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<SEC-DOCUMENT>0000891836-03-000476.txt : 20030812
<SEC-HEADER>0000891836-03-000476.hdr.sgml : 20030812
<ACCEPTANCE-DATETIME>20030812113000
ACCESSION NUMBER:		0000891836-03-000476
CONFORMED SUBMISSION TYPE:	SC 13D/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20030812
GROUP MEMBERS:		I.I.I. INDUSTRIAL INVESTMENTS INC.
GROUP MEMBERS:		INVERTUB S.A.
GROUP MEMBERS:		ROCCA &PARTNERSSOCIEDADANONIMA
GROUP MEMBERS:		SAN FAUSTIN N.V.
GROUP MEMBERS:		SIDERCA INTERNATIONAL APS
GROUP MEMBERS:		SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL
GROUP MEMBERS:		SIDERTUBES S.A.
GROUP MEMBERS:		SIDTAM LIMITED

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TUBES OF STEEL OF MEXICO SA
		CENTRAL INDEX KEY:			0000100084
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES  ROLLING MILLS (COKE OVENS) [3312]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-31361
		FILM NUMBER:		03836440

	BUSINESS ADDRESS:	
		STREET 1:		EDIFICIO PARQUE REFORMA
		STREET 2:		CAMPOS ELISEOS 400 - COL CHAPULTEPEC POL
		CITY:			MEXICO D F MEX
		STATE:			O5
		ZIP:			11560
		BUSINESS PHONE:		5252020003

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TUBOS DE ACERO DE MEXICO S A
		DATE OF NAME CHANGE:	19930421

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TUBES OF STEEL OF MEXICO S A
		DATE OF NAME CHANGE:	19880406

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TENARIS SA
		CENTRAL INDEX KEY:			0001190723
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES  ROLLING MILLS (COKE OVENS) [3312]
		IRS NUMBER:				000000000

	FILING VALUES:
		FORM TYPE:		SC 13D/A

	BUSINESS ADDRESS:	
		STREET 1:		420 FIFTH AVENUE
		STREET 2:		18TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10018
		BUSINESS PHONE:		212-376-6500

	MAIL ADDRESS:	
		STREET 1:		23 AVENUE MONTEREY
		CITY:			LUXEMBOURG
		STATE:			N4
		ZIP:			L 2086
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D/A
<SEQUENCE>1
<FILENAME>sc0255.htm
<DESCRIPTION>SCHEDULE 13D, AMENDMENT 39
<TEXT>
<HTML>
<HEAD>
<TITLE>
Schedule 13D
</TITLE>
</HEAD>
<BODY>


<CENTER>

<B><FONT FACE="Times New Roman, Times, Serif" SIZE=2>UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION<BR>
Washington, D.C. 20549</FONT></B><BR><BR>


<B><FONT FACE="Times New Roman, Times, Serif" SIZE=4>SCHEDULE 13D</FONT><BR>
<FONT FACE="Times New Roman, Times, Serif" SIZE=2>Under the Securities Exchange Act of 1934<BR>
(Amendment No. 39)*</FONT></B><BR><BR>

<FONT FACE="Times New Roman, Times, Serif" SIZE=2>TUBOS DE ACERO DE MEXICO, S.A.</FONT><BR>
<HR SIZE=1 NOSHADE>
<FONT FACE="Times New Roman, Times, Serif" SIZE=1>(Name of Issuer)</FONT><BR><BR>

<FONT FACE="Times New Roman, Times, Serif" SIZE=2>Common Stock</FONT><BR>
<HR SIZE=1 NOSHADE>
<FONT FACE="Times New Roman, Times, Serif" SIZE=1>(Title of Class of Securities)</FONT><BR><BR>

<FONT FACE="Times New Roman, Times, Serif" SIZE=2>898592506</FONT><BR>
<HR SIZE=1 NOSHADE>
<FONT FACE="Times New Roman, Times, Serif" SIZE=1>(CUSIP Number)</FONT><BR><BR>

