or her Employer.
         Leaves of absence shall be granted by an Employer to its Employees on a
         uniform, nondiscriminatory basis. In no event shall more than 501 Hours
         of  Service be  credited on  account of any  single  continuous  period
         during which the individual performs no duties.  An Employee's Hours of
         Service shall be credited  to the appropriate Plan Years or eligibility
         computation  period  determined in  accordance  with the  provisions of
         Section 2530.200b-2(b) and (c) of the Department of Labor  Regulations,
         which are  incorporated herein by this reference.  In determining Hours
         of Service for  the purposes of this Plan,  periods of employment by an
         Affiliated Company and services performed as a leased employee  (within
         the meaning of Section 414(n) of the Code) of an Employer or Affiliated
         Company shall be deemed to be periods of employment by an Employer.

                 (r)  "Investment  Fund"  means  any  fund  authorized  for  the
         investment of Trust assets pursuant to Section 4.2.


                                       -4-








                 (s)  "Matching  Contribution" means a  contribution  made by an
         Employer to  the Plan for a Participant pursuant to Section 3.2.

                 (t) "Matching Plan Account"  means the account  established and
         maintained under  this Plan by the Committee  to record a Participant's
         interest under this  Plan attributable to  matching  contributions made
         for such Participant pursuant to the provisions of the Matching Plan as
         in effect on December 31, 2001.

                 (u)  "Matching  Plan" means the  Pioneer Natural Resources USA,
         Inc. Matching Plan,  as in effect from time to time prior to January 1,
         2002.

                 (v)  "Mesa After-Tax Account" means the account established and
         maintained  under this  Plan by the Committee to record a Participant's
         interest under  this Plan  attributable to  his or her  accrued benefit
         derived from after-tax contributions to the Mesa Profit-Sharing Plan as
         in effect on September 30, 1997.

                 (w)  "Mesa Premium Account"  means the account  established and
         maintained under this Plan by the  Committee to record a  Participant's
         interest under this Plan  attributable to  Employer  contributions made
         for such  Participant  pursuant to the  provisions of the  Mesa Premium
         Plan as in effect on September 30, 1997.

                 (x)  "Mesa Premium Plan"  means the Mesa Employees Premium Plan
         and Trust Agreement  as in effect from time to time prior to October 1,
         1997.

                 (y) "Mesa Profit-Sharing Account" means the account established
         and  maintained  under   this  Plan   by  the  Committee  to  record  a
         Participant's  interest  under  this  Plan  attributable  to his or her
         accrued benefit derived from employer contributions to the Mesa Profit-
         Sharing Plan as in effect on September 30, 1997.

                 (z) "Mesa  Profit-Sharing Plan"  means the  Mesa Profit-Sharing
         Plan and  Trust Agreement  as in  effect  from  time to  time  prior to
         October 1, 1997.

                 (aa) "Non-Highly  Compensated  Employee"  means for a Plan Year
         any  Employee who  is not a Highly  Compensated Employee  for such Plan
         Year.

                 (bb) The  "Normal  Retirement  Date" of a Participant means the
         day such Participant attains the age of 65 years.

                 (cc) "One Year Break in Service"  means a  12-consecutive-month
         Period of Severance during which an Employee fails to complete a single
         Hour of Service.

                 (dd) "Participant"  means any  individual who was a participant
         in either the Superseded Plan or the  Matching Plan or  who has elected
         to participate in this Plan pursuant to Section 2.2,  and whose  Vested
         Interest under this Plan has not been fully distributed.


                                       -5-








                 (ee) "Period of Service" means,  for purposes of determining a
         Participant's Vested Interest in his or her Employer Account,  the sum,
         rounded  downward to the  nearest  whole year,  of each  period of time
         commencing with an Employee's  Employment Date or Reemployment Date and
         ending  on the  first  date  thereafter a  Period of  Severance  begins
         (except as provided in  subsection (ff)  of this Section in the case of
         an Employee's  maternity or  paternity leave of  absence).  Included in
         such sum to be  credited to an  Employee shall  be each  period of time
         during  which the  Employee is on an  authorized  leave of  absence for
         reasons of vacation,  sickness,  layoff or another occasion  designated
         and applied by an Employer or Affiliated Company on a nondiscriminatory
         basis,  but  in no event  exceeding one  year  in length.  A  Period of
         Service  also  includes  any  Period  of  Severance  of  less  than  12
         consecutive  months.  If an  Employee who  has no  vested right  to any
         amount credited to his or her Employer Account or Matching Plan Account
         incurs a One Year Break in Service,  such Employee shall forfeit his or
         her prior  Period of Service  unless he or  she completes an additional
         one-year Period of Service before the number  of his or her consecutive
         One Year  Breaks in  Service  equals  five.  Solely for the  purpose of
         determining the Period of Service  completed by a  Covered Employee who
         was in the employ of  Colorado Interstate  Gas Company on  May 1, 2001,
         periods  of  employment  by  Colorado   Interstate  Gas  Company  or  a
         subsidiary  thereof  prior to May 1,  2001,  shall be  considered to be
         periods of employment by an Employer.

                  Any provision of this Plan to the contrary notwithstanding, if
         a Participant participated  in the Superseded  Plan prior to October 1,
         1997,  the  Period of Service  completed  by such  Participant prior to
         January 1,  1998,  shall be (i)  such  Participant's  years of  Vesting
         Service determined under the  Retirement Savings Plan for  Employees of
         Parker & Parsley as of June 27,  1996,  (ii) plus one year for the Plan
         Year  ending  December  31,  1996,   if  during  such  Plan  Year  such
         Participant completed  a Year of  Service under the  Retirement Savings
         Plan for Employees of  Parker & Parsley as in effect at the end of such
         year,  (iii) plus one year for the  Plan Year ending December 31, 1997,
         if such Participant  either (A)  completed a year of Vesting Service as
         of September 30, 1997,  under the Superseded  Plan as in effect on such
         date or (B) completed a one-year Period  of Service under the foregoing
         provisions of this  definition  during the entire  such Plan Year.  For
         purposes of clause  (ii) of the preceding sentence, a Participant shall
         be credited  with a  number of  Hours of  Service  applying the monthly
         equivalency method set forth in Labor Reg. ss. 2530.200b-3(e)(1)(iv) to
         any fractional  part of a year credited to such  Participant as of June
         28, 1996.

                 (ff)  "Period of Severance"  means a  period of time commencing
         with the  date an  Employee  ceases to be  employed  by an  Employer or
         Affiliated  Company for reasons of  Retirement,  Permanent  Disability,
         death, being discharged, or voluntarily ceasing employment, or with the
         first  anniversary of  the date  of his  or her  absence for  any other
         reason, and ending with the date such Employee resumes  employment with
         an Employer or  Affiliated Company;  provided, however, that solely for



                                       -6-








         purposes  of determining  whether an  Employee incurs a  One Year Break
         in Service,  the Period of Severance of an  Employee who is absent from
         work due to the pregnancy of the Employee,  the birth of a child of the
         Employee, the placement of a child with the Employee in connection with
         the adoption of  such child by such Employee,  or caring for such child
         for a period  beginning immediately  following such  birth or placement
         shall not  commence until the  second anniversary of the  first date of
         such absence and the  period between the first and second anniversaries
         of the first date of such  absence shall be considered neither a Period
         of Service nor a Period of Severance.

                 (gg) "Permanent  Disability"  means  the  total  and  permanent
         incapacity of a Participant to  perform the usual  duties of his or her
         employment with an  Employer or Affiliated Company as determined by the
         Committee. Such incapacity shall be deemed to exist when certified by a
         physician acceptable to the Committee.

                 (hh) "Pioneer Stock"  means the common stock of Pioneer Natural
         Resources Company, a Delaware corporation, and any successor thereto.

                 (ii) "Plan"  means  this  Pioneer  Natural  Resources USA, Inc.
         401(k) and Matching Plan (Amended and Restated  Effective as of January
         1, 2002), as in effect from time to time.

                 (jj) "Plan Year" means the calendar year.

                 (kk) "Pre-Tax  Account"  means   the  account  established  and
         maintained under  this Plan by the  Committee to record a Participant's
         interest  under this Plan attributable to (i) Pre-Tax Contributions and
         Pre-Tax  Bonus  Contributions  made by an  Employer on  behalf of  such
         Participant  and  (ii)  any  amounts  credited  to his or her  Employee
         Pre-Tax Contribution Account under the Superseded  Plan as in effect on
         September 30, 1997.

                 (ll) "Pre-Tax Bonus Contribution" means a  contribution made by
         an Employer to this Plan on behalf of a Participant pursuant to Section
         3.1(b).

                 (mm) "Pre-Tax Contribution"  means a  contribution  made  by an
         Employer to this Plan on  behalf of a  Participant pursuant  to Section
         3.1(a).

                 (nn)  "Prior  Plan   Employer   Account"   means   the  account
         established and maintained under this Plan by the Committee to record a
         Participant's  interest  under  this Plan  attributable to any  amounts
         credited to  his or her  BOUSA  Employer Matching  Contribution Account
         under the Retirement Savings Plan for Employees of  Parker & Parsley as
         in effect on June 27, 1996.

                 (oo) "Prior Plan Pre-Tax Account" means the account established
         and  maintained  under   this  Plan  by  the   Committee  to  record  a
         Participant's  interest  under  this  Plan  attributable to any amounts

                                       -7-








         credited to  his or her  Plan A Salary Deferral Contribution Account or
         his or  her BOUSA  Plan Salary Deferral  Contribution Account under the
         Retirement Savings  Plan for Employees of Parker & Parsley as in effect
         on June 27, 1996.

                 (pp) "Qualified  Joint and  Survivor Annuity"  means an annuity
         which is  payable  for the  life  of the  Participant  with a  survivor
         annuity payable for the  life of his  or her spouse equal to 50% of the
         amount of  the annuity  payable  during the  life of  the  Participant;
         provided,  however,  that  in  the  case  of a  Participant  who is not
         married, a Qualified Joint and Survivor  Annuity means an annuity which
         is payable for the life of the Participant.  "Alternate Qualified Joint
         and Survivor Annuity" means an annuity which is payable for the life of
         the Participant with a  survivor annuity payable for the life of his or
         her spouse equal to  75% or 100% of the  amount of the  annuity payable
         during the life of the Participant.

                 (qq)  "Qualified  Preretirement  Survivor  Annuity"   means  an
         annuity which is  payable for the life of the  Participant's  surviving
         spouse.

                 (rr)  "Reemployment  Date"  means  the  date  an Employee first
         performs an Hour of Service following a Period of Severance.

                 (ss)  "Retirement"  means  the  termination  of a Participant's
         employment  with an Employer or  Affiliated Company  on or after his or
         her Normal Retirement Date  for any reason other than death or transfer
         to the employment of another Employer or Affiliated Company.

                 (tt)  "Rollover  Account"  means  the  account  established and
         maintained under this Plan by  the Committee to record a  Participant's
         interest  under  this  Plan   attributable  to  (i)  Rollover  Property
         contributed by such  Participant to this  Plan pursuant to Section 3.9,
         (ii) any  amounts credited to his  or her Rollover Contribution Account
         under the Superseded Plan as in effect on September 30, 1997, and (iii)
         any amounts  credited to  his or her  Rollover  Account  under the Mesa
         Profit-Sharing Plan as in effect on September 30, 1997.

                 (uu)  "Rollover  Property"  means  property the  value of which
         would be excluded from the gross income of the transferor under Section
         402(c), 403(a)(4) or 408(d)(3) of the Code if transferred to the Plan.

                 (vv) "Superseded Plan" means the Pioneer Natural Resources USA,
         Inc. 401(k) Plan,  as in effect from  time to  time prior to January 1,
         2002.  Prior to August 7,  1997,  the Superseded  Plan was known as the
         Retirement Savings Plan for Employees of Parker & Parsley.


                                       -8-








                 (ww)  "Total  Pre-Tax  Contributions"  means  the  sum  of  the
         Pre-Tax Contributions and Pre-Tax Bonus Contributions made on behalf of
         a Participant.

                 (xx)  "Trust"  means  the  trust  fund  established pursuant to
         Section 4.1.

                 (yy)  "Trustee"  means the  individual or  corporate trustee or
         trustees  from time to time appointed and acting as trustee or trustees
         of the Trust established pursuant to the Plan.

                 (zz)  "Valuation Date" means each business day.

                 (aaa)  The "Vested  Interest" of a  Participant  means the then
         vested  portion  of  the  amount  credited  to  the  Accounts  of  such
         Participant at the particular point in time in question.

         Section 1.2 Construction.  The titles to the  Articles and the headings
of the Sections in this Plan are placed herein for convenience of reference only
and in case of any conflict the text of this instrument, rather than such titles
or headings,  shall control.  Whenever a noun or pronoun is used in this Plan in
plural form and there  be only one person or entity within the scope of the word
so used, or in singular form and  there be more than one person or entity within
the scope  of the  word so used,  such noun or  pronoun shall  have a  plural or
singular meaning as appropriate under the circumstance.


