<PAGE>   1
                                                                     EXHIBIT 4.4




                              EOG RESOURCES, INC.
                          EMPLOYEE STOCK PURCHASE PLAN

<PAGE>   2
                               TABLE OF CONTENTS


                                                                    Page

ARTICLE 1   PURPOSE, COMMITMENT AND INTENT

   1.1   Purpose ................................................     1
   1.2   Share Commitment .......................................     1
   1.3   Intent .................................................     1
   1.4   Shareholder Approval ...................................     1

ARTICLE 2   DEFINITIONS

   2.1   "Affiliate" ............................................     2
   2.2   "Beneficiary" ..........................................     2
   2.3   "Board of Directors" ...................................     2
   2.4   "Code" .................................................     2
   2.5   "Committee" ............................................     2
   2.6   "Company" ..............................................     2
   2.7   "Compensation" .........................................     2
   2.8   "Employee" .............................................     2
   2.9   "Employer" .............................................     2
   2.10  "Exercise Date" ........................................     2
   2.11  "Fair Market Value" or "FMV" ...........................     2
   2.12  "Grant Date" ...........................................     2
   2.13  "Offering Period" ......................................     2
   2.14  "Option" ...............................................     2
   2.15  "Option Price"..........................................     2
   2.16  "Participant" ..........................................     2
   2.17  "Plan" .................................................     3
   2.18  "Shares" ...............................................     3
   2.19  "Stock" ................................................     3

ARTICLE 3   ELIGIBILITY

   3.1   General Requirements ..................................      3
   3.2   Limitations Upon Participation ........................      3

ARTICLE 4   PARTICIPATION

   4.1   Grant and Exercise of Option ..........................      3
   4.2   Payroll Deduction .....................................      3
   4.3   Payroll Deductions Continuing .........................      4
   4.4   Right to Stop Payroll Deductions ......................      4
   4.5   Accounting for Funds ..................................      4


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                               TABLE OF CONTENTS

                                                                            Page

   4.6   Employer's Use of Funds...........................................   4

ARTICLE 5   IN SERVICE WITHDRAWAL, TERMINATION OF
            EMPLOYMENT, DEATH

   5.1   In Service Withdrawal.............................................   4
   5.2   Termination of Employment.........................................   4
   5.3   Death.............................................................   4

ARTICLE 6   EXERCISE OF OPTIONS

   6.1   Purchase of Stock.................................................   5
   6.2   Accounting for Stock..............................................   5
   6.3   Issuance of Shares................................................   5
   6.4   Restriction on Shares.............................................   5

ARTICLE 7   ADMINISTRATION

   7.1   Powers of Committee...............................................   6
   7.2   Standard of Judicial Review of Committee Actions..................   6

ARTICLE 8   ADOPTION OF PLAN BY OTHER EMPLOYERS

   8.1   Adoption Procedure................................................   6
   8.2   No Joint Venture Implied..........................................   7

ARTICLE 9   TERMINATION AND AMENDMENT OF THE PLAN

   9.1   Termination.......................................................   7
   9.2   Amendment.........................................................   7

ARTICLE 10   MISCELLANEOUS

  10.1   Designation of Beneficiary........................................   7
  10.2   Plan Not An Employment Contract...................................   8
  10.3   All Participants' Rights Are Equal................................   8
  10.4   Options Granted Are Not Transferable..............................   8
  10.5   Voting of Stock...................................................   8
  10.6   No Shareholder Rights.............................................   8


                                       ii
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                               TABLE OF CONTENTS


                                                                            PAGE
                                                                            ----
  10.7    Governmental Regulations............................................8
  10.8    Notices.............................................................8
  10.9    Indemnification of Committee........................................8
  10.10   Tax Withholding.....................................................8
  10.11   Gender and Number...................................................9
  10.12   Severability........................................................9
  10.13   Governing Law; Parties to Legal Actions.............................9



                                      iii


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                                                                     EXHIBIT 4.4


                              EOG RESOURCES, INC.

