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Exhibit 21

The following is a list of U. S. Steel’s subsidiaries at December 31, 2005.

 

     State or Country

Subsidiary

   of Incorporation
Adela Investment Company S.A.    Luxembourg
Chrome Deposit Corporation    Indiana
Clairton 1314B Partnership, L.P.    Delaware
Compagnie de Gestion de Mifergui-Nimba, LTEE.    Delaware
Cygnus Mines Limited    Canada
Delaware ÁñÁ«ÊÓƵ Corporation    Delaware
Double Eagle Steel Coating Company    Michigan
Double G Coatings, Inc.    Delaware
Double G Coatings Company, L.P.    Delaware
Essex Minerals Company (Societe des Mineraux Essex)    New Jersey
Farms Sewer Company, Inc.    New York
Farms Water Company, Inc.    New York
Feralloy Processing Co.    Indiana
Grant Assurance Corporation    Vermont
La Pointe Iron Company    Wisconsin
New Deal Development, Inc.    Delaware
New View Technologies    Delaware
Oilfield Technologies, Inc.    Delaware
Olympic Laser Processing    Michigan
Orinoco Mining Company    Delaware
Pasadena Yacht and Country Club, Inc.    Delaware
Perdido Land Development Co., Inc.    Delaware
Phil Prop, Inc.    Delaware
PITCAL, Inc.    Delaware
ÁñÁ«ÊÓƵ-POSCO Industries    California
ProCoil Company, LLC    Delaware
Smart Screen Systems, Inc.    Minnesota
Societe Des mines de Fer de Guinee Pour L’Exploitation Des Monts Nimba (Mifergui Nimba)    Guinea
Steel Health Resources, LLC    Indiana
Straightline Source, Inc.    Delaware


Straightline, Inc.    Delaware
Swan Point Yacht & Country Club, Inc.    Delaware
Transtar, Inc.    Delaware
Birmingham Southern Railroad Company    Alabama
Delray Connecting Railroad    Michigan
Elgin, Joliet and Eastern Railway Company    Delaware
Fairfield Southern Company, Inc.    Delaware
Lake Terminal Railroad Company, The    Delaware
McKeesport Connecting Railroad Company    Delaware
Tracks Traffic and Management Services, Inc.    Delaware
Union Railroad Company    Delaware
Warrior & Gulf Navigation Company    Delaware
Mobile River Terminal Company    Alabama
Sisco Stevedoring, LLC    Alabama
The Southern International Services Company, Inc.    Alabama
The Southern International Services Company II, Inc.    Alabama
Transtar Logistics, LLC    Delaware
U. S. Steel China, LLC    Delaware
U. S. Steel International of Canada, LTD.    Delaware
U. S. Steel Mining Company, LLC    Alabama
ÁñÁ«ÊÓƵ Mine Management, Inc.    Alabama
United States Steel International, Inc.    New Jersey
Compania de Representaciones Mercantiles, Cubacero, S.A.    Cuba
United States Steel Export Company de Mexico, S.R.L. de C.V.    Mexico
Acero Prime, S.R.L. de C.V.    Mexico
Acero Prime Servicios, S.R.L. de C.V.    Mexico
United States Steel International de Mexico, S.R.L. de C.V.    Mexico
U. S. Steel Receivables, LLC    Delaware
U. S. Steel Timber Company, LLC    Alabama
ÁñÁ«ÊÓƵ Coal Sales, LLC    Delaware
ÁñÁ«ÊÓƵ Galvanizing, Inc.    Delaware
PRO-TEC Coating Company    Ohio
PRO-TEC Coating Company, Inc.    Ohio
ÁñÁ«ÊÓƵ International Services, LLC    Delaware
ÁñÁ«ÊÓƵ Oilwell Supply Co., LTD.    Delaware
ÁñÁ«ÊÓƵ Oilwell Tubular, Inc.    Delaware
ÁñÁ«ÊÓƵ Portfolio Delaware, Inc.    Delaware
ÁñÁ«ÊÓƵ Tubular Processing, Inc.    Delaware
U. S. Steel Holdings, Inc.    Delaware


ÁñÁ«ÊÓƵ Global Holdings I B.V.    Netherlands
U. S. Steel Kosice (ÁñÁ«ÊÓƵK)    Slovakia
OBAL – SERVIS, a.s. Kosice    Slovakia
U. S. Steel Kosice – Austria GmbH    Austria
Elektroservis VN a VVN a.s. Kosice    Slovakia
Energoservis a.s. Kosice    Slovakia
Hutnictvi zeleza (Czech Republic)    Czech Republic
U. S. Steel Kosice Belgium    Belgium
U. S. Steel Kosice Bohemia a.s.    Czech Republic
U. S. Steel Kosice France S.A.    France
U. S. Steel Kosice SBS, s.r.o.    Slovakia
U. S. Steel Kosice Germany GmbH    Germany
U. S. Steel Hungary Kft.    Hungary
U. S. Steel Kosice – Labortest, S.R.O.    Slovakia
U. S. Steel Kosice – Switzerland AG V    Switzerland
U. S. Steel Kosice (UK) Limited    United Kingdom
SZ Stahl GmbH (Germany)    Germany
Waltzwerke Finow GmbH    Germany
Betrieber Gesellschaft Norbahn GmbH    Germany
Stawa Stahlbau GmbH    Germany
Vozmult a.s. Kosice    Slovakia
Refrako, s.r.o.    Slovakia
Trgovinsko Preduzece, ÁñÁ«ÊÓƵKS d.o.o.    Serbia
Reliningserv, s.r.o.    Slovakia
Vulkmont a.s. Kosice    Slovakia
U. S. Steel Global Holdings II B.V.    Netherlands
U. S. Steel Serbia, d.o.o.    Serbia
ÁñÁ«ÊÓƵB Industrial Business Zone d.o.o.    Serbia
ÁñÁ«ÊÓƵB Kucevo d.o.o.    Serbia
ÁñÁ«ÊÓƵB SPIN d.o.o.    Serbia
ÁñÁ«ÊÓƵB Stara Zelezara d.o.o.    Serbia
U. S. Steel Balkan, d.o.o.    Serbia
U. S. Steel Europe, B.V.    Netherlands
U. S. Steel Holdings III, Inc.    Delaware
United States Steel Credit Corporation    Delaware
UEC Technologies, LLC    Pennsylvania
Met-Chem Canada Inc.    Canada
UEC Sail Information Technology, LTD.    India
USX Engineers and Consultants, Inc.    Delaware


USX International Sales Company, Inc.    Barbados
USX Participacoes LTDA.    Brazil
Merinds Mineracao    Brazil
Mineracao Carajas, LTDA.    Brazil
Mineracao Maraba, LTDA.    Brazil
USX RTI Holdings, Inc.    Delaware
Republic Technologies International Holdings LLC    Delaware
Republic Technologies International LLC    Delaware
Worthington Specialty Processing    Missouri