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 May 3, 2007


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


                                  TENARIS, S.A.
                           46a, Avenue John F. Kennedy
                                L-1855 Luxembourg
                    (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   X           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   X
                                 -------          -------


     If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): 82- . -



       Tenaris to Complete Acquisition of Hydril on May 7, 2007


    LUXEMBOURG--(BUSINESS WIRE)--May 2, 2007--Tenaris S.A. (NYSE:TS)
(BCBA:TS) (BMV:TS) (BI:TEN) and Hydril Company (NASDAQ:HYDL) announced
today that, following the vote today by a majority of Hydril's
stockholders in favor of the proposed acquisition by Tenaris, the
acquisition should be completed on May 7, 2007. On that date, Tenaris
will transfer to the paying agent for the transaction US$97 per share
in cash for each issued and outstanding share of Hydril's common stock
and Class B common stock, and a subsidiary of Tenaris will merge with
and into Hydril.

    To finance the acquisition and the payment of related obligations
and to refinance existing debt, Tenaris and the subsidiary that will
merge with and into Hydril have entered into syndicated term loan
facilities in an aggregate principal amount of US$2.0 billion. Tenaris
will consolidate Hydril's balance sheet and results of operations in
its consolidated financial statements from May 7, 2007.

    Tenaris is the leading global manufacturer and supplier of tubular
products and related services for the world's oil and gas industry and
other industrial applications. With Hydril, Tenaris will add an
industry-leading supplier of high performance premium connection and
pressure control products and services for the oil and gas industry.

    Some of the statements contained in this press release are
"forward-looking statements." Forward-looking statements are based on
management's current views and assumptions and involve known and
unknown risks that could cause actual results, performance or events
to differ materially from those expressed or implied by those
statements.


    CONTACT: Tenaris
             Nigel Worsnop, 1-888-300-5432
             www.tenaris.com



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 Tenaris's press release announcing
that the completion of the acquisition of Hydril on May 7, 2007.


                                    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.


Date: May 3, 2007


                                  Tenaris, S.A.


By: /s/ Cecilia Bilesio
    -------------------
Cecilia Bilesio
Corporate Secretary