Exhibit 99

Tenaris Announces Sidor Debt Restructuring

    LUXEMBOURG--June 23, 2003--Tenaris S.A. (NYSE:TS) (Buenos
Aires:TS) (BMV:TS) (MTA Italy:TEN), announced today that its
associated companies, Consorcio Siderurgia Amazonia Ltd. (Amazonia)
and Siderurgica del Orinoco C.A. (Sidor), have reached an agreement
with their financial creditors and the Venezuelan government relating
to the restructuring of Sidor's and Amazonia's financial debt. Under
the terms of the agreements, Sidor's and Amazonia's aggregate
financial debt has been reduced from US$1,883 million to US$791
million, certain shareholders of Amazonia have contributed US$133.5
million in cash to a newly created company for the acquisition and
capitalization of Sidor's and Amazonia's financial debt, the
government of Venezuela has increased its participation in Sidor from
30% to 40.3% and all the guarantees provided by the shareholders of
Amazonia with respect to loans made to Sidor have been released and
replaced with a security on the fixed assets of Sidor which, together
with the pledges on the shares of Amazonia and the shares that
Amazonia holds in Sidor, have been placed in trust for the benefit of
Sidor's financial creditors and the Venezuelan government. In
addition, a portion of Sidor's excess cash (determined in accordance
with an agreed-upon formula) will be applied to repay Sidor's
financial debt and the remainder will be distributed to the Venezuelan
government and the newly created company referred to above.
    Tenaris's subsidiary, Tubos de Acero de Mexico S.A. (AMEX: TAM)
(BMV:TAMSA) (Tamsa), has participated in this restructuring agreement
by making an aggregate cash contribution (mainly in the form of new
subordinated convertible debt) of US$32.9 million to the newly created
company and by capitalizing in Amazonia convertible debt previously
held by Tamsa in the amount of US$18.0 million plus accrued interest.
Tamsa's indirect participation in Amazonia has increased from 14.1% to
14.5% and may further increase up to 21.2% if and when all of its new
subordinated convertible debt is converted into equity.
    Sidor's remaining financial debt is now made up of three tranches,
one of US$350.5 million to be repaid over 8 years with one year of
grace, one of US$26.3 million to be repaid over 12 years with one year
of grace and the remaining tranche of US$368.6 million, to be repaid
over 15 years with one year of grace. In addition, Sidor's commercial
debt with certain Venezuelan government-owned suppliers has been fixed
in the amount of US$45.4 million, to be repaid over the next five
years.
    As a result of this restructuring, Tenaris, through its
subsidiary, Tamsa, has retained a participation in a business with
competitive costs and an improved financial structure that will
continue to supply the steel bars used as raw material for Tenaris's
seamless pipe operations in Venezuela.
    Tenaris is a leading global manufacturer of seamless steel pipe
products and provider of pipe handling, stocking and distribution
services to the oil and gas, energy and mechanical industries and a
leading regional supplier of welded steel pipes for gas pipelines in
South America. Organized in Luxembourg, it has pipe manufacturing
facilities in Argentina, Brazil, Canada, Italy, Japan, Mexico and
Venezuela and a network of customer service centers present in over 20
countries worldwide.

    CONTACT: Tenaris
             Gerardo Varela, 888/300-5432
             www.tenaris.com