SERVICES AND SECONDMENT AGREEMENT

Execution Version

SERVICES AND SECONDMENT AGREEMENT

WESTERN GAS HOLDINGS, LLC

AND

ANADARKO PETROLEUM CORPORATION

TABLE OF CONTENTS

		ARTICLE I
		SECONDMENT
1.1		Seconded Employees			2
1.2		Period of Secondment			2
1.3		Withdrawal, Departure or Resignation			3
1.4		Termination of Secondment			3
1.5		Supervision			4
1.6		Seconded Employee Qualifications; Approval			4
		ARTICLE II
		SECONDMENT SERVICES
2.1		Secondment Services			5
2.2		Cancellation or Reduction of Secondment Services			5
2.3		Workers’ Compensation			5
		ARTICLE III
		SERVICES REIMBURSEMENT
3.1		Operational, Management, Reporting and Routine Maintenance Expenses			6
3.2		Seconded Employees			6
		ARTICLE IV
		ALLOCATION; RECORDS; AGENT
4.1		Allocation; Records			8
4.2		Agent			8
		ARTICLE V
		TERM
		ARTICLE VI
		GENERAL PROVISIONS
6.1		Accuracy of Recitals			10
6.2		Choice of Law; Submission to Jurisdiction			10
6.3		Notices			10
6.4		Further Assurances			11
6.5		Entire Agreement			11
6.6		Effect of Waiver or Consent			11
6.7		Amendment or Modification			11
6.8		Assignment; Third-Party Beneficiaries			11
6.9		Counterparts			11
6.10		Severability			11
6.11		Interpretation			12
6.12		Titles and Headings			12
6.13		Relationship of the Parties			12

6.14		Binding Effect			12
6.15		Time of the Essence			13
6.16		Delay or Partial Exercise Not Waiver			13
6.17		Withholding or Granting of Consent			13
6.18		Laws and Regulations			13
6.19		No Recourse Against Officers or Directors			13
6.20		Signatories Duly Authorized			13
6.21		Incorporation of Exhibits by References			13
6.22		Dispute Resolution and Arbitration			13
6.23		Continuation of Work During Dispute			14
6.24		Legal Compliance			15

SERVICES AND SECONDMENT AGREEMENT

     This Services and Secondment Agreement (the “ Agreement ”), dated as of May 14, 2008 (the “ Effective Date ”), is entered into between Anadarko Petroleum Corporation, a Delaware corporation (“ Anadarko ”), and Western Gas Holdings, LLC, a Delaware limited liability company (“ General Partner ”) and the general partner of Western Gas Partners, LP, a Delaware limited partnership (the “ Partnership ”). Anadarko and the General Partner are hereinafter each referred to as a “ Party ” and are collectively referred to as the “ Parties .” Capitalized terms used herein but not defined shall have the meanings given them in that certain Omnibus Agreement by and among the Partnership, the General Partner and Anadarko, dated May 14, 2008 (the “ Omnibus Agreement ”).

RECITALS:

     WHEREAS, Anadarko will cause the Anadarko Entities to provide to the Partnership Group the services necessary to operate, manage, maintain and report the operating results of the Partnership’s assets, including gathering pipelines, compressors, treating facilities, transportation pipelines or related equipment or assets (the “ Partnership Assets ”);

     WHEREAS, in connection with the provision of the services under this Agreement, Anadarko desires to second to the General Partner certain personnel employed or contracted by the Anadarko Entities in connection with the Partnership Assets;

     NOW THEREFORE, in consideration of the premises and the mutual covenants and agreements contained herein, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Anadarko and the General Partner hereby agree as follows:

      v

      SECONDMENT

I) Seconded Employees.

     Subject to the terms of this Agreement, Anadarko agrees to cause the Anadarko Entities to second to the General Partner, and the General Partner agrees to accept the secondment of, those certain specifically identified individuals (each, a “ Seconded Employee ” and collectively, the “ Seconded Employees ”) listed on Exhibit A (the “ Seconded Employee Schedule ”) for the purpose of performing job functions related to the Partnership Assets (the “ Secondment ”). The Seconded Employees will remain at all times employees of the Anadarko Entities but, in addition, they will also be temporary employees of the General Partner during the Period of Secondment (as defined below) and shall, at all times during the Period of Secondment, work under the direction, supervision and control of the General Partner. Anadarko will retain the right to cause the Anadarko Entities to hire or discharge the Seconded Employees but, subject to the provisions in Section 1.2, will not have the right to cause the Anadarko Entities to terminate the Secondment to the General Partner or otherwise exercise direction, supervision or control over the Seconded Employees. For each Seconded Employee, the “ Period of Secondment ” shall be that period of time as set forth in Section 1.2. Seconded Employees shall have no authority or apparent authority to act on behalf of the Anadarko Entities during the Period of Secondment. The Seconded Employee Schedule sets forth the names of the Seconded Employees seconded by the Anadarko Entities, the job functions of the Seconded Employees and the starting date for the Period of Secondment for each Seconded Employee. Individuals may be added or removed from the Seconded Employee Schedule from time to time by the execution by the Parties of a completed “Addition/Removal/Change of Responsibility of Seconded Employee” form, the form of which is attached to this Agreement as Exhibit B , which will be fully binding on the Parties for all purposes under this Agreement. Those rights and obligations of the Parties under this Agreement that relate to individuals that were on the Seconded Employee Schedule but then later removed from the Seconded Employee Schedule, which rights and obligations accrued before the removal of such individual, will survive the removal of such individual from the Seconded Employee Schedule to the extent necessary to enforce such rights and obligations.

