1

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                                  SCHEDULE 13D
                                 (Rule 13d-101)

                        UNDER THE SECURITIES ACT OF 1934
                               (AMENDMENT NO. 1)(1)

                           PATTERSON-UTI ENERGY, INC.
 ................................................................................
                                (Name of Issuer)

                     COMMON STOCK, PAR VALUE $0.01 PER SHARE
 ................................................................................
                         (Title of Class of Securities)

                                   703481 10 1
 ................................................................................
                                 (CUSIP Number)

               MARK S. SIEGEL C/O REMY CAPITAL PARTNERS III, L. P.
        1801 CENTURY PARK EAST, SUITE 1111, LOS ANGELES, CALIFORNIA 90067
                                 (310) 843-0050
 ................................................................................
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                  JULY 20, 2001
 ................................................................................
             (Date of Event which Requires Filing of this Statement)


If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following
box [ ].

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7 for other parties
to whom copies are to be sent.

----------
(1) 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).

                                  Page 1 of 10
   2

                                  SCHEDULE 13D

CUSIP NO. 703481 10 1                                         PAGE 2 OF 10 PAGES

--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSONS
    IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

    REMY CAPITAL PARTNERS III, L.P.
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
    (a) [X]

    (b) [ ]
--------------------------------------------------------------------------------
3   SEC USE ONLY

--------------------------------------------------------------------------------
4   SOURCE OF FUNDS

    OO*
--------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
    ITEM 2(d) OR 2(e)    [ ]

    N/A
--------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION

    DELAWARE
--------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           -0-
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH
 REPORTING          4,729,524
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                    -0-
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    4,729,524
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     4,729,524
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES   [ ]

     N/A
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     6.2%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     PN
--------------------------------------------------------------------------------
*See Item 3 herein.

                                  Page 2 of 10
   3

                                  SCHEDULE 13D

CUSIP NO. 703481 10 1                                         PAGE 3 OF 10 PAGES

--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSONS
    IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

    REMY INVESTORS AND CONSULTANTS, INCORPORATED
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
    (a) [X]

    (b) [ ]
--------------------------------------------------------------------------------
3   SEC USE ONLY

--------------------------------------------------------------------------------
4   SOURCE OF FUNDS

    OO*
--------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
    ITEM 2(d) OR 2(e)    [ ]

    N/A
--------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION

    CALIFORNIA
--------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           -0-
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH
 REPORTING          4,729,524
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                    -0-
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    4,729,524
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     4,729,524
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES   [ ]

     N/A
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     6.2%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     CO
--------------------------------------------------------------------------------
*See Item 3 herein.

                                  Page 3 of 10
   4

                                  SCHEDULE 13D

CUSIP NO. 703481 10 1                                         PAGE 4 OF 10 PAGES

--------------------------------------------------------------------------------
1   NAME OF REPORTING PERSONS
    IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

    MARK S. SIEGEL
--------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
    (a) [X]

    (b) [ ]
--------------------------------------------------------------------------------
3   SEC USE ONLY

--------------------------------------------------------------------------------
4   SOURCE OF FUNDS

    OO*
--------------------------------------------------------------------------------
5   CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
    ITEM 2(d) OR 2(e)    [ ]

    N/A
--------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION

    UNITED STATES
--------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           1,280,000
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH
 REPORTING          4,729,524
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                    1,280,000
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER

                    4,729,524
--------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     6,009,524
--------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES   [ ]

     N/A
--------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     7.8%
--------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON

     IN
--------------------------------------------------------------------------------
*See Item 3 herein.

                                  Page 4 of 10
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                       SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C.
                                  SCHEDULE 13D
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

ITEM 1.  SECURITY AND ISSUER

         No change since the Schedule 13D filed on May 18, 2001 (the "Initial
Schedule 13D") by the Reporting Persons (as that term is defined in the Initial
Schedule 13D) ("No Change").

ITEM 2.  IDENTITY AND BACKGROUND

         No Change.


ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION

         On July 20, 2001, the Board of Directors of the Issuer (as that term is
defined in the Initial Schedule 13D) granted Mark S. Siegel an option to
purchase 250,000 shares of the Issuer's Common Stock (as that term is defined in
the Initial Schedule 13D) at $15.85 per share.

ITEM 4.  PURPOSE OF TRANSACTION

         No Change.