                                   ARTICLE II.

                          ELIGIBILITY AND PARTICIPATION

         Section 2.1 Eligibility. Each participant in either the Superseded Plan
or the Matching Plan on December 31,  2001,  shall continue as a  Participant in
this Plan as of January 1, 2002.  Each other Covered Employee shall be  eligible
to become a participant in this Plan on the first day of the first pay period in
the calendar  month next following  his or her Employment Date. If a Participant
ceases  to be a  Covered Employee,  such Participant shall  remain a Participant
under  this Plan  but no contributions  shall be made to the  Plan on his or her
behalf while he or she is not a Covered Employee.

         Section 2.2 Participation.  Each  Covered  Employee  who is eligible to
participate  in the Plan may elect,  on a form  prescribed by the  Committee, to
participate in this  Plan on  the first  day of  the first  pay  period  in  the
calendar month following the filing of such election. Any Participant who ceases
to be a Covered Employee shall thereupon cease to  be eligible to participate in
the Plan;  provided,  however,  that  if  any  such  Participant  is  thereafter
reemployed as a Covered Employee, he or she shall be eligible to elect to resume
participating in the Plan as of the date of such reemployment.


                                       -9-








                                  ARTICLE III.

                   CONTRIBUTIONS, LIMITATIONS AND FORFEITURES

         Section 3.1 Pre-Tax and Pre-Tax Bonus Contributions.

                  (a)  Each  Participant may  elect to have his or her  Employer
         make a Pre-Tax Contribution to  the Plan on his or her  behalf for each
         pay period  in an amount equal to at least 2% and not in excess of 30%,
         of his  or her  Basic  Compensation  for  that  pay  period.  All  such
         contributions shall be made by uniform payroll deductions pursuant to a
         compensation reduction agreement  which authorizes  the Employer to pay
         such contributions to the Trustee on behalf of the Participant.

                  (b) In addition, each Participant may elect to have his or her
         Employer  make a Pre-Tax  Bonus Contribution  to the Plan on his or her
         behalf in an  amount equal  to at least 2% and not in excess of 30%, of
         the bonus payable to such Participant under the Employer's annual bonus
         program.

                  (c) The  Committee  shall  establish  and  maintain  for  each
         Participant  a Pre-Tax Account.  All  amounts  attributable to  Pre-Tax
         Contributions and  Pre-Tax  Bonus Contributions made  by an Employer on
         behalf  of such  Participant  pursuant  to  this  Section 3.1  shall be
         credited to such Participant's Pre-Tax Account.

                  (d) A Participant may change the applicable percentage of such
         payroll (or  bonus)  deductions as  of the  first  day of the first pay
         period  of  any  calendar  month,  or at  any  time  suspend his or her
         election   to  have   Pre-Tax  Contributions   and/or   Pre-Tax   Bonus
         Contributions made  to the Plan,  provided that written  notice of such
         change  or  suspension  is  delivered  to  the  Committee  within  such
         reasonable period of  time prior  to the effective date  thereof as the
         Committee may require.

                  (e)   Any   provision   of   this   Plan   to   the   contrary
         notwithstanding,  the amount of Total Pre-Tax Contributions made to the
         Plan by an Employer on behalf of a Participant for a calendar year when
         added to the amount of any  other elective deferrals within the meaning
         of Section 402(g)(3) of the Code made  with respect to such Participant
         pursuant to any  other plan, contract or  arrangement of an Employer or
         Affiliated  Company for such  calendar year shall not exceed the dollar
         limitation contained in Section 402(g) of  the Code in  effect for such
         calendar year, except to the extent permitted under  Section 3.3 of the
         Plan and Section 414(v) of the Code,  if applicable.  If the percentage
         of Total Pre-Tax Contributions elected by a Participant results in such
         contributions equaling the  limitation imposed by Section 402(g) of the
         Code prior  to the  end of a  calendar  year, then such election by the
         Participant  shall  be  deemed  to be  an  election to  make  After-Tax
         Contributions  to the  Plan  at the  time  such  dollar  limitation  is
         exceeded  unless   otherwise  elected  by  the  Participant;  provided,
         however, that to the extent permitted by Section 414(v) of the Code and
         the  regulations thereunder,  such election shall first be deemed to be


                                      -10-








         an election  to make  Catch-Up Contributions to the Plan.  In the event
         such contributions are not timely recharacterized and the limitation of
         this  subsection  (e) is exceeded with  respect to a  Participant for a
         Plan Year,  then if  such  Participant  notifies  the Committee  of the
         amount of Total Pre-Tax  Contributions that  exceeded  such  limitation
         within such  reasonable period  of time  prior to  the  first  April 15
         following  such  year as the  Committee may  prescribe in its  absolute
         discretion,  the  excess  Total  Pre-Tax  Contributions (along with any
         income  allocable  thereto for  such year,  but  not for the gap period
         following such year) shall be distributed to such  Participant no later
         than such  April 15.  A Participant will be deemed  to have so notified
         the Committee of excess elective deferrals for a calendar year if,  and
         only to the  extent,  such  excess  arises on  account of Total Pre-Tax
         Contributions  made to this Plan  and elective  deferrals made to other
         plans maintained by an Employer or Affiliated Company for such calendar
         year.  Any such excess  deferrals distributed to a Participant shall be
         distributed first from any Pre-Tax Bonus Contributions and then, to the
         extent necessary, from  Pre-Tax Contributions.  The income allocable to
         any excess  Total Pre-Tax Contributions for a Participant for a taxable
         year shall be  determined by multiplying the amount of income allocable
         to such Participant's Pre-Tax Account for such year by a fraction,  the
         numerator of which is the amount of excess Total Pre-Tax  Contributions
         for such  year and  the denominator  of which  is the sum of the amount
         credited to such Participant's  Pre-Tax Account  as of the beginning of
         such  year  plus  the   amount of   such  Participant's  Total  Pre-Tax
         Contributions for such year.  If any  portion of a Pre-Tax Contribution
         is  distributed or  recharacterized pursuant  to this  subsection,  any
         portion  of a  Matching  Contribution  (along with any income allocable
         thereto)  made to  this Plan  for such  Participant  that  matches  the
         distributed or recharacterized Pre-Tax Contribution shall be forfeited.

                  (f)  An  Employer  may  amend  or  revoke  any   Participant's
         compensation reduction agreement at any time during a Plan Year if such
         amendment or  revocation is deemed  by such Employer to be necessary or
         appropriate to ensure that all applicable limitations,  including those
         set forth in Sections 3.1(e), 3.7 and 10.3 are met for such year.

         Section 3.2  Matching  Contributions.  For each pay period an  Employer
shall make to the Plan for  each Participant in its  employ and allocate to such
Participant's  Employer Account a  Matching Contribution equal to 200 percent of
the  Pre-Tax Contributions made  by the  Employer on  such  Participant's behalf
during  such  pay  period  which  are  not in  excess of  five  percent  of such
Participant's  Basic  Compensation  for  such  pay  period.  The Committee shall
establish and maintain an  Employer Account for each Participant.  All  Matching
Contributions made for  a Participant pursuant to this Section shall be credited
to such Participant's Employer Account.

         Section 3.3  Catch-Up Contributions. All  Employees who are eligible to
make Pre-Tax Contributions to this Plan and who have  attained age 50 before the
close of the Plan Year shall be eligible to make Catch-Up Contributions pursuant
to a compensation reduction agreement and in accordance with, and subject to the
limitations of, Section 414(v) of the Code and the regulations thereunder.  Such
Catch-Up  Contributions  shall not be  taken into  account for  purposes  of the
provisions of the Plan implementing the required limitations  of Sections 402(g)
and 415 of the Code.  The Plan shall not be  treated as  failing to  satisfy the


                                      -11-








provisions  of the Plan  implementing  the  requirements  of Section  401(k)(3),
401(k)(11),  401(k)(12), 410(b), or 416 of the Code, as applicable, by reason of
the making of such Catch-Up Contributions.

         Section 3.4 After-Tax Contributions.

                  (a)  Each   Participant   may  elect  to  make  an   After-Tax
         Contribution  to the Plan  for each pay period in an amount which, when
         combined with any  Pre-Tax Contributions  made to the Plan on behalf of
         such  Participant for  that  pay  period,  shall not  exceed 50% of the
         Compensation of such Participant during such pay period.

                  (b)  The  Committee  shall  establish  and  maintain  for each
         Participant an After-Tax Account. All amounts attributable to After-Tax
         Contributions made  by a Participant pursuant to this Section 3.4 shall
         be credited to such Participant's After-Tax Account.

                  (c) After-Tax Contributions may be made in whole or in part by
         uniform payroll  deductions  which  the  Participant  shall in  writing
         authorize his or her Employer to withhold and pay over to the  Trustee.
         A Participant may  change  the  applicable  percentage of  such payroll
         deductions as of the first day of the  first pay period of any calendar
         month,  or at any  time suspend his or her  election to  have After-Tax
         Contributions  made to the Plan,  provided that written  notice of such
         change  or  suspension  is  delivered  to  the  Committee  within  such
         reasonable period  of time prior  to the effective  date thereof as the
         Committee may require.

                  (d) At any time and from time to time during a Plan Year,  the
         Company may limit the After-Tax  Contributions made by a Participant or
         suspend the  making of  After-Tax Contributions  if the Company, in its
         absolute  discretion,  deems  such  to be  necessary or  appropriate to
         ensure  that all  applicable limitations,  including those set forth in
         Sections 3.7 and 10.3, are satisfied for such year.

         Section 3.5 Payment of Contributions.  Pre-Tax Contributions,  Catch-Up
Contributions and After-Tax Contributions made to the Plan by an Employer for or
on behalf of Participants  for a pay period shall be paid to the Trustee in cash
as soon as  practicable  after such pay period ends,  but no later than the 15th
business day after the end of the month in which such pay period  ends.  Pre-Tax
Bonus  Contributions made to the Plan on behalf of Participants shall be paid to
the Trustee in cash as soon as practicable  after the bonus payment is made, but
no later than the 15th day of the month after the end of the month in which such
bonus payment is made. Matching  Contributions made to the Plan for a pay period
shall be paid to the Trustee as soon as  practicable,  but no later than 30 days
after the end of the month in which such pay period ends.

         Section 3.6 Return of  Employer  Contributions.  Contributions  made to
this Plan are conditioned  upon being currently  deductible under Section 404 of
the Code.  Any provision of this Plan to the contrary  notwithstanding,  upon an
Employer's  request,  any such contribution or portion thereof made to this Plan
by  such  Employer  which  (i)  was  made  under  a  mistake  of  fact  which is

                                      -12-








subsequently discovered,  or (ii) is disallowed as a deduction under Section 404
of the Code,  shall be  returned to such  Employer to the extent not  previously
distributed to Participants or their beneficiaries;  provided, however, that the
amounts  returnable to an Employer  pursuant to this Section shall be reduced by
any Trust losses  allocable  thereto and shall be returned to such Employer only
if such  return is made  within  one year  after  the  mistaken  payment  of the
contribution or the date of the  disallowance of the deduction,  as the case may
be.  Except as provided in this  Section,  no  contribution  made by an Employer
pursuant to this Plan shall ever revert to or be recoverable by any Employer.

         Section 3.7  Nondiscrimination Testing.