                          EMPLOYEE STOCK PURCHASE PLAN

                                   ARTICLE 1

                         PURPOSE, COMMITMENT AND INTENT

     1.1  Purpose.  The purpose of this Plan is to provide Employees of the
Company and its Affiliates which adopt the Plan with an opportunity to purchase
Stock of the Company through offerings of options at a discount and thus develop
a stronger incentive to work for the continued success of the Company and its
Affiliates. Therefore, this Plan is available to all Employees of every Employer
upon their fulfilling the eligibility requirements of Section 3.1. Any Affiliate
may adopt it with the approval of the Committee by fulfilling the requirements
of Section 8.1. This Plan is sponsored by the Company. The Plan will terminate
on the tenth anniversary of the date of commencement of the initial offering
period under the Plan.

     1.2  Share Commitment.  The aggregate number of Shares authorized to be
sold pursuant to Options granted under this Plan is 500,000 Shares, subject to
adjustment as provided in this Section. Any Shares relating to Options that are
granted, but subsequently lapse, are canceled, or are otherwise not exercised by
the Exercise Date, shall be available for future grants of Options.

     In the event of any stock dividend, split-up, recapitalization, merger,
consolidation, combination or exchange of Shares, or the like, as a result of
which shares shall be issued in respect of the outstanding Shares, or the Shares
shall be changed into the same or a different number of the same or another
class of stock, the total number of Shares authorized to be committed to this
Plan, the number of Shares subject to each outstanding Option and the Option
Price applicable to each Option shall be appropriately adjusted by the
Committee.

     1.3  Intent.  It is the intention of the Company to have the Plan qualify
as an "employee stock purchase plan" under section 423 of the Code. Therefore,
the provisions of the Plan are to be construed in a manner consistent with the
requirements of section 423 of the Code.

     1.4  Shareholder Approval.  To be effective for an Employer, this Plan must
be approved by the shareholders of that Employer within 12 months before or
after the Plan is approved by the board of directors of that Employer. The
approval of shareholders must comply with all applicable provisions of the
corporate charter, bylaws and applicable laws of the jurisdiction prescribing
the method and degree of shareholder approval required for the issuance of
corporate stock or options.

                                   ARTICLE 2

                                  DEFINITIONS

     The words and phrases defined in this Article shall have the meaning set
out in these definitions throughout this Plan, unless the context in which any
word or phrase appears reasonably requires a broader, narrower, or different
meaning.


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     2.1  "Affiliate" means any parent corporation and any subsidiary
corporation. The term "parent corporation" means any corporation (other than the
Company) in an unbroken chain of corporations ending with the Company if, at the
time of the action or transaction, each of the corporations other than the
Company owns stock possessing 50% or more of the total combined voting power of
all classes of stock in one of the other corporations in the chain. The term
"subsidiary corporation" means any corporation (other than the Company) in an
unbroken chain of corporations beginning with the Company if, at the time of the
granting of the Option, each of the corporations other than the last corporation
in the unbroken chain owns stock possessing 50% or more of the total combined
voting power of all classes of stock in one of the other corporations in the
chain.

     2.2  "Beneficiary" means the person who is entitled to receive amounts
under the Plan upon the death of a Participant.

     2.3  "Board of Directors" means the board of directors of the Company.

     2.4  "Code" means the Internal Revenue Code of 1986, as amended from time
to time.

     2.5  "Committee" means the Compensation Committee of the Board of Directors
of the Company.

     2.6  "Company" means EOG Resources, Inc.

     2.7  "Compensation" means the Employee's regular rate of wages from the
Employer.

     2.8  "Employee" means any person who is a common law employee of the
Employer excluding only those whose customary employment with the Employer is 20
hours or less per week.

     2.9  "Employer" means the Company and each Affiliate which has adopted the
Plan as provided in Section 8.1 of the Plan.

