LUXEMBOURG -- (Marketwire) -- 05/22/09 -- Tenaris S.A. (NYSE: TS) (BAE: TS) (MXSE: TS) (MILAN: TEN) ("Tenaris") announced today that Venezuela's President Hugo Chávez has announced the decision to nationalize its majority-owned subsidiaries Tavsa, Tubos de Acero de Venezuela S.A. and Matesi, Materiales Siderúrgicos S.A. and its minority interest in Complejo Siderúrgico de Guayana, C.A. No details have been provided regarding the expropriation process.

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