As filed with the U.S. Securities and Exchange Commission on April 10, 2006
Registration No. 333-


 
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
____________________
FORM F-6
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
For Depositary Shares Evidenced by American Depositary Receipts
___________________
TENARIS S.A.
(Exact name of issuer of deposited securities as specified in its charter)

Not applicable
(Translation of issuer's name into English)

Grand Duchy of Luxembourg
(Jurisdiction of incorporation or organization of issuer)

JPMORGAN CHASE BANK, N.A.
(Exact name of depositary as specified in its charter)

4 New York Plaza, New York, NY 10004
Telephone (212) 623-0636
(Address, including zip code, and telephone number, including area code, of depositary's principal executive offices)
____________________
Giovanni Gallo
Techint Inc.
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.
Ziegler, Ziegler & Associates LLP
570 Lexington Avenue, 44th Floor
New York, New York 10022
(212) 319-7600

It is proposed that this filing become effective under Rule 466
G immediately upon filing
x on April 26, 2006 at 4:30 p.m. (EST)

If a separate registration statement has been filed to register the deposited shares, check the following box. G
 
CALCULATION OF REGISTRATION FEE
 
Title of each class of
Securities to be registered
 
Amount
to be registered
 
Proposed maximum
aggregate offering
price per unit (1)
 
Proposed maximum
aggregate offering
price (2)
 
Amount of
registration fee
 
American Depositary Shares evidenced by American
Depositary Receipts, each American Depositary Share
representing two (2) ordinary shares of Tenaris S.A.
 
250,000,000
 
$0.05
 
$12,500,000
 
$1,337.50
(1)
Each unit represents one American Depositary Share.
(2)
Estimated solely for the purpose of calculating the registration fee. Pursuant to Rule 457(k), such estimate is computed on the basis of the maximum aggregate fees or charges to be imposed in connection with the issuance of American Depositary Receipts evidencing American Depositary Shares.

Pursuant to Rule 429, the Prospectus contained herein also relates to American Depositary Shares registered under Form F-6 Registration Statement No. 333-100591.


PART I
INFORMATION REQUIRED IN PROSPECTUS
 
The Prospectus consists of the proposed form of American Depositary Receipt (AADR@ or AAmerican Depositary Receipt@) included as Exhibit A to the Amendment to Deposit Agreement filed as Exhibit (a)(2) to this Registration Statement, which is incorporated herein by reference.

CROSS REFERENCE SHEET

Item 1. DESCRIPTION OF SECURITIES TO BE REGISTERED
 
Item Number and Caption
 
Location in Form of American Depositary
Receipt Filed Herewith as Prospectus
     
(1) Name and address of Depositary
 
Introductory paragraph
(2) Title of American Depositary Receipts and identity of deposited securities
 
Face of American Depositary Receipt, top center
Terms of Deposit:
   
(i) Amount of deposited securities represented by one unit of American Depositary Shares
 
Face of American Depositary Receipt, upper right corner
(ii) Procedure for voting, if any, the deposited securities
 
Paragraph (12)
(iii) Collection and distribution of dividends
 
Paragraphs (4), (5), (7) and (10)
(iv) Transmission of notices, reports and proxy soliciting material
 
Paragraphs (3), (8) and (12)
(v) Sale or exercise of rights
 
Paragraphs (4), (5) and (10)
(vi) Deposit or sale of securities resulting from dividends, splits or plans of reorganization
 
Paragraphs (4), (5), (10) and (13)
(vii) Amendment, extension or termination of the Deposit Agreement
 
Paragraphs (16) and (17)
(viii) Rights of holders of receipts to inspect the transfer books of the Depositary and the list of Holders of receipts
 
Paragraph (3)
(ix) Restrictions upon the right to deposit or withdraw the underlying securities
 
Paragraphs (1), (2), (4), and (5)
(x) Limitation upon the liability of the Depositary
 
Paragraph (14)
(3) Fees and Charges
 
Paragraph (7)


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Item 2. AVAILABLE INFORMATION

 
Item Number and Caption 
 
Location in Form of American Depositary
Receipt Filed Herewith as Prospectus 
     
(a) Statement that Tenaris S.A. is subject to the periodic reporting requirements of the Securities Exchange Act of 1934 and, accordingly, files certain reports with the Commission -- and that such reports can be inspected by holders of American Depositary Receipts and copied at public reference facilities maintained by the Commission in Washington, D.C.
 