                 (a) Any provision of this Plan to the contrary notwithstanding,
         if for any Plan  Year the actual deferral  percentage for  the group of
         Highly   Compensated  Employees  eligible  to  elect  to  have  Pre-Tax
         Contributions or Pre-Tax Bonus Contributions made during such Plan Year
         fails to satisfy one of the following tests:

                           (1) the actual deferral  percentage for said group of
                  Highly Compensated  Employees is not  more than 1.25 times the
                  actual deferral percentage for the preceding Plan Year for all
                  Non-Highly Compensated Employees eligible during the preceding
                  Plan Year  to elect  to have  Pre-Tax Contributions or Pre-Tax
                  Bonus Contributions made on their behalf, or

                           (2) the excess of the  actual deferral percentage for
                  said group  of Highly  Compensated  Employees  over the actual
                  deferral  percentage  for  the  preceding  Plan  Year  for all
                  Non-Highly Compensated Employees eligible during the preceding
                  Plan Year to elect  to have  Pre-Tax  Contributions or Pre-Tax
                  Bonus Contributions made on their  behalf is not more than two
                  percentage points, and the actual deferral percentage for said
                  group of  Highly Compensated  Employees is  not more  than two
                  times  the actual  deferral percentage  for the preceding year
                  for all  Non-Highly Compensated  Employees eligible during the
                  preceding Plan  Year to elect to have Pre-Tax Contributions or
                  Pre-Tax Bonus Contributions made on their behalf,

         then the actual deferral  percentage of Participants who are members of
         said group of Highly Compensated Employees shall be reduced by reducing
         the actual deferral percentages  of the  Highly  Compensated  Employees
         with the largest individual actual deferral percentages  to the largest
         uniform  actual   deferral  percentage   (commencing  with  the  Highly
         Compensated  Employee  with the  largest actual deferral percentage and
         reducing his or her actual deferral  percentage to the extent necessary
         to satisfy  one of  the above tests or  to lower such  actual  deferral
         percentage to the actual deferral percentage of the  Highly Compensated
         Employee  with  the  next  largest  actual  deferral  percentage,   and
         repeating this process  as necessary) that permits  the actual deferral
         percentage for  said group of  Highly Compensated Employees  to satisfy
         one of said  tests.  For purposes  of this  subsection  (a),  the  term
         "actual deferral percentage"  for a specified  group of Employees for a


                                      -13-








         Plan Year  means the  average of the ratios  (calculated separately for
         each  Employee  in  such group and  after any  distributions  to Highly
         Compensated Employees  required to  satisfy the  limitation  imposed by
         Section 402(g)  of the  Code) of  (i) the  aggregate  amount  of  Total
         Pre-Tax  Contributions made  on behalf  of each  such Employee for that
         year, to (ii) the amount of such Employee's  Compensation for that year
         or, in the  Committee's discretion,  only for such portion of that year
         during which the  Employee was eligible to participate in the Plan.  If
         two or  more  plans that  include  cash or  deferred  arrangements  are
         considered  as one  plan for purposes of Section 401(a)(4) or 410(b) of
         the Code  (other than  for purposes  of the  average benefit percentage
         test),  the cash or deferred arrangements  included in such plans shall
         be treated as one arrangement for purposes of this subsection (a). If a
         Highly  Compensated Employee is a  participant in  two or  more cash or
         deferred arrangements of an Employer,  then for purposes of determining
         the actual  deferral ratio of such Employee,  all such cash or deferred
         arrangements (other than those that may not be permissively aggregated)
         shall be treated as one cash or deferred arrangement.

                  (b) The aggregate  amount of any  Total  Pre-Tax Contributions
         which may not  be credited to Pre-Tax Accounts for a  Plan Year because
         of  the  limitation  contained  in  subsection  (a)  of  this  Section,
         calculated by adding together the dollar amount of excess contributions
         determined in  subsection (a) of  this Section for each affected Highly
         Compensated  Employee,  shall  be  distributed  to  Highly  Compensated
         Employees (along with any income allocable to such excess contributions
         for such  Plan Year,  but not  for the  gap period following  such Plan
         Year) no later than the last day of the Plan Year immediately following
         such year  (and, if practicable,  within 2 1/2  months after the end of
         such year). The amount of Total Pre-Tax Contributions to be distributed
         to a particular Highly Compensated  Employee shall be determined on the
         basis of the amount of Total Pre-Tax Contributions made for each Highly
         Compensated  Employee  commencing with the  Highly Compensated Employee
         with the largest  amount of  Total Pre-Tax  Contributions for such Plan
         Year and reducing his  or her Total Pre-Tax Contributions to the extent
         necessary  to  lower  such  amount  to  the  amount  of  Total  Pre-Tax
         Contributions of  the Highly Compensated Employee with the next largest
         amount of  Total Pre-Tax Contributions,  and repeating  this process as
         necessary to distribute such aggregate amount; provided,  however, that
         the amount of Total Pre-Tax Contributions to be distributed shall first
         be reduced  by any  excess  deferrals  to  be  distributed  pursuant to
         Section  402(g) of  the Code.  Any such excess  contribution  shall  be
         distributed  first  from any  Pre-Tax  Contributions  and then,  to the
         extent necessary,   from  Pre-Tax  Bonus   Contributions.   The  income
         allocable to any such excess contributions for a Participant for a Plan
         Year shall be determined  by multiplying the amount of income allocable
         to such Participant's Pre-Tax Account for such year by a fraction,  the
         numerator  of which is the  amount of the excess contributions for such
         year and the denominator  of which is the sum of the amount credited to
         such Participant's  Pre-Tax Account  as of  the beginning  of such year
         plus the amount  of such Participant's Total Pre-Tax  Contributions for
         such year.  Any provision of this Plan to the contrary notwithstanding,
         Total Pre-Tax  Contributions otherwise  distributable  pursuant to this
         subsection  (b) to a  Participant  who is  eligible  to  make  Catch-Up


                                      -14-








         Contributions to the  Plan shall,  to the  extent permitted  by Section
         414(v)  of the  Code and  the regulations  thereunder,  be treated as a
         Catch-Up Contribution. If any portion of a Pre-Tax Contribution made by
         an  Employer  on  behalf  of  a  Participant  is  distributed  to  such
         Participant or  is treated as  a Catch-Up Contribution  pursuant to the
         foregoing  provisions of this subsection (b), any portion of a Matching
         Contribution  (along with any income  allocable  thereto) made for such
         Participant  that  matches  the  distributed  Pre-Tax  Contribution  or
         recharacterized Catch-Up Contribution shall be forfeited.

                 (c) Any provision of this Plan to the contrary notwithstanding,
         if for  any Plan  Year the  contribution  percentage for  the  group of
         Highly Compensated  Employees  eligible to  receive  an  allocation  of
         Matching Contributions or to make  After-Tax  Contributions to the Plan
         for such Plan Year fails to satisfy one of the following tests:

                           (1) the contribution  percentage  for  said  group of
                  Highly Compensated Employees is not  more than  1.25 times the
                  contribution  percentage  for the  preceding Plan Year for all
                  Non-Highly  Compensated  Employees  eligible for the preceding
                  Plan Year to receive an allocation of  Matching  Contributions
                  or make After-Tax Contributions, or

                           (2) the excess  of the  contribution  percentage  for
                  said  group  of   Highly   Compensated   Employees  over   the
                  contribution  percentage for  the preceding  Plan Year for all
                  Non-Highly  Compensated  Employees eligible for  the preceding
                  Plan Year to  receive an  allocation of Matching Contributions
                  or   make  After-Tax  Contributions  is  not  more  than   two
                  percentage  points,  and the  contribution percentage for said
                  group of  Highly  Compensated  Employees is  not more than two
                  times the contribution percentage for the  preceding Plan Year
                  for all  Non-Highly  Compensated  Employees  eligible  for the
                  preceding  Plan  Year to  receive  an  allocation  of Matching
                  Contributions or make After-Tax Contributions,

         then the  contribution  percentage of Participants  who are  members of
         said group of Highly Compensated Employees shall be reduced by reducing
         the contribution  percentages of the Highly Compensated  Employees with
         the largest  individual contribution percentages to the largest uniform
         contribution  percentage   (commencing   with  the  Highly  Compensated
         Employee  with the largest contribution  percentage and reducing his or
         her contribution  percentage to the  extent necessary to satisfy one of
         the  above  tests  or  to  lower such  contribution  percentage  to the
         contribution  percentage  of the  Highly Compensated Employee  with the
         next  largest contribution  percentage,  and repeating  this process as
         necessary) that  permits the contribution percentage for  said group of
         Highly Compensated Employees to satisfy one of said tests. For purposes
         of this  subsection  (c),  the  term  "contribution  percentage"  for a
         specified group  of Employees for  a Plan Year means the average of the
         ratios (calculated separately for each Employee in such group and after
         application  of the  reduction  provisions of  subsection  (a)  and the
         forfeiture provisions of subsection  (b) of this  Section) of  (i)  the
         aggregate amount  of After-Tax Contributions and Matching Contributions


                                      -15-








         made by or  for such Employee  (and,  at the election of the Committee,
         the Total Pre-Tax  Contributions made on  behalf of  such Employee) for
         that year,  to (ii) the amount of such Employee's Compensation for that
         year or,  in the Committee's discretion,  only for such portion of that
         year during which the Employee was eligible to participate in the Plan.
         If two  or more  plans to  which  matching  contributions  or  employee
         after-tax  contributions  are  made  are  considered as  one  plan  for
         purposes of Section 410(b) of the Code  (other than for purposes of the
         average  benefit percentage  test),  such plans shall be treated as one
         plan for purposes of determining  the contribution percentages for this
         subsection (c).  If a  Highly Compensated Employee  is a participant in
         two or more plans to which matching contributions or employee after-tax
         contributions  are   made,   then  for  purposes  of  determining   the
         contribution ratio of such Employee,  all such  plans (other than those
         that may not be permissively aggregated) shall be treated as one plan.

                  (d) The aggregate  amount of  any  Matching  Contributions and
         After-Tax  Contributions  which  may  not be credited to  Participant's
         Accounts  for a  Plan  Year  because  of the  limitation  contained  in
         subsection  (c)  of this  Section,  calculated  by adding  together the
         dollar  amount  of   excess  aggregate   contributions   determined  in
         subsection  (c) of this  Section for each  affected Highly  Compensated
         Employee,  shall be forfeited if forfeitable,  but if not  forfeitable,
         distributed to such Highly Compensated Employees (along with any income
         allocable to such  excess aggregate  contributions for such  Plan Year,
         but not for the  gap period following such Plan Year) no later than the
         last day  of the  Plan Year  immediately  following  such year (and, if
         practicable,  within  2 1/2 months  after  the end of  such year).  The
         amount to be  distributed  to a  particular Highly Compensated Employee
         shall   be  determined  on  the   basis  of  the  amount  of   Matching
         Contributions  and  After-Tax  Contributions  made by  or for each such
         Highly Compensated  Employee  commencing  with the  Highly  Compensated
         Employee  with  the  largest  amount  of  Matching  Contributions   and
         After-Tax  Contributions  for such Plan Year and reducing  first his or
         her   After-Tax  Contributions   and  then,   if  necessary,   Matching
         Contributions to the extent necessary to lower such total amount to the
         amount of  Matching Contributions and  After-Tax  Contributions  of the
         Highly  Compensated Employee with the next  largest amount of  Matching
         Contributions  and After-Tax Contributions,  and repeating this process
         as necessary to distribute such aggregate amount.  The income allocable
         to any such excess aggregate contributions for a Participant for a Plan
         Year shall be determined  by multiplying the amount of income allocable
         to such Participant's Employer Account or After-Tax Account,  whichever
         is applicable,  for such year by a fraction,  the numerator of which is
         the amount of the excess  aggregate contributions for such year and the
         denominator  of  which  is  the  sum  of  the  amount  credited to such
         Participant's  Employer  Account  or  After-Tax  Account,  whichever is
         applicable,  as of  the beginning  of such  year  plus  the  amount  of
         Matching Contributions or After-Tax Contributions, as applicable,  made
         for such Participant for such year.

                  (e)   Any   provision  of   this  Section   to  the   contrary
         notwithstanding, the Company in its discretion may cause the provisions
         of subsections (a) and (c)  of this Section to be satisifed without use

                                      -16-








         of the  corrective provisions  set forth in  subsections (b) and (d) of
         this  Section   by   requiring   each  Employer  to  make  a  qualified
         non-elective contribution  and/or a  qualified matching contribution to
         the Plan  to be  allocated  to the  Pre-Tax Accounts (with respect to a
         contribution  intended  to  be  taken  into  account  for  purposes  of
         determining the  actual deferral percentage pursuant to subsection (a))
         or the Employer Accounts (with respect to a contribution intended to be
         taken  into  account  for  purposes  of  determining  the  contribution
         percentage  pursuant to  subsection (c)) of those Participants who were
         Non-Highly Compensated  Employees  in the  employ of  (or on authorized
         leave of absence from) an Employer on the last day of such Plan Year. A
         qualified  non-elective contribution shall be allocated to the eligible
         Participants in the proportion that the Basic Compensation of each such
         eligible Participant  while both a  Participant and a  Covered Employee
         during that year bears to the  Basic Compensation of all  such eligible
         Participants  while both Participants and Covered Employees during that
         year.  A  qualified  matching contribution  shall be  allocated  to the
         eligible Participants in the proportion that the Pre-Tax  Contributions
         made with respect to each such eligible  Participant for such Plan Year
         bears to  the  Pre-Tax  Contributions  made with  respect  to  all such
         eligible Participants for such Plan Year.

                 (f) Any provision of this Plan to the contrary notwithstanding,
         the  determination   of  the   actual   deferral  percentage  and   the
         contribution  percentage  required   by  this  Section  for  Non-Highly
         Compensated  Employees  for the  preceding Plan  Year shall be  made in
         accordance  with  Sections  401(k)  and  401(m) of  the  Code  and  any
         regulations or other authorities issued thereunder.

         Section 3.8  Application of Forfeitures.  As soon as  practicable after
the  valuation  of all  Accounts  at the  end of each  Plan  Year,  all  amounts
forfeited  during that Plan Year shall first be applied to restore any forfeited
Accounts  required to be restored  pursuant  to  Sections  6.5 and 6.8,  and any
forfeitures  in excess of the amount  needed to restore any such  Account may be
applied to pay  administrative  expenses in  accordance  with  Section  7.4. Any
remaining  forfeitures  for such Plan Year, if any,  shall be used to reduce the
amount of the earliest subsequent  Matching  Contributions an Employer otherwise
would be required to make to the Plan.