<FONT FACE="Times New Roman, Times, Serif" SIZE=2>Mr. Fernando R. Mantilla<BR>
Av. Leandro N. Alem 1067, 28th Floor, 1001 &#150; Buenos Aires, Argentina (54-11) 4018-2245</FONT><BR>
<HR SIZE=1 NOSHADE>
<FONT FACE="Times New Roman, Times, Serif" SIZE=1>(Name, Address and Telephone Number of Person Authorized to<BR>
Receive Notices and Communications)</FONT><BR><BR>

<FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 11, 2003</FONT><BR>
<HR SIZE=1 NOSHADE>
<FONT FACE="Times New Roman, Times, Serif" SIZE=1>(Date of Event which Requires Filing of this Statement)</FONT>
</CENTER>
<BR>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>
If the filing person has previously filed a statement on Schedule&nbsp;13G to
report the acquisition that is the subject of this Schedule&nbsp;13D, and is
filing this schedule because of &sect;&sect;240.13d-1(e), 240.13d-1(f) or
240.13d-1(g), check the following box. [_]</FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>
<B>Note</B>:&nbsp;&nbsp; Schedules filed in paper format shall include a signed
original and five copies of the schedule, including all exhibits. See
&sect;240.13d-7 for other parties to whom copies are to be sent.</FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>
*The remainder of this cover page shall be filled out for a reporting
person&#146;s initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter disclosures provided in a prior cover page.</FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>
The information required on the remainder of this cover page shall not be
deemed to be &#147;filed&#148; for the purpose of Section&nbsp;18 of the
Securities Exchange Act of 1934 (&#147;Act&#148;) or otherwise subject to the
liabilities of that section of the Act but shall be subject to all other
provisions of the Act (however, see the Notes).</FONT></P>

<!-- MARKER PAGE="sheet: 1; page: 1" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SIDERCA Sociedad An&oacute;nima Industrial y Comercial
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings Is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;ARGENTINA</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 2; page: 2" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SIDERCA INTERNATIONAL ApS
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;DENMARK</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 3; page: 3" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ROCCA &amp; PARTNERS Sociedad An&oacute;nima
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;BRITISH VIRGIN ISLANDS</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 4; page: 4" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SAN FAUSTIN N.V.
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;NETHERLANDS ANTILLES</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 5; page: 5" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SIDERTUBES S.A.
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;LUXEMBOURG</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 6; page: 6" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I.I.I. INDUSTRIAL INVESTMENTS INC.
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;BRITISH VIRGIN ISLANDS</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 7; page: 7" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;TENARIS S.A.
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;LUXEMBOURG</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 8; page: 8" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;INVERTUB S.A.
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;ARGENTINA</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 9; page: 9" -->

<BR>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
<TD>CUSIP No.&nbsp;898592506</TD>
</TR></TABLE>


<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>1</TD>
     <TD WIDTH=95%>Name of Reporting Persons.<BR>
                   I.R.S. Identification Nos. of above persons (entities only).<BR><BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SIDTAM LIMITED
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>2</TD>
     <TD WIDTH=95%>Check the Appropriate Box if a Member of a Group (See Instructions)<BR>
     (a)<BR>
     (b)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>3</TD>
     <TD WIDTH=95%>SEC Use Only</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>4</TD>
     <TD WIDTH=95%>Source of Funds (See Instructions) NOT APPLICABLE</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>5</TD>
     <TD WIDTH=95%>Check if Disclosure of Legal Proceedings is<BR>
Required Pursuant to Items 2(d) or 2(e)</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>6</TD>
     <TD WIDTH=95%>Citizenship or Place of Organization:&nbsp;&nbsp;BRITISH VIRGIN ISLANDS</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR>
     <TD ALIGN=CENTER WIDTH=15% ROWSPAN=4>
<FONT SIZE=-1><B>NUMBER OF<BR>
SHARES<BR>
BENEFICIALLY<BR>
OWNED BY<BR>
EACH<BR>
REPORTING<BR>
PERSON<BR>
WITH</B></FONT>
</TD>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>7</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Voting Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>8</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Voting Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>9</TD>
     <TD  WIDTH=80% VALIGN=TOP>Sole Dispositive Power:&nbsp;&nbsp;NONE</TD>
</TR>
<TR>
     <TD WIDTH=5% VALIGN=TOP ALIGN=CENTER>10</TD>
     <TD  WIDTH=80% VALIGN=TOP>Shared Dispositive Power:&nbsp;&nbsp;320,414,223 Shares of TAMSA Common Stock (1 ADR=5 shares)</TD>
</TR>
</TABLE>