     2.10  "Exercise Date" means the last business day of the Offering Period,
which is the day that all Options that Participants have elected to exercise are
to be exercised.

     2.11  "Fair Market Value" or "FMV" of the Stock as of any date means the
closing price of the Stock on that date (or if there was no sale on a given
date, the next preceding date on which there was a sale) on the principal
securities exchange on which the Stock is listed.

     2.12  "Grant Date" means the first business day of the Offering Period,
which is the day the Committee grants all eligible Employees an Option under
this Plan.

     2.13  "Offering Period" means the six-month periods commencing on July 1
and January 1 of each year. The initial offering period shall begin July 1, 2001
unless the Committee determines that the initial Offering Period shall commence
on January 1, 2002.

     2.14  "Option" means an option granted under this Plan to purchase shares
of Stock at the Option Price on the Exercise Date.

     2.15  "Option Price" means the price to be paid for each Share upon
exercise of an Option, which shall be the lesser of (a) 85% of the FMV of a
Share on the Grant Date or (b) 85% of the FMV of a Share on the Exercise Date.

     2.16  "Participant" means a person who is eligible to be granted an Option
under this Plan and who elects to have payroll deductions withheld under the
Plan for the purpose of exercising that Option on the Exercise Date.


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     2.17  "Plan" means the EOG Resources, Inc. Employee Stock Purchase Plan, as
set out in this document and as it may be amended from time to time.

     2.18  "Shares" means shares of Stock.

     2.19  "Stock" means the Company's common stock.

                                   ARTICLE 3

                                  ELIGIBILITY

     3.1  General Requirements.  Each Employee is eligible to participate in the
Plan for a given Offering Period if he is an Employee on the Grant Date, subject
to the limitations imposed in Section 3.2.

     3.2  Limitations Upon Participation.  Any provision of this Plan to the
contrary notwithstanding, no Employee shall be granted an Option:

          (a) if, immediately after the grant, the Employee would own, including
     all outstanding options which are still exercisable to purchase Stock, five
     percent or more of the total combined voting power or value of all classes
     of Stock of the Company or of any parent or subsidiary of the Company
     within the meaning of sections 423 and 424 of the Code;

          (b) which permits the Employee to purchase Stock under all employee
     stock purchase plans, as defined in section 423 of the Code, of the Company
     and all Affiliates at a rate which exceeds $25,000 in Fair Market Value of
     the Stock (determined at the time the Option is granted) for each calendar
     year in which the option granted to the Employee is outstanding at any time
     as provided in sections 423 and 424 of the Code; or

          (c) which permits the Employee rights to purchase Stock in excess of
     the number of Shares set by the Committee if it deems such a restriction to
     be appropriate.

                                   ARTICLE 4

                                 PARTICIPATION

     4.1  Grant and Exercise of Option.  Effective as of the Grant Date the
Committee shall grant an Option to each Participant that shall be exercisable on
the Exercise Date only through funds accumulated by the Employee through payroll
deductions made during the Offering Period together with any funds remaining in
the Participant's payroll deduction account at the beginning of the Offering
Period. Except as may be determined otherwise by the Committee and announced to
Employees prior to an Offering Period, the number of Shares included in an
Option deemed to have been granted to an Employee on the Grant Date shall be
determined by dividing $12,500 by the FMV of a share of Stock on such date.

     4.2  Payroll Deduction.  For an Employee to become eligible to receive an
Option granted for a given Offering Period, the Employee must complete a payroll
deduction form and file it with the Employer no earlier than 30 nor later than
15 days prior to the beginning of the Offering Period. The payroll deduction
form shall permit a Participant to elect to have withheld from his Compensation
an amount no less than one percent, nor more than ten percent, of his
Compensation (only in whole percentages) taken pro rata from the Compensation
paid to him by the Employer. Each payroll deduction shall begin on the first pay
period ending after the beginning of an Offering Period and shall continue
through the last pay period ending prior to the


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<PAGE>   8

Exercise Date. No Participant shall be permitted to begin payroll deductions at
any other time. A Participant may not make additional contributions to his Plan
account.