         Section 3.9  Rollover Contributions. With the consent of and subject to
such  reasonable  conditions and limitations as may be imposed by the Committee,
any Covered  Employee  (regardless  of whether he or she is a  Participant)  may
contribute  Rollover Property in cash to the Plan. Each contribution of Rollover
Property  shall be credited  to the  Covered  Employee's  Rollover  Account.  An
Employee  who is not a  Participant,  but for whom a  Rollover  Account is being
maintained,  shall be accorded all of the rights and privileges of a Participant
under  the Plan  except  that no  contributions  (other  than  contributions  of
Rollover  Property)  shall be made for or on behalf of such Employee until he or
she meets the eligibility and participation  requirements of Article II. Subject
to the  Committee's  consent,  the Plan will accept (i) a direct  rollover of an
eligible rollover  distribution  from: (A) a qualified plan described in Section
401(a) or 403(a) of the Code, including after-tax employee contributions, (B) an
annuity contract  described in Section 403(b) of the Code,  excluding  after-tax
employee contributions, or (C) an eligible plan under Section 457(b) of the Code


                                      -17-








which is maintained by a state,  political subdivision of a state, or any agency
or  instrumentality  of a state or political  subdivision of a state;  or (ii) a
Participant  contribution  of an  eligible  rollover  distribution  from:  (A) a
qualified plan described in Section 401(a) or 403(a) of the Code, (B) an annuity
contract  described in Section 403(b) of the Code, or (C) an eligible plan under
Section 457(b) of the Code which is maintained by a state, political subdivision
of a state, or any agency or instrumentality of a state or political subdivision
of a state.  The Plan will accept a  Participant  rollover  contribution  of the
portion  of a  distribution  from an  individual  retirement  account or annuity
described in Section  408(a) or 408(b) of the Code that is eligible to be rolled
over and would otherwise be includible in gross income of the Participant.


                                   ARTICLE IV.

                            TRUST FUND AND VALUATIONS

         Section 4.1  Trust and Trustee.  All of the  contributions  paid to the
Trustee pursuant to this Plan and the Superseded Plan,  together with the income
therefrom  and the  increments  thereof,  shall be held in trust by the  Trustee
under the terms and  provisions  of the  separate  trust  agreement  between the
Trustee and the  Company,  a copy of which is attached  hereto and  incorporated
herein by this  reference for all purposes,  establishing  a trust fund known as
the PIONEER  NATURAL  RESOURCES  USA,  INC.  401(k) AND  MATCHING  TRUST for the
exclusive benefit of the Participants and their beneficiaries.

         Section 4.2  Trust  Investment  Options.  All  amounts  credited  to  a
Participant's  Accounts  may be invested in Pioneer  Stock and/or one or more of
the Investment Funds at the direction of such Participant in accordance with the
provisions of this Section.  The assets of the Trust (other than Pioneer  Stock)
shall be divided into such number and kind of separate  and distinct  Investment
Funds as the Committee in its absolute  discretion  shall authorize from time to
time. The assets of the Trust allocated to a particular Investment Fund shall be
invested by the Trustee and/or one or more investment managers duly appointed in
accordance with the provisions of the trust agreement establishing the Trust, as
the case may be, in such  type of  property  acceptable  to the  Trustee  as the
Trustee is directed to acquire and hold for such Investment  Fund. Upon becoming
a  Participant  in the  Plan,  each  Participant  shall  direct,  in the  manner
prescribed  by the  Committee  in its  absolute  discretion,  that  all  amounts
credited to his or her Accounts under the Plan shall be invested,  in percentage
multiples  authorized by the Committee,  in one or more of the Investment Funds.
Subject to such  conditions  and  limitations  as the  Committee in its absolute
discretion may prescribe from time to time for  application to all  Participants
on a uniform  basis, a Participant  may change his or her  investment  direction
with respect to future  contributions  or redirect the investment of the amounts
credited to his or her Accounts provided that notice of such change is delivered
to or in the manner directed by the Committee  within such reasonable  period of
time prior to the effective date thereof as the Committee may require.


                                      -18-








         Section 4.3  Valuation and Adjustment of Accounts. As of each Valuation
Date,  the Trustee  shall  determine  the fair market value of all assets of the
Trust with the value of the  assets of each  Investment  Fund  being  separately
determined.  On the  basis  of  such  valuations  and in  accordance  with  such
procedures as may be specified from time to time by the  Committee,  the portion
of each Account  invested in a particular  Investment  Fund shall be adjusted by
the  Committee to reflect its  proportionate  share of the income  collected and
accrued,  realized  and  unrealized  profits and losses,  expenses and all other
transactions  attributable to that particular  Investment Fund for the valuation
period then ended. All cash dividends,  stock dividends,  stock splits and other
amounts  received  by the  Trustee  with  respect to  Pioneer  Stock held for an
Account (including the forfeiture account  established  pursuant to Section 6.5)
shall be credited to such Account. The amount of any distribution, withdrawal or
forfeiture  shall  be  determined  on the  basis of the  most  recent  valuation
preceding the date of  distribution,  withdrawal or forfeiture,  as the case may
be.


                                   ARTICLE V.

                                     VESTING

         Section 5.1   Fully  Vested  Accounts.   The   amounts  credited  to  a
Participant's  After-Tax Account,  Mesa After-Tax Account, Mesa Premium Account,
Mesa Profit-Sharing Account, Pre-Tax Account, Prior Plan Employer Account, Prior
Plan Pre-Tax Account, and Rollover Account shall be fully vested at all times.

         Section 5.2  Vesting of Employer Account.

                  (a) The amounts credited  to the Employer Account and Matching
         Plan Account  of a  Participant  shall  become  fully  vested  upon the
         occurrence of any of the  following events while  the Participant is in
         the employ  of (or on  authorized leave of absence from) an Employer or
         Affiliated Company:  (i)  the  completion of  an Hour of Service by the
         Participant on  or after the date  he  or she attains age 60,  (ii) the
         Participant's death,  or (iii) the  Participant's Permanent Disability.
         Unless sooner vested pursuant to the preceding sentence,  and except as
         provided in subsection (b) of this Section and Section 5.3, the amounts
         credited to a Participant's Employer Account and Matching  Plan Account
         shall vest in accordance with the following schedule:


                     Period of Service
                  Completed by Participant             Percentage Vested
                  ------------------------             -----------------
                                                 
                      Less than 1 year                        None
                           1 year                              25%
                           2 years                             50%
                           3 years                             75%
                      4 or more years                          100%



                                      -19-









                  (b) If a  Participant  makes  an  in-service  withdrawal under
         Section 6.6 from  his or  her  Employer  Account  at a  time  when  the
         Participant  is not  fully vested,  the Participant's vested  amount in
         such account on  any date thereafter shall be an amount X determined by
         the following formula: X = P(AB + D) - D. For purposes of this formula,
         P is  the Participant's  vested  percentage  under  the  Plan's vesting
         schedule  on  the  relevant  date,  AB  is the  account  balance on the
         relevant date  and D is  the amount  of  the  Participant's  in-service
         withdrawal.

         Section 5.3  Special Vesting Provisions.

                 (a) Any provision of this Plan to the contrary notwithstanding,
         the  amounts credited  to the  Employer  Account  and/or  Matching Plan
         Account  of a  Participant who is  specifically  designated by the Vice
         President  Administration   of  the  Company  as  being   involuntarily
         terminated in  connection  with the  divestiture program  and corporate
         restructuring announced on February 10, 1998, shall become fully vested
         and nonforfeitable on the date of such involuntary termination.

                 (b) Any provision of this Plan to the contrary notwithstanding,
         the amounts  credited  to the  Employer  Account  and/or  Matching Plan
         Account  of a Participant  who is  specifically designated  by the Vice
         President   Administration  of  the  Company  as  being   involuntarily
         terminated in  connection with the corporate restructuring announced on
         November 11, 1998,  shall become fully vested and nonforfeitable on the
         date of such involuntary termination.

                 (c) Any provision of this Plan to the contrary notwithstanding,
         the amounts credited to  the Matching Plan Account of a Participant who
         is specifically designated by the  Vice President Administration of the
         Company as being  involuntarily  terminated in connection with the sale
         by the Company of the Plum Creek Plant,  Leon County, Texas, to a third
         party shall become fully vested  and nonforfeitable on the date of such
         involuntary termination.

                 (d) Any provision of this Plan to the contrary notwithstanding,
         the amounts credited to the Matching  Plan Account of a Participant who
         is specifically  designated by the  Vice President - Administration and
         Risk  Management of the  Company as  being involuntarily  terminated in
         connection with one of  the following events shall become  fully vested
         and nonforfeitable on the date of such involuntary termination:

                     (i)    the transfer of operations of the  Howard Parker/Joe
                            Parsley Joint Venture wells to a third party;

                     (ii)   the sale of Iatan Field properties to a third party;


                                      -20-








                     (iii)  the reorganization  of Offshore Operations effective
                            September 22, 1999;

                      (iv)  the restructuring and consolidation  of the Domestic
                            Reservoir Engineering  Department effective February
                            15, 2000; or

                       (v)  the sale of NationsBank building, Midland, Texas.

                 (e) Any provision of this Plan to the contrary notwithstanding,
         the amounts credited  to the Matching Plan Account of a Participant who
         is specifically designated  by the  Vice President - Administration and
         Risk Management of the  Company  as being  involuntarily  terminated in
         connection  with  the  implementation  of  the  TOW  Production  System
         technology, shall become fully vested and nonforfeitable on the date of
         such involuntary termination.


                                   ARTICLE VI.

                    VALUATIONS, DISTRIBUTIONS AND WITHDRAWALS

         Section 6.1  Time of Distribution.

                 (a) Distribution  to a  Participant or  beneficiary  under this
         Article  shall be  made or  commence being made  no later than  60 days
         after the close  of the  Plan Year in which the latest of the following
         occurs:  (i) the Participant's Normal Retirement Date,  (ii) the  tenth
         anniversary   of   the  year   in  which   the  Participant   commenced
         participation in the Plan,  or (iii)  the Participant's separation from
         the employment  of an  Employer for any  reason  other than  his or her
         transfer to the employment of another Employer or Affiliated Company.

                 (b) Any provision of this Plan to the contrary notwithstanding,
         in the case of a Participant who is a five-percent owner (as defined in
         Section 416(i) of the Code), distribution to such Participant under the
         Plan shall  be made or commence being made no later than April 1 of the
         calendar  year following  the calendar  year in  which the  Participant
         attains age 70 1/2.  Distributions that commence being made pursuant to
         the preceding sentence to a  Participant who has not separated from the
         employment of an Employer or Affiliated  Company shall be made pursuant
         to Section 6.2 as if the Participant  had terminated employment at such
         time  and shall be  made in  accordance  with the  minimum distribution
         requirements of  Section  401(a)(9)  of the  Code and such  regulations
         thereunder as may be applicable from time to time (or for periods prior
         to the  effective date  of final regulations under Section 401(a)(9) of
         the Code, pursuant to the regulations that were proposed on January 17,
         2001);  provided, however,  that if the Participant elects to waive the
         normal form of payment in accordance with Section 6.2,  the alternative
         form of  distribution  shall  be  the  minimum  amounts  required to be
         distributed  pursuant  to  Section  401(a)(9)  of  the  Code  and  such


                                      -21-








         regulations thereunder as  may be applicable  from time to time (or for
         periods prior to the effective date of  final regulations under Section
         401(a)(9) of the  Code pursuant  to regulations  that were  proposed on
         January 17, 2001),  with any amount  remaining upon the  termination of
         the Participant's employment or the death of the Participant to be paid
         in accordance with Section 6.2 or Section 6.3, whichever is applicable.
         Further, any other Participant who attained age 70 1/2 prior to January
         1, 1999, and who elected  to continue to receive distributions prior to
         such Participant's  termination of employment shall be entitled receive
         an annual distribution in  accordance with the  preceding  sentence (or
         may elect  a larger  or smaller  amount for  such annual  distribution)
         unless and until  such Participant revokes such election. Any provision
         of this Plan to the contrary notwithstanding,  no distribution shall be
         made from this Plan that would violate Section 401(k) of the Code.

                 (c) Subject to the  provisions of  this  Article requiring that
         distributions  and  withdrawals  be  made  in  the form  of an  annuity
         contract, distributions and  withdrawals shall be made in cash,  except
         that amounts credited to  an Account that are invested in Pioneer Stock
         may, at the election of the Participant,  be distributed in the form of
         Pioneer Stock with cash in lieu of fractional shares.