<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>11</TD>
     <TD WIDTH=95%>Aggregate Amount Beneficially Owned by Each Reporting Person:&nbsp;&nbsp;320,414,223</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>12</TD>
     <TD WIDTH=95%>Check if the Aggregate Amount in Row (11) Excludes Certain
Shares (See Instructions)<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;NOT APPLICABLE
</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>13</TD>
     <TD WIDTH=95%>Percent of Class Represented by Amount in Row (11)&nbsp;&nbsp;94.44%</TD>
</TR>
</TABLE>
<TABLE CELLPADDING=5 CELLSPACING=0 BORDER=1 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5% ALIGN=CENTER>14</TD>
     <TD WIDTH=95%>Type of Reporting Person (See Instructions)&nbsp;&nbsp;&nbsp;CO</TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 10; page: 10" -->

<BR>
<P ALIGN=CENTER><B>AMENDMENT No. 39 TO
SCHEDULE 13D</B></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>This Amendment No. 39 amends the
Statement on Schedule 13D originally filed on September 24, 1992 and amended and restated
as of November 11, 2002, as amended (&#147;Schedule 13D&#148;), on behalf of Siderca
Sociedad An&oacute;nima, Industrial y Comercial (&#147;Siderca SAIC&#148;), and Siderca
International ApS (&#147;Siderca ApS&#148;), together with Rocca &amp; Partners S.A.
(&#147;Rocca &amp; Partners&#148;), San Faust&iacute;n N.V. (&#147;San
Faust&iacute;n&#148;), Sidertubes S.A. (&#147;Sidertubes&#148;), I.I.I. Industrial
Investments Inc. (&#147;III BVI&#148;), Tenaris S.A. (&#147;Tenaris&#148;), Invertub
Sociedad An&oacute;nima (&#147;Invertub&#148;) and Sidtam Limited (&#147;Sidtam&#148;)
(collectively, &#147;Reporting Persons&#148;), relating to the common shares, without par
value (the &#147;TAMSA Shares&#148;), of Tubos de Acero de M&eacute;xico, S.A., a Mexican
company (&#147;TAMSA&#148;). </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%>&nbsp;</TD>
     <TD WIDTH=10%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Item 2.</FONT></TD>
     <TD WIDTH=85%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>Identity and Background</U></FONT></TD>
</TR>
</TABLE>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>No changes. </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%>&nbsp;</TD>
     <TD WIDTH=10%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Item 3.</FONT></TD>
     <TD WIDTH=85%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>Source and Amount of Funds and
Other Consideration</U></FONT></TD>
</TR>
</TABLE>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Not applicable. </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%>&nbsp;</TD>
     <TD WIDTH=10%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Item 4.</FONT></TD>
     <TD WIDTH=85%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>Purpose of the Transaction</U></FONT></TD>
</TR>
</TABLE>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>As reported in Amendment No. 36 to
the Schedule 13D, Tenaris announced on March 31, 2003 that, subject to the approvals of
the U.S. and Mexican securities regulators and TAMSA&#146;s extraordinary shareholders
meeting, it intended to effect an exchange of its shares and ADSs for any TAMSA shares and
ADSs not held by Tenaris or its affiliates. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Reference is now made to the press
release issued by Tenaris on August 11, 2003 announcing the commencement of Tenaris&#146;s
offer (the &#147;Exchange Offer&#148;) to exchange one Tenaris ADS (representing 10
ordinary shares of Tenaris) for every 9.4520 common shares of TAMSA tendered, and one
Tenaris ADS for every 1.8904 Tamsa ADSs tendered. The Exchange Offer and withdrawal rights
will expire on September 12, 2003, unless extended. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Holders of TAMSA shares may tender
these shares into the Exchange Offer only if they deposit these shares for TAMSA ADSs with
JPMorgan Chase Bank, as depositary for TAMSA&#146;s ADR program, or the
TAMSA depositary, prior to 5:00 P.M., New York City time, on September 10, 2003. Holders
of TAMSA shares who have not tendered their TAMSA ADSs by the expiration date will be
deemed to have instructed the TAMSA depositary to tender their TAMSA ADSs in exchange for
Tenaris ADSs. However, in order to receive Tenaris ADSs in exchange for TAMSA ADSs
tendered by the TAMSA depositary on their behalf, holders of TAMSA ADSs must surrender
their TAMSA ADS certificates to the TAMSA depositary by March 12, 2004. </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%>&nbsp;</TD>
     <TD WIDTH=10%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Item 5.</FONT></TD>
     <TD WIDTH=85%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>Interest in Securities of the Issuer</U></FONT></TD>
</TR>
</TABLE>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>No changes. </FONT></P>

