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                                                                   EXHIBIT 10(d)


                      MITCHELL ENERGY & DEVELOPMENT CORP.
                             1999 STOCK OPTION PLAN

I. PURPOSE OF THE PLAN

     The MITCHELL ENERGY & DEVELOPMENT CORP. 1999 STOCK OPTION PLAN (the "Plan")
is intended to provide a means whereby certain employees of MITCHELL ENERGY &
DEVELOPMENT CORP., a Texas corporation (the "Company"), and its subsidiaries may
develop a sense of proprietorship and personal involvement in the development
and financial success of the Company, and to encourage them to remain with and
devote their best efforts to the business of the Company, thereby advancing the
interests of the Company and its shareholders. Accordingly, the Company may
grant to certain employees ("Optionees") the option ("Option") to purchase
shares of Class B Common Stock, par value $0.10, of the Company ("Stock"), as
hereinafter set forth. Options granted under the Plan may be either incentive
stock options, within the meaning of section 422(b) of the Internal Revenue Code
of 1986, as amended (the "Code"), ("Incentive Stock Options") or options which
do not constitute Incentive Stock Options ("Non-Qualified Stock Options").

II. ADMINISTRATION

     The Plan shall be administered by a committee (the "Committee") of, and
appointed by, the Board of Directors of the Company (the "Board"), and the
Committee shall be (a) comprised solely of two or more outside directors (within
the meaning of section 162(m) of the Code and applicable interpretive authority
thereunder), and (b) constituted so as to permit the Plan to comply with Rule
16b-3 ("Rule 16b-3"), promulgated under the Securities Exchange Act of 1934, as
amended (the "1934 Act"). The Committee shall have sole authority to select the
Optionees from among those individuals eligible hereunder and to establish the
number of shares which may be issued under each Option; provided, however, that,
notwithstanding any provision in the Plan to the contrary, the maximum number of
shares that may be subject to Options granted under the Plan to an individual
Optionee during any calendar year may not exceed 250,000 (subject to adjustment
in the same manner as provided in Paragraph VIII hereof with respect to shares
of Stock subject to Options then outstanding). The limitation set forth in the
preceding sentence shall be applied in a manner which will permit compensation
generated under the Plan to constitute "performance-based" compensation for
purposes of section 162(m) of the Code, including, without limitation, counting
against such maximum number of shares, to the extent required under section
162(m) of the Code and applicable interpretive authority thereunder, any shares
subject to Options that are cancelled or repriced. In selecting the Optionees
from among individuals eligible hereunder and in establishing the number of
shares that may be issued under each Option, the Committee may take into account
the nature of the services rendered by such individuals, their present and
potential contributions to the Company's success and such other factors as the
Committee in its discretion shall deem relevant. The Committee is authorized to
interpret the Plan and may from time to time adopt such rules and regulations,
consistent with the provisions of the Plan, as it may deem advisable to carry
out the Plan. All decisions made by the Committee in selecting the Optionees, in
establishing the number of shares which may be issued under each Option and in
construing the provisions of the Plan shall be final.

III. OPTION AGREEMENTS

          (a) Each Option shall be evidenced by a written agreement between the
     Company and the Optionee ("Option Agreement") which shall contain such
     terms and conditions as may be approved by the Committee. The terms and
     conditions of the respective Option Agreements need not be identical.
     Specifically, an Option Agreement may provide for the surrender of the
     right to purchase shares under the Option in return for a payment in cash
     or shares of Stock or a combination of cash and shares of Stock equal in
     value to the excess of the fair market value of the shares with respect to
     which the right to purchase is surrendered over the option price therefor
     ("Stock Appreciation Rights"), on such terms and


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     conditions as the Committee in its sole discretion may prescribe; provided,
     that, except as provided in Subparagraph VIII(c) hereof, the Committee may
     retain final authority (i) to determine whether an Optionee shall be
     permitted, or (ii) to approve an election by an Optionee, to receive cash
     in full or partial settlement of Stock Appreciation Rights. Further, an
     Option Agreement may authorize and provide for an Optionee to exercise the
     Option and direct immediate market sale of any treasury Stock thereby
     acquired pursuant to an extension of credit by the Company to such Optionee
     for the aggregate exercise price and upon such other terms and conditions
     as the Committee may determine. Moreover, an Option Agreement may provide
     for the payment of the option price, in whole or in part, by the delivery
     of a number of shares of Stock (plus cash if necessary) having a fair
     market value equal to such option price.

