<Page> As filed with the U.S. Securities and Exchange Commission on [_______], 2003 Registration No. 333- 13702 ================================================================================ SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ---------- POST-EFFECTIVE AMENDMENT TO FORM F-6 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 For Depositary Shares Evidenced by American Depositary Receipts ---------- Tubos de Acero de Mexico, S.A. (Exact name of issuer of deposited securities as specified in its charter) Tubes of Steel of Mexico, S.A. (Translation of issuer's name into English) United Mexican States (Jurisdiction of incorporation or organization of issuer) JPMORGAN CHASE BANK (Exact name of depositary as specified in its charter) 1 Chase Manhattan Plaza, New York, NY 10081 Telephone (212) 552-4944 (Address, including zip code, and telephone number, including area code, of depositary's principal executive offices) ---------- Alfredo Berisso 420 Fifth Avenue, 18th Floor New York, New York 10018 (212) 376-6500 (Address, including zip code, and telephone number, including area code, of agent for service) Copy to: Scott A. Ziegler, Esq. Ann B. Fisher, Esq. Ziegler, Ziegler & Associates LLP Sullivan & Cromwell LLP 570 Lexington Avenue, 44th Floor 125 Broad Street New York, New York 10022 New York, New York 10004 (212) 319-7600 (212) 558-4000 It is proposed that this filing become effective under Rule 466 [X] immediately upon filing [_] on (Date) at (Time) If a separate registration statement has been filed to register the deposited shares, check the following box. [_] CALCULATION OF REGISTRATION FEE ======================================================================================================================== Proposed maximum Proposed maximum Title of each class of Amount aggregate price aggregate offering Amount of Securities to be registered to be registered per unit price registration fee - ------------------------------------------------------------------------------------------------------------------------ American Depositary Shares evidenced by N/A N/A N/A N/A American Depositary Receipts, each American Depositary Share representing five shares of Common Stock, no par value, of Tubos de Acero de Mexico, S.A. ======================================================================================================================== Pursuant to Rule 429, the Prospectus contained herein also relates to American Depositary Shares registered under Form F-6 Registration Statement Nos. 33-41380 and 33-35558. <Page> PART I INFORMATION REQUIRED IN PROSPECTUS The Prospectus consists of the proposed form of American Depositary Receipt ("ADR" or "American Depositary Receipt") included as Exhibit A to the Amendment No. 2 to Deposit Agreement filed as Exhibit (a)(3) to this Registration Statement, which is incorporated herein by reference. CROSS REFERENCE SHEET Item 1. DESCRIPTION OF SECURITIES TO BE REGISTERED Location in Form of American Depositary Item Number and Caption Receipt Filed Herewith as Prospectus - ----------------------- --------------------------------------- (1) Name and address of Depositary Face of American Depositary Receipt, last paragraph (2) Title of American Depositary Receipts and identity of Face of American Depositary Receipt, top center deposited securities Terms of Deposit: (i) Amount of deposited securities represented by one Face of American Depositary Receipt, upper right unit of American Depositary Shares corner (ii) Procedure for voting, if any, the deposited Reverse Paragraphs (13) and (14) securities (iii) Collection and distribution of dividends Face Paragraph (5), Reverse Paragraphs (12) and (13) (iv) Transmission of notices, reports and proxy Reverse Paragraphs (14) and (16) soliciting material (v) Sale or exercise of rights Face Paragraph (5) and Reverse Paragraph (12) (vi) Deposit or sale of securities resulting from Face Paragraphs (5) and (6), Reverse Paragraphs (12) dividends, splits or plans of reorganization and (15) (vii) Amendment, extension or termination of the Face Paragraph (9), Reverse Paragraph (19) Deposit Agreement (viii) Rights of holders of receipts to inspect the Reverse Paragraph (16) transfer books of the Depositary and the list of Holders of receipts (ix) Restrictions upon the right to deposit or Face Paragraphs (3), (5), (6), and (7) withdraw the underlying securities (x) Limitation upon the liability of the Depositary Reverse Paragraph (10) (3) Fees and Charges Face Paragraphs (10) and (17) <Page> Item 2. AVAILABLE INFORMATION Location in Form of American Depositary Item Number and Caption