         (a) THE ACQUISITION BY ANY PERSON OF ADDITIONAL SECURITIES OF THE
             ISSUER, OR THE DISPOSITION OF SECURITIES OF THE ISSUER;

             Each Reporting Person has no present intention, plan, or proposal
             with respect to this paragraph.

         (b) AN EXTRAORDINARY CORPORATE TRANSACTION, SUCH AS A MERGER,
             REORGANIZATION OF LIQUIDATION, INVOLVING THE ISSUER OR OF ANY OF
             ITS SUBSIDIARIES;

             Each Reporting Person has no present intention, plan, or proposal
             with respect to this paragraph.

         (c) A SALE OR TRANSFER OF A MATERIAL AMOUNT OF ASSETS OF THE ISSUER OR
             ANY OF ITS SUBSIDIARIES;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (d) ANY CHANGE IN THE PRESENT BOARD OF DIRECTORS OR MANAGEMENT OF THE
             ISSUER, INCLUDING ANY PLANS OR PROPOSALS TO CHANGE THE NUMBER OR
             TERM OF DIRECTORS OR TO FILL ANY EXISTING VACANCIES ON THE BOARD;


                                  Page 5 of 10
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             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (e) ANY MATERIAL CHANGE IN THE PRESENT CAPITALIZATION OR DIVIDEND
             POLICY OF THE ISSUER;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (f) ANY OTHER MATERIAL CHANGE IN THE ISSUER'S BUSINESS OR CORPORATE
             STRUCTURE, INCLUDING BUT NOT LIMITED TO, IF THE ISSUER IS A
             REGISTERED CLOSED-END INVESTMENT COMPANY, ANY PLANS OR PROPOSALS TO
             MAKE ANY CHANGES IN THE INVESTMENT POLICY FOR WHICH A VOTE IS
             REQUIRED BY SECTION 13 OF THE INVESTMENT COMPANY ACT OF 1940;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (g) CHANGES IN THE ISSUER'S CHARTER, BYLAWS OR INSTRUMENTS
             CORRESPONDING THERETO OR OTHER ACTIONS WHICH MAY IMPEDE THE
             ACQUISITION OF CONTROL OF THE ISSUER BY ANY PERSON;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (h) CAUSING A CLASS OF SECURITIES OF THE ISSUER TO BE DELISTED FROM A
             NATIONAL SECURITIES EXCHANGE OR TO CEASE TO BE AUTHORIZED TO BE
             QUOTED IN AN INTER-DEALER QUOTATION SYSTEM OF A REGISTERED NATIONAL
             SECURITIES ASSOCIATION;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (i) A CLASS OF EQUITY SECURITIES OF THE ISSUER BECOMING ELIGIBLE FOR
             TERMINATION OF REGISTRATION PURSUANT TO SECTION 12(g)(4) OF THE
             ACT;

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

         (j) ANY ACTION SIMILAR TO ANY OF THOSE ENUMERATED ABOVE.

             Each Reporting Person has no present intention, plan or proposal
             with respect to this paragraph.

ITEM 5.  INTEREST IN SECURITIES OF ISSUER

         (a) AMOUNT OF SHARES OWNED


                                  Page 6 of 10
   7
             Remy Capital beneficially owns 4,729,524 shares of the Issuer's
             Common Stock of the Issuer (approximately 6.2% of the Issuer's
             outstanding shares). Remy Investors is deemed to be the beneficial
             owner of all shares beneficially owned by Remy Capital. Mark S.
             Siegel is the sole shareholder of Remy Investors and is deemed to
             be the beneficial owner of all shares beneficially owned by Remy
             Investors. In addition, Mr. Siegel owns presently exercisable
             options to purchase 1,280,000 shares of the Issuer's Common Stock
             and, accordingly, is deemed to be the beneficial owner of an
             aggregate of 6,009,524 shares of the Issuer's Common Stock
             (approximately 7.8% of the Issuer's outstanding shares).

         (b) NUMBER OF SHARES AS TO WHICH SUCH PERSON HAS:

             (i)      SOLE POWER TO VOTE OR DIRECT THE VOTE

                      Remy Capital:                  0
                      Remy Investors:                0
                      Mark S. Siegel:                1,280,000

             (ii)     SHARED POWER TO VOTE OR DIRECT THE VOTE

                      Remy Capital:                  4,729,524
                      Remy Investors:                4,729,524
                      Mark S. Siegel:                4,729,524

             (iii)    SOLE POWER TO DISPOSE OR DIRECT THE DISPOSITION OF:

                      Remy Capital:                  0
                      Remy Investors:                0
                      Mark S. Siegel:                1,280,000

             (iv)     SHARED POWER TO DISPOSE OR DIRECT THE DISPOSITION OF:

                      Remy Capital:                  4,729,524
                      Remy Investors:                4,729,524
                      Mark S. Siegel:                4,729,524

         (c) TRANSACTIONS IN THE REPORTED CLASS OF SECURITIES

             The information disclosed in Item 5(c) of the Initial Schedule 13D
             is hereby deleted in its entirety. On July 20, 2001, the Board of
             Directors of the Issuer granted Mark S. Siegel an option to
             purchase 250,000 shares of the Issuer's Common Stock at $15.85 per
             share.

