UPDATE 1-Consolidated Thompson offers to buy Wabush Mines

* Consolidated Thompson offers to buy 100 pct of mines

* Aggregate purchase price of US$120 mln

* To be financed with cash, credit facilities (Adds detail, background, share price)

LOS ANGELES, Oct 9 (Reuters) - Consolidated Thompson Iron Mines Ltd (CLM.TO) said on Friday it has offered to buy 100 percent of the Wabush Mines joint venture for $120 million, from U.S. Steel Canada Inc, ArcelorMittal (ISPA.AS) and Cliffs Natural Resources Inc (CLF.N).

The Canadian arm of U.S. Steel Corp (X.N) and ArcelorMittal Dofasco Inc have accepted the Montreal-based mining company's offer for their 44.6 percent and 28.6 percent respective interests in the Wabush Mines joint venture.

The deal is subject to a right of first refusal by the third Wabush Mines stake holder, Cliffs Natural Resources Inc (CLF.N), as well as regulatory approvals.

ArcelorMittal, the world's largest steelmaker which picked up its stake through its Dofasco purchase, said in its statement it will receive US$34.28 million for its interest.

Wabush Mines owns and operates iron ore mining and pellet facilities in Newfoundland and Labrador and Quebec. Wabush's total rated annual production capacity is 6.4 million tons of iron ore pellets.

Consolidated Thompson said it would finance the transaction with existing cash and credit facilities. It is using UBS Securities Canada Inc as its financial adviser and Cassels Brock & Blackwell LLP as its legal adviser.

The Canadian government in July took Pittsburgh-based U.S. Steel Corp to court over cutbacks at its Stelco subsidiary. U.S. Steel blamed market conditions for its move to temporarily shut down most of its operations at two former Stelco plants in Hamilton and Nanticoke, Ontario.

In 2006, Dofasco was bought by Europe-based Arcelor, which merged with Mittal Steel to create a company that now accounts for nearly 10 percent of global steel production.

Shares of U.S. Steel closed 0.6 percent lower on Friday at $43.85. (Reporting by Laura Isensee; editing by Carol Bishopric)