     4.3  Payroll Deductions Continuing.  A Participant's election to have
payroll deductions shall remain in effect for all ensuing Offering Periods until
changed by the Participant by filing an appropriate amended payroll deduction
form not earlier than 30 nor later than 15 days prior to the commencement of the
Offering Period for which it is to be effective.

     4.4  Right to Stop Payroll Deductions.  A Participant may discontinue
payroll deductions and his participation in the Plan as provided in Section 5.1,
but no other change may be made during an Offering Period and, specifically, a
Participant may not alter the rate of his payroll deductions for that Offering
Period.

     4.5  Accounting for Funds.  As of each payroll deduction period, the
Employer shall cause to be credited to the Participant's payroll deduction
account in a ledger established for that purpose, the funds withheld from and
attributable to the Employee's compensation for that period. No interest shall
be credited to the Participant's payroll deduction account at any time. The
obligation of the Employer to the Participant for this account shall be a
general corporate obligation and shall not be funded through a trust nor secured
by any assets which would cause the Participant to be other than a general
creditor of the Employer.

     4.6  Employer's Use of Funds.  All payroll deductions received or held by
an Employer may be used by the Employer for any corporate purposes, and the
Employer shall not be obligated to segregate such payroll deductions.

                                   ARTICLE 5

                             IN SERVICE WITHDRAWAL
                           TERMINATION OF EMPLOYMENT
                                     DEATH

     5.1  In Service Withdrawal.  A Participant may, at any time on or before 15
days prior to the Exercise Date, or such other date as shall be determined by
the Committee from time to time, elect to withdraw all funds then credited to
his payroll deduction account by giving written notice to his Employer in
accordance with the rules established by the Committee. All funds credited to
the Participant's payroll deduction account shall be paid to him as soon as
administratively feasible. The withdrawal election terminates the Participant's
right to exercise his Option on the Exercise Date and his entitlement to elect
any further payroll deductions for the then current Offering Period. Should the
Participant wish to participate in any future Offering Period, the Participant
must file a new payroll deduction election form with the Committee within the
time frame required for participation for that Offering Period.

     5.2  Termination of Employment.  If a Participant's employment is
terminated for any reason other than death prior to the Exercise Date, the
Option granted to the Participant for that Option Period shall lapse. The
Participant's payroll deduction account shall be returned to him as soon as
administratively feasible.

     5.3  Death.  If a Participant dies before the Exercise Date, the Option
granted to the Participant for that Offering Period shall lapse. The
Participant's payroll deduction account shall be returned to him as soon as
administratively feasible. If the Participant dies after the Exercise Date but
prior to the delivery of his certificate, the Stock shall be delivered to his
Beneficiary (or to his estate if he has no Beneficiary). If there is no
Beneficiary, the Stock shall be held in the Participant's account until the
representative of the estate has been appointed and provides such evidence as
may be required by the Committee before the certificate is


                                       4
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delivered to the proper party together with a check in the amount of any
remaining funds in the Participant's payroll deduction account.

                                   ARTICLE 6

                              EXERCISE OF OPTIONS

     6.1  Purchase of Stock.  Subject to the limitations in Sections 3.2 and 4.1
of the Plan, on the Exercise Date of each Offering Period each Participant's
payroll deduction account shall be used to purchase the maximum number of whole
shares of Stock that can be purchased at the Option Price for that Offering
Period. Any funds remaining in a Participant's payroll deduction account after
the exercise of his Option for an Offering Period shall remain in the
Participant's account to be used in the ensuing Offering Period, together with
new payroll deductions, if any, for that Offering Period to exercise the next
succeeding Option which is to be exercised. If in any Offering Period the total
number of shares of Stock to be purchased by all Participants exceed the number
of shares of Stock committed to the Plan, then each Participant shall be
entitled to purchase only his pro rata portion of the shares of Stock remaining
available under the Plan based on the balances in each Participant's payroll
deduction account as of the Exercise Date. No fractional shares of Stock may be
purchased under this Plan. After the purchase of all shares of Stock available
on the Exercise Date, all Options granted for the Offering Period to the extent
not used shall terminate.

