Nunavut Iron Ore Acquisition Inc, backed by a U.S. private equity firm, said on Sunday it opposes anti-shareholder actions of Canadian miner Baffinland Iron Ore Mines.

ArcelorMittal , the world's largest steelmaker, has offered to purchase Baffinland.

Nunavut said in a statement that its offer remains superior to the amended ArcelorMittal offer and that Baffinland's new poison pill and larger break fee are designed to eliminate shareholders' right to choose.

Nunavut, a wholly owned subsidiary of Iron Ore Holdings LP, was incorporated in Canada in August specifically for the purpose of bidding for Baffinland.

Its parent company Iron Ore Holdings LP was incorporated in the United States for the same purpose. Both are backed by private equity firm the Energy and Minerals Group.

Baffinland is a Toronto-based junior mining explorer that is sitting on enough iron ore to supply all of Europe from its Mary River project on Baffin Island in the infrastructure-poor Canadian Arctic territory of Nunavut.

(Reporting by Jennifer Saba, editing by Matthew Lewis)