                 (d) Any provision of this Plan to the contrary notwithstanding,
         (i) all  distributions from  the Plan shall  be made in accordance with
         Section 401(a)(9) of the Code and the regulations thereunder,  and (ii)
         all optional forms of benefit under the Plan, the Superseded Plan,  the
         Matching Plan, the Mesa Premium Plan,  and the Mesa Profit-Sharing Plan
         that are protected benefits  under Section  411(d)(6) of the Code shall
         continue to be optional  forms of benefit for Participants to whom such
         optional  forms  of   benefit  apply  notwithstanding  any   subsequent
         amendment  purporting to  revise or delete  any such  optional  form of
         benefit, except  to the extent that such  optional forms of benefit may
         be deleted in accordance with applicable law.

         Section 6.2  Distribution of Retirement and Disability Benefits.

                 (a) Except  as  otherwise  provided in  this Section,  upon the
         Retirement  or  termination  of  employment  on  account  of  Permanent
         Disability of a  Participant,  the  Vested Interest of such Participant
         shall  be  distributed  to such  Participant  by  the  Trustee  at  the
         direction of the Committee in a single distribution; provided, however,
         that if  such  Participant's Vested  Interest exceeds $5,000, he or she
         may elect to receive his or her  Vested Interest in monthly,  quarterly
         or annual installment  distributions over a period of two or more years
         with the first  such installment to be payable within 90 days after the
         end of the Plan Year in  which the Participant's employment terminates.
         Such installment  payments may be  made over  a period of  years not to
         exceed one or a combination of  the following periods:  (i) the life of
         the Participant,  (ii) the  lives of the  Participant  and  his or  her
         designated beneficiary, (iii) a period certain not extending beyond the
         life  expectancy  of the  Participant,  and (iv) a  period  certain not
         extending  beyond the  joint life and  last survivor  expectancy of the
         Participant and  his or  her designated  beneficiary.  Any provision of


                                      -22-








         Section 6.3  to the  contrary  notwithstanding,  if a  Participant  who
         elected  installment  payments  dies prior  to the  distribution of the
         entire amount  of his or her  Vested  Interest,  the remaining  portion
         thereof   shall  be   distributed  to   his  or  her   beneficiary   or
         beneficiaries,  as determined in accordance  with Section 6.3(a),  in a
         single   distribution   within   90  days   after  the   end   of   the
         Plan Year  during  which  the  Participant  died.  Notwithstanding  the
         foregoing provisions of this Section 6.2, no distribution shall be made
         upon a Participant's  termination of employment on account of Permanent
         Disability prior to his  or her  Normal Retirement Date unless (i) such
         Participant  elects  to   receive  such  distribution   or   (ii)  such
         Participant's Vested Interest does not  exceed $5,000.  For purposes of
         determining  whether  the  value  of a  Participant's  Vested  Interest
         exceeds or does not exceed $5,000,  the value of a Participant's Vested
         Interest  shall be  determined  without  regard  to  the  value  of the
         Participant's Rollover Account.

                  (b) Except as otherwise provided in this subsection (b),  upon
         the  Retirement or  termination of employment  on account  of Permanent
         Disability of a Participant whose Vested Interest exceeds $5,000,  such
         Participant's Matching Plan Account,  Mesa Premium Account,  Prior Plan
         Employer Account and Prior Plan Pre-Tax Account shall be distributed to
         him or her by the Trustee at the direction of the Committee in the form
         of a Qualified Joint and Survivor Annuity contract to be purchased from
         a company selected  by the  Committee and commencing in payment as soon
         as practicable.  Not more than  90 days prior  to the date such annuity
         contract is to  commence in payment,  the  Committee shall provide such
         Participant with a  written explanation of (i) the terms and conditions
         of the Qualified Joint  and Survivor Annuity,  (ii) his or her right to
         make,  and the effect of,  an election to waive the Qualified Joint and
         Survivor Annuity form of benefit, (iii) the rights of his or her spouse
         with  respect to  the receipt  and waiver  of the  Qualified  Joint and
         Survivor  Annuity,  and  (iv) the right to make,  and the  effect of, a
         revocation of an  election to  waive the  Qualified Joint  and Survivor
         Annuity.  The written  explanation shall be  required at  least 30 days
         prior to the date the Qualified Joint and Survivor  Annuity contract is
         to commence in payment; provided, however, that a Participant may elect
         (with any applicable spousal consent)  to waive such requirement if the
         distribution to the  Participant commences no earlier than 8 days after
         such explanation is provided.  After receiving the written explanation,
         the Participant may  elect at any time during the 90-day period ending
         on the date the annuity contract is to commence in payment to waive the
         Qualified Joint  and Survivor  Annuity  form  of benefit  and  also may
         revoke any such election during such period. Any such election to waive
         a Qualified  Joint and  Survivor  Annuity form of  benefit by a married
         Participant will be  effective only if the  spouse of  such Participant
         consents in  writing within  the 90-day  period  preceding such date to
         both the  election and  the optional  form of  benefit  selected by the
         Participant and  such  consent  is  witnessed by a  notary public.  Any
         amount  payable from the  Matching Plan Account,  Mesa Premium Account,
         Prior Plan  Employer  Account or  Prior Plan  Pre-Tax Account  upon the
         Retirement or Permanent Disability of a Participant  who has elected to
         waive the  Qualified  Joint  and Survivor  Annuity  form of  benefit as
         provided above shall be distributed to such Participant  by the Trustee
         at the direction of the Committee in accordance with  subsection (a) of
         this Section;  provided,  however, that a Participant who has an amount


                                      -23-








         payable from his or  her Matching Plan  Account or Mesa Premium Account
         may, in addition to the  optional forms available under subsection (a),
         elect to have  such amounts  paid in the form of an Alternate Qualified
         Joint and  Survivor Annuity.  For purposes of  determining  whether the
         value of a Participant's Vested Interest exceeds $5,000, the value of a
         Participant's Vested Interest shall be determined without regard to the
         value of the Participant's Rollover Account.

         Section 6.3  Distribution of Death Benefit.

                  (a) Except  as otherwise  provided in  this Section,  upon the
         death of a Participant,  the Vested  Interest of such Participant shall
         be distributed by the Trustee at the direction of the Committee to such
         Participant's  beneficiary or  beneficiaries  determined  in accordance
         with this subsection (a).  Any amount payable  under the  Plan upon the
         death of a married  Participant shall  be distributed  to the surviving
         spouse of such Participant unless such Participant designates otherwise
         with the written consent of  his or her spouse which is  witnessed by a
         notary public.  Any amount payable  under the  Plan upon the death of a
         Participant who is not married or who is married but has designated, as
         provided above,  a beneficiary other than  his or her spouse,  shall be
         distributed  to the  beneficiary or  beneficiaries  designated  by such
         Participant.  Such designation of beneficiary or beneficiaries shall be
         made in writing on a form  prescribed by the Committee and,  when filed
         with or as directed by the Committee, shall become effective and remain
         in effect  until  changed  by the  Participant  by the  filing of a new
         beneficiary  designation  form  with  the  Committee.  If an  unmarried
         Participant fails to so designate a beneficiary, or in the event all of
         a Participant's designated beneficiaries are individuals who predecease
         such  Participant,  then the  Committee  shall  direct  the  Trustee to
         distribute the amount  payable  under  the Plan  to such  Participant's
         surviving spouse,  if any,  but if none,  to such Participant's estate.
         All distributions under this  subsection (a) shall be made in a single
         distribution  as soon as  practicable  following a Participant's death;
         provided,  however,  that if the Participant's  Vested Interest exceeds
         $5,000, he or she may elect (or if the Participant does not elect,  his
         or her designated beneficiary may  elect) that distribution be made in
         monthly,  quarterly or annual installments over a period of two or more
         years with the first  such installment  to be  payable  within  90 days
         after  the  end  of  the  Plan  Year in  which  the  Participant  died.
         Installment payments may be made only to an individual over a period of
         years not to exceed one or a combination of the following periods:  (i)
         the life of the Participant's designated beneficiary,  or (ii) a period
         certain not extending  beyond the  life expectancy of the Participant's
         designated beneficiary.  For purposes of  determining whether the value
         of a  Participant's  Vested  Interest  exceeds  $5,000,  the value of a
         Participant's Vested Interest shall be determined without regard to the
         value of the Participant's Rollover Account.

                  (b) Any provision of  subsection  (a) of  this  Section to the
         contrary  notwithstanding,   except  as  otherwise   provided  in  this
         subsection (b),  upon the death  of a married  Participant whose Vested
         Interest exceeds $5,000, such Participant's Matching Plan Account, Mesa
         Premium Account,  Prior Plan  Employer  Account and  Prior Plan Pre-Tax


                                      -24-


         Account shall be distributed to his or her surviving spouse in the form
         of a Qualified  Preretirement Survivor Annuity contract to be purchased
         from a company selected  by the  Committee and commencing in payment on
         the date that would have been such Participant's Normal Retirement Date
         if he or she  were still living.  The Committee shall provide each such
         married  Participant  with  a  written  explanation  of  the  Qualified
         Preretirement   Survivor  Annuity   provided   above,   including   the
         Participant's  right  to  waive  the  distribution  of  such  Qualified
         Preretirement Survivor  Annuity with the  consent of  his or her spouse
         and to  revoke  any such waiver,  within  whichever  of  the  following
         periods ends last: (i) the period  beginning with the first  day of the
         Plan Year  in which  the Participant  attains the  age of 32 and ending
         with the close  of the  Plan Year preceding  the Plan Year in which the
         Participant attains the age of 35,  (ii) the  one-year period after the
         individual becomes a  Participant,  or (iii) the  one-year period after
         separation from  employment in the case  of a Participant who separates
         before attaining age 35. Each married Participant may elect at any time
         prior to such Participant's  death to waive the Qualified Preretirement
         Survivor  Annuity form of  benefit  provided  above so  that his or her
         entire benefit may be paid  to his  or her  designated beneficiary.  No
         election to waive the  Qualified Preretirement Survivor Annuity will be
         effective upon the Participant's  death unless such election designates
         a beneficiary  that  cannot be  changed  without  spousal  consent, the
         Participant's surviving spouse consents in writing to such election and
         such consent is witnessed by a notary public. A spousal consent will be
         valid only with respect  to the spouse  who signs the  consent and such
         consent shall be irrevocable. A married Participant may revoke any such
         election to  waive the  Qualified Preretirement Survivor Annuity at any
         time prior to his or her death.  The amount payable under the Plan upon
         the death of a married Participant who has elected,  as provided above,
         to  waive  the  Qualified  Preretirement   Survivor  Annuity  shall  be
         distributed  in accordance with  subsection (a)  of this  Section.  The
         surviving spouse of any deceased Participant may elect in writing after
         the Participant's death to receive the entire benefit otherwise payable
         to such surviving spouse in accordance with this subsection (a) of this
         Section.   For  purposes  of   determining  whether   the  value  of  a
         Participant's   Vested  Interest   exceeds  $5,000,   the  value  of  a
         Participant's Vested Interest shall be determined without regard to the
         value of the Participant's Rollover Account.

         Section 6.4  Distribution of Separation from Employment Benefit.

                  (a) Except  as  otherwise  provided  in  this  Section,  if  a
         Participant separates from the employment  of an Employer or Affiliated
         Company  for any reason  other than his  or her  Retirement,  Permanent
         Disability,  death or transfer to the employment of another Employer or
         Affiliated Company,  the Accounts of such Participant shall be retained
         in trust and shall continue to  be credited with applicable earnings as
         provided in Section 4.3,  and the  Vested Interest of  such Participant
         shall be  distributed to him or her by the Trustee  at the direction of
         the Committee  in accordance with Section 6.2(a) as soon as practicable
         after his or her Normal Retirement Date  (or,  if the  Participant dies
         prior to such date,  the Vested  Interest of such  Participant shall be
         distributed  upon  his or her  death in  accordance with  Section 6.3);
         provided, however,  that (i) each such Participant shall have the right


                                      -25-








         to elect on a  form prescribed  by the  Committee to  receive an  early
         distribution of his  or her Vested Interest as  soon as practicable and
         (ii) the  Committee  shall require  an early  distribution of  any such
         Participant's Vested Interest  which does not exceed $5,000 in the form
         of a single  distribution.  The  Vested  Interest of a  Participant who
         elects to receive an  early distribution shall be distributed to him or
         her in the same manner as provided in Section 6.2(a) for a distribution
         upon Retirement or Permanent Disability. Any provision of this Plan to
         the  contrary  notwithstanding,   for  purposes  of   this  Article   a
         Participant  shall  not   be  treated  as  having  separated  from  the
         employment of an Employer or Affiliated Company prior to such time that
         a distribution  can be  made to  such  Participant in  accordance  with
         Section 401(k) of the Code and the regulations thereunder. For purposes
         of  determining  whether the  value of a Participant's  Vested Interest
         exceeds  $5,000,   the  value   of  a  Participant's  Vested   Interest
         shall  be determined  without regard  to the value of the Participant's
         Rollover Account.

