Exhibit 10.7

                             FIRST SUPPLEMENT TO THE
                             KERR-McGEE CORPORATION
                     SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN
               AS AMENDED AND RESTATED EFFECTIVE FEBRUARY 26, 1999
              (As it applies to Employee Plan Participants who were
             Participants in the Superseded Plan as of May 2, 1994)


(A)      Applicability:
         --------------

         (1) This First  Supplement to the Kerr-McGee  Corporation  Supplemental
             Executive  Retirement Plan (the "First Supplement") forms a part of
             the Kerr-McGee  Corporation  Supplemental Executive Retirement Plan
             as  in  effect  on  and  after  February  26,  1999  ("Plan").  The
             provisions  of this  First  Supplement  shall  apply  only to those
             employee  Participants who were Participants in the superseded Plan
             as of May 2, 1994 ("First Supplement Employees").

         (2) There shall be no duplication  of benefits  provided under the Plan
             and this First Supplement,  and the actuarially equivalent benefits
             payable under one shall be inclusive of the actuarially  equivalent
             benefits  payable  under the  other  unless  specifically  provided
             otherwise in the provisions of the Plan or this First Supplement.

         (3) All terms used in this  First  Supplement  shall have the  meanings
             assigned to them in the provisions of the Plan,  unless a different
             meaning is plainly required by the context.

(B)      Minimum Benefits Applicable to First Supplement Employees
         ---------------------------------------------------------

         (1) Minimum   Retirement   Income:   The  monthly   retirement   income
             determined  under  Section  4.2(a)(i)  of  the  Plan  for  a  First
             Supplement  Employee  before  reduction  for the  offset in Section
             4.2(a)(ii)  shall not be less than 70% of the  Participant's  Final
             Average  Monthly  Pay  multiplied  by the Early  Retirement  Factor
             specified   in   Section   4.2(a)  of  the  Plan   based  upon  the
             Participant's attained age at the date of his retirement.

         (2) Minimum  Disability   Retirement  Income:  The  monthly  retirement
             income  determined under Section  4.2(b)(i) of the Plan for a First
             Supplement  Employee  before  reduction  for the  offset in Section
             4.2(b)(ii)  shall not be less than 70% of the  Participant's  Final
             Average  Monthly  Pay  multiplied  by the Early  Retirement  Factor
             specified in Section 4.2(a) of the Plan for retirement at age 52.

         (3) Minimum  Benefit  for  Termination  Due to Change of  Control:  The
             monthly retirement income determined under Section 4.2(c)(i) of the
             Plan  for a First  Supplement  Employee  before  reduction  for the
             offset  in  Section  4.2(c)(ii)  shall  not be less than 70% of the
             Participant's  Final  Average  Monthly Pay  multiplied by the Early
             Retirement  Factor  specified  in Section  4.2(a) of the Plan based
             upon  the  Participant's  attained  age  as  of  the  date  of  his
             termination of service; or if the Participant's  attained age as of
             the date of his  termination of service is less than age 52, by the
             product of the Early Retirement  Factor specified in Section 4.2(a)
             of the Plan for  retirement  at age 52 multiplied by a factor which
             will  convert  a  monthly   retirement   income  payable  for  life
             commencing at age 52 to an Actuarially Equivalent amount of monthly
             retirement  income payable for life commencing at the Participant's
             attained age as of the date of his termination of service.

         (4) Minimum Death Benefit:  For the purpose of determining  the benefit
             provided  under  Section  4.2(d)  of the Plan on  behalf of a First
             Supplement  Employee,  the Minimum  Benefit in Section (B)(3) above
             with respect to Section 4.2(C)(i) of the Plan shall apply; provided
             the  Participant's  date of death shall be used in lieu of his date
             of termination of service and Final Average Monthly Pay and Monthly
             Offset   Amounts  shall  be  determined  as  of  the  date  of  the
             Participant's  death.  In the  case  of  the  death  of a  Disabled
             Participant, the benefit shall be computed as if he remained in the
             active  service  of the  Employer  until  his  death  and his Final
             Average  Monthly  Pay at the date of his  death was the same as his
             Final Average  Monthly Pay at the date of his termination of active
             service due to Disability.

         (5) Monthly Offset Amount for Minimum Benefits:  Solely for the purpose
             of determining a minimum  benefit for a First  Supplement  Employee
             under Section (B) herein, the Monthly Offset Amount in Section 2.14
             of the Plan shall  include in addition to and in the same manner as
             the  amounts  described  in (a) through  (c) of Section  2.14,  the
             following amounts:

                  (a) the monthly  amount of retirement  income or other benefit
             which is  payable  to or on behalf of the  Participant  on or after
             such specified  date under any qualified  defined  benefit  pension
             plan in which the Participant participated prior to his last period
             of  employment  with the  Employer  while in the  employment  of an
             employer which is not an Employer as defined herein; and

                  (b) the monthly  amount of any  employer-sponsored  retirement
             income or other benefit which, in the opinion of the Committee,  is
             for the purpose of providing  defined benefit pension plan benefits
             that are in addition to those provided under the qualified  defined
             benefit  pension plan of an employer  which is not an Employer,  as
             defined  herein,  and is payable to or on behalf of the Participant
             on and after such  specified date under any  non-qualified  plan in
             which  the  Participant  participated  prior to his last  period of
             employment  with  the  Employer  while  in the  employment  of such
             employer.

(C)      Right to Amend or Terminate First Supplement.
         ---------------------------------------------

             The provisions of Section 9.1 of the Plan with respect to amendment
         and  termination  thereof  shall  apply  with equal force to this First
         Supplement.


              IN WITNESS WHEREOF, KERR-McGEE CORPORATION has,  on its behalf and
         on behalf of its participating affiliates, caused this First Supplement
         to  be  executed  by  its  duly  authorized  officers on the 9th day of
         January, 2001, effective as of February 26, 1999.


                                     KERR-McGEE CORPORATION



                                     By:(William E. Bradford)
                                        ---------------------------------
                                         William E. Bradford,
                                         Director and Chair of the
                                         Executive Compensation Committee