II) Period of Secondment.

     Anadarko will cause the Anadarko Entities to second to the General Partner each Seconded Employee on the start date set forth on the Seconded Employee Schedule and continue

to second, during the period (and only during the period) that the Seconded Employee is performing services for the General Partner, until the earliest of:

A) the end of the term of this Agreement;

B) the end date, if any, set forth for the Seconded Employee on the Seconded Employee Schedule (or another end date for such Seconded Employee as mutually agreed in writing by the Parties) (the “ End Date ”);

C) a withdrawal, departure, resignation or termination of such Seconded Employee under Section 1.3;

D) the date on which WGR Holdings, LLC ceases to own a majority of the issued and outstanding voting equity of the General Partner and the General Partner has entered into satisfactory arrangements which it determines, in good faith, will provide it with suitable qualified and experienced full-time or seconded employees necessary to operate, manage and maintain the Partnership Assets and

E) a termination of Secondment for such Seconded Employee under Section 1.4.

     At the end of the Period of Secondment for any Seconded Employee, such Seconded Employee will no longer be subject to the direction of the General Partner with regard to the Seconded Employee’s day-to-day activities.

III) Withdrawal, Departure or Resignation.

     Anadarko will use reasonable efforts to cause the Anadarko Entities to prevent any early withdrawal, departure or resignation of any Seconded Employee prior to the End Date for such Seconded Employee’s Period of Secondment. If any Seconded Employee tenders his resignation to an Anadarko Entity as an employee of such Anadarko Entity, Anadarko will promptly notify the General Partner. During the Period of Secondment for any Seconded Employee, Anadarko will cause the Anadarko Entities to not voluntarily withdraw or terminate any Seconded Employee except with the written consent of the General Partner (which may be through the execution of a completed Addition/Removal/Change of Responsibility of Seconded Employee form), such consent not to be unreasonably withheld. Anadarko will indemnify, defend and hold harmless the General Partner and its directors, officers and employees against any and all costs, expenses (including reasonable attorneys’ fees), claims, demands, losses, liabilities, obligations, actions, lawsuits and other proceedings, judgments and awards (each, a “ Loss ” and collectively, the “ Losses ”) arising out of or in any way connected with or related to the termination of employment of any Seconded Employee by any Anadarko Entity without the consent of THE GENERAL PARTNER, EVEN THOUGH SUCH LOSS MAY BE CAUSED IN PART BY THE NEGLIGENCE OF ONE OR MORE OF THE PARTNERSHIP ENTITIES, except to the extent that such Losses (i) arise solely out of or result solely from the negligence, gross negligence or willful misconduct of any of the Partnership Entities, or (ii) arise in connection with the termination of a Seconded Employee for cause. Upon the termination of employment, the Seconded Employee will cease performing services for the General Partner.

IV) Termination of Secondment.

     The General Partner will have the right to terminate the Secondment to it of any Seconded Employee for any reason at any time. Subject to Section 1.2, Anadarko will not have the right to cause any Anadarko Entity to terminate the Secondment to the General Partner of any Seconded Employee. Upon the termination of any Seconded Employee’s Period of Secondment, Anadarko will be solely liable for any costs or expenses associated with the termination of the

Secondment, except as otherwise specifically set forth in this Agreement. Anadarko will indemnify, defend and hold harmless the General Partner and its directors, officers and employees against all Losses arising out of or in any way connected with or related to the termination of the Secondment of any Seconded Employee by THE GENERAL PARTNER, EVEN THOUGH SUCH LOSS MAY BE CAUSED IN PART BY THE NEGLIGENCE OF ONE OR MORE OF THE PARTNERSHIP ENTITIES, except to the extent that such Losses arise solely out of or result solely from the negligence, gross negligence or willful misconduct of any of the Partnership Entities. Upon the termination of a Secondment, the Seconded Employee will cease performing services for the General Partner. At no time will the General Partner have the right to terminate the employment with the Anadarko Entities of the Seconded Employees.

V) Supervision.

     During the Period of Secondment, the General Partner shall:

A) be ultimately and fully responsible for the daily work assignments of the Seconded Employee (and with respect to Seconded Employees that also provide services to the Anadarko Entities in connection with its operations (“ Shared Seconded Employees ”), during those times that the Shared Seconded Employees are performing services for the General Partner hereunder), including supervision of their day-to-day work activities and performance consistent with the purposes stated in Section 1.1 and the job functions set forth in the Seconded Employee Schedule;

B) set the hours of work and the holidays and vacation schedules (other than with respect to Shared Seconded Employees, as to which the General Partner and Anadarko shall jointly determine) for the Seconded Employee and

C) have the right to determine training which will be received by the Seconded Employee.