     6.2  Accounting for Stock.  After the Exercise Date of each Offering Period
a report shall be given to each Participant stating the amount of his payroll
deduction account, the number of shares of Stock purchased and the applicable
Option Price.

     6.3  Issuance of Shares.  As soon as administratively feasible after the
end of the Offering Period the Committee shall advise the appropriate officer of
the Company that the terms of the Plan have been complied with and that it is
appropriate for the officer to cause to be issued the shares of Stock upon which
Options have been exercised under the Plan. The Committee may determine to hold
such shares of Stock until the Participant requests such shares of Stock. The
Committee may determine in its discretion the manner of delivery of the shares
of Stock purchased under the Plan, which may be by electronic account entry into
new or existing accounts, delivery of certificates or any other means as the
Committee, in its discretion, deems appropriate. The Committee may, in its
discretion, hold the certificate for any shares of Stock or cause it to be
legended in order to comply with the securities laws of the applicable
jurisdiction.

     6.4  Restriction on Shares.  A Participant shall be free to undertake a
disposition (as that term is defined in Section 424(c) of the Code) of the
shares in his account at any time, whether by sale, exchange, gift, or other
transfer of legal title, but in the absence of such a disposition of the shares,
the shares must remain in the Participant's account at the brokerage or other
financial services firm designated by the Committee until the holding period set
forth in Section 423(a) of the Code has been satisfied. With respect to Shares
for which such holding period has been satisfied, the Participant may direct
that those Shares be moved to another account of Participant's choosing or
request that a stock certificate be issued and delivered to him.

     Notwithstanding anything to the contrary contained in this Plan, a
Participant shall not transfer or otherwise dispose of Stock in violation of the
Company's Insider Trading Policy.


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<PAGE>   10

                                   ARTICLE 7

                                 ADMINISTRATION

     7.1  Powers of Committee.  The Committee has the exclusive responsibility
for the general administration of the Plan, and has all powers necessary to
accomplish that purpose, including but not limited to the following rights,
powers, and authorities:

          (a) to make rules for administering the Plan so long as they are not
     inconsistent with the terms of the Plan;

          (b) to construe all provisions of the Plan;

          (c) to correct any defect, supply any omission, or reconcile any
     inconsistency which may appear in the Plan;

          (d) to select, employ, and compensate at any time any consultants,
     accountants, attorneys, and other agents the Committee believes necessary
     or advisable for the proper administration of the Plan;

          (e) to determine all questions relating to eligibility, Fair Market
     Value, Option Price and all other matters relating to benefits or
     Participants' entitlement to benefits;

          (f) to resolve all controversies relating to the administration of
     the Plan, including but not limited to any differences of opinion arising
     between the Employer and a Participant, and any questions it believes
     advisable for the proper administration of the Plan; and

          (g) to delegate any clerical or record-keeping duties of the Committee
     as the Committee believes is advisable to properly administer the Plan.

     7.2  Standard of Judicial Review of Committee Actions.  The Committee has
full and absolute discretion in the exercise of each and every aspect of its
authority under the Plan. Notwithstanding anything to the contrary, any action
taken, or ruling or decision made, by the Committee in the exercise of any of
its powers and authorities under the Plan shall be final and conclusive as to
all parties other than the Company and its Affiliates, including without
limitation all Participants and their Beneficiaries, regardless of whether the
Committee or one or more of its members may have an actual or potential conflict
of interest with respect to the subject matter of the action, ruling, or
decision. No final action, ruling, or decision of the Committee shall be subject
to de novo review in any judicial proceeding; and no final action, ruling, or
decision of the Committee may be set aside unless it is held to have been
arbitrary and capricious by a final judgment of a court having jurisdiction with
respect to the issue.

