CSN Announces Share Buyback

SAO PAULO, Brazil, March 20 /PRNewswire-FirstCall/ -- CSN (Bovespa: CSNA3, NYSE: SID), Company that combines steel, mining, infrastructure and cement businesses, announces that the Board of Directors authorized, on this date, the acquisition of up to 10,800,000 Company shares to be held in treasury for subsequent sale or cancellation.

The acquisition shall obey the following limits and conditions, pursuant to CVM Instruction 10/80:

I - The Company's objective: to maximize the creation of shareholder value
through efficient capital structure management.

II - Number of shares to be acquired: up to 10,800,000.

III - Maximum term for the completion of the authorized operations: to
April 28, 2008.

IV - Number of shares outstanding: 455,343,843

V - Acquisition location: Sao Paulo Stock Exchange - BOVESPA

VI - Maximum share price: the price may not exceed the stock market price.

VII - Brokers: Itau Corretora de Valores S.A., Pactual CTVM S.A. and
Credit Suisse First Boston CTVM S.A.

Rio de Janeiro, March 20, 2008.

Companhia Siderurgica Nacional
Otavio de Garcia Lazcano
Investor Relations Officer

First Call Analyst:
FCMN Contact: joao.marin@mz-ir.com

Source: Companhia Siderurgica Nacional

CONTACT: Investors Relations of Companhia Siderurgica Nacional,
+55-11-3049-7591, invrel@csn.com.br

Web site: http://www.csn.com.br/ir

2008-03-20 18:57:33 0317683 PRNEWSWIRE