Tenaris Provides Information Required Under New Luxembourg Transparency Legislation

Market Wire, February, 2008

Tenaris S.A. (NYSE: TS) (BAE: TS) (MXSE: TS) (MILAN: TEN), pursuant to recently enacted Luxembourg legislation implementing the EU Transparency Directive, reminds investors that as of the date hereof the number of issued shares of its capital is 1,180,536,830 ordinary shares, par value U.S. $1.00 per share, each entitling the holder thereof to one vote at Tenaris's general shareholders' meetings.

Under the new legislation, investors in Tenaris's securities who directly or indirectly own or otherwise control 5% or more of the shares of Tenaris's capital or the rights to vote such shares should give notice thereof to Tenaris by March 19, 2008, for further publication to the market. The number of shares and votes set forth above should be used for purposes of determining whether an investor reaches or exceeds such threshold. In addition, investors should notify Tenaris and the Luxembourg securities commission (the CSSF) on an ongoing basis whenever their direct or indirect ownership or other control rights over shares of Tenaris's capital or rights to vote such shares either reaches, exceeds or falls below any of the following thresholds: 5%, 10%, 15%, 20%, 25%, 33.33%, 50% and 66.66%.

Further information is or will be made available, as appropriate, at: www.tenaris.com/en/Investors/sharecapitalandvotes.asp .

This information does not constitute legal advice. Investors are encouraged to seek advice of counsel in connection with their obligations under the new legislation and the consequences of failing to comply with any such obligations."

Tenaris is a leading global supplier of steel tubes and related services for the world's energy industry and certain other industrial applications.

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