FORM 6 - K



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                        Report of Foreign Private Issuer
                    Pursuant to Rule 13a - 16 or 15d - 16 of
                       the Securities Exchange Act of 1934


                                As of 12/28/2006



                                  Ternium S.A.
                 (Translation of Registrant's name into English)


                                  Ternium S.A.
                     46a, Avenue John F. Kennedy - 2nd floor
                                L-1855 Luxembourg
                               (352) 4661-11-3815
                    (Address of principal executive offices)


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

                                        /
                                       /
                          Form 20-F [\/] Form 40-F____

      Indicate by check mark whether the registrant by furnishing the
information contained in this Form is also thereby furnishing the information to
the Commission pursuant to Rule 12G3-2(b) under the Securities Exchange Act of
1934.
                                                /
                                               /
                                 Yes____ No [\/]



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






The attached material is being furnished to the Securities and Exchange
Commission pursuant to Rule 13a-16 and Form 6-K under the Securities Exchange
Act of 1934, as amended.

This report contains Ternium S.A.'s press release announcing that Ternium
purchases CVRD's ownership stake in Siderar.


                                    SIGNATURE

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


                                  TERNIUM S.A.


By: /s/ Roberto Philipps              By: /s/ Daniel Novegil
------------------------------        ---------------------------------------
Name: Roberto Philipps                         Name: Daniel Novegil
Title: Chief Financial Officer                 Title: Chief Executive Officer


Dated: December 28, 2006

               Ternium Purchases CVRD's Ownership Stake in Siderar


    LUXEMBOURG--(BUSINESS WIRE)--Dec. 28, 2006--Ternium S.A. (NYSE:TX)
announced today that, in a private transaction, it acquired from CVRD
International S.A., a wholly-owned subsidiary of Companhia Vale do Rio
Doce (NYSE:RIO) (NYSE:RIOPR), or CVRD, 16,860,000 shares, or 4.85%, of
Siderar S.A. for an aggregate purchase price of US$107.5 million. The
price per share paid to CVRD is US$6.376 which reflects a discount to
market price. Upon consummation of this transaction, Ternium has
increased its ownership in Siderar to 211,701,012 shares, or 60.93%.

    Ternium is one of the leading steel companies in the Americas,
offering a wide range of flat and long steel products. Ternium has
operating locations in Mexico, Argentina and Venezuela that provide it
with a strong position from which to serve its core markets. In
addition, Ternium reaches the global markets through its own
distribution network. More information about Ternium is available on
the Company's Web site at www.ternium.com.



    CONTACT: Ternium
             Investor Relations:
             Sebastian Marti
             USA (1) 866 890 0443
             Mexico (52) 81 8865 1240
             Argentina (54) 11 4018 2389
             www.ternium.com