Exhibit 8.1

LIST OF SIGNIFICANT SUBSIDIARIES

The following is a list of Mittal Steel Company N.V.s
operating subsidiaries as of December 31, 2006, each wholly- or majority-owned directly or indirectly through intermediate holding companies:



|                                                                |  |  |  |                     |  | 
|--------------------------------------------------------------- |  |  |  | ------------------- |  | 
|Name of Subsidiary                                              |  |  |  | Country             |  | 
|Companhia Siderúrgica de Tubarão S.A.                           |  |  |  | Brazil              |  | 
|Dofasco Inc.                                                    |  |  |  | Canada              |  | 
|Mittal Steel Lázaro Cárdenas S.A. de C.V.                       |  |  |  | Mexico              |  | 
|Mittal Steel USA Inc.                                           |  |  |  | USA                 |  | 
|Aceria Compacta de Bizkaia S.A.                                 |  |  |  | Spain               |  | 
|Arcelor Atlantique et Lorraine SAS                              |  |  |  | France              |  | 
|Arcelor Bremen GmbH                                             |  |  |  | Germany             |  | 
|Arcelor Eisenhüttenstadt GmbH                                   |  |  |  | Germany             |  | 
|Arcelor España S.A.                                             |  |  |  | Spain               |  | 
|Arcelor Méditerranée SAS                                        |  |  |  | France              |  | 
|Arcelor Steel Belgium N.V.                                      |  |  |  | Belgium             |  | 
|Arcelor Piombino S.p.a.                                         |  |  |  | Italy               |  | 
|Cockerill Sambre S.A.                                           |  |  |  | Belgium             |  | 
|Industeel Belgium S.A.                                          |  |  |  | Belgium             |  | 
|Industeel France S.A.                                           |  |  |  | France              |  | 
|Mittal Steel Galati S.A.                                        |  |  |  | Romania             |  | 
|Mittal Steel Ostrava a.s.                                       |  |  |  | Czech Republic      |  | 
|Mittal Steel Poland S.A.                                        |  |  |  | Poland              |  | 
|Acindar Industria Argentina de Aceros S.A.                      |  |  |  | Argentina           |  | 
|Arcelor Bergara, S.A.                                           |  |  |  | Spain               |  | 
|Arelor Huta Warszawa Sp. z.o.o.                                 |  |  |  | Poland              |  | 
|Arcelor Madrid, S.L.                                            |  |  |  | Spain               |  | 
|Arcelor Olaberría, S.L.                                         |  |  |  | Spain               |  | 
|Arcelor Profil Luxembourg S.A.                                  |  |  |  | Luxembourg          |  | 
|Arcelor Rodange S.A.                                            |  |  |  | Luxembourg          |  | 
|Belgo Siderurgia S.A.                                           |  |  |  | Brazil              |  | 
|Mittal Canada Inc.                                              |  |  |  | Canada              |  | 
|Mittal Steel Hamburg GmbH                                       |  |  |  | Germany             |  | 
|Mittal Steel Hochfeld GmbH                                      |  |  |  | Germany             |  | 
|Mittal Steel Point Lisas Ltd.                                   |  |  |  | Trinidad and Tobago |  | 
|Mittal Steel Ruhrort GmbH                                       |  |  |  | Germany             |  | 
|JSC Mittal Steel Temirtau                                       |  |  |  | Kazakhstan          |  | 
|Mittal Steel Annaba Spa                                         |  |  |  | Algeria             |  | 
|Mittal Steel Liberia Limited                                    |  |  |  | Liberia             |  | 
|Mittal Steel South Africa Ltd.                                  |  |  |  | South Africa        |  | 
|OJSC Mittal Steel Kryviy Rih                                    |  |  |  | Ukraine             |  | 
|Société Nationale de Sidérurgie, S.A.                           |  |  |  | Morocco             |  | 
|Acesita S.A.                                                    |  |  |  | Brazil              |  | 
|Ugine & Alz Belgium N.V.                                        |  |  |  | Belgium             |  | 
|Ugine & Alz France S.A.                                         |  |  |  | France              |  | 
|Arcelor Construction France S.A.                                |  |  |  | France              |  | 
|Arcelor International America, LLC                              |  |  |  | USA                 |  | 
|Arcelor Auto Processing France SAS                              |  |  |  | France              |  | 
|Produits dUsines Métallurgiques Pum-Station Service Acier S.A. |  |  |  | France              |  | 
|Ravené Schäfer GmbH                                             |  |  |  | Germany             |  |