LUXEMBOURG -- (Marketwire) -- 02/04/13 -- Tenaris S.A. (NYSE: TS) (BAE: TS) (BVM: TS) (MILAN: TEN) (Tenaris) announced that its Brazilian subsidiary Confab Industrial S.A. (Confab) was notified of a lawsuit filed in Brazil by Companhia Siderúrgica Nacional (CSN) and various entities affiliated with CSN against Confab and various subsidiaries of Ternium S.A. The entities named in the CSN lawsuit had acquired a participation in Usinas Siderúrgicas de Minas Gerais S.A. - USIMINAS (Usiminas) in January 2012.

The CSN lawsuit alleges that, under applicable Brazilian laws and rules, the acquirers were required to launch a tag-along tender offer to all minority holders of Usiminas ordinary shares for a price per share equal to 80% of the price per share paid in such acquisition, or 28.8 Brazilian reais (BRL), and seeks an order to compel the acquirers to launch an offer at that price plus interest. If so ordered, the offer would need to be made to 182,609,851 ordinary shares of Usiminas not belonging to Usiminas' control group, and Confab would have a 17.9% share in the offer.

Tenaris believes that CSN's allegations are groundless and without merit, as confirmed by several opinions of Brazilian counsel and previous decisions by Brazil's securities regulator Comissão de Valores Mobiliários, including a February 2012 decision determining that the above mentioned acquisition did not trigger any tender offer requirement. Accordingly, Tenaris will defend itself vigorously.

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