         (d) - (e) Not Applicable.

ITEM 6.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT
         TO SECURITIES OF ISSUER

         No Change.

                                  Page 7 of 10
   8

ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS.

                  The following exhibits to this Schedule 13D are filed herewith
or are incorporated by reference as indicated:

                  (1)*     Joint Acquisition Statement.

                  (2)      Agreement and Plan of Merger dated as of February 4,
                           2001 between Patterson Energy, Inc. and UTI Energy
                           Corp. (incorporated by reference to Exhibit 10.1 to
                           Patterson's Current Report on Form 8-K, dated
                           February 4, 2001, filed with the Securities and
                           Exchange Commission on February 16, 2001).

                  (3)      Registration Rights Agreement dated March 25, 1994
                           between Bear Stearns and UTI Energy Corp., assigned
                           on March 14, 1995 to Remy Capital (incorporated by
                           reference to Exhibit 3 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (4)      Form of Stock Option Agreement between UTI Energy
                           Corp. and Mark S. Siegel, relating to the grant to
                           Mr. Siegel of options to purchase 165,000 shares at
                           $8.125 per share effective February 13, 1997, and
                           (ii) the grant to Mr. Siegel of options to purchase
                           135,000 shares at $20.00 per share effective July 27,
                           1997 (incorporated by reference to Exhibit 4 to
                           Schedule 13D filed by the Reporting Persons, dated
                           August 20, 1997 and filed with the Securities and
                           Exchange commission on August 26, 1997 relating to
                           UTI Energy Corp., a predecessor to Patterson-UTI
                           Energy, Inc. (the "UTI Schedule 13D")).

                  (5)      Form of Amended and Restated Stock Option Agreement
                           between UTI Energy Corp. and Mark S. Siegel, relating
                           to the grant on August 12, 1998 to Mr. Siegel of
                           repriced options to purchase 135,000 shares at $9.875
                           per share effective July 27, 1997 (incorporated by
                           reference to Exhibit 7 to Schedule 13D filed by the
                           Reporting Persons, dated and filed December 28, 2000
                           with the Securities and Exchange Commission relating
                           to the UTI Schedule 13D).

                  (6)      Form of Amended and Restated Stock Option Agreement
                           between UTI Energy Corp. and Mark S. Siegel, relating
                           to the grant on August 12, 1998 to Mr. Siegel of
                           repriced options to purchase 250,000 shares at $9.875
                           per share effective November 20, 1997 (incorporated
                           by reference to Exhibit 8 to Schedule 13D filed by
                           the Reporting Persons, dated and filed December 28,
                           2000 with the Securities and Exchange Commission
                           relating to the UTI Schedule 13D).

                  (7)      Form of Stock Option Agreement between UTI Energy
                           Corp. and Mark S. Siegel, relating to the grant to
                           Mr. Siegel of options to purchase 90,000 shares at
                           $9.8125 per share effective April 26, 1999
                           (incorporated by reference to Exhibit 9 to Schedule
                           13D filed by the Reporting Persons, dated and filed
                           December 28, 2000 with the Securities and Exchange
                           Commission relating to the UTI Schedule 13D).

                  (8)      Affiliate Letter of Remy Capital accepted by UTI and
                           Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 8 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                                  Page 8 of 10
   9

                  (9)      Affiliate Letter of Remy Investors accepted by UTI
                           and Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 9 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (10)     Affiliate Letter of Mark S. Siegel accepted by UTI
                           and Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 10 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (11)*    Form of Stock Option Agreement between Patterson-UTI
                           Energy, Inc. and Mark Siegel, relating to the grant
                           to Mr. Siegel of options to purchase 250,000 shares
                           of Common Stock at $15.85 per share effective July
                           20, 2001.

-------------------
*Filed herewith.

