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                                                                     EXHIBIT 4.1


                       AMENDMENT NO. 1 TO RIGHTS AGREEMENT


         Amendment No. 1, dated as of May 23, 2001, to the Rights Agreement,
dated as of November 15, 1996 (the "Rights Agreement"), between Marine Drilling
Companies, a Texas corporation (the "Company"), and American Stock Transfer &
Trust Company, a New York trust company, as Rights Agent (the "Rights Agent").

         WHEREAS, the Company and the Rights Agent entered into the Rights
Agreement specifying the terms of the Rights (as defined therein);

         WHEREAS, the Company desires to amend the Rights Agreement in
accordance with Section 29 of the Rights Agreement;

         WHEREAS, the Company proposes to enter into an Agreement and Plan of
Merger, dated as of May 23, 2001 (the "Merger Agreement"), among Pride
International, Inc., a Louisiana corporation ("Pride"), PM Merger, Inc., a
Delaware corporation and wholly-owned subsidiary of Pride ("Newco"), the Company
and AM Merger, Inc., a Delaware corporation and wholly-owned subsidiary of Pride
("Merger Sub").

         WHEREAS, the Company proposed to enter into a stock option agreement
(the "Pride Stock Option Agreement") concurrently with the execution and
delivery of the Merger Agreement, pursuant to which Marine will grant Pride the
option to purchase shares of Marine's common stock, par value $.01 per share,
upon the terms and subject to the conditions set forth therein.

         WHEREAS, the Board of Directors of the Company has determined it
advisable and in the best interest of its stockholders to amend the Rights
Agreement to enable the Company to enter into the Merger Agreement, the Pride
Stock Option Agreement and consummate the transactions contemplated thereby
without causing Newco or Pride or any of its subsidiaries to become an
"Acquiring Person" (as defined in the Rights Agreement).

         NOW, THEREFORE, in consideration of the premises and mutual agreements
set forth herein and in the Rights Agreement, the parties hereby agree as
follows:

         Section 1. Definitions. Capitalized terms used and not otherwise
defined herein shall have the meaning assigned to such terms in the Rights
Agreement.

         Section 2. Amendments to Rights Agreement. The Rights Agreement is
hereby amended as set forth in this Section 2.

         (a) The definition of "Acquiring Person" in Section 1 of the Rights
Agreement is amended to add the following sentence at the end thereof:


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         "Notwithstanding anything in this Agreement to the contrary, none of
         Pride, Newco, Merger Sub or any Affiliate or Associate of any of them
         shall be deemed to be an Acquiring Person, either individually or
         collectively, solely by virtue of (i) the execution and delivery of the
         Merger Agreement or the Pride Stock Option Agreement, (ii) the
         conversion of shares of Common Stock into the right to receive Newco
         common stock and/or Pride common stock in accordance with Article 4 of
         the Merger Agreement or (iii) the consummation of the Mergers (as such
         term is defined in the Merger Agreement) or any other transaction
         contemplated by the Merger Agreement."

         (b) The definition of "Distribution Date" in Section 1 of the Rights
Agreement is amended to add the following sentence at the end thereof:

         "Notwithstanding anything in this Agreement to the contrary, a
         Distribution Date shall not be deemed to have occurred solely as the
         result of (i) the execution and delivery of the Merger Agreement, (ii)
         the conversion of shares of Common Stock into the right to receive
         Newco common stock in accordance with Article 4 of the Merger Agreement
         or (iii) the consummation of the Mergers (as such term is defined in
         the Merger Agreement) or any other transaction contemplated by the
         Merger Agreement."

         (c) The definition of "Final Expiration Date" in Section 1 of the
Rights Agreement is amended to read in its entirety as follows:

         "'Final Expiration Date' shall mean the earlier of the Effective Time
         (as defined in the Merger Agreement) or the close of business on
         November 19, 2006."

         (d) The definition of "Share Acquisition Date" in Section 1 of the
Rights Agreement is amended to add the following sentence at the end thereof:

         "Notwithstanding anything in this Agreement to the contrary, a Share
         Acquisition Date shall not be deemed to have occurred solely as the
         result of (i) the execution and delivery of the Merger Agreement, (ii)
         the conversion of shares of Common Stock into the right to receive
         Newco common stock in accordance with Article 4 of the Merger Agreement
         or (iii) the consummation of the Mergers (as such term is defined in
         the Merger Agreement) or any other transaction contemplated by the
         Merger Agreement."


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         (e) The following definitions shall be added to Section 1 of the Rights
Agreement:

         "Merger Agreement" shall mean the Agreement and Plan of Merger, dated
         as of May 23, 2001, by and among Newco, Pride, Merger Sub and the
         Company."

         "Newco" shall mean PM Merger Inc., a corporation organized under the
         laws of Delaware and a wholly-owned subsidiary of Pride."

         "Merger Sub" shall mean AM Merger, Inc. a corporation organized under
         the laws of Delaware and a wholly-owned subsidiary of Pride."

         "Pride" shall mean Pride International, Inc., a corporation organized
         under the laws of Louisiana."

         Section 3. Miscellaneous.

         (a) The term "Agreement" as used in the Rights Agreement shall be
deemed to refer to the Rights Agreement as amended hereby.

         (b) This Amendment shall be effective as of the date first above
written, and, except as set forth herein, the Rights Agreement shall remain in
full force and effect and shall be otherwise unaffected hereby.

         (c) The Rights Agreement shall terminate and be of no further force and
effect upon the Final Expiration Date.

         (d) This Amendment may be executed in two or more counterparts, each of
which shall be deemed to be an original, but all for which together shall
constitute one and the same instrument.

         (e) This Amendment shall be deemed to be a contract made under the laws
of the State of Texas and for all purposes shall be governed by and construed in
accordance with the laws of such State applicable to contracts to be made and
performed entirely within such State.

                            [SIGNATURE PAGE FOLLOWS]



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         IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1
to be duly executed and attested, all as of the day and year first above
written.

Attest:                                MARINE DRILLING COMPANIES, INC.


By: /s/ DOMINIQUE R. COLVARD           By: /s/ JAN RASK
   --------------------------------       --------------------------------------
Name:   Dominique R. Colvard           Name:   Jan Rask
     ------------------------------         ------------------------------------
Title:  Witness                        Title:  President and Chief Executive
      -----------------------------            Officer
                                             -----------------------------------


Attest:                                AMERICAN STOCK TRANSFER &
                                           TRUST COMPANY


By: /s/ PAULA CAROPPOLI                By: /s/ ISAAC S. KAGAN
   --------------------------------       --------------------------------------
Name:   Paula Caroppoli                Name:   Isaac S. Kagan
     ------------------------------         ------------------------------------
Title:  Vice President                 Title:  Vice President
      -----------------------------          -----------------------------------


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