PIONEER NATURAL RESOURCES COMPANY CHANGE IN CONTROL AGREEMENT

PIONEER NATURAL RESOURCES COMPANY

CHANGE IN CONTROL AGREEMENT

This Change in Control Agreement ( “Agreement” ) is entered into, as of May 19, 2008, among Pioneer Natural Resources Company, a Delaware corporation ( “Parent” ), Pioneer Natural Resources USA, Inc., a Delaware corporation that is a wholly-owned subsidiary of Parent ( “Employer” ), and Frank Hall ( “Employee” ). As henceforth used in this Agreement, the term “Company” shall be deemed to include Parent and its direct or indirect majority-owned subsidiaries.

Recitals

Parent and Employer acknowledge that Employee possesses skills and knowledge instrumental to the successful conduct of the Company’s business. Parent and Employer are willing to enter into this Agreement with Employee in order to better ensure themselves of access to the continued services of Employee both before and after a Change in Control.

NOW, THEREFORE, for and in consideration of the mutual covenants and agreements set forth herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties to this Agreement hereby agree as follows:

1.           Term . The term of this Agreement shall commence on the date indicated above (the “Effective Date” ) and end on September 30, 2008. Thereafter, on the date on which the term of this Agreement (as it may be extended from time to time under this paragraph 1) would otherwise expire, so long as Employee is still an employee of the Company on such date, such term will be automatically extended for 12 months, unless Parent shall have provided written notice to Employee at least 6 months before the date that the term would otherwise expire that it does not want the term to be extended. Parent may deliver a conditional notice of non-renewal that will be effective only if Employee does not agree, within the time period specified by Parent, to any amendment or modification of this Agreement that Parent shall request be executed as a condition to allowing the term hereof to be extended. Notwithstanding the foregoing, and regardless of whether Parent has theretofore delivered a notice of non-renewal and/or sought agreement from Employee to amendments to this Agreement, if a Potential Change in Control or a Change in Control occurs during the term hereof, the term of this Agreement shall be automatically extended to the second anniversary of the date on which the Change in Control occurs (the “Change in Control Date” ); provided, however, that if no Change in Control has occurred prior to the first anniversary of the occurrence of a Potential Change in Control and the Board of Directors of Parent (the “Board” ), acting in good faith, thereafter adopts a resolution that such Potential Change in Control will not result in the occurrence of a Change in Control, the term of this Agreement shall expire on a date specified by the Board not earlier than the first anniversary of the adoption of such resolution (unless otherwise extended pursuant to the second sentence of this paragraph 1).

2.           Operation of Agreement . Except as expressly provided below, no benefits shall be payable under this Agreement if Employee is not employed by the Company on the Change in Control Date. Notwithstanding anything else contained herein to the contrary, if Employee’s employment is terminated (a) by the Company and such termination is not a Termination for Cause and (b) after the occurrence of a Potential Change in Control but prior to a Change in

Control and a Change in Control occurs within 12 months after such termination, Employee shall be deemed, solely for purposes of determining Employee’s rights under this Agreement, to have remained employed until the Change in Control Date and to have been terminated by the Company without cause immediately thereafter; provided, however, that , in such case, the Separation Payment payable hereunder shall be reduced by the amount of any other cash severance benefits theretofore paid to Employee in connection with such termination. If Employee is still an employee of the Company on the Change in Control Date, or Employee is deemed, for purposes of this Agreement, to continue to be in the employ of the Company until the Change in Control Date pursuant to the immediately preceding sentence, upon the occurrence of a Change in Control this Agreement shall supercede any other individual agreement between Parent and Employer and Employee the primary purpose of which is to provide Employee the right to receive severance benefits and certain other benefits ancillary to such severance benefits in connection with the termination of Employee’s employment (the “ Severance Agreement ”), subject, if applicable, to the offset set forth in the immediately preceding sentence.

3.           Certain Definitions . As used in this Agreement, the following terms shall have the meanings set forth below:

(a)        “Accrued Obligations” shall mean any vested amounts or benefits owing to Employee under any of the Company’s employee benefit plans and programs in which Employee has participated, including any compensation previously deferred by Employee (together with any accrued earnings thereon) and not yet paid.

(b)        “Base Salary” shall mean Employee’s annualized base salary at the rate in effect at the relevant date or event as reflected in Employer’s regular payroll records.

(c)        “Change in Control” shall mean an event that constitutes a “change in control” as defined in Parent’s Long-Term Incentive Plan (the “LTIP” ), as in effect on the Effective Date or as subsequently amended from time to time (except that any amendment to such definition adopted on or after, or within 180 days prior to, a Change in Control or Potential Change in Control shall not be applied in determining the definition of such term under this Agreement unless such amendment is favorable to Employee).

