---------------------------------
                                                        OMB APPROVAL
                                                 OMB Number:      3235-0145
                                                 Expires: December 31, 2005
                                                 Estimated average burden
                                                 hours per response.........11
                                               ---------------------------------

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                 SCHEDULE 13G/A

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO. 1 )*


                           ENCORE ACQUISITION COMPANY
--------------------------------------------------------------------------------
                                (Name of Issuer)

                          COMMON STOCK, $0.01 PAR VALUE
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    29255W100
                    ----------------------------------------
                                 (CUSIP Number)



                                DECEMBER 2, 2003
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


      Check the  appropriate  box to designate  the rule  pursuant to which this
      Schedule is filed:

              [ ] Rule 13d-1(b)

              [ ] Rule 13d-1(c)

              [X] Rule 13d-1(d)

      *The  remainder  of this cover  page  shall be filled out for a  reporting
      person's  initial filing on this form with respect to the subject class of
      securities,  and for any subsequent amendment containing information which
      would alter the disclosures provided in a prior cover page.

      The information  required in the remainder of this cover page shall not be
      deemed to be "filed"  for the  purpose  of  Section  18 of the  Securities
      Exchange Act of 1934 ("Act") or otherwise  subject to the  liabilities  of
      that  section of the Act but shall be subject to all other  provisions  of
      the Act (however, see the Notes).

      PERSONS WHO RESPOND TO THE  COLLECTION  OF  INFORMATION  CONTAINED IN THIS
      FORM ARE NOT  REQUIRED  TO RESPOND  UNLESS THE FORM  DISPLAYS A  CURRENTLY
      VALID OMB CONTROL NUMBER.



                                Page 1 of 8 pages




CUSIP No.   29255W100
.............................
--------------------------------------------------------------------------------
      1. Names of Reporting Persons.
         I.R.S. Identification Nos. of above persons (entities only).
Warburg, Pincus Equity Partners, L.P. .
13-3986317......................................................................
--------------------------------------------------------------------------------
      2.   Check the Appropriate Box if a Member of a Group (See Instructions)

           (a)..................................................................
--------------------------------------------------------------------------------
           (b) [X]..............................................................
--------------------------------------------------------------------------------
      3.   SEC Use Only ........................................................
--------------------------------------------------------------------------------
      4.   Citizenship or Place of Organization Delaware
           .....................................................................
--------------------------------------------------------------------------------
Number of Shares        5.   Sole Voting Power Not Applicable
Beneficially by              ...................................................
Owned by Each      -------------------------------------------------------------
Reporting               6.   Shared Voting Power 7,419,943
Person With:                 ...................................................
                   -------------------------------------------------------------
                        7.   Sole Dispositive Power Not Applicable
                             ...................................................
                   -------------------------------------------------------------
                        8.   Shared Dispositive Power 7,419,943
                             ...................................................
--------------------------------------------------------------------------------
      9.   Aggregate Amount Beneficially Owned by Each Reporting Person
                                                                       7,419,943
           .....................................................................

      10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See
           Instructions)  Not Applicable
           ..................................

      11.  Percent of Class Represented by Amount in Row (9)  24.5%
           .....................................................................
--------------------------------------------------------------------------------
      12. Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
PN .............................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................

--------------------------------------------------------------------------------


                                Page 2 of 8 pages



CUSIP No.  29255W100
.................................................................................
--------------------------------------------------------------------------------
      13.  Names of Reporting Persons.
           I.R.S.  Identification  Nos. of above persons (entities only).
Warburg Pincus & Co.
13-6358475......................................................................
--------------------------------------------------------------------------------
      14.  Check the Appropriate Box if a Member of a Group (See Instructions)

           (a)..................................................................

           (b) [X]..............................................................
--------------------------------------------------------------------------------
      15.  SEC Use Only
           .....................................................................
--------------------------------------------------------------------------------
      16.  Citizenship or Place of Organization Delaware
           .....................................................................
--------------------------------------------------------------------------------
Number of Shares        17.  Sole Voting Power Not Applicable
Bene-ficially by             ...................................................
Owned by Each      -------------------------------------------------------------
Reporting               18.  Shared Voting Power 7,419,943
Person With:                 ...................................................
                   -------------------------------------------------------------
                        19.  Sole Dispositive Power Not Applicable
                             ...................................................
                   -------------------------------------------------------------
                        20.  Shared Dispositive Power  7,419,943
                             ...................................................
                   -------------------------------------------------------------
      21.  Aggregate Amount Beneficially Owned by Each Reporting Person
                                                                       7,419,943
           .....................................................................