     In the course and scope of performing any Seconded Employee’s job functions, the Seconded Employee will be integrated into the organization of the General Partner, will report into the General Partner’s management structure, and will be under the direct management and supervision of the General Partner. The General Partner shall designate one of its officers to be responsible for the supervisory function set forth in this Section 1.5 on behalf of the General Partner.

VI) Seconded Employee Qualifications; Approval.

     Anadarko will cause the Anadarko Entities to provide such suitably qualified and experienced Seconded Employees as it is able to make available to the General Partner, and the General Partner will have the right to approve or reject each such Seconded Employee.

      v

      SECONDMENT SERVICES

I) Secondment Services.

     Anadarko shall cause the Anadarko Entities to second Seconded Employees to the General Partner to provide the General Partner with those services necessary to operate, manage, maintain and report the operating results of the Partnership Assets (the “ Secondment Services ”).

II) Cancellation or Reduction of Secondment Services.

     The General Partner may terminate or reduce the level of any of the Secondment Services on 30 days’ prior written notice to Anadarko. In the event the General Partner terminates the Secondment Services, the General Partner shall pay Anadarko the monthly installment for the last month (or portion thereof) in which it received such services. Upon payment thereof, the General Partner shall have no further payment obligations. In the event that the General Partner reduces the level of any of the Secondment Services, the Parties will negotiate in good faith to determine an appropriate Services Reimbursement (as defined in Section 3.1 below) for the reduced Secondment Services.

III) Workers’ Compensation.

     At all times, Anadarko will cause the Anadarko Entities to maintain workers’ compensation insurance (either through an insurance company or self-insured arrangement) applicable to the Seconded Employees. Anadarko will cause the Anadarko Entities to name the General Partner as an also insured employer under such insurance policy. Prior to being assigned any duties by the General Partner, each Seconded Employee must sign an acknowledgement that the Seconded Employee is an employee during the Secondment Period of both the Anadarko Entities and the General Partner and that for any work place injury, the Seconded Employee’s sole remedy will be under such Anadarko Entity’s workers’ compensation insurance policy. Notwithstanding the foregoing, nothing herein shall preclude a Seconded Employee from participating in benefit programs generally available to employees of Anadarko Entities.

      v

      SERVICES REIMBURSEMENT

I) Operational, Management, Reporting and Routine Maintenance Expenses.

     On or before the fifth business day of each month, Anadarko shall send an invoice to the General Partner for that amount of money associated with all expenses incurred by the Anadarko Entities in connection with the performance of the Secondment Services during the preceding month (the “ Services Reimbursement ”). The General Partner shall pay such invoice within 30 days of receipt.

II) Seconded Employees.

     Among other items, the Services Reimbursement shall include all reasonable cash expenses incurred by the Anadarko Entities for the Seconded Employees, including, but not limited to:

A) compensation, salary and wages (including payroll and withholding taxes associated therewith);

B) 401(k) costs and any matching 401(k) contributions;

C) vacation and sick leave benefits;

D) medical and health insurance benefits;

E) disability insurance;

F) workers’ compensation insurance;

G) life insurance;

H) severance payments, if any and

I) any other employee benefit for which the Anadarko Entities incur costs.

     The costs and expenses described in (a) through (i) above are referred to as “ Seconded Employee Expenses .” For the avoidance of any doubt, the Seconded Employee Expenses shall not include any payments made to Seconded Employees under Anadarko’s Value Creation Plan (or any successor plan thereto) and the excess of actual bonus amounts awarded under Anadarko’s Annual Incentive Plan (“ AIP ”) to any Seconded Employee over 120% of such Seconded Employee’s AIP bonus target (collectively, “ Excess Bonus Expenses ”). Where it is not reasonably practicable to determine the cost of such a cost or expense, Anadarko or the applicable Anadarko Entity may make a good faith reasonable estimate of such cost or expense (and provided that any such estimates, other than with respect to benefit load, are “trued up” within 10 days of the end of each quarter based on the actual amount of the expenses, expenditures or payments in respect of which estimates were made in the immediately preceding

quarter). Anadarko or the applicable Anadarko Entity may include the costs and expenses described in (b) through (i) above in a percentage benefit load based upon the amount of costs and expenses incurred in (a) above. Subject to the parenthetical clause included in this paragraph, the General Partner shall accept any estimate or benefit load described in this paragraph, provided that such estimate is reasonable and made in good faith.

      v

      ALLOCATION; RECORDS; AGENT

I) Allocation; Records.

     Anadarko will use commercially reasonable efforts to maintain an allocation schedule reflecting the direct and indirect costs of the Seconded Employee Expenses based on the Secondment Services. The General Partner will use commercially reasonable efforts to keep and maintain books/records reflecting hours worked and