                                   ARTICLE 8

                      ADOPTION OF PLAN BY OTHER EMPLOYERS

     8.1  Adoption Procedure.  With the approval of the Committee, any Affiliate
may adopt this Plan by:

          (a) a certified resolution or consent of the board of directors of the
     adopting Affiliate or an executed adoption instrument (approved by the
     board of directors of the adopting Affiliate) agreeing to be bound as an
     Affiliate by all the terms, conditions and limitations of this Plan; and

          (b) providing all information required by the Committee.


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<PAGE>   11

     8.2  No Joint Venture Implied.  The document which evidences the adoption
of the Plan by an Affiliate shall become a part of this Plan. However, neither
the adoption of this Plan by an Affiliate nor any act performed by it in
relation to this Plan shall create a joint venture or partnership relation
between it and the Company or any other Affiliate.

                                   ARTICLE 9

                     TERMINATION AND AMENDMENT OF THE PLAN

     9.1  Termination.  The Company may, by action of the Board of Directors,
terminate the Plan at any time and for any reason. The Plan shall automatically
terminate upon the purchase by Participants of all shares of Stock committed to
the Plan, unless the number of Shares committed to the Plan are increased by the
Board of Directors and approved by the shareholders of the Company. Upon
termination of the Plan, as soon as administratively feasible there shall be
refunded to each Participant the remaining funds in his payroll deduction
account, and there shall be forwarded to the Participants certificates for all
shares of Stock held under the Plan for the account of Participants. The
termination of this Plan shall not affect the current Options already
outstanding under the Plan to the extent there are Shares committed, unless the
Participants agree.

     9.2  Amendment.  The Board of Directors reserves the right to modify, alter
or amend the Plan at any time and from time to time to any extent that it deems
advisable, including, without limiting the generality of the foregoing, any
amendment deemed necessary to ensure compliance of the Plan with Section 423 of
the Code. The Board of Directors may suspend operation of the Plan for any
period as it may deem advisable. However, no amendment or suspension shall
operate to reduce any amounts previously allocated to a Participant's payroll
deduction account, to reduce a Participant's rights with respect to shares of
Stock previously purchased and held on his behalf under the Plan nor to affect
the current Option a Participant already has outstanding under the Plan without
the Participant's agreement. Any amendment changing the aggregate number of
Shares to be committed to the Plan or the class of employees eligible to receive
Options under the Plan must have shareholder approval as set forth in Section
1.4.

                                   ARTICLE 10

                                 MISCELLANEOUS

     10.1  Designation of Beneficiary.

          (a) A Participant may file a written designation of a Beneficiary who
     is to receive any cash and Shares credited to the Participant's account
     under the Plan. If a Participant is married and the designated Beneficiary
     is not the Participant's spouse, written spousal consent shall be required
     for the designation to be effective.

          (b) A Participant may change his designation of a Beneficiary at any
     time by written notice. If a Participant dies when he has not validly
     designated a Beneficiary under the Plan, the Company shall deliver such
     Shares and cash to the executor or administrator of the estate of the
     Participant, or if no such executor or administrator has been appointed (to
     the knowledge of the Company), the Company, in its discretion, may deliver
     such Shares and cash to the spouse or to any one or more dependents or
     relatives of the Participant, or if no spouse, dependent or relative is
     known to the Company, then to such other person as the Company may
     designate.


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<PAGE>   12

     10.2  Plan Not An Employment Contract.  The adoption and maintenance of
this Plan is not a contract between the Employer and its Employees which gives
any Employee the right to be retained in its employment. Likewise, it is not
intended to interfere with the rights of the Employer to discharge any Employee
at any time or to interfere with the Employee's right to terminate his
employment at any time.