                  (b) Any  provision of  subsection  (a) of  this Section to the
         contrary  notwithstanding,   except  as   otherwise  provided  in  this
         subsection (b), if a Participant's whose Vested Interest exceeds $5,000
         separates from the employment of an  Employer or Affiliated Company for
         any reason  other  than his  or her  Retirement,  Permanent Disability,
         death or transfer to the  employment of another Employer  or Affiliated
         Company,   such  Participant's  Matching  Plan  Account,  Mesa  Premium
         Account,  Prior Plan Employer Account and/or Prior Plan Pre-Tax Account
         shall  be distributed  to  such  Participant  by  the  Trustee  at  the
         direction of  the Committee  upon such  Participant's Normal Retirement
         Date by payment  of the entire amount  in the form of a Qualified Joint
         and Survivor  Annuity contract  to be purchased from a company selected
         by the  Committee and  commencing in  payment as  soon  as  practicable
         thereafter  (or,  if  the  Participant dies  prior to his or her Normal
         Retirement Date, the Vested Interest of such Participant under the Plan
         shall be  distributed upon his or  her death in accordance with Section
         6.3);  provided,  however,  that  each  such Participant shall have the
         right  to elect  on a form  prescribed  by the  Committee to receive an
         early distribution  of the amount  credited to his or her Matching Plan
         Account, Mesa Premium Account, Prior Plan Employer Account and/or Prior
         Plan Pre-Tax Account as soon as practicable  after such election.  If a
         Participant  elects  under  this  subsection  (b) to  receive  an early
         distribution,  such  distribution  shall be  made in  the form of (i) a
         Qualified  Joint and Survivor  Annuity contract to  be purchased from a
         company selected  by the Committee and commencing in payment as soon as
         practicable  following such election,  or (ii) upon satisfaction of the
         notice  and waiver requirements  of Section 6.2(b),  in accordance with
         subsection (a) of this Section.

         Section 6.5  Forfeitures.

                  (a) Unless  sooner forfeited  as provided below,  any unvested
         portion  of  the  Accounts of a  Participant  who  separates  from  the
         employment of  an  Employer or  Affiliated Company for any reason other
         than his or her Retirement, Permanent Disability,  death or transfer to
         the  employment of  another Employer  or  Affiliated  Company  shall be


                                      -26-








         forfeited upon the  earlier of the date  of such Participant's death or
         the date  such Participant incurs  five consecutive  One Year Breaks in
         Service  unless  such  Participant  is  reemployed  by  an  Employer or
         Affiliated Company prior to such date.

                  (b) If a Participant  receives a complete  distribution of his
         or her Vested  Interest  under Section 6.4  by the close  of the second
         Plan Year following  the Plan Year in which his or her  separation from
         employment occurred,  any portion  of such Participant's Accounts which
         is not vested  at the time of such  distribution  shall be forfeited at
         such time.  If a  Participant who  separates  from the employment of an
         Employer or  Affiliated  Company for  any reason other  than his or her
         Retirement,  Permanent Disability,  death or transfer to the employment
         of another Employer or  Affiliated Company,  is not entitled to receive
         any distribution from the  Plan due to  the fact  that such Participant
         has no  Vested  Interest,  such  Participant  shall be  deemed  to have
         received a  distribution  from  the Plan  of his  or her  entire Vested
         Interest  under the Plan  and any amount credited to such Participant's
         Accounts  shall  be  forfeited  at the  time of  such  separation  from
         employment.  If  a  Participant,  any  portion  of  whose  Accounts  is
         forfeited pursuant to  this subsection (b),  is reemployed as a Covered
         Employee prior  to  incurring  five  consecutive  One  Year  Breaks  in
         Service, the amount so forfeited shall be restored to such individual's
         Accounts,  out of current-year forfeitures or, if such forfeitures are
         insufficient,   by  an  additional  Employer  contribution;   provided,
         however,  that no  amount shall  be  restored  to  the  Accounts  of an
         individual who previously received a distribution of the vested portion
         of such Accounts  unless he or  she repays to the Plan, while a Covered
         Employee and within five years of  the date of  such reemployment,  the
         full amount previously distributed from  such Accounts for crediting to
         his or her Accounts.

                  (c) If a Participant who has not yet incurred five consecutive
         One Year Breaks  in Service  receives a  distribution under Section 6.4
         after the end  of the second Plan  Year following the year in which his
         or her  separation  from  employment  occurred,  any  portion  of  such
         Participant's  Accounts  which  is  not  vested  at the  time  of  such
         distribution shall  be retained  in such Account and shall be forfeited
         upon the  earlier of the date of such  Participant's death or the  date
         such Participant incurs five  consecutive One  Year  Breaks in  Service
         unless  such  Participant  is reemployed  by an  Employer or Affiliated
         Company prior to such date. If a  Participant  receives a  distribution
         from the Plan after the  end of the second Plan Year following the year
         in  which  his  or  her separation  from  employment  occurred  and  is
         reemployed by an Employer or Affiliated Company prior to incurring five
         consecutive  One Year Breaks  in Service,  then the unvested balance in
         his or  her Accounts  shall be  transferred to a segregated account for
         such  Participant and the  amount that  the Participant  is entitled to
         receive from such segregated account as of  any later date  shall be an
         amount equal to X, which amount shall be  determined in accordance with
         the following formula: X = P(AB + D) - D,  where P is the Participant's
         vested percentage  at such later date,  AB is the  amount in his or her
         segregated account at such later date,  and D is the amount distributed
         to the  Participant in  connection with  his or  her earlier separation
         from employment.



                                      -27-








                  (d) All amounts forfeited under  the Plan shall be credited to
         a forfeiture account and invested  by the  Trustee at  the direction of
         the  Committee in  its discretion until such forfeited amounts  and any
         earnings attributable  thereto are applied  in accordance with  Section
         3.8.

         Section 6.6 In-Service Withdrawals.

         (a)      A Participant in the employ of an Employer may make --

                    (i)    a withdrawal of all or a portion (in multiples of 10%
                           or  in  whole  dollar  amounts)  of  the total amount
                           credited  to  his  or  her  After-Tax  Account,  Mesa
                           After-Tax Account or Rollover Account;

                   (ii)    if the Participant has attained the age of 59 1/2,  a
                           withdrawal of  all or a portion  (in multiples of 10%
                           or in  whole dollar  amounts)  of  the  total  vested
                           amount credited to  his or her  Accounts  (other than
                           his or  her Matching  Plan  Account and  Mesa Premium
                           Account); or

                  (iii)    a hardship withdrawal of such amount as the Committee
                           shall  determine  to  be  necessary   to  satisfy  an
                           immediate   and   heavy  financial   need   of   such
                           Participant from his or her Pre-Tax Account and Prior
                           Plan Pre-Tax Account, other than earnings credited to
                           either  such  Account  for any  period of  time after
                           December  31,   1988,   and   qualified   nonelective
                           contributions allocated to either such Account;

         provided, however,  that (i) no withdrawal may be made unless notice of
         such  withdrawal is delivered to or  in the  manner  prescribed  by the
         Committee  by the  withdrawing Participant  within such  period of time
         prior to the effective  date thereof  as the Committee may prescribe in
         its discretion, (ii) no withdrawal may be made by a Participant to whom
         a loan  from the  Trust is  then  outstanding  unless the  Committee is
         satisfied that such loan will remain  nontaxable and  fully  secured by
         the   withdrawing   Participant's   Vested   Interest   following  such
         withdrawal,  and (iii)  withdrawals from the Prior Plan Pre-Tax Account
         and Prior Plan Employer Account may be made only pursuant to the notice
         and consent requirements of Section 6.2(b).  The Committee shall direct
         the Trustee to  distribute any  withdrawn amount to such Participant as
         soon as practicable following the effective date of the withdrawal. Any
         withdrawal  from an  Account pursuant  to this  Section  shall be taken
         proportionally  from  each  Investment  Fund in  which such  Account is
         invested.  The Committee may prescribe  uniform  and  nondiscriminatory
         rules and procedures  limiting the  number of  times that a Participant
         may make withdrawals during a  Plan Year and the  minimum amount that a
         Participant may withdraw on any single occasion.

                  (b) A hardship  withdrawal  will be  considered  to be made on
         account of an immediate and  heavy financial need of a Participant only
         if the Committee  determines that such  withdrawal is on account of (i)
         expenses  for  medical care  described in  Section 213(d)  of the  Code


                                      -28-








         previously  incurred  by  such  Participant  or his  or  her  spouse or
         dependents  (as defined  in Section  152 of the Code)  or necessary for
         such individuals  to obtain such care,  (ii) costs  directly related to
         the purchase  of a principal  residence for such Participant (excluding
         mortgage payments),  (iii)  payment of  tuition and related educational
         fees  for   the  next  12  months   of  post-secondary  education   for
         such  Participant or  his or  her spouse, children or dependents (as so
         defined),  or (iv)  payments necessary to prevent  the eviction of such
         Participant from his or her  principal residence or  foreclosure on the
         mortgage of such residence.

                 (c) A hardship  withdrawal  will  be considered to be necessary
         to satisfy an immediate and heavy financial need  of a Participant only
         if the Committee  determines that (i)  the amount of such withdrawal is
         not in excess  of the amount of such need plus any amounts necessary to
         pay any federal,  state or local  income taxes or  penalties reasonably
         anticipated to  result from  the withdrawal,  and (ii) such Participant
         has obtained  all distributions  and withdrawals,  other than  hardship
         withdrawals,  and all  nontaxable loans  currently available  under all
         plans maintained by the Employers.

                 (d) Any provision of this Plan to the contrary notwithstanding,
         if  a  Participant  makes  a  hardship  withdrawal,   (i)  no   Pre-Tax
         Contributions or Pre-Tax Bonus Contributions shall be made on behalf of
         such  Participant for 6 months after  receipt of such withdrawal and no
         contributions shall  be made by or on behalf of such Participant to any
         other  deferred  compensation  plan   maintained  by  an  Employer   or
         Affiliated  Company for  6 months  after receipt of such withdrawal and
         (ii) the Total Pre-Tax Contributions made on behalf of such Participant
         for the  calendar  year immediately following the calendar year of such
         withdrawal shall not  exceed the  amount by  which the limitation under
         Section  402(g)  of the  Code for such next  calendar  year exceeds the
         amount  of  the  Total  Pre-Tax  Contributions  made  on behalf of such
         Participant for the calendar year of such withdrawal.

         Section 6.7 Distributions to Minors and Persons Under Legal Disability.
If any  distribution under the Plan  becomes payable to a  minor or other person
under a legal  disability,  such distribution  may be made to the duly appointed
guardian or other  legal representative  of the  estate of such  minor or person
under legal disability.

         Section 6.8 Benefits Payable to Missing Participant or Beneficiary.  If
the  Committee  cannot  locate  a  Participant  or  beneficiary  entitled  to  a
distribution  under this  Plan  within  a  period  of  three  years  after  such
Participant or  beneficiary becomes  entitled to the  distribution,  the amounts
credited to  the Accounts of such Participant or beneficiary shall be forfeited;
provided,  however,   that  if  a  claim  for  any  such  forfeited  amounts  is
subsequently  made by any  person entitled  to the  distribution, such forfeited
amounts shall be restored (without adjustment for  earnings or appreciation) out
of current-year  forfeitures,  or if such  forfeitures are insufficient,  by  an
additional Employer contribution.


                                      -29-








         Section 6.9  Plan Loans.

                 (a)  Subject   to  such  conditions  and  limitations   as  the
         Committee  may  from time  to time  prescribe  for  application  to all
         Participants and beneficiaries on a uniform basis,  at the request of a
         Participant or beneficiary  of a deceased Participant who is a party in
         interest  (within  the  meaning  of  Section  3(14)  of  the   Employee
         Retirement Income Security Act of 1974, as amended) with respect to the
         Plan  (hereinafter called  the "Borrower"),  the Committee shall direct
         the Trustee  to loan to  such Borrower from his or her  Accounts (other
         than the Borrower's Matching Plan Account and  Mesa Premium Account) an
         amount of money which,  when added to the  total outstanding balance of
         all other  loans to  such Borrower  from the  Plan or  from a qualified
         employer  plan  (within  the  meaning  of  Section  72(p) of  the Code)
         maintained  by an Employer or  Affiliated Company,  does not exceed the
         lesser of (i)  $50,000 (reduced, however, by the excess, if any, of the
         highest  total outstanding balance  of all such  other loans during the
         one-year period  ending on  the day  before the date such loan is made,
         over the outstanding  balance of all such  other loans on the date such
         loan is made),  or (ii) one-half  of such Participant's Vested Interest
         under the Plan (or, in the case of a loan to a beneficiary, one-half of
         such beneficiary's Accounts).