<!-- MARKER PAGE="sheet: 11; page: 11" -->

<BR>
<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%>&nbsp;</TD>
     <TD WIDTH=10%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Item 7.</FONT></TD>
     <TD WIDTH=85%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>Material to be Filed as Exhibits</U></FONT></TD>
</TR>
</TABLE>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>The press release, dated August 11,
2003, announcing the commencement of the Exchange Offer, previously filed under Rule 425
under the Securities Act of 1933, as amended, is incorporated by reference. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Powers of attorney for Tenaris S.A.,
I.I.I. Industrial Investments Inc. and Invertub S.A. are incorporated by reference into
this Amendment to the ones filed as exhibits to Amendment No. 34 to the Schedule 13D.
Powers of attorney for each of the other Reporting Persons are incorporated by reference
into this Amendment to the ones filed as exhibits to Amendment No. 23 to the Schedule 13D
of Siderca ApS. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>The written agreement of the
Reporting Persons related to the filing of this Schedule 13D as required by Rule
13d-k(1)(iii) is included in the signature pages hereto and is hereby filed as an exhibit
hereto. </FONT></P>

<!-- MARKER PAGE="sheet: 12; page: 12" -->

<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by ROCCA &amp; PARTNERS S.A. to sign this statement, certify that
the information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of SAN FAUSTIN N.V., SIDERCA Sociedad An&oacute;nima Industrial y
Comercial, SIDERCA INTERNATIONAL ApS, SIDERTUBES S.A., I.I.I. INDUSTRIAL INVESTMENTS Inc.,
TENARIS S.A., INVERTUB Sociedad An&oacute;nima and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 13; page: 13" -->

<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by SAN FAUSTIN N.V. to sign this statement, certify that the
information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SIDERCA Sociedad An&oacute;nima
Industrial y Comercial, SIDERCA INTERNATIONAL ApS, SIDERTUBES S.A., I.I.I. INDUSTRIAL
INVESTMENTS Inc., TENARIS S.A., INVERTUB Sociedad An&oacute;nima and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 14; page: 14" -->

<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by I.I.I. INDUSTRIAL INVESTMENTS Inc. to sign this statement,
certify that the information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERCA INTERNATIONAL ApS, SIDERTUBES S.A., TENARIS
S.A., INVERTUB Sociedad An&oacute;nima and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 15; page: 15" -->