      22.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See
           Instructions)  Not Applicable

           .....................................................................
      23.  Percent of Class Represented by Amount in Row (9)  24.5%

           .....................................................................
--------------------------------------------------------------------------------
      24.  Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------
PN .............................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................

--------------------------------------------------------------------------------


                               Page 3 of 8 pages



CUSIP No.   29255W100
...............................
--------------------------------------------------------------------------------
      25.  Names of Reporting Persons.
           I.R.S. Identification  Nos. of above persons (entities only).
Warburg Pincus LLC
13-3536050......................................................................
--------------------------------------------------------------------------------
      26.  Check the Appropriate Box if a Member of a Group (See Instructions)

           (a)..................................................................

           (b)|X|...............................................................
--------------------------------------------------------------------------------
      27.  SEC Use Only
--------------------------------------------------------------------------------
      28.  Citizenship or Place of Organization  Delaware
           .....................................................................
--------------------------------------------------------------------------------
Number of Shares        29.  Sole Voting Power  Not Applicable
Bene-ficially by   .............................................................
Owned by Each      -------------------------------------------------------------
Reporting               30.  Shared Voting Power 7,419,943
Person With:       .............................................................
                   -------------------------------------------------------------
                        31.  Sole Dispositive Power Not Applicable
                   .............................................................
                   -------------------------------------------------------------
                        32.  Shared Dispositive Power  7,419,943

                   .............................................................
--------------------------------------------------------------------------------
      33.  Aggregate Amount Beneficially Owned by Each Reporting Person
                                                                       7,419,943
           ..................................................................

      34.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See
           Instructions)  Not Applicable
           ..................................
--------------------------------------------------------------------------------
      35.  Percent of Class Represented by Amount in Row (9)  24.5%
           .....................................................................
--------------------------------------------------------------------------------
      36.  Type of Reporting Person (See Instructions)
--------------------------------------------------------------------------------

OO .............................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................
.................................................................................

--------------------------------------------------------------------------------


                                Page 4 of 8 pages





PRELIMINARY  NOTE:  This  information  contained  in this  Schedule 13G is being
amended to reflect a sale by Warburg,  Pincus Equity Partners, L.P. of 2,193,357
shares of the Issuer's Common Stock for a per share sale price of $19.3775.

ITEM 1.

      (A) NAME OF ISSUER:

      Encore Acquisition Company

      (B) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

      777 Main Street, Suite 1400, Fort Worth, Texas 76102

ITEM 2.

      (A) NAME OF PERSON FILING:

      Filed by and on  behalf  of  Warburg,  Pincus  Equity  Partners,  L.P.,  a
      Delaware limited partnership,  ("WPEP");  Warburg Pincus & Co., a New York
      general  partnership  ("WP"),  which is the general  partner of WPEP;  and
      Warburg Pincus LLC, a New York limited liability company ("WP LLC"), which
      manages  WPEP.  The  members of WP LLC are  substantially  the same as the
      partners of WP.

      (B) ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

      The business address of each of the foregoing is 466 Lexington Avenue, New
      York, NY 10017 (C) CITIZENSHIP: Delaware (D) TITLE OF CLASS OF SECURITIES:

      Common Stock, par value $0.01

      (E) CUSIP NUMBER:

      29255W100

ITEM  3.  IF  THIS  STATEMENT  IS  FILED  PURSUANT  TO   SS.SS.240.13D-1(B)   OR
      240.13D-2(B) OR (C), CHECK WHETHER THE PERSON FILING IS A:

Not Applicable

ITEM 4. OWNERSHIP.

WARBURG, PINCUS EQUITY PARTNERS, L.P.

      (A) AMOUNT BENEFICIALLY OWNED:

      7,419,943

      (B) PERCENT OF CLASS:

      24.5% (based on 30,275,113 shares outstanding as of December 2, 2003).