                 (b) Any such  loan made to a Borrower  shall be  evidenced by a
         promissory  note  or  other  evidence of  indebtedness  payable  to the
         Trustee, shall bear a reasonable rate of interest,  shall be secured by
         one-half of  the Participant's  vested interest  under the Plan (or, in
         the case of a loan to a beneficiary,  by one-half of such beneficiary's
         Accounts),  shall be repayable  in substantially equal payments no less
         frequently than quarterly and  shall be repayable within five years or,
         in the case of a  loan that is to  be used to acquire any dwelling unit
         which within a reasonable period of time is to be used as the principal
         residence  of the  Participant,  within such  period  greater than five
         years  as  shall  be  determined  by  the  Committee  in  its  absolute
         discretion.

                 (c) Any provision of this Plan to the contrary notwithstanding,
         (i) the  promissory note  or other  evidence of indebtedness evidencing
         any such loan shall be held by  the Trustee  as a segregated investment
         allocated to  and made  solely for the  benefit  of the  Account of the
         Borrower from which such loan was made,  and (ii) no loan shall be made
         to a married  Participant  from a  Prior  Plan Pre-Tax Account or Prior
         Plan Employer Account unless the spouse of such Participant consents in
         writing thereto within the 90-day  period preceding  the date such loan
         is made and such consent is witnessed by a notary public.

         Section 6.10  Qualified  Domestic  Relations  Orders.  Any provision of
this Plan to the contrary notwithstanding:

                 (a)  The  Committee  shall  establish  and  maintain  for  each
         alternate  payee named with respect  to a  Participant under a domestic
         relations order  which is determined by the Committee to be a qualified
         domestic  relations order  (as defined  in Section  414(p) of the Code)


                                      -30-








         such separate  Accounts  as the  Committee  may deem to be necessary or
         appropriate to reflect such alternate  payee's interest in the Accounts
         of such Participant.  Such alternate payee's Accounts shall be credited
         with the  alternate payee's  interest in the  Participant's Accounts as
         determined under such qualified domestic relations order. The alternate
         payee may  change  investment  direction  with  respect  to  his or her
         Account balances in accordance with  Section 4.2 in  the same manner as
         the Participant.

                  (b) Except to the extent  otherwise provided  in the qualified
         domestic  relations order  naming an alternate payee  with respect to a
         Participant,  (i) the alternate payee may  designate a beneficiary on a
         form prescribed by and filed with or as directed by the Committee, (ii)
         if no such  beneficiary  is validly  designated  or if  the  designated
         beneficiary  is  a  person  who  predeceases the  alternate payee,  the
         beneficiary  of  the  alternate payee  shall  be the  alternate payee's
         estate,  and (iii)  the  beneficiary  of the  alternate payee  shall be
         accorded  under the  Plan  all of  the  rights  and  privileges  of the
         beneficiary of a Participant.

                  (c) An alternate  payee named  with respect  to a  Participant
         shall be entitled to receive a distribution from the Plan in accordance
         with  the qualified  domestic relations  order  naming  such  alternate
         payee. Such distribution may be made only in  a form provided under the
         Plan and shall include only such amounts as are vested.  If a qualified
         domestic  relations order  so provides,  a lump sum distribution of the
         total vested  amount credited  to the alternate payee's Accounts may be
         made  to  the alternate  payee at  any  time  prior  to  the  date  the
         Participant  named in such  qualified domestic  relations order attains
         his or her earliest retirement age (as defined in  Section 414(p)(4)(B)
         of the Code). To the extent provided by a qualified domestic  relations
         order, the alternate payee named with respect to a Participant may make
         withdrawals (other than  hardship withdrawals) from his or her Accounts
         in accordance  with Article  VI in the  same  manner as the Participant
         with  respect  to  whom  such  alternate  payee was  named  under  said
         qualified domestic relations order.

                  (d) If  a  portion  of  any  unvested  amount  credited to the
         Employer Account or Matching Plan Account of a Participant named in the
         qualified domestic relations order is credited to the  Employer Account
         or Matching  Plan Account,  whichever is  applicable,  of the alternate
         payee named  in such  qualified domestic  relations order,  the portion
         credited  to the alternate  payee's Employer  Account or  Matching Plan
         Account shall vest and/or be forfeited at the same time and in the same
         manner as the Participant's Employer Account or  Matching Plan Account,
         whichever is applicable.

         Section 6.11   Transfer  of  Eligible   Rollover  Distribution.   If  a
Participant is entitled to receive an eligible rollover distribution (as defined
in Section  402(c) of  the Code  and the regulations  thereunder) from the Plan,
such  Participant may elect to have the Committee direct the Trustee to transfer
the  entire  amount  of  such  distribution  directly  to  any  of the following
"eligible  retirement  plans"  specified  by  such  Participant:  an  individual
retirement account  described  in Section  408(a) of  the  Code,  an  individual
retirement  annuity  described in  Section 408(b)  of the  Code  (other  than an


                                      -31-








endowment contract),  a defined contribution plan qualified under Section 401(a)
of the Code the terms of which permit rollover  contributions or an annuity plan
described in Section  403(a) of the Code. If the surviving  spouse of a deceased
Participant is entitled to receive an eligible  rollover  distribution  from the
Plan, such surviving  spouse may elect to have the Committee  direct the Trustee
to  transfer  the  entire  amount  of such  distribution  directly  to either an
individual  retirement  account  described  in Section  408(a) of the Code or an
individual  retirement  annuity  described in Section  408(b) of the Code (other
than an endowment  contract) specified by such surviving spouse. If an alternate
payee under a qualified  domestic  relations order (as defined in Section 414(p)
of the Code) is the spouse or former spouse of the Participant  specified in the
qualified  domestic  relations order, this Section shall apply to such alternate
payee as if the alternate payee were a Participant. A distributee of an eligible
rollover distribution who is entitled to make an election under this Section may
specify that some portion less than the entire  amount of such  distribution  be
transferred in accordance  with this Section.  The preceding  provisions of this
Section to the contrary notwithstanding, (i) an "eligible retirement plan" shall
also mean an annuity  contract  described  in Section  403(b) of the Code and an
eligible plan under  Section  457(b) of the Code which is maintained by a state,
political subdivision of a state, or any agency or instrumentality of a state or
political  subdivision  of a state and which  agrees to  separately  account for
amounts  transferred  into  such plan from this  Plan,  (ii) the  definition  of
"eligible  retirement  plan" shall also apply in the case of a distribution to a
surviving  spouse,  or to a spouse or former spouse who is the  alternate  payee
under a qualified  domestic relations order, as defined in Section 414(p) of the
Code,  (iii) any amount that is  distributed on account of hardship shall not be
an eligible rollover  distribution and the distributee may not elect to have any
portion of such a distribution paid directly to an eligible retirement plan, and
(iv) a  portion  of a  distribution  shall not fail to be an  eligible  rollover
distribution   merely  because  the  portion  consists  of  after-tax   employee
contributions  which are not  includible  in gross  income,  provided  that such
portion may be transferred only to an individual  retirement  account or annuity
described  in  Section  408(a) or (b) of the  Code,  or to a  qualified  defined
contribution  plan described in Section 401(a) or 403(a) of the Code that agrees
to  separately  account  for  amounts  so  transferred,   including   separately
accounting  for the portion of such  distribution  which is  includible in gross
income and the portion of such distribution which is not so includible.


                                  ARTICLE VII.

                               PLAN ADMINISTRATION

         Section 7.1 401(k) and Matching Plan Committee.  The plan administrator
of the Plan shall be a 401(k) and Matching Plan  Committee  composed of at least
three  individuals  appointed by the Board of  Directors  of the  Company.  Each
member of the Committee so appointed shall serve in such office until his or her
death,  resignation  or removal by the Board of Directors  of the  Company.  The
Board of Directors of the Company may remove any member of the  Committee at any
time by giving written notice thereof to the members of the Committee. Vacancies
shall  likewise  be filled  from time to time by the Board of  Directors  of the



                                      -32-








Company.  The members of the Committee  shall receive no  remuneration  from the
Plan for their services as Committee members.

         Section 7.2  Powers,  Duties  and  Liabilities of  the  Committee.  The
Committee  shall  have  discretionary  and  final  authority  to  interpret  and
implement the provisions of the Plan,  including without limitation authority to
determine  eligibility for benefits under the Plan, and shall perform all of the
duties and  exercise  all of the powers and  discretion  granted to it under the
terms of the Plan.  The Committee  shall act by a majority of its members at the
time in office and such action may be taken  either by a vote at a meeting or in
writing without a meeting.  The Committee may by such majority action  authorize
any one or more of its members to execute any document or documents on behalf of
the Committee,  in which event the Committee shall notify the Trustee in writing
of such action and the name or names of its member or members so  authorized  to
act.  Every  interpretation,  choice,  determination  or other  exercise  by the
Committee of any discretion given either expressly or by implication to it shall
be  conclusive  and binding upon all parties  directly or  indirectly  affected,
without  restriction,  however,  on the right of the Committee to reconsider and
redetermine such actions.  In performing any duty or exercising any power herein
conferred,  the  Committee  shall in no event perform such duty or exercise such
power  in  any  manner  which  discriminates  in  favor  of  Highly  Compensated
Employees.  The Employers  shall  indemnify and hold harmless each member of the
Committee against any claim, cost, expense (including attorneys' fees), judgment
or liability  (including any sum paid in settlement of a claim with the approval
of the  Employers)  arising out of any act or omission to act as a member of the
Committee appointed under this Plan, except in the case of willful misconduct.

         Section 7.3  Rules, Records and Reports.  The Committee  may adopt such
rules and procedures for the  administration  of the Plan as are consistent with
the terms hereof, and shall keep adequate records of the Committee's proceedings
and acts and of the status of the  Participants'  Accounts.  The  Committee  may
employ  such  agents,   accountants  and  legal  counsel  (who  may  be  agents,
accountants  or legal  counsel for an  Employer) as may be  appropriate  for the
administration  of the Plan. The Committee shall at least annually  provide each
Participant  with a report  reflecting  the status of his or her Accounts in the
Trust and shall  cause  such  other  information,  documents  or  reports  to be
prepared,  provided  and/or  filed  as may  be  necessary  to  comply  with  the
provisions of the Employee  Retirement  Income Security Act of 1974 or any other
law.

         Section 7.4 Administration Expenses and Taxes. Unless otherwise paid by
the  Employers in their  absolute  discretion,  the  Committee  shall direct the
Trustee to pay all  reasonable  and necessary  expenses  (including  the fees of
agents,  accountants and legal counsel)  incurred by the Committee in connection
with the administration of the Plan. Should any tax of any character  (including
transfer  taxes) be levied upon the Trust assets or the income  therefrom,  such
tax shall be paid from and charged against the assets of the Trust.


                                      -33-








                                  ARTICLE VIII.

                            AMENDMENT AND TERMINATION

         Section 8.1 Amendment. The Board of Directors of the Company shall have
the right and power at any time and from  time to time to amend  this  Plan,  in
whole or in part, on behalf of all  Employers.  Any such  amendment  made by the
Board of Directors  of the Company  shall be made by or pursuant to a resolution
duly adopted by the Board of Directors of the Company, and shall be evidenced by
such resolution or by a written instrument  executed by such person as the Board
of Directors of the Company shall  authorize for such purpose.  With the consent
of the Board of Directors of the Company and subject to such procedure as it may
prescribe,  the Board of  Directors  of each  Employer  shall have the right and
power at any time and from time to time to amend this Plan, in whole or in part,
with respect to the Plan's  application  to the  Participants  of the particular
amending  Employer  and the assets  held in the Trust for their  benefit,  or to
transfer  such assets or any  portion  thereof to a new trust for the benefit of
such Participants.  However, in no event shall any amendment or new trust permit
any portion of the trust fund to be used for or  diverted  to any purpose  other
than the exclusive  benefit of the  Participants  and their  beneficiaries,  nor
shall any amendment or new trust reduce a  Participant's  Vested  Interest under
the Plan.

         Section 8.2  Termination.  The Board of Directors  of the Company shall
have the  right and  power at any time to  terminate  this Plan on behalf of all
Employers,  or to terminate this Plan as it applies to the  Participants who are
or were employees of any particular  Employer,  by giving written notice of such
termination  to the  Committee  and Trustee.  Any  provision of this Plan to the
contrary  notwithstanding,  upon the  termination or partial  termination of the
Plan  as to any  Employer,  or in  the  event  any  Employer  should  completely
discontinue  making  contributions to the Plan without formally  terminating it,
all  amounts  credited  to the  Accounts of the  affected  Participants  of that
particular Employer shall be fully vested.

         Section 8.3  Benefit Plan Design Committee.  Any action permitted to be
taken by the Board with  respect to the  amendment  of this Plan may be taken by
the Benefit Plan Design  Committee.  The Benefit Plan Design  Committee shall be
composed of at least two individuals  appointed by the Board of Directors of the
Company.  Each member of the Benefit Plan Design  Committee  so appointed  shall
serve in such  office  until his or her  death,  resignation  or  removal by the
Board.  The Board may remove any member of the Benefit Plan Design  Committee at
any time by giving  written  notice  thereof to the members of the Benefit  Plan
Design  Committee.  Vacancies  shall likewise be filled from time to time by the
Board.  The Benefit Plan Design Committee shall act by a majority of its members
at the time in office and such action may be taken either by a vote at a meeting
or in writing without a meeting.