(1)       In the case of a termination for which a Notice of Termination is required, the date of receipt of such Notice of Termination or, if later, the date specified therein; and

(2)       In all other cases, the actual date on which Employee’s employment terminates.

(e)        “Disability” shall mean Employee’s physical or mental impairment or incapacity of sufficient severity such that

(1)       In the opinion of a qualified physician selected by Parent with the consent of Employee or Employee’s legal representative (which consent shall not be unreasonably withheld), after taking into account all reasonable

accommodations that the Company has made or could make, Employee is unable to continue to perform Employee’s duties and responsibilities as an employee of the Company; and

(2)       Employee’s condition entitles Employee to long-term disability benefits under any employee benefit plan maintained by the Company or any of its affiliates that are at least comparable to those made available to Employee by the Company prior to the Change in Control.

For purposes of subparagraph (e)(1) above, Employee agrees to provide such access to Employee’s medical records and to submit to such physical examinations and medical tests as, in the opinion of the physician selected by Parent, is reasonably necessary to make the determination required as to Employee’s ability to perform Employee’s duties and responsibilities.

(f)         “Earned Salary” shall mean the Base Salary earned by Employee, but unpaid, through Employee’s Date of Termination.

(g)        “Normal Retirement Date” shall mean the date on which Employee attains age 60.

(h)        “Notice of Termination” shall mean a written notice given, in the case of a Termination for Cause, within 45 days of Parent’s or Employer’s having actual knowledge of the events giving rise to such termination, and in the case of a Termination for Good Reason, within 90 days of the later to occur of (x) the Change in Control Date or (y) Employee’s having actual knowledge of the events giving rise to such termination. Any such Notice of Termination shall

(1)       Indicate the specific termination provision in this Agreement relied upon;

(2)       Set forth in reasonable detail the facts and circumstances claimed to provide a basis for termination of Employee’s employment under the provision so indicated; and

(3)       If the Date of Termination is other than the date of receipt of such notice, specify the Date of Termination (which date shall be not more than 30 days after the giving of such notice).

The failure by Employee to set forth in the Notice of Termination any fact or circumstance which contributes to a showing of Termination for Good Reason shall not waive any right of Employee hereunder or preclude Employee from asserting such fact or circumstance in enforcing Employee’s rights hereunder.

(i)         “Potential Change in Control” shall mean the occurrence of any of the following events:

(1)       Any person or group shall have announced publicly an intention to effect a Change in Control, or commenced any action (such as the commencement of a tender offer for Parent’s common stock or the solicitation of

proxies for the election of any of Parent’s directors) that, if successful, could reasonably be expected to result in the occurrence of a Change in Control;

(2)       Parent enters into an agreement the consummation of which would constitute a Change in Control; or

(3)       Any other event occurs which the Board declares to be a Potential Change in Control.

(j)         “Separation Payment” shall mean any lump sum cash payment in excess of Earned Salary and Accrued Obligations payable to Employee under this Agreement.

(1)       the average of the target bonuses made available to Employee under any Company annual bonus program (which, if not stated as the target for a full year of service, shall be annualized) for the year in which the Change in Control Date occurs and for each of the last 2 years ended prior to the year in which the Change in Control Date occurs (or, if less, the number of years prior to the year in which the Change in Control Date occurs during which Employee was employed by the Company); and

(2)       Employee’s highest target bonus made available to Employee under the annual bonus program in which Employee participated for services rendered or to be rendered by Employee in any calendar year after the calendar year in which the Change in Control Date occurs; in either case as reflected in Employer’s records.

(l)         “Termination for Cause” shall mean a termination of Employee’s employment by Parent and Employer due to the occurrence of any of the following

(1)       Employee’s continued failure (i) to substantially perform Employee’s duties and responsibilities (other than any such failure resulting from Employee’s physical or mental impairment or incapacity) or (ii) to comply with any material written policy of the Company generally applicable to all officers of the Company and, if applicable, the successor in interest to Parent or, if such successor is a subsidiary of any other entity, the direct or indirect ultimate parent of such successor (such successor or such ultimate parent entity, the “Parent Successor” ), which specifically provides that Employee may be dismissed (or Employee’s employment terminated) as a consequence of any such failure to comply, in either case more than 10 business days after written demand for substantial performance or compliance with the policy is delivered by Parent specifically identifying the manner in which Parent believes Employee has not substantially performed Employee’s duties and responsibilities or not complied with the written policy;

(2)       Employee’s engaging in an act or acts of gross misconduct which result in, or are intended to result in, material damage to the Company’s business or reputation;

(3)       Employee’s failure, following a written request from Parent, reasonably to cooperate (including, without limitation, the refusal by Employee to be interviewed or deposed, or to give testimony) in connection with any investigation or proceeding, whether internal or external (including, without limitation, by any governmental or quasi-governmental agency), into the business practices or operations of the Company; or

(4)       Employee’s conviction of (or plea of guilty or nolo contendere to a charge of) any felony or any crime or misdemeanor, in either case, involving moral turpitude or financial misconduct which results in significant monetary damage to the Company.

