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Exhibit 21
UNITED STATES STEEL CORPORATION
SUBSIDIARIES AND JOINT VENTURES AS OF DECEMBER 31, 2019

Company Name
Chisholm Coal LLC
Chrome Deposit Corporation
Compagnie de Gestion de Mifergui- Nimba, LTEE
Cygnus Mines Limited
Double G Coatings, Inc.
Double G Coatings Company, L.P.
Essex Minerals Company
Fairfield Primary Operations, LLC
Feralloy Processing Company
GCW/ÁñÁ«ÊÓƵ Energy, LLC
Grant Assurance Corporation
Kanawha Coal LLC
Oilfield Technologies, Inc.
Orinoco Mining Company
Perdido Land Development Co., Inc.
PITCAL, Inc.
 
ÁñÁ«ÊÓƵ-POSCO Industries
Pitcal Pipe, LLC
Preserve Village Developers, LLC
Stelco Holding Company
 
Ontario Coal Company
 
Ontario Eveleth Company
 
Ontario Hibbing Company
 
 
Hibbing Development Company
 
 
 
Hibbing Taconite Company
 
Stelco Coal Company
 
 
Stelco Erie Corporation
 
 
Ontario Tilden Company
Swan Point Yacht & Country Club, Inc.
Timber Wolf Land, LLC
Transtar, LLC
 
Delray Connecting Railroad Company
 
Gary Railway Company
 
Tracks Traffic and Management Services, Inc.
 
Texas & Northern Railway Company
 
The Lake Terminal Railroad Company
 
 
Lorain Northern Company
 
Union Railroad Company, LLC
 
Birmingham Southern Railroad Company
 
 
Fairfield Southern Company, Inc.
 
 
Warrior & Gulf Navigation LLC
U. S. Steel China, LLC
U. S. Steel Holdco LLC
 
Big River Steel Holdings LLC
 
 
Big River Steel Metallics Funding LLC
 
 
BRS Intermediate Holdings LLC
 
 
 
Big River Steel LLC
 
 
 
 
BRS Finance Corp




UNITED STATES STEEL CORPORATION
SUBSIDIARIES AND JOINT VENTURES AS OF DECEMBER 31, 2019


 
BRS Stock Holdco LLC
 
 
Big River Steel Corp
 
U. S. Steel Blocker LLC
U. S. Steel Holdings, Inc.
 
U. S. Steel Global Holdings I B.V.
 
 
U. S. Steel Global Holdings VI B.V.
 
 
 
U. S. Steel Košice, s.r.o. (ÁñÁ«ÊÓƵK)
 
 
 
 
OBAL-SERVIS, a.s. Košice
 
 
 
 
Ferroenergy s.r.o.
 
 
 
 
U. S. Steel Košice – Labortest, s.r.o.
 
 
 
 
U. S. Steel Services s.r.o.
 
 
 
 
U. S. Steel Europe - Bohemia a.s.
 
 
 
 
U. S. Steel Europe - France S.A.
 
 
 
 
U.S. Steel Košice - SBS, s.r.o.
 
 
 
 
U. S. Steel Europe - Germany GmbH
 
 
 
 
RMS, Košice s.r.o.
 
 
U. S. Steel Global Holdings II, B.V.
 
 
U. S. Steel Canada Limited Partnership
 
U. S. Steel Holdings IV, Inc.
U. S. Steel International of Canada, LTD.
U. S. Steel LRD Canada North Inc.
U. S. Steel Mining Company, LLC
U. S. Steel Timber Company, LLC
U. S. Steel Tubular Products Holdings, LLC
 
U. S. Steel Seamless Tubular Operations, LLC
 
U. S. Steel Tubular Products, Inc.
 
 
U. S. Steel Tubular Products Middle East DMCC
 
 
U.S. Steel Oilwell Services, LLC
 
 
 
Patriot Premium Threading Services, LLC
 
 
ÁñÁ«ÊÓƵ Construction Products, LLC
 
 
 
U. S. Steel Tubular Products Canada Inc.
 
 
U.S. Steel Produtos Tubulares do Brasil Ldta.
 
 
Zinklahoma, Inc.
 
 
Star Brazil US, LLC 2
 
 
Star Brazil US, LLC 1
 
 
 
Lone Star Brazil Holdings 1 Ltda.
 
 
Lone Star Steel Holdings, Inc.
 
 
 
Lone Star Steel Holdings II, Inc.
 
 
 
 
Fintube (Thailand) Limited
UEC Technologies, LLC
 
189548 Canada Inc.
 
USX Engineers and Consultants
 
UEC Sail Information Technology, LTD.
United States Steel International, Inc.
 
United States Steel Export Company de Mexico, S.R.L. de C.V.
 
United States Steel International de Mexico, S.R.L. de C. V.
ÁñÁ«ÊÓƵ Galvanizing, Inc.
 
PRO-TEC Coating Company, LLC
 
 
PRO-TEC Coating Company, Inc.




UNITED STATES STEEL CORPORATION
SUBSIDIARIES AND JOINT VENTURES AS OF DECEMBER 31, 2019


ÁñÁ«ÊÓƵ International Services, LLC
ÁñÁ«ÊÓƵ Lakeside, LLC
 
Chicago Lakeside Development, LLC
ÁñÁ«ÊÓƵ Oilwell Supply Co., LTD.
ÁñÁ«ÊÓƵ Oilwell Tubular, Inc.
ÁñÁ«ÊÓƵ Portfolio Delaware, Inc.
ÁñÁ«ÊÓƵ WSP, LLC
 
Worthington Specialty Processing
 
 
ProCoil Company, LLC
 
 
Worthington Taylor, LLC
USX International Sales Company, Inc.