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                                                               EXHIBIT 10.6(c)

                           Amendment No. Three to the

                              Oryx Energy Company
                           Executive Retirement Plan
                            As Amended And Restated
                           Effective January 1, 1995

WHEREAS, Oryx Energy Company (the "Company") last amended and restated the
Executive Retirement Plan (the "Plan") effective January 1, 1995 and last
amended the Plan effective January 1, 1997; and

WHEREAS, the Company desires further to amend the Plan;

NOW, THEREFORE, pursuant to the powers reserved in Article IX of the Plan, the
Plan is hereby amended as follows:

                                       I.

     Effective January 1, 1998, the first sentence of the first paragraph in
     Section 3.08(b) is amended to include the year 1998, by the revision of the
     phrase "under an outplacement program during 1995, 1996, or 1997" to read
     "under an outplacement program during 1995, 1996, 1997 or 1998".

                                      II.

     Except for the amendments reflected in this instrument, the Plan shall
     remain in full force and effect.

IN WITNESS WHEREOF, the Company has caused this instrument to be executed this
4th day of September, 1997.



                                         ORYX ENERGY COMPANY


                                         By:    /s/ FRANCES G. HEARTWELL
                                            --------------------------------
                                         Name:  Frances G. Heartwell
                                              ------------------------------
                                         Title: Vice President, Human Resources
                                                   and Administration
                                               -----------------------------

ATTEST:

By:     /s/ WILLIAM C. LEMMER
   --------------------------------
Title:  Vice President, General
        Counsel and Secretary
      -----------------------------


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                           Amendment No. Four to the

                              Oryx Energy Company
                           Executive Retirement Plan
                            As Amended And Restated
                             as of January 1, 1995

     WHEREAS, Oryx Energy Company (the "Company") last amended the restated
Executive Retirement Plan (the "Plan") with Amendment No. Three effective
January 1, 1996; and

     WHEREAS, the Company desires further to amend the Plan;

     NOW, THEREFORE, pursuant to the powers reserved in Article IX of the Plan,
the Plan is hereby amended, effective September 4, 1997, as follows:

                                       I.

     Section 3.02 is amended, in the fourth line, by changing the words, "five
years of Executive Service" to "thirty months of Executive Service".

                                      II.

     Section 3.04 is amended, in the fifth and sixth lines, by changing the
words, "five years of Executive Service" to "thirty months of Executive
Service".

                                      III.

     Section 3.08(b) is amended, in the sixth and seventh lines, by changing the
words, "actual Executive Service equals at least five years" to "actual
Executive Service equals at least thirty months".

                                      IV.

     Section 6.02 is amended by changing the phrase, "his 55th birthday", and
the phrase, "five years of Executive Service", to "his 52nd birthday" and
"thirty months of Executive Service", respectively, in the places where such
phrases appear in said Section.

                                       V.

     Section 6.04 is amended, in the second paragraph, by changing the phrase,
"age 55", to "age 52".

                                      VI.

     Except for the amendments reflected in this instrument, the Plan shall
remain in full force and effect.






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     IN WITNESS WHEREOF, the Company has caused this Amendment to be executed
effective as of September 4, 1997.




                                         ORYX ENERGY COMPANY


                                         By:    /s/ FRANCES G. HEARTWELL
                                            --------------------------------
                                         Name:  Frances G. Heartwell
                                              ------------------------------
                                         Title: Vice President, Human Resources
                                                   and Administration
                                               -----------------------------

ATTEST:

By:     /s/ WILLIAM C. LEMMER
   --------------------------------
Title:  Vice President, General
        Counsel and Secretary
      -----------------------------