      (C) NUMBER OF SHARES AS TO WHICH THE PERSON HAS:

           (i) Sole power to vote or to direct the vote: -0-


                               Page 5 of 8 pages


           (ii)  Shared power to vote or to direct the vote: 7,419,943

           (iii) Sole power to dispose or to direct the disposition of: -0-

           (iv)  Shared  power to  dispose  or to  direct  the  disposition  of:
                 7,419,943

WARBURG PINCUS & CO.

      (A) AMOUNT BENEFICIALLY OWNED:

      7,419,943

      (B) PERCENT OF CLASS:

      24.5% (based on 30,275,113 shares outstanding as of December 2, 2003).

      (C) NUMBER OF SHARES AS TO WHICH THE PERSON HAS:

           (i)   Sole power to vote or to direct the vote: - 0 -

           (ii)  Shared power to vote or to direct the vote: 7,419,943

           (iii) Sole power to dispose or to direct the disposition of: -0-

           (iv)  Shared  power to  dispose  or to  direct  the  disposition  of:
                 7,419,943

WARBURG PINCUS LLC

      (A) AMOUNT BENEFICIALLY OWNED:

      7,419,943

      (B) PERCENT OF CLASS:

      24.5% (based on 30,275,113 shares outstanding as of December 2, 2003).

      (C) NUMBER OF SHARES AS TO WHICH THE PERSON HAS:

           (i)   Sole power to vote or to direct the vote: -0-

           (ii)  Shared power to vote or to direct the vote: 7,419,943

           (iii) Sole power to dispose or to direct the disposition of: -0-

           (iv)  Shared  power to  dispose  or to  direct  the  disposition  of:
                 7,419,943

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

Not Applicable.

ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

Not Applicable.

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
        SECURITY BEING REPORTED ON BY THE


                                Page 6 of 8 pages



PARENT HOLDING COMPANY

Not Applicable.

ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

Not Applicable.

ITEM 9. NOTICE OF DISSOLUTION OF GROUP

Not Applicable.

ITEM 10. CERTIFICATION

                      By  signing  below  I  certify  that,  to the  best  of my
                      knowledge  and belief,  the  securities  referred to above
                      were  acquired  and are  held in the  ordinary  course  of
                      business  and were not  acquired  and are not held for the
                      purpose of or with the effect of changing  or  influencing
                      the control of the issuer of the  securities  and were not
                      acquired  and are  not  held  in  connection  with or as a
                      participant  in any  transaction  having  that  purpose or
                      effect.

                                    SIGNATURE

    After  reasonable  inquiry and to the best of my  knowledge  and  belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.

Dated:  DECEMBER 3, 2003                   WARBURG, PINCUS EQUITY PARTNERS, L.P.
      --------------------

                                           By:      WARBURG, PINCUS & CO.
                                                    its General Partner

                                           By:
                                                    ----------------------------
                                                    Name:  Scott A. Arenare
                                                    Title: Partner






                                Page 7 of 8 pages



                                 Exhibit Index:


      1. Exhibit A - Joint Filing  Agreement,  dated as of February 7, 2002, (by
         and among Warburg,  Pincus Equity Partners,  L.P., Warburg Pincus & Co.
         and  Warburg  Pincus  LLC  pursuant  to  Rule  13d-1(k)(1)   under  the
         Securities  Exchange  Act of 1934)  filed with the SEC with Form 13G on
         February 7, 2002, is incorporated by reference.




     The original  statement  shall be signed by each person on whose behalf the
statement is filed or his authorized representative.  If the statement is signed
on behalf of a person by his authorized  representative  other than an executive
officer  or   general   partner  of  the   filing   person,   evidence   of  the
representative's  authority to sign on behalf of such person shall be filed with
the  statement,  provided,  however,  that a power of attorney  for this purpose
which is already on file with the Commission may be  incorporated  by reference.
The name and any title of each person who signs the statement  shall be typed or
printed beneath his signature.

NOTE:  Schedules  filed in paper format shall include a signed original and five
copies  of the  schedule,  including  all  exhibits.  SEEss.240.13d-7  for other
parties for whom copies are to be sent.



    ATTENTION: INTENTIONAL MISSTATEMENTS OR OMISSIONS OF FACT CONSTITUTE FEDERAL
    CRIMINAL VIOLATIONS (SEE 18 U.S.C. 1001)











                                Page 8 of 8 pages