          (b) For all purposes under the Plan, the fair market value of a share
     of Stock on a particular date shall be equal to the closing price of the
     Stock reported on the New York Stock Exchange Composite Tape on that date;
     or, if no prices are reported on that date, on the last preceding date on
     which such prices of the Stock are so reported. If the Stock is traded over
     the counter at the time a determination of its fair market value is
     required to be made hereunder, its fair market value shall be deemed to be
     equal to the average between the reported high and low or closing bid and
     asked prices of Stock on the most recent date on which Stock was publicly
     traded. In the event Stock is not publicly traded at the time a
     determination of its value is required to be made hereunder, the
     determination of its fair market value shall be made by the Committee in
     such manner as it deems appropriate.

          (c) Each Option and all rights granted thereunder shall not be
     transferable other than by will or the laws of descent and distribution and
     shall be exercisable during the Optionee's lifetime only by the Optionee or
     the Optionee's guardian or legal representative.

IV. ELIGIBILITY OF OPTIONEE

     Options may be granted only to individuals who are employees on a full-time
basis (including officers and directors who are also employees) of the Company
or any parent or subsidiary corporation (as defined in section 424 of the Code)
of the Company at the time the Option is granted. Options may be granted to the
same individual on more than one occasion. No Incentive Stock Option shall be
granted to an individual if, at the time the Option is granted, such individual
owns stock possessing more than 10% of the total combined voting power of all
classes of stock of the Company or of its parent or subsidiary corporation,
within the meaning of section 422(b)(6) of the Code, unless (i) at the time such
Option is granted the option price is at least 110% of the fair market value of
the Stock subject to the Option and (ii) such Option by its terms is not
exercisable after the expiration of five years from the date of grant. To the
extent that the aggregate fair market value (determined at the time the
respective Incentive Stock Option is granted) of stock with respect to which
Incentive Stock Options are exercisable for the first time by an individual
during any calendar year under all incentive stock option plans of the Company
and its parent and subsidiary corporations exceeds $100,000, such excess
Incentive Stock Options shall be treated as Non-Qualified Stock Options. The
Committee shall determine, in accordance with applicable provisions of the Code,
Treasury Regulations and other administrative pronouncements, which of an
Optionee's Incentive Stock Options will not constitute Incentive Stock Options
because of such limitation and shall notify the Optionee of such determination
as soon as practicable after such determination.

V. SHARES SUBJECT TO THE PLAN

     The aggregate number of shares which may be issued under Options granted
under the Plan shall not exceed 1,750,000 shares of Stock. Such shares may
consist of authorized but unissued shares of Stock or previously issued shares
of Stock reacquired by the Company. Any of such shares which remain unissued and
which are not subject to outstanding Options at the termination of the Plan
shall cease to be subject to the Plan, but, until termination of the Plan, the
Company shall at all times make available a sufficient number of shares to meet
the requirements of the Plan. Should any Option hereunder expire or terminate
prior to its exercise in full, the shares theretofore subject to such Option may
again be subject to an Option granted under the Plan to the extent permitted
under Rule 16b-3. The aggregate number of shares which may be issued
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under the Plan shall be subject to adjustment in the same manner as provided in
Paragraph VIII hereof with respect to shares of Stock subject to Options then
outstanding. Exercise of an Option in any manner, including an exercise
involving a Stock Appreciation Right, shall result in a decrease in the number
of shares of Stock which may thereafter be available, both for purposes of the
Plan and for sale to any one individual, by the number of shares as to which the
Option is exercised. Separate stock certificates shall be issued by the Company
for those shares acquired pursuant to the exercise of an Incentive Stock Option
and for those shares acquired pursuant to the exercise of any Option which does
not constitute an Incentive Stock Option.

VI. OPTION PRICE

     The purchase price of Stock issued under each Option shall be determined by
the Committee, but such purchase price shall not be less than the fair market
value of Stock subject to the Option on the date the Option is granted.

VII. TERM OF PLAN

     The Plan shall be effective upon the date of its adoption by the Board,
provided the Plan is approved by the shareholders of the Company within twelve
months thereafter. Notwithstanding any provision in this Plan or in any Option
Agreement, no Option shall be exercisable prior to such shareholder approval.
Except with respect to Options then outstanding, if not sooner terminated under
the provisions of Paragraph IX, the Plan shall terminate upon and no further
Options shall be granted after the expiration of ten years from the date of its
adoption by the Board.

