<PAGE>
                                                                    EXHIBIT 10.1



October 25, 2001




Mr. Joe E.  Boyd
Santa Fe International Corporation
c/o Dallas Office

Dear Joe:

In connection with the transition contemplated by the Agreement and Plan of
Merger (the "Merger Agreement"), dated August 31, 2001, Santa Fe International
Corporation (the "Company") wishes to amend the terms of your Executive
Severance Protection Agreement (the "Severance Agreement"), dated as of October
18, 1999, and to communicate to you certain modifications to your outstanding
equity awards.

         1.   The provisions of this letter agreement (the "Letter Agreement")
              are supplemental to and amend the provisions of the Severance
              Agreement, pursuant to Section 8 thereof, and the Company Employee
              Severance Protection Plan, effective as of May 2, 1997 (the
              "Severance Plan"), and, in the event of a conflict, the provisions
              of this Letter Agreement shall govern. By this reference, the
              Severance Plan is specifically incorporated herein and the defined
              terms and definitions of said Severance Plan are incorporated
              herein mutatis mutandis. Unless provided otherwise in this Letter
              Agreement, capitalized terms that are not otherwise defined in
              this Letter Agreement shall have the meanings assigned to them in
              the Severance Plan.

         2.   Notwithstanding anything to the contrary in Section 4.1 of the
              Severance Plan, the definition of the Designated Period is hereby
              amended to constitute the period from the Change in Control until
              the third anniversary of the Change in Control.

         3.   At the Effective Time (as such term is defined in the Merger
              Agreement), (a) all of your then outstanding options to purchase
              Company ordinary shares (such then outstanding options, being
              hereinafter referred to as the "Old Options") shall vest and
              become exercisable, and (b) all of your then outstanding
              restricted ordinary shares shall vest. In addition, pursuant to
              this Letter Agreement, and notwithstanding anything to the
              contrary in any stock option plan of the Company or Award
              Agreements thereunder, if your employment is terminated at any
              time in circumstances entitling you to a Severance Benefit
              pursuant to Section 4.2 of the Severance Plan, your Old Options
              shall remain exercisable for three years following the date of the
              termination of your employment (or until the expiration of the
              original term of the Old Options, if earlier).


<PAGE>

                                                                Mr. Joe E.  Boyd
                                                                October 25, 2001
                                                                        Page Two


         4.   Section 6(a) of the Severance Agreement is hereby amended by
              inserting the following parenthetical after the words "applicable
              company pension plan" in the first sentence thereof:

                  (which, for purposes of this Agreement, shall include any
                  retirement plan sponsored by the Company, including but not
                  limited to, qualified or non-qualified pension plans,
                  supplemental pension plans, supplemental executive retirement
                  plans or any other pension-type plans providing monthly or
                  lump sum cash benefits at retirement)

         5.   Section 6(b) of the Severance Agreement is hereby amended by
              inserting the words "and/or financial planning services" after the
              words "outplacement service" in such section.

         6.   The Severance Agreement as amended herein and the Severance Plan
              shall continue in full force and effect.

         7.   This Letter Agreement may be amended or terminated only by a
              written instrument signed by both parties hereto making specific
              reference to this Letter Agreement and expressing the plan or
              intention to modify or terminate it.

         8.   This Letter Agreement may be executed by the parties hereto in
              counterparts, each of which shall be deemed an original, but both
              such counterparts shall together constitute one and the same
              document.

If this Letter Agreement sets forth our agreement on the subject matter hereof,
kindly sign and return to the Company the enclosed copy of this Letter
Agreement, which will then constitute our agreement with each provision
contained herein.


Sincerely,


SANTA FE INTERNATIONAL CORPORATION


By: /s/ C. Stedman Garber, Jr.
        C. Stedman Garber, Jr.


ACCEPTED AND AGREED:


    /s/ Joe E. Boyd
        Joe E. Boyd

<PAGE>












October 25, 2001




Mr. Roger B.  Hunt
Santa Fe International Corporation
c/o Dallas Office

Dear Roger:

In connection with the transition contemplated by the Agreement and Plan of
Merger (the "Merger Agreement"), dated August 31, 2001, Santa Fe International
Corporation (the "Company") wishes to amend the terms of your Executive
Severance Protection Agreement (the "Severance Agreement"), dated as of October
18, 1999, and to communicate to you certain modifications to your outstanding
equity awards.

         1.   The provisions of this letter agreement (the "Letter Agreement")
              are supplemental to and amend the provisions of the Severance
              Agreement, pursuant to Section 8 thereof, and the Company Employee
              Severance Protection Plan, effective as of May 2, 1997 (the
              "Severance Plan"), and, in the event of a conflict, the provisions
              of this Letter Agreement shall govern. By this reference, the
              Severance Plan is specifically incorporated herein and the defined
              terms and definitions of said Severance Plan are incorporated
              herein mutatis mutandis. Unless provided otherwise in this Letter
              Agreement, capitalized terms that are not otherwise defined in
              this Letter Agreement shall have the meanings assigned to them in
              the Severance Plan.

         2.   Notwithstanding anything to the contrary in Section 4.1 of the
              Severance Plan, the definition of the Designated Period is hereby
              amended to constitute the period from the Change in Control until
              the third anniversary of the Change in Control.

         3.   At the Effective Time (as such term is defined in the Merger
              Agreement), (a) all of your then outstanding options to purchase
              Company ordinary shares (such then outstanding options, being
              hereinafter referred to as the "Old Options") shall vest and
              become exercisable, and (b) all of your then outstanding
              restricted ordinary shares shall vest. In addition, pursuant to
              this Letter Agreement, and notwithstanding anything to the
              contrary in any stock option plan of the Company or Award
              Agreements thereunder, if your employment is terminated at any
              time in circumstances entitling you to a Severance Benefit
              pursuant to Section 4.2 of the Severance Plan, your Old Options
              shall remain exercisable for three years following the date of the
              termination of your employment (or until the expiration of the
              original term of the Old Options, if earlier).