     10.3  All Participants' Rights Are Equal.  All Participants will have the
same rights and privileges under this Plan as are required by section 423 of the
Code and section 1.423-2(f) of the regulations promulgated under that section of
the Code.

     10.4  Options Granted Are Not Transferable.  No Option granted a
Participant under this Plan is transferable by the Participant and must be
exercisable only by him. In the event any Participant attempts to violate the
terms of this Section, any Option held by the Participant shall be terminated by
the Company and upon return to the Participant of the remaining funds in his
payroll deduction account, all of his rights under the Plan will terminate.

     10.5  Voting of Stock.  Shares of Stock held under the Plan for the account
of each Participant shall be voted by the holder of record of those shares in
accordance with the Participant's instructions.

     10.6  No Shareholder Rights.  No eligible Employee or Participant shall by
reason of participation in the Plan have any rights of a shareholder of the
Company until he acquires shares of Stock as provided in this Plan.

     10.7  Governmental Regulations.  The obligation to sell or deliver the
shares of Stock under this Plan is subject to the approval of all governmental
authorities required in connection with the authorization, purchase, issuance or
sale of that Stock.

     10.8  Notices.  All notices and other communication in connection with the
Plan shall be in the form specified by the Committee and shall be deemed to have
been duly given when sent to the Participant at his last known address or to his
designated personal representative or beneficiary, or to the Employer or its
designated representative, as the case may be.

     10.9  Indemnification of Committee.  In addition to all other rights of
indemnification as they may have as directors or as members of the Committee,
the members of the Committee shall be indemnified by the Company against the
reasonable expenses, including attorneys' fees, actually and necessarily
incurred in connection with the defense of any action, suit or proceeding, or in
connection with any appeal, to which they or any of them may be a party by
reason of any action taken or failure to act under or in connection with the
Plan or any Option granted under the Plan, and against all amounts paid in
settlement (provided the settlement is approved by independent legal counsel
selected by the Company) or paid by them in satisfaction of a judgment in any
action, suit or proceeding, except in relation to matters as to which it is
adjudged in the action, suit or proceeding, that the Committee member is liable
for gross negligence or willful misconduct in the performance of his duties.

     10.10  Tax Withholding.  At the time a Participant's Option is exercised or
at the time a Participant disposes of some or all of the Stock purchased under
the Plan, the Participant must make adequate provision for the Employer's
federal, state or other tax withholding obligations, if any, which arise upon
the exercise of the Option or the disposition of the Stock. At any time, the
Employer may, but shall not be obligated to, withhold from the Participant's
compensation the amount necessary for the Employer to meet applicable
withholding obligations.


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<PAGE>   13

     The IRS recently issued guidance providing that it will not require the
withholding or payment of FICA or FUTA taxes or withholding for Federal income
taxes at the time a participant's Options are exercised or at the time a
participant disposes of some or all of the Stock purchased under the Plan prior
to January 1, 2003. The IRS stated that further guidance regarding withholding
may be issued effective January 1, 2003 in which it may require the withholding
and payment of FICA, FUTA, and Federal income taxes upon an exercise or
disposition made on or after that date.

     10.11  Gender and Number.  If the context requires it, words of one gender
when used in this Plan shall include the other genders, and words used in the
singular or plural shall include the other.

     10.12  Severability.  Each provision of this Plan may be severed. If any
provision is determined to be invalid or unenforceable, that determination shall
not affect the validity or enforceability of any other provision.

     10.13  Governing Law; Parties to Legal Actions.  The provisions of this
Plan shall be construed, administered, and governed under the laws of the State
of Texas and, to the extent applicable, by the securities, tax, employment and
other laws of the United States which are applicable to an employee stock
purchase plan.


                                       9