                                      -34-








                                   ARTICLE IX.

                              TOP-HEAVY PROVISIONS

         Section 9.1 Top-Heavy Definitions. Unless the context clearly indicates
otherwise, when used in this Article:

                  (a)  "Top-Heavy  Plan"  means   this  Plan  if,   as  of   the
         Determination  Date,  the aggregate  of the  Accounts of  Key Employees
         under  the Plan  exceeds  60% of the  aggregate of the  Accounts of all
         Participants and  former Participants under the  Plan. The aggregate of
         the Accounts of any Participant or former Participant shall include any
         distributions (other than related rollovers or  transfers from the Plan
         within the  meaning of  regulations  under Section  416(g) of the Code)
         made from such individual's Accounts during  the one-year period ending
         on  the  Determination  Date,  but  shall  not  include  any  unrelated
         rollovers or transfers (within the meaning of regulations under Section
         416(g)  of the Code)  made to such individual's Accounts after December
         31, 1983; provided,  however,  that in the  case of a distribution made
         for a reason other than separation from service,  death, or disability,
         this provision shall be applied by substituting  "five-year period" for
         "one-year period". The Account of any Participant or former Participant
         who (i) is not a Key Employee for the Plan Year in question but who was
         a Key Employee in a prior Plan Year,  or (ii) has not completed an Hour
         of Service during the one-year period ending on the Determination Date,
         shall not be taken into account.  The determination of whether the Plan
         is a Top-Heavy Plan shall  be made after aggregating all other plans of
         an Employer and any  Affiliated Company qualifying under Section 401(a)
         of the Code in which a Key  Employee is a  participant or which enables
         such a plan to meet the requirements of Section 401(a)(4) or 410 of the
         Code, and after aggregating any other plan of an Employer or Affiliated
         Company,  which  is not  already aggregated,  if such aggregation group
         would  continue to  meet the requirements of Sections 401(a)(4) and 410
         of the Code and if such permissive  aggregation  thereby eliminates the
         top-heavy status of any plan within such permissive  aggregation group.
         For  purposes of  determining  the  aggregate  of the  Accounts  of any
         Participant  or  former  Participant,  the  distributions included,  as
         provided  above,  shall include  distributions under  a terminated plan
         which,  had it not been terminated, would have been aggregated with the
         Plan under  Section  416(g)(2)(A)(i) of the Code.  The determination of
         whether this Plan is a Top-Heavy Plan shall be made in  accordance with
         Section 416(g) of the Code.

                  (b) "Determination Date" means,  for purposes  of  determining
         whether the Plan is  a Top-Heavy Plan for a particular  Plan Year,  the
         last day of the preceding Plan Year.

                  (c) "Key Employee"  means  any  Employee  or  former  Employee
         (including a beneficiary of such  Employee or  former  Employee) who at
         any time during the Plan Year that includes the Determination Date is:


                                      -35-








                           (1) an officer of an Employer having Compensation for
                  such  Plan Year  greater  than  $130,000  (as  adjusted  under
                  Section 416(i)(1) of the  Code for Plan  Years beginning after
                  December 31, 2002);

                           (2)  a 5% owner of the Employer; or

                           (3)  a 1% owner of the Employer  having  Compensation
                  for such Plan Year of more than $150,000.

         The determination of  who is a  Key Employee will be made in accordance
         with Section 416(i)(1) of the Code  and the  applicable regulations and
         other guidance of general applicability issued thereunder.

                  (d) "Non-Key Employee"  means any  Employee or former Employee
         (including a  beneficiary  of such Employee or  former Employee) who is
         not a Key Employee.

         Section 9.2  Minimum Contribution  Requirement.  Any  provision of this
Plan to the contrary  notwithstanding,  if the Plan is a Top-Heavy  Plan for any
Plan Year,  then the Employers will  contribute to the Employer  Account of each
Non-Key  Employee who is both  eligible to  participate  and in the employ of an
Employer on the last day of such Plan Year, an amount  which,  when added to the
total amount of Matching Contributions and forfeitures otherwise allocable under
the Plan to such Non-Key  Employee for such year,  shall equal the lesser of (i)
3% of such Non-Key  Employee's  Compensation for such year or (ii) the amount of
contributions (including Total Pre-Tax Contributions) and forfeitures (expressed
as a percentage of  Compensation)  allocable  under the Plan for or on behalf of
the Key Employee for whom such percentage is the highest for the Plan Year after
taking  into  account  contributions  under  other  defined  contribution  plans
maintained by the Employer in which a Key Employee is a participant  (as well as
any other plan of an Employer which enables such a plan to meet the requirements
of Section  401(a)(4) or 410 of the Code);  provided,  however,  that no minimum
contribution  shall be made for a Non-Key  Employee  under this  Section for any
Plan Year if the Employer maintains another qualified plan under which a minimum
benefit  or  contribution  is being  accrued  or made for such Plan Year for the
Non-Key  Employee  in  accordance  with  Section  416(c) of the Code.  A Non-Key
Employee who is not a Participant,  but for whom a contribution is made pursuant
to this  Section,  shall be  accorded  all of the  rights  and  privileges  of a
Participant   under  the  Plan   except  that  no   contributions   (other  than
contributions  pursuant to this Section)  shall be made for or on behalf of such
Non-Key  Employee  until  he or she  meets  the  eligibility  and  participation
requirements of Article II.

         Section 9.3 Minimum Vesting Schedule. Any provision of this Plan to the
contrary  notwithstanding,  if the Plan is a  Top-Heavy  Plan for any Plan Year,
then  effective  as of  the  first  day  of  such  Plan  Year  with  respect  to
Participants  who  complete an Hour of Service on or after such day, the vesting
schedule  provided  in  Section  5.2 shall be  applied  to that  portion of such
Participants'  Employer Account which is attributable to any amounts credited to



                                      -36-








his or her Employer  Nonelective  Contribution Account under the Superseded Plan
as in effect on September 30, 1997, as if to read as follows:


                      Period of Service
                  Completed by Participant           Percentage Vested
                  ------------------------           -----------------
                                               
                      Less than 3 years                     None
                       3 or more years                      100%




                                   ARTICLE X.

                        MISCELLANEOUS GENERAL PROVISIONS

         Section 10.1  Spendthrift  Provision.  No  right  or  interest  of  any
Participant  or  beneficiary  under  the Plan may be  assigned,  transferred  or
alienated,  in whole or in part,  either directly or by operation of law, and no
such right or interest shall be liable for or subject to any debt, obligation or
liability of such Participant or beneficiary;  provided,  however,  that nothing
herein shall prevent the payment of amounts from a Participant's  Accounts under
the Plan in  accordance  with the terms of a court order which the Committee has
determined  to be a qualified  domestic  relations  order (as defined in Section
414(p) of the Code).

         Section 10.2  Claims Procedure.  If any person  (hereinafter called the
"Claimant") feels that he or she is being denied a benefit to which he or she is
entitled under the Plan, such Claimant may file a written claim for said benefit
with any member of the  Committee.  Within 60 days of the  receipt of such claim
the Committee shall determine and notify the Claimant as to whether he or she is
entitled to such benefit.  Such notification shall be in writing and, if denying
the claim for benefit,  shall set forth the  specific  reason or reasons for the
denial,  make specific  reference to the pertinent  provisions of the Plan,  and
advise the  Claimant  that he or she may,  within 60 days of the receipt of such
notice,  in writing  request to appear  before  the  Committee  for a hearing to
review  such  denial.  Any  such  hearing  shall  be  scheduled  at  the  mutual
convenience of the Committee or its designated  representative and the Claimant,
and  at  such   hearing  the  Claimant   and/or  his  or  her  duly   authorized
representative  may examine any  relevant  documents  and present  evidence  and
arguments  to support  the  granting  of the benefit  being  claimed.  The final
decision of the Committee with respect to the claim being reviewed shall be made
within 60 days following the hearing  thereon and the Committee shall in writing
notify the Claimant of its final decision, again specifying the reasons therefor
and the pertinent  provisions of the Plan upon which such decision is based. The
final decision of the Committee shall be conclusive and binding upon all parties
having or claiming to have an interest in the matter being reviewed.

         Section 10.3  Maximum Contribution Limitation.  Any  provision  of this
Plan to the  contrary  notwithstanding  (except  to the extent  permitted  under
Section 3.3 of the Plan and Section 414(v) of the Code, if applicable),  the sum
of  (i)  the  Employer  contributions,  (ii)  the  forfeitures,  and  (iii)  the


                                      -37-








Participant   contributions   (excluding  rollover  contributions  and  employee
contributions to a simplified  employee pension  allowable as a deduction,  each
within the meaning specified in Section  415(c)(2) of the Code),  allocated to a
Participant  with  respect to a Plan Year shall in no event exceed the lesser of
$40,000 (as adjusted for increases in the cost-of-living under Section 415(d) of
the Code) or 100% of such  Participant's  Compensation  for that  year.  For the
purposes of applying the limitation  imposed by this Section,  each Employer and
its Affiliated Companies shall be considered a single employer,  and all defined
contribution  plans  (meaning plans  providing for  individual  accounts and for
benefits  based  solely upon the amounts  contributed  to such  accounts and any
forfeitures,  income,  expenses,  gains and losses  allocated to such  accounts)
described in Section 415(k) of the Code,  whether or not terminated,  maintained
by an Employer or its Affiliated Companies shall be considered a single plan. If
the total amount  allocable to a  Participant's  Accounts for a particular  Plan
Year  would,  but for this  sentence,  exceed  the  foregoing  limitation,  such
Participant's  After-Tax  Contributions  shall first be distributed and then, to
the extent  necessary,  Total Pre-Tax  Contributions  shall be distributed first
from any Pre-Tax Bonus  Contributions and then from Pre-Tax  Contributions.  Any
Matching  Contributions  corresponding to any distributed Pre-Tax  Contributions
shall be credited to a suspense account and thereafter reallocated (prior to the
allocation  of  subsequent   forfeitures   and  the  making  of  any  additional
contributions  to  the  Plan)  to  reduce  the  earliest   subsequent   Matching
Contributions  an  Employer  would  otherwise  be  required  to make to the Plan
pursuant  to Section  3.2 for such year and the next  succeeding  Plan Year.  No
adjustment shall be made to such suspense account to reflect income, profits and
losses,   expenses  or  other  transactions  affecting  the  Plan.  Any  Pre-Tax
Contributions  or  Pre-Tax  Bonus  Contributions  distributed  to a  Participant
pursuant to this  Section  shall not be taken into account in  determining  such
Participant's actual deferral percentage for purposes of Section 3.7.

         Section 10.4  Employment Noncontractual. The establishment of this Plan
shall not enlarge or  otherwise  affect the terms of any  Employee's  employment
with an Employer and an Employer may terminate the employment of any Employee as
freely and with the same effect as if this Plan had not been adopted.

         Section 10.5  Limitations  on  Responsibility.  The  Employers  do  not
guarantee or indemnify the Trust against any loss or  depreciation of its assets
which may occur,  nor  guarantee  the  payment  of any  amount  which may become
payable to a Participant or his or her beneficiaries  pursuant to the provisions
of this Plan. All payments to Participants and their beneficiaries shall be made
by the Trustee at the direction of the  Committee  solely from the assets of the
Trust  and the  Employers  shall  have no legal  obligation,  responsibility  or
liability for any such payments.

         Section 10.6  Merger or Consolidation. In no  event shall  this Plan be
merged or consolidated  into or with any other plan, nor shall any of its assets
or liabilities be transferred to any other plan,  unless each Participant  would
be  entitled  to  receive  a  benefit  if the  plan  in  which  he or  she  then
participates  terminated  immediately  following such merger,  consolidation  or
transfer,  which is equal to or  greater  than the  benefit he or she would have
been entitled to receive if the Plan had been  terminated  immediately  prior to
such merger, consolidation or transfer.


                                      -38-







         Section 10.7  Applicable Law. This Plan shall be governed and construed
in  accordance  with the  internal  laws  (and not the  principles  relating  to
conflicts of laws) of the State of Texas except where superseded by federal law.

         Section 10.8  USERRA Compliance.  Notwithstanding any provision of this
Plan to the contrary, contributions, benefits and service credit with respect to
qualified military service will be provided in accordance with Section 414(u) of
the Code.

         IN WITNESS WHEREOF,  this restatement has been executed as of this ____
day of December, 2001, to be effective as of January 1, 2002.

                           PIONEER NATURAL RESOURCES USA, INC.



                           By______________________________________________
                             Larry Paulsen, Vice President - Administration





                                      -39-