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 September 14, 2006

                                  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- . -



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
the sale of a participation in Dalmine Energie to E.ON.



                                    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: September 14, 2006


Tenaris, S.A.


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


            Tenaris to Sell Participation in Dalmine Energie to E.ON



    LUXEMBOURG--(BUSINESS WIRE)--Sept. 13, 2006--Tenaris S.A.
(NYSE:TS) (BCBA:TS) (BVM:TS) (BI:TEN) announced today that it has
signed a letter of intent with E.ON Sales and Trading GmbH, an
indirect subsidiary of E.ON AG, for the sale to E.ON of a 75% interest
in Dalmine Energie, Tenaris's Italian energy supply business, for a
purchase price of approximately EUR39 million (approximately US$50
million), subject to adjustments. The purchase price reflects an
enterprise valuation for Dalmine Energie of approximately EUR72
million (approximately US$92 million). The transaction, which is
subject to negotiation and execution of definitive documentation,
clearance by the applicable competition authorities and customary due
diligence conditions, is expected to close before the end of 2006.

    Dalmine Energie began operations in 2000 following the partial
deregulation of the Italian energy sector and initially supplied
electricity to Tenaris's Dalmine seamless pipe mill and to other users
in the north of Italy. Since then, it has grown rapidly and become a
leading supplier of electric energy and natural gas to the Italian
industrial and commercial market with sales (including sales to
Tenaris) of approximately 3.0 TWh of electricity and almost 1.1
billion cubic meters of natural gas.

    Tenaris is the leading global manufacturer and supplier of tubular
products and services used in the drilling, completion and production
of oil and gas and a leading supplier of tubular products and services
used in process and power plants and in specialized industrial and
automotive applications.


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