Mittal Steel Announces New Steps in the Offer Procedure

Now that the main terms of the proposed offer have been officiallypublished, the supervisory authorities will review the draft offerdocumentation, which once approved will be made public. Thepublication of such documents will mark the opening of the acceptanceperiod, during which shareholders will be able to tender their sharesto the proposed offer.

About Mittal Steel

Mittal Steel is the world's largest and most global steel company.The company has operations in sixteen countries, covering fourcontinents. Mittal Steel encompasses all aspects of modernsteelmaking, to produce a comprehensive portfolio of both flat andlong steel products to meet a wide range of customer needs. It servesall the major steel consuming sectors, including automotive,appliance, machinery and construction. For 2004, Mittal Steel hadrevenues of US$31.2 billion and steel shipments of 57.6 million tons(pro-forma inc. ISG), employing 164,000 employees. The shares of thecompany trade on the New York Stock Exchange and Euronext Amsterdamunder the ticker symbol "MT".

No Offer

No offer to exchange or purchase any Arcelor shares will be madein the Netherlands or in any jurisdiction other than Luxembourg,France, Spain, Belgium and the United States. This communication doesnot constitute an offer to exchange or purchase any Arcelor shares.Such an offer will be made only pursuant to an official offer documentapproved by the appropriate regulators.

Important Information

In connection with its proposed acquisition of Arcelor S.A.,Mittal Steel Company will file important documents with the UnitedStates Securities and Exchange Commission (SEC), including aregistration statement on Form F-4, a prospectus for the exchangeoffer and related documents. Investors and Arcelor security holdersare urged to carefully read all such documents when they becomeavailable because they will contain important information. Investorsand Arcelor security holders may obtain copies of the documents, whenavailable, free of charge on the SEC's website at www.sec.gov, as wellas from Mittal Steel on its website at www.mittalsteel.com.

Appendix

Mittal Steel Company N.V. ("Mittal Steel") proposes to launch avoluntary takeover bid (the "Offer") on all shares and convertiblebonds (called "OCEANE" and referred to below as the "ConvertibleBonds") issued by the Luxembourg limited liability company ArcelorS.A. ("Arcelor").

The Offer will be carried out simultaneously in Luxembourg, Spain,France and Belgium. It will also be extended to the United States.

Market participants are reminded of the transparency and reportingobligations prescribed by the regulations in effect in the markets onwhich the shares of Mittal Steel or Arcelor are listed.

1. Scope of the Offer

The Offer includes:

(i) a primary mixed cash and exchange offer, a secondary cashtender offer and a secondary exchange offer for all Arcelor sharesissued prior to February 6, 2006 (including treasury shares held byArcelor or its subsidiaries) or to be issued before the end of theacceptance period of the Offer upon conversion of the existingConvertible Bonds, upon exercise of Arcelor stock subscription optionsgranted prior to February 6, 2006 or upon exchange of Usinor shares(issued upon exercise of Usinor stock subscription options grantedprior to February 6, 2006);

(ii) a mixed cash and exchange offer for all Convertible Bondsissued prior to February 6, 2006.

If, between February 6, 2006 and the settlement date of the Offer,Arcelor issues any new voting securities or any new securitiesconferring the right to subscribe for, acquire or convert into votingsecurities (other than the securities listed in subsection (i) above)(the "New Securities"), Mittal Steel will (without prejudice tosection 4.3 below):

(a) withdraw the Offer, subject to the prior consent of thesupervisory authorities (insofar as required by applicable law); or

(b) extend the Offer to the New Securities, possibly afteramending the terms of the Offer to reflect the changed economics;provided that:

(1) such amendment is (insofar as required by applicable law)subject to the prior verification by the supervisory authorities ofthe fact that it reflects the changed economics; and

(2) if the terms of the Offer are so amended, the holders ofArcelor securities who have already tendered securities in the Offer,will be entitled to revoke their tenders within three working daysafter the publication of Mittal Steel's press release announcing theamendment of the terms.

2. Consideration of the Offer

2.1. Arcelor shares

The Offer for Arcelor shares includes a primary offer and twosubsidiary offers, which each form an integral part of the Offer. Anyshareholder may freely elect to divide its shares over one, two orthree of these "baskets".

2.1.1. Primary offer. The consideration of the primary mixed cashand exchange offer for Arcelor shares consists of 4 Mittal Steel classA common shares and EUR 35,25 in cash for every 5 Arcelor shares.

2.1.2. Secondary offers. Alternatively, Arcelor shareholders maytender their shares in a secondary cash tender offer or in a secondaryexchange offer.

Tenders in the secondary offers are subject to an adjustmentmechanism designed to ensure that in the aggregate the portion oftendered Arcelor shares exchanged for Mittal Steel shares and theportion of tendered Arcelor shares exchanged for cash (excluding theeffect of the treatment of fractional shares that would otherwise beissued and the impact of any adjustment referred to in section 2.1.3below) will be 75% and 25%, respectively, with the consequence thatthe aggregate value of the cash portion of the Offer will not exceedEUR 4.875.000.000 (four thousand eight hundred seventy-five millioneuros). As a result, shareholders having tendered shares in thesecondary cash tender offer may receive between 25% and 100% in cashand the balance in Mittal Steel shares, and shareholders havingtendered in the secondary exchange offer may receive between 75% and100% in Mittal Steel shares and the balance in cash; the exactproportions will depend on the total number of Arcelor shares tenderedamong the secondary offers.