Receipt Filed Herewith as Prospectus - ----------------------- --------------------------------------- (b) Statement that the foreign issuer is subject to Reverse Paragraph (21) the periodic reporting requirements of the Securities Exchange Act of 1934 and, accordingly, files certain reports with the Securities and Exchange Commission <Page> PART II INFORMATION NOT REQUIRED IN PROSPECTUS Item 3. EXHIBITS (a)(3) Form of Amendment No. 2 to Deposit Agreement. (e) Certification under Rule 466. (f) Powers of Attorney for certain officers and directors and the authorized representative of Tubos de Acero de Mexico. Previously filed. Item 4. UNDERTAKINGS (a) The Depositary hereby undertakes to make available at the principal office of the Depositary in the United States, for inspection by holders of the American Depositary Receipts, any reports and communications received from the issuer of the deposited securities which are both (1) received by the Depositary as the holder of the deposited securities, and (2) made generally available to the holders of the underlying securities by the issuer. (b) If the amounts of fees charged are not disclosed in the prospectus, the Depositary undertakes to prepare a separate document stating the amount of any fee charged and describing the service for which it is charged and to deliver promptly a copy of such fee schedule without charge to anyone upon request. The Depositary undertakes to notify each registered holder of an American Depositary Receipt thirty days before any change in the fee schedule. <Page> SIGNATURE Pursuant to the requirements of the Securities Act of 1933, as amended, JPMorgan Chase Bank, on behalf of the legal entity created by the Deposit Agreement, certifies that it has reasonable grounds to believe that all the requirements for filing on Form F-6 are met and has duly caused this Post-Effective Amendment to Registration Statement on Form F-6 to be signed on its behalf by the undersigned, thereunto duly authorized, in The City of New York, State of New York, on May 22, 2003. Legal entity created by the form of Deposit Agreement for the issuance of ADRs evidencing American Depositary Shares By: JPMORGAN CHASE BANK, as Depositary By: /s/ Jordana Chutter ---------------------------------- Name: Jordana Chutter Title: Vice President <Page> SIGNATURES Pursuant to the requirements of the Securities Act of 1933, Tubos de Acero de Mexico, S.A. certifies that it has reasonable grounds to believe that all the requirements for filing on Form F-6 are met and has duly caused this Post-Effective Amendment to Registration Statement on Form F-6 to be signed on its behalf by the undersigned, thereunto duly authorized, on May 20, 2003. TUBOS DE ACERO DE MEXICO, S.A. By: /s/ Gerardo Varela ---------------------------------- Name: Gerardo Varela Title: Chief Financial Officer By: /s/ Cecilia Bilesio ---------------------------------- Name: Cecilia Bilesio Title: Corporate Affairs Pursuant to the requirements of the Securities Act of 1933, as amended, this Post-Effective Amendment to Registration Statement on Form F-6 has been signed by the following persons in the capacities indicated as of May 20, 2003. Signatures Title ---------- ----- /s/ Paolo Rocca* Chairman and Principal Executive Officer - -------------------------------- Paolo Rocca /s/ Gerardo Varela Principal Financial Officer and - -------------------------------- Principal Accounting Officer Gerardo Varela /s/ Guillermo Vogel Director - -------------------------------- Guillermo F. Vogel /s/ Vincenzo Crapanzano Director - -------------------------------- Vincenzo Crapanzano /s/ Adalberto Cortesi* Director - -------------------------------- Adalberto Cortesi Director - -------------------------------- Carlos Abedrop <Page> Signatures Title ---------- ----- Director - -------------------------------- Roberto Einaudi Director - -------------------------------- Gianfelice Rocca /s/ Luis Alberto Aziz Director - -------------------------------- Luis Alberto Aziz /s/ Alfredo Berisso Authorized Representative in - -------------------------------- the United States Alfredo Berisso *Signature of Paolo Rocca by Cecilia Bilesio, Attorney-in-fact. Signature of Adalberto Cortesi by Felix Todd, Attorney-in-fact. Original powers of attorney authorizing Cecilia Bilesio and Felix Todd to sign this amendment to the Registration Statement on behalf of the above-named directors and executive officers have been filed with the Commission. <Page> INDEX TO EXHIBITS Exhibit Sequentially Number Numbered Page - ------- -------------- (a)(3) Form of Amendment to Deposit Agreement. (e) Rule 466 Certification