Feb. 23, 2007 — Mittal Steel Co. NV announced pro forma net income of $US 2.37 billion on sales of $US 23.2 billion for the fourth quarter, and pro forma net income of $US 7.97 billion on sales of $US 88.6 billion for the twelve months ended December 31, 2006.

Pro Forma Scope — The company notes that pro forma information reflects the combined business as if the acquisition of Arcelor and its subsidiaries had taken place at the beginning of the period presented.

The pro forma results for 2006 and 2005 include the results of the following acquisitions as if the acquisitions were made on January 1, 2006 and January 1, 2005 respectively:

• The acquisition of Arcelor on August 1, 2006.
• The acquisition of certain subsidiaries of Stelco on January 30, 2006.
• The acquisition of Mittal Steel Kryviy Rih on November 26, 2005.
• The acquisition of Mittal Steel USA ISG Inc. on April 15, 2005.

Furthermore, the results of Arcelor include the following significant acquisitions as if those acquisitions were made on January 1, 2006 and January 1, 2005 respectively:

• The acquisition of Sonasid on June 1, 2006.
• The acquisition of Dofasco on March 1, 2006.
• The acquisition of Acesita on October 1, 2005.

Fourth Quarter Results — Pro forma net income of $US 2.37 billion ($1.72 basic earnings per share) compares to net income of $US 2.18 billion ($1.58 basic earnings per share) for the previous quarter. Sales of $US 23.2 billion compare to sales of $US 22.1 billion for the previous quarter.

Shipments were 26.7 million tonnes, as compared with 26.9 million metric tonnes for the three months ended September 30, 2006. Pro forma operating income was $3.2 billion, as compared with $3.4 billion for the three months ended September 30, 2006.

Full Year Results — Pro forma net income of $US 7.97 billion compares to pro forma net income of $US 8.26 billion for the previous year. Pro forma basic earnings per share of $5.76 compare to pro forma basic earnings per share of $5.97 for the previous year. Pro forma sales, $US 88.6 billion, compare to pro forma sales of $US 80.2 billion for the previous year. Pro forma operating income was $11.8 billion, as compared with $11.6 billion for the twelve months ended December 31, 2005.

Total steel shipments were 110.5 million tonnes as compared with 102.9 million tonnes for the twelve months ended December 31, 2005. Shipments were 110.5 million tonnes. Pro forma EBITDA of $15.3 billion compares favorably with the previous year.

Management Comments — “I am pleased to report a strong performance in 2006 for Arcelor Mittal, with strong cash flow from operations and EBITDA in line with guidance,” said Lakshmi N. Mittal, President and CEO of Arcelor Mittal. “This strong set of pro forma numbers clearly demonstrates the benefits of the merger between Arcelor and Mittal Steel.

“On a pro forma basis, Arcelor Mittal has now reported consistent EBITDA of approximately US$15 billion for three years, illustrating how our diversified geographic and product profile is helping deliver sustainable results.

The integration of Mittal Steel with all of its recent acquisitions is progressing well, and we are on track to deliver anticipated synergies. Simultaneously, we are continuing to execute our strategy and further build on our market leading position, as seen by our recent acquisitions and expansion plans both in steel and mining.

Looking forward, the market is stable and we are anticipating performance for the first quarter 2007 to be in-line with fourth quarter 2006 levels.”

Recent Development (North America) — On February 20, 2007, the U.S. Department of Justice (DOJ) informed the company that the DOJ has selected the Sparrows Point steel mill for divestiture under the consent decree filed by the DOJ in August 2006. Selection of the Sparrows Point facility by the DOJ ends the period during which Arcelor Mittal must hold Dofasco separate from its operations.

First Quarter Outlook — The company expects first quarter 2007 EBITDA to be between $4.0-4.2 billion, and overall shipments levels to remain in line with fourth quarter 2006 levels. Flat Carbon Americas profitability is expected to continue to suffer from de-stocking, while performance for Flat Carbon Europe segment is expected to remain positive. The performance of the Long Carbon Americas and Europe is expected to increase. The company expects performance of the Stainless Steel segment to remain at high levels , while the performance of AM3S and AACIS is expected to remain stable. The company expects a normalized tax rate of approximately 25% for the year.