<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by SIDERTUBES S.A. to sign this statement, certify that the
information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERCA INTERNATIONAL ApS, I.I.I. INDUSTRIAL
INVESTMENTS Inc., INVERTUB Sociedad An&oacute;nima, TENARIS S.A. and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 16; page: 16" -->


<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by TENARIS S.A. to sign this statement, certify that the
information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERCA INTERNATIONAL ApS, SIDERTUBES S.A., I.I.I.
INDUSTRIAL INVESTMENTS Inc., INVERTUB Sociedad An&oacute;nima and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 17; page: 17" -->


<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by INVERTUB S.A. to sign this statement, certify that the
information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERCA INTERNATIONAL ApS, SIDERTUBES S.A., I.I.I.
INDUSTRIAL INVESTMENTS Inc., TENARIS S.A. and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 18; page: 18" -->

<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL to sign this
statement, certify that the information set forth in this Schedule 13D is true, complete
and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA INTERNATIONAL
ApS, SIDERTUBES S.A., I.I.I. INDUSTRIAL INVESTMENTS Inc., TENARIS S.A., INVERTUB S.A. and
SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 19; page: 19" -->


<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by SIDERCA INTERNATIONAL ApS to sign this statement, certify that
the information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERTUBES S.A., I.I.I. INDUSTRIAL INVESTMENTS
Inc., TENARIS S.A., INVERTUB Sociedad An&oacute;nima and SIDTAM LIMITED. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 20; page: 20" -->

<P ALIGN=CENTER><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>SIGNATURE</U> </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;After
reasonable inquiry and to the best of my knowledge and belief, I, Fernando Mantilla,
attorney duly authorized by SIDTAM LIMITED to sign this statement, certify that the
information set forth in this Schedule 13D is true, complete and correct. </FONT></P>

<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant
to Rule 13d-1(k)(1), the undersigned joins in the filing of this Schedule 13D on his own
behalf and on behalf of ROCCA &amp; PARTNERS S.A., SAN FAUSTIN N.V., SIDERCA Sociedad
An&oacute;nima Industrial y Comercial, SIDERCA INTERNATIONAL ApS, I.I.I. INDUSTRIAL
INVESTMENTS Inc., TENARIS S.A., INVERTUB Sociedad An&oacute;nima and SIDERTUBES S.A. </FONT></P>

<P ALIGN=LEFT><FONT FACE="Times New Roman, Times, Serif" SIZE=2>August 12, 2003 </FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=65%></TD>
     <TD WIDTH=35%><FONT FACE="Times New Roman, Times, Serif" SIZE=2><U>/s/ Fernando
Mantilla&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U><BR>
Fernando Mantilla<BR>
Attorney-in-fact </FONT></TD>
</TR>
</TABLE>

<!-- MARKER PAGE="sheet: 21; page: 21" -->


<P><FONT FACE="Times New Roman, Times, Serif" SIZE=2><B>Exhibit index:</B></FONT></P>

<TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
<TR VALIGN=TOP>
     <TD WIDTH=5%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>99.1</FONT></TD>
     <TD WIDTH=95%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Press release, dated August 11, 2003,  announcing the commencement of the Exchange Offer.</FONT></TD>
</TR>

<TR VALIGN=TOP>
     <TD WIDTH=5%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>99.1</FONT></TD>
     <TD WIDTH=95%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Powers of attorney (incorporated by reference to Amendments No. 23 and 34)</FONT></TD>
</TR>

<TR VALIGN=TOP>
     <TD WIDTH=5%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>99.2</FONT></TD>
     <TD WIDTH=95%><FONT FACE="Times New Roman, Times, Serif" SIZE=2>Written agreement of the Reporting Persons (included in signature pages)</FONT></TD>
</TR>
</TABLE>

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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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