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                                   FORM 6-K/A
                     U.S. SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                        REPORT OF FOREIGN PRIVATE ISSUER
                   PURSUANT TO RULE 13A-16 OR 15D-16 UNDER THE
                         SECURITIES EXCHANGE ACT OF 1934


                               dated May 24, 2005


                         Commission File Number 1-14878


                                   GERDAU S.A.
                    (Exact Name as Specified in its Charter)

                                       N/A
                       ----------------------------------
                       (Translation of Registrant's Name)

                                Av. Farrapos 1811
             Porto Alegre, Rio Grande do Sul - Brazil CEP 90220-005
                    (Address of principal executive offices)


         Indicate by check mark whether the registrant files or will file annual
reports under cover Form 20-F or Form 40-F.

         Form 20-F    X    Form 40-F      
                                    ------

         Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(1): ____

         Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(7): ____

         Indicate by check mark whether by furnishing the information contained
in this Form, the registrant is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

         Yes                        No  X    
             ------

         If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): Not applicable.

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                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused the Report to be signed on its behalf by the
undersigned, thereunto duly authorized.


Date:  May 24, 2005

                                     GERDAU S.A.




                                     By:/s/ Osvaldo  Burgos Schirmer
                                        ----------------------------------------
                                        Name: Osvaldo Burgos Schirmer
                                        Title: Chief Financial Officer



The balance sheet at December 31, 2004 and statement of income for the year then
ended currently being filed in this 6-K/A have been modified with respect to the
unaudited balance sheet and statement of income filed on Form 6-K dated February
3, 2005 because after re-consideration of the application of Interpretation 46
of the Financial Accounting Standards Board it has been concluded that the
interest in Dona Francisca Energetica S.A. should not be consolidated but
accounted for following the equity method. Net income and shareholders equity
have not been modified and the effects resulting from the deconsolidation of
Dona Francisca Energetica S.A. as well as the effects of other reclassifications
in the main captions of the financial statements are presented below:



                                                EFFECT OF NON
                          AS ORIGINALLY      CONSOLIDATING DFESA         OTHER             AS CURRENTLY
                            PRESENTED                              RECLASSIFICATIONS         PRESENTED

                                                                                 
Current assets         3,435,425              (43,937)            (68,461)             3,323,027
Non-current assets     3,622,440              (93,218)            -                    3,529,222
Current liabilities    1,791,834              (11,068)            (68,461)             1,712,305
Non-current
liabilities            2,083,970            (108,582)             -                    1,975,388
Minority interest         659,476             (17,505)            -                       641,971
Shareholders equity
                       2,522,585            -                     -                    2,522,585
Net sales              6,966,770              (14,621)            -                    6,952,149
Operating income       1,639,179              (10,929)            -                    1,628,250
Net income             1,158,358            -                     -                    1,158,358



                                  EXHIBIT INDEX


Exhibit                             Description of Exhibit
-------                             ----------------------

99.1                       Consolidated financial statements as of December 31,
                           2004 and 2003 and for each of the three years in the
                           period ended December 31, 2004 and report of
                           independent registered public accounting firm