For purposes of subparagraph (l)(2) above, an act, or failure to act, on Employee's part shall only be considered "misconduct" if done, or omitted, by Employee not in good faith and without reasonable belief that such act, or failure to act, was in the best interest of the Company.

(m)       “Termination for Good Reason” shall mean a termination of Employee’s employment by Employee due to the occurrence of any of the following, without the express written consent of Employee, after the occurrence of a Potential Change in Control or a Change in Control:

(1)       The assignment to Employee of any duties inconsistent in any material adverse respect with Employee’s position, authority or responsibilities as in effect immediately prior to a Potential Change in Control or a Change in Control, or (ii) any other material adverse change in such position, including titles, authority or responsibilities, which, in the case of any officer of Parent, shall be deemed to have occurred unless, following the Change in Control Date, Employee holds such position or positions with the Parent Successor that are substantially comparable to the position or positions held by Employee with Parent immediately prior to the Change in Control Date (or, if higher, immediately prior to the occurrence of a Potential Change in Control);

(2)       Any failure by the Company or the Parent Successor, other than an insubstantial or inadvertent failure remedied promptly after receipt of notice thereof given by Employee, to provide Employee with an annual Base Salary which is at least equal to the Base Salary payable to Employee immediately prior to the Change in Control Date (or, if higher, immediately prior to the occurrence of a Potential Change in Control) or, if more favorable to Employee, at the rate made available to Employee at any time thereafter (the “Protected Base Salary” );

(3)       Any failure by the Company or the Parent Successor, other than an insubstantial or inadvertent failure remedied promptly after receipt of notice thereof given by Employee, to provide Employee with a reasonably achievable opportunity (determined in a manner consistent with the Company’s practices

prior to the Change in Control) to receive an annual bonus ranging from 100%, at targeted levels of performance, to 200%, at superior levels of performance, of Employee’s Target Bonus;

(4)       Any failure by the Company or the Parent Successor, other than an insubstantial or inadvertent failure remedied promptly after receipt of notice thereof given by Employee, to provide Employee with annual awards of long-term incentive compensation that have a value (using the same valuation methodologies used for valuing long-term incentive compensation awards of a similar type made to senior officers of Parent and, if applicable, the Parent Successor) at least equal to the average dollar value assigned thereto by the Company at the date of grant of the last three annual long-term incentive compensation awards (including, without limitation, equity and equity-based awards) granted to Employee in respect of Employee’s employment with the Company (or if Employee has received less than three such annual grants, the average of the value of the number of grants received by Employee prior to the Change in Control Date);

(5)       Any failure by the Company or the Parent Successor, other than an insubstantial or inadvertent failure remedied promptly after receipt of notice thereof given by Employee, to permit Employee (and, to the extent applicable, Employee’s dependents) to participate in or be covered under all pension, retirement, deferred compensation, savings, medical, dental, health, disability, group life, accidental death and travel accident insurance plans and programs at a level that is materially less favorable in the aggregate than the benefits provided under the plans of the Company and its affiliated companies prior to the Change in Control Date (or, if more favorable to Employee, at the level made available to Employee or other similarly situated officers at any time thereafter); or

(6)       If, not later than the Change in Control Date, any Parent Successor shall have failed to agree in writing to assume and perform this Agreement as required by paragraph 7(h) hereof.

(a)        Right to Terminate . Nothing in this Agreement shall be construed in any way to limit the right of the Company to terminate Employee’s employment, with or without cause, or for Employee to terminate Employee’s employment with the Company, with or without reason; provided, however, that the Company and Employee must nonetheless comply with any duty or obligation such party has at law or under any agreement (including paragraph 6 of this Agreement) between the parties.

(b)        Termination due to Death or Disability . Employee’s employment with the Company shall be terminated upon Employee’s death. By written notice to the other party, either the Company or Employee may terminate Employee’s employment due to Disability.

5.           Amounts Payable Upon Termination of Employment . The following provisions shall apply to any termination of Employee’s employment occurring (or which,

pursuant to paragraph 2, is deemed to occur) at the time of, or at any time within 2 years following, a Change in Control:

(a)        Death, Disability or Normal Retirement . In the event that Employee’s employment terminates due to Employee’s death or Disability (regardless of whether such Disability termination is initiated by Employee or the Company) or due to the voluntary retirement by Employee (which is not a Termination for Good Reason) at or after attaining Normal Retirement Date, Parent or Employer shall pay Employee (or, if applicable, Employee’s beneficiaries or legal representative(s)):

(1)       The Earned Salary, as soon as practicable (but not more than 10 days) following Employee’s Date of Termination;

(2)       The Accrued Obligations, in accordance with app