Paragraph (8)

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PART II
INFORMATION NOT REQUIRED IN PROSPECTUS
 
Item 3. EXHIBITS
 
 
(a)(1)
Form of Deposit Agreement. Form of Deposit Agreement among Tenaris S.A., JPMorgan Chase Bank, as depositary (the "Depositary"), and all holders from time to time of ADRs issued thereunder (the "Deposit Agreement"). Previously filed as exhibit (a) to Registration Statement No. 333-100591 and incorporated herein by reference.
 
(a)(2)
Form of Amendment to Deposit Agreement. Form of Amendment to Deposit Agreement dated as of April , 2006 among Tenaris S.A., the Depositary, and all holders from time to time of ADRs issued thereunder, including the Form of American Depositary Receipt, is filed herewith as Exhibit (a)(2).
 
(b)
Any other agreement to which the Depositary is a party relating to the issuance of the American Depositary Shares registered hereunder or the custody of the deposited securities represented thereby. Not Applicable.
 
(c)
Every material contract relating to the deposited securities between the Depositary and the issuer of the deposited securities in effect at any time within the last three years. Not Applicable.
 
(d)
Opinion of Ziegler, Ziegler & Associates LLP, counsel to the Depositary, as to the legality of the securities being registered. Filed herewith as Exhibit (d).
 
(e)
Certification under Rule 466. Filed herewith as Exhibit (e).
 
(f)
Power of Attorney. Included as part of the signature pages hereto.
 
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.
 
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SIGNATURE

Pursuant to the requirements of the Securities Act of 1933, as amended, JPMorgan Chase Bank, N.A. , 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 Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in The City of New York, State of New York, on April 3, 2006.
 
     
  Legal entity created by the form of Deposit Agreement for the issuance of ADRs evidencing American Depositary Shares
 
 
 
 
 
 
 
By:
JPMORGAN CHASE BANK, N.A., as Depositary
     
  By:   /s/ Joseph M. Leinhauser
 
Name: Joseph M. Leinhauser
  Title: Vice President
 
 

 
SIGNATURES
 
Pursuant to the requirements of the Securities Act of 1933, Tenaris 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 Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, on April 3, 2006.
 
     
  TENARIS S.A.
 
 
 
 
 
 
  By:   /s/ Paolo Rocca
 
Name: Paolo Rocca
  Title: Chairman and Chief Executive Officer
 
POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Paolo Rocca and Carlos Condorelli , and each of them, jointly and severally, his true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including pre-effective and post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue thereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities indicated as of the dates indicated
 

 
Signatures  
Title
 
Date
         
/s/ Paolo Rocca   Chief Executive Officer and Chairman  
April 3, 2006
Paolo Rocca   (principal executive officer)    
         
/s/ Guillermo Vogel   Director, Vice President, Finance  
April 3, 2006
Guillermo Vogel         
         
/s/ Carlos Condorelli   Chief Financial Officer  
April 3, 2006
Carlos Condorelli   (principal financial and accounting officer)    
         
/s/ Roberto Bonatti   Director  
April 3, 2006
Roberto Bonatti         
          



Signatures  
Title
 
Date
         
          Director  
, 2006
Carlos Franck        
         
/s/ Bruno Marchettini   Director  
April 3, 2006
Bruno Marchettini        
         
       Director  
, 2006
Roberto Monti        
         
      Director  
, 2006
Gianfelice Mario Rocca        
         
       Director  
, 2006
Jaime Serra Puche        
         
/s/ Amadeo Vázquez y Vázquez   Director  
April 3, 2006
Amadeo Vázquez y Vázquez        
         
/s/ Giovanni Gallo   Authorized Representative in the  
April 3, 2006
Giovanni Gallo   United States    
   
 

 
INDEX TO EXHIBITS

Exhibit
Number
   
     
(a)(2)
Form of Amendment to Deposit Agreement.
 
(d)
Opinion of Ziegler, Ziegler & Associates LLP, counsel to the Depositary, as to the legality of the securities to be registered.
 
(e) Rule 466 Certification