Aug. 31, 2006 — Mittal Steel Co. NV announced the final results of its offer for Arcelor securities, following completion of the centralization of tenders in the subsequent offering period.

The following additional Arcelor securities were tendered during this subsequent offering period, which had run from July 27 through August 17 in Belgium, France, Luxembourg, Spain and the U.S.:

• 12,721,665 Arcelor shares (including Arcelor shares underlying Arcelor ADSs tendered in the U.S. offer); and
• 57,651 Arcelor convertible bonds (OCEANEs 2017).

An additional 7,547 Arcelor shares have been acquired by Mittal Steel as of August 25, 2006 pursuant to the previously-announced mandatory sell-out procedure under Luxembourg law that has been open since August 18, 2006.

Together with the 594.5 million Arcelor shares and 19.9 million Arcelor convertible bonds tendered during the initial offering period (which closed on July 13), these results indicate that, on the settlement date of the subsequent offering period, Mittal Steel will hold 607,278,965 Arcelor shares and 19,916,184 Arcelor convertible bonds representing 93.72% of Arcelor’s issued share capital and 93.80% of Arcelor’s voting rights. (These figures exclude any shares that Mittal Steel may acquire on or after the date hereof pursuant to the mandatory sell-out procedure.)

Pursuant to Luxembourg law, the remaining shareholders of Arcelor are entitled to sell their Arcelor shares to Mittal Steel at a price of €40.40 per Arcelor share until November 17, 2006 (inclusive).