<PAGE>

                                                              Mr. Roger B.  Hunt
                                                                October 25, 2001
                                                                        Page Two



         4.   Section 6(a) of the Severance Agreement is hereby amended by
              inserting the following parenthetical after the words "applicable
              company pension plan" in the first sentence thereof:

                  (which, for purposes of this Agreement, shall include any
                  retirement plan sponsored by the Company, including but not
                  limited to, qualified or non-qualified pension plans,
                  supplemental pension plans, supplemental executive retirement
                  plans or any other pension-type plans providing monthly or
                  lump sum cash benefits at retirement)

         5.   Section 6(b) of the Severance Agreement is hereby amended by
              inserting the words "and/or financial planning services" after the
              words "outplacement service" in such section.

         6.   The Severance Agreement as amended herein and the Severance Plan
              shall continue in full force and effect.

         7.   This Letter Agreement may be amended or terminated only by a
              written instrument signed by both parties hereto making specific
              reference to this Letter Agreement and expressing the plan or
              intention to modify or terminate it.

         8.   This Letter Agreement may be executed by the parties hereto in
              counterparts, each of which shall be deemed an original, but both
              such counterparts shall together constitute one and the same
              document.

If this Letter Agreement sets forth our agreement on the subject matter hereof,
kindly sign and return to the Company the enclosed copy of this Letter
Agreement, which will then constitute our agreement with each provision
contained herein.


Sincerely,


SANTA FE INTERNATIONAL CORPORATION


By: /s/ Joe Boyd
        Joe Boyd


ACCEPTED AND AGREED:


    /s/ Roger B. Hunt
        Roger B. Hunt


<PAGE>





October 25, 2001




Mr. Seals M.  McCarty
Santa Fe International Corporation
c/o Dallas Office

Dear Seals:

In connection with the transition contemplated by the Agreement and Plan of
Merger (the "Merger Agreement"), dated August 31, 2001, Santa Fe International
Corporation (the "Company") wishes to amend the terms of your Executive
Severance Protection Agreement (the "Severance Agreement"), dated as of October
18, 1999, and to communicate to you certain modifications to your outstanding
equity awards.

         1.   The provisions of this letter agreement (the "Letter Agreement")
              are supplemental to and amend the provisions of the Severance
              Agreement, pursuant to Section 8 thereof, and the Company Employee
              Severance Protection Plan, effective as of May 2, 1997 (the
              "Severance Plan"), and, in the event of a conflict, the provisions
              of this Letter Agreement shall govern. By this reference, the
              Severance Plan is specifically incorporated herein and the defined
              terms and definitions of said Severance Plan are incorporated
              herein mutatis mutandis. Unless provided otherwise in this Letter
              Agreement, capitalized terms that are not otherwise defined in
              this Letter Agreement shall have the meanings assigned to them in
              the Severance Plan.

         2.   Notwithstanding anything to the contrary in Section 4.1 of the
              Severance Plan, the definition of the Designated Period is hereby
              amended to constitute the period from the Change in Control until
              the third anniversary of the Change in Control.

         3.   At the Effective Time (as such term is defined in the Merger
              Agreement), (a) all of your then outstanding options to purchase
              Company ordinary shares (such then outstanding options, being
              hereinafter referred to as the "Old Options") shall vest and
              become exercisable, and (b) all of your then outstanding
              restricted ordinary shares shall vest. In addition, pursuant to
              this Letter Agreement, and notwithstanding anything to the
              contrary in any stock option plan of the Company or Award
              Agreements thereunder, if your employment is terminated at any
              time in circumstances entitling you to a Severance Benefit
              pursuant to Section 4.2 of the Severance Plan, your Old Options
              shall remain exercisable for three years following the date of the
              termination of your employment (or until the expiration of the
              original term of the Old Options, if earlier).



<PAGE>

                                                            Mr. Seals M. McCarty
                                                                October 25, 2001
                                                                        Page Two



         4.   Section 6(a) of the Severance Agreement is hereby amended by
              inserting the following parenthetical after the words "applicable
              company pension plan" in the first sentence thereof:

                  (which, for purposes of this Agreement, shall include any
                  retirement plan sponsored by the Company, including but not
                  limited to, qualified or non-qualified pension plans,
                  supplemental pension plans, supplemental executive retirement
                  plans or any other pension-type plans providing monthly or
                  lump sum cash benefits at retirement)

         5.   Section 6(b) of the Severance Agreement is hereby amended by
              inserting the words "and/or financial planning services" after the
              words "outplacement service" in such section.

         6.   The Severance Agreement as amended herein and the Severance Plan
              shall continue in full force and effect.


         7.   This Letter Agreement may be amended or terminated only by a
              written instrument signed by both parties hereto making specific
              reference to this Letter Agreement and expressing the plan or
              intention to modify or terminate it.

         8.   This Letter Agreement may be executed by the parties hereto in
              counterparts, each of which shall be deemed an original, but both
              such counterparts shall together constitute one and the same
              document.

If this Letter Agreement sets forth our agreement on the subject matter hereof,
kindly sign and return to the Company the enclosed copy of this Letter
Agreement, which will then constitute our agreement with each provision
contained herein.


Sincerely,


SANTA FE INTERNATIONAL CORPORATION


By: /s/ Joe Boyd
        Joe Boyd


ACCEPTED AND AGREED:


    /s/ Seals M. McCarty
        Seals M. McCarty