VIII. RECAPITALIZATION OR REORGANIZATION

          (a) The existence of the Plan and the Options granted hereunder shall
     not affect in any way the right or power of the Board or the shareholders
     of the Company to make or authorize any adjustment, recapitalization,
     reorganization or other change in the Company's capital structure or its
     business, any merger or consolidation of the Company, any issue of debt or
     equity securities, the dissolution or liquidation of the Company or any
     sale, lease, exchange or other disposition of all or any part of its assets
     or business or any other corporate act or proceeding.

          (b) The shares with respect to which Options may be granted are shares
     of Stock as presently constituted, but if, and whenever, prior to the
     expiration of an Option theretofore granted, the Company shall effect a
     subdivision or consolidation of shares of Stock or the payment of a stock
     dividend on Stock without receipt of consideration by the Company, the
     number of shares of Stock with respect to which such Option may thereafter
     be exercised (i) in the event of an increase in the number of outstanding
     shares shall be proportionately increased, and the purchase price per share
     shall be proportionately reduced, and (ii) in the event of a reduction in
     the number of outstanding shares shall be proportionately reduced, and the
     purchase price per share shall be proportionately increased. If prior to
     the expiration of an Option theretofore granted, the Company shall effect a
     spinoff of a subsidiary by issuance of shares of stock in the subsidiary to
     shareholders of the Company or effect any other transaction which
     essentially accomplishes the same result, the Committee shall adjust the
     exercise price of an Option to reflect any decrease in the value of the
     Stock resulting from such spinoff or transaction.

          (c) If the Company recapitalizes, reclassifies its capital stock, or
     otherwise changes its capital structure (a "recapitalization"), the number
     and class of shares of Stock covered by an Option theretofore granted shall
     be adjusted so that such Option shall thereafter cover the number and class
     of shares of stock and securities to which the Optionee would have been
     entitled pursuant to the terms of the recapitalization if, immediately
     prior to the recapitalization, the Optionee had been the holder of record
     of the number of shares of Stock then covered by such Option. If (i) the
     Company shall not be the surviving entity in any merger, consolidation or
     other reorganization (or survives only as a subsidiary of an entity other
     than a previously wholly-owned subsidiary of the Company), (ii) the Company
     sells, leases or exchanges all or substantially all of its assets to any
     other person or entity (other than a wholly-owned subsidiary of the
     Company), (iii) the Company is to be dissolved and liquidated, (iv) any
     person or


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     entity, including a "group" as contemplated by Section 13(d)(3) of the 1934
     Act, acquires or gains ownership or control (including, without limitation,
     power to vote) of more than 50% of the outstanding shares of the Company's
     voting stock (based upon voting power), or (v) as a result of or in
     connection with a contested election of directors, the persons who were
     directors of the Company before such election shall cease to constitute a
     majority of the Board (each such event is referred to herein as a
     "Corporate Change"), provided, however, in the event of the death of George
     P. Mitchell, the majority shareholder of the Company and the Chief
     Executive Officer of the Company, the transfer of George P. Mitchell's
     shares of the Company's stock upon his death shall not result in or
     constitute a Corporate Change, no later than (a) ten days after the
     approval by the shareholders of the Company of such merger, consolidation,
     reorganization, sale, lease or exchange of assets or dissolution or such
     election of directors or (b) thirty days after a change of control of the
     type described in clause (iv), the Committee, acting in its sole discretion
     without the consent or approval of any Optionee, shall act to effect one or
     more of the following alternatives, which may vary among individual
     Optionees and which may vary among Options held by any individual Optionee:
     (1) accelerate the time at which Options then outstanding may be exercised
     so that such Options may be exercised in full for a limited period of time
     on or before a specified date (before or after such Corporate Change) fixed
     by the Committee, after which specified date all unexercised Options and
     all rights of Optionees thereunder shall terminate, (2) require the
     mandatory surrender to the Company by selected Optionees of some or all of
     the outstanding Options held by such Optionees (irrespective of whether
     such Options are then exercisable under the provisions of the Plan) as of a
     date, before or after such Corporate Change, specified by the Committee, in
     which event the Committee shall thereupon cancel such Options and the
     Company shall pay to each Optionee an amount of cash per share equal to the
     excess, if any, of the amount calculated in Subparagraph (d) below (the
     "Change of Control Value") of the shares subject to such Option over the
     exercise price(s) under such Options for such shares, (3) make such
     adjustments to Options then outstanding as the Committee deems appropriate
     to reflect such Corporate Change (provided, however, that the Committee may
     determine in its sole discretion that no adjustment is necessary to Options
     then outstanding) or (4) provide that the number and class of shares of
     Stock covered by an Option theretofore granted shall be adjusted so that
     such Option shall thereafter cover the number and class of shares of stock
     or other securities or property (including, without limitation, cash) to
     which the Optionee would have been entitled pursuant to the terms of the
     agreement of merger, consolidation or sale of assets and dissolution if,
     immediately prior to such merger, consolidation or sale of assets and
     dissolution, the Optionee had been the holder of record of the number of
     shares of Stock then covered by such Option.