                                  Page 9 of 10
   10

                                   SIGNATURES

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


Dated: September 26, 2001

                                         /s/ MARK S. SIEGEL
                          ------------------------------------------------------
                                             Mark S. Siegel


                          REMY CAPITAL PARTNERS, III, L.P.

                          By: Remy Investors and Consultants, Incorporated, its
                              General Partner

                                         /s/ MARK S. SIEGEL
                              --------------------------------------------------
                                             Mark S. Siegel
                                             President


                          REMY INVESTORS AND CONSULTANTS, INCORPORATED


                          By:            /s/ MARK S. SIEGEL
                             ---------------------------------------------------
                                             Mark S. Siegel
                                             President

                                  Page 10 of 10
   11

                                 EXHIBIT INDEX

                  The following exhibits to this Schedule 13D are filed herewith
or are incorporated by reference as indicated:

                  (1)*     Joint Acquisition Statement.

                  (2)      Agreement and Plan of Merger dated as of February 4,
                           2001 between Patterson Energy, Inc. and UTI Energy
                           Corp. (incorporated by reference to Exhibit 10.1 to
                           Patterson's Current Report on Form 8-K, dated
                           February 4, 2001, filed with the Securities and
                           Exchange Commission on February 16, 2001).

                  (3)      Registration Rights Agreement dated March 25, 1994
                           between Bear Stearns and UTI Energy Corp., assigned
                           on March 14, 1995 to Remy Capital (incorporated by
                           reference to Exhibit 3 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (4)      Form of Stock Option Agreement between UTI Energy
                           Corp. and Mark S. Siegel, relating to the grant to
                           Mr. Siegel of options to purchase 165,000 shares at
                           $8.125 per share effective February 13, 1997, and
                           (ii) the grant to Mr. Siegel of options to purchase
                           135,000 shares at $20.00 per share effective July 27,
                           1997 (incorporated by reference to Exhibit 4 to
                           Schedule 13D filed by the Reporting Persons, dated
                           August 20, 1997 and filed with the Securities and
                           Exchange commission on August 26, 1997 relating to
                           UTI Energy Corp., a predecessor to Patterson-UTI
                           Energy, Inc. (the "UTI Schedule 13D")).

                  (5)      Form of Amended and Restated Stock Option Agreement
                           between UTI Energy Corp. and Mark S. Siegel, relating
                           to the grant on August 12, 1998 to Mr. Siegel of
                           repriced options to purchase 135,000 shares at $9.875
                           per share effective July 27, 1997 (incorporated by
                           reference to Exhibit 7 to Schedule 13D filed by the
                           Reporting Persons, dated and filed December 28, 2000
                           with the Securities and Exchange Commission relating
                           to the UTI Schedule 13D).

                  (6)      Form of Amended and Restated Stock Option Agreement
                           between UTI Energy Corp. and Mark S. Siegel, relating
                           to the grant on August 12, 1998 to Mr. Siegel of
                           repriced options to purchase 250,000 shares at $9.875
                           per share effective November 20, 1997 (incorporated
                           by reference to Exhibit 8 to Schedule 13D filed by
                           the Reporting Persons, dated and filed December 28,
                           2000 with the Securities and Exchange Commission
                           relating to the UTI Schedule 13D).

                  (7)      Form of Stock Option Agreement between UTI Energy
                           Corp. and Mark S. Siegel, relating to the grant to
                           Mr. Siegel of options to purchase 90,000 shares at
                           $9.8125 per share effective April 26, 1999
                           (incorporated by reference to Exhibit 9 to Schedule
                           13D filed by the Reporting Persons, dated and filed
                           December 28, 2000 with the Securities and Exchange
                           Commission relating to the UTI Schedule 13D).

                  (8)      Affiliate Letter of Remy Capital accepted by UTI and
                           Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 8 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).
   12

                  (9)      Affiliate Letter of Remy Investors accepted by UTI
                           and Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 9 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (10)     Affiliate Letter of Mark S. Siegel accepted by UTI
                           and Patterson on March 13, 2001 (incorporated by
                           reference to Exhibit 10 to the Initial Schedule 13D
                           filed by the Reporting Persons, dated and filed May
                           18, 2001 with the Securities and Exchange
                           Commission).

                  (11)*    Form of Stock Option Agreement between Patterson-UTI
                           Energy, Inc. and Mark Siegel, relating to the grant
                           to Mr. Siegel of options to purchase 250,000 shares
                           of Common Stock at $15.85 per share effective July
                           20, 2001.

-------------------
*Filed herewith.