Subject to the preceding paragraph, the consideration of thesecondary cash tender offer is EUR 28,21 in cash for each Arcelorshare.

Subject to the same paragraph, the consideration of the secondaryexchange offer consists of 16 Mittal Steel class A common shares for15 Arcelor shares.

2.1.3. Possible adjustments to the level or composition of theconsideration. The consideration offered for Arcelor shares would beadjusted downwards, or, as the case may be, the cash and shareportions of such consideration would be rebalanced, according toconditions set forth in the prospectus, if Arcelor made certaindistributions (including dividends in excess of EUR 0,80 per share),or directly or indirectly acquired its own shares, in the periodbetween February 6, 2006 and the settlement date of the Offer.

Any such adjustment is (insofar as required by applicable law)subject to the prior verification by the supervisory authorities as toits consistency with the conditions set forth in the prospectus andthe correct application thereof.

If the consideration is so adjusted, the holders of Arcelor shareswho have already tendered shares in the Offer, will be entitled torevoke their tenders within three working days after the publicationof Mittal Steel's press release announcing said adjustment.

2.2. Convertible Bonds

The consideration of the mixed cash and exchange offer forConvertible Bonds consists of 4 Mittal Steel class A common shares andEUR 40 in cash for every 5 Convertible Bonds.

3. Mittal Steel shares offered in consideration

The Mittal Steel shares offered will be new class A common shares,with identical rights as existing class A common shares andentitlement to any dividends declared after their date of issuance.

Class A common shares are entitled to one vote per share whileclass B common shares (which are not offered as consideration in theOffer) are currently entitled to 10 votes per share. Upon successfulcompletion of the Offer, the controlling shareholder intends to reducethe voting rights attached to the class B common shares from 10 to twovotes per share. The controlling shareholder would, however, maintainthe absolute majority of voting rights in Mittal Steel and remain incontrol of the company.

The new Mittal Steel shares will be issued by decision of theBoard of Directors of Mittal Steel taken after approval of thetransaction and of the increase of Mittal Steel's authorized capitalby the Extraordinary General Shareholders' Meeting of Mittal Steel,which will be held before the end of the acceptance period of theOffer. The Mittal family holding companies, which together holdapproximately 97% of the voting rights of Mittal Steel, haveundertaken to vote in favor of the approval of the transaction and theincrease of authorized capital necessary to consummate the Offer.

Mittal Steel class A common shares are currently listed onEuronext Amsterdam and the New York Stock Exchange. If the Offer issuccessful, application for listing will also be made to theLuxembourg Stock Exchange, the Spanish Stock Exchanges, EuronextBrussels and Euronext Paris.

4. Conditions

The Offer is subject to the following conditions:

4.1. Minimum tender condition

The number of Arcelor shares tendered to the Offer represent morethan 50% of the total issued share capital and voting rights ofArcelor, on a fully diluted basis, on the date of public announcementof the results of the Offer.

4.2. Absence of events or actions that alter Arcelor's substance

Between February 6, 2006 and the settlement date of the Offer, noexceptional event beyond the control of Mittal Steel occurs relatingto Arcelor (other than any decision or action taken by competentcompetition authorities in relation to the currently proposedcombination of Mittal Steel and Arcelor) nor does Arcelor take anyaction that, in either case, materially alters Arcelor's substance,substantially and adversely affects the economics of the Offer orsubstantially and adversely affects the ability of Mittal Steel tocomplete the Offer. Upon the occurrence of such an event or action,Mittal Steel may withdraw the Offer, subject to the prior consent ofthe supervisory authorities (insofar as required by applicable law).

4.3. Shareholder approval of new securities

If New Securities (as defined in section 1 above) are issued, theymust be issued or specifically authorized by the shareholders' meetingof Arcelor after February 6, 2006 (in the manner required foramendment of the Articles of Association), except for (i) sharesissued upon conversion of existing Convertible Bonds or upon exerciseof the options and exchange rights referred to in section 1 (i) above,and (ii) securities issued in the ordinary course pursuant tomanagement or employee incentive schemes in effect on February 6,2006. Any failure of this condition of shareholder approval willentitle Mittal Steel to withdraw the Offer. Unless the Offer iswithdrawn, it will be extended to the New Securities, possibly afteramendment of its terms in accordance with section 1 (b) above.

The above conditions are for the exclusive benefit of MittalSteel, which reserves the right to maintain the Offer, even if one ormore of said conditions were not satisfied. Mittal Steel's decisionsin respect of the above conditions will be announced as follows:

(a) the decision to invoke or waive the condition set forth insection 4.1 above: in the press release publishing the results of theOffer;

(b) any decision to withdraw the Offer for failure of one of theconditions set forth in sections 4.2 and 4.3 above: as soon aspossible after the occurrence of the relevant event or action and inany event no later than the scheduled settlement date of the Offer.

For further information, visit our web site: www.mittalsteel.com