          (d) For the purposes of clause (2) in Subparagraph (c) above, the
     "Change of Control Value" shall equal the amount determined in clause (i),
     (ii) or (iii), whichever is applicable, as follows: (i) the price per share
     offered to shareholders of the Company in any such merger, consolidation,
     reorganization, sale of assets or dissolution transaction, (ii) the price
     per share offered to shareholders of the Company in any tender offer or
     exchange offer whereby a Corporate Change takes place, or (iii) if such
     Corporate Change occurs other than pursuant to a tender or exchange offer,
     the fair market value per share of the shares into which such Options being
     surrendered are exercisable, as determined by the Committee as of the date
     determined by the Committee to be the date of cancellation and surrender of
     such Options. In the event that the consideration offered to shareholders
     of the Company in any transaction described in this Subparagraph (d) or
     Subparagraph (c) above consists of anything other than cash, the Committee
     shall determine the fair cash equivalent of the portion of the
     consideration offered which is other than cash.

          (e) Any adjustment provided for in Subparagraphs (b) or (c) above
     shall be subject to any required shareholder action.

          (f) Except as hereinbefore expressly provided, the issuance by the
     Company of shares of stock of any class or securities convertible into
     shares of stock of any class, for cash, property, labor or services, upon
     direct sale, upon the exercise of rights or warrants to subscribe therefor,
     or upon conversion of shares or obligations of the Company convertible into
     such shares or other securities, and in any case whether or not for fair
     value, shall not affect, and no adjustment by reason thereof shall be made
     with


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     respect to, the number of shares of Stock subject to Options theretofore
     granted or the purchase price per share.

IX. AMENDMENT OR TERMINATION OF THE PLAN

     The Board in its discretion may terminate the Plan at any time with respect
to any shares for which Options have not theretofore been granted. The Board
shall have the right to alter or amend the Plan or any part thereof from time to
time; provided, that no change in any Option theretofore granted may be made
which would impair the rights of the Optionee without the consent of such
Optionee; and provided, further, that (i) the Board may not make any alteration
or amendment which would decrease any authority granted to the Committee
hereunder in contravention of Rule 16b-3 and (ii) the Board may not make any
alteration or amendment which would materially increase the benefits accruing to
participants under the Plan, increase the aggregate number of shares which may
be issued pursuant to the provisions of the Plan, change the class of
individuals eligible to receive Options under the Plan or extend the term of the
Plan, without the approval of the shareholders of the Company.

X. SECURITIES LAWS

          (a) The Company shall not be obligated to issue any Stock pursuant to
     any Option granted under the Plan at any time when the offering of the
     shares covered by such Option have not been registered under the Securities
     Act of 1933 and such other state and federal laws, rules or regulations as
     the Company or the Committee deems applicable and, in the opinion of legal
     counsel for the Company, there is no exemption from the registration
     requirements of such laws, rules or regulations available for the offering
     and sale of such shares.

          (b) It is intended that the Plan and any grant of an Option made to a
     person subject to Section 16 of the 1934 Act meet all of the requirements
     of Rule 16b-3. If any provision of the Plan or any such Option would
     disqualify the Plan or such Option under, or would otherwise not comply
     with, Rule 16b-3, such provision or Option shall be construed or deemed
     amended to conform to Rule 16b-3.