Mittal Steel and International Steel Group announce effectiveness of registration statement for Proposed Merger.

Mittal Steel Company N.V. ("Mittal Steel") [NYSE and Euronext Amsterdam: MT] and International Steel Group Inc. ("ISG") [NYSE: ISG] today announced that the registration statement on Form F-4 filed by Mittal Steel with the Securities and Exchange Commission in connection with the proposed merger involving ISG and Mittal Steel has been declared effective as of March 11, 2005. The definitive proxy statement/prospectus contained in the registration statement, together with a form of proxy, will be first mailed to ISG stockholders on or about Monday, March 14, 2005. A form of election will be mailed under separate cover to ISG stockholders, to be used to elect cash, Mittal Steel class A common shares or a combination of both in respect of their ISG shares, as provided in the merger agreement. The form of election will also be posted on ISG’s website at www.intlsteel.com.