(Adds detail on deal, background)
By Anjuli Davies and Freya Berry
LONDON, April 13 (Reuters) - Mining companies and private equity firms are circling Anglo American's AAL.L metallurgical coal assets in Australia, which could be valued at around $1.5 billion in a sale, several sources familiar with the matter said on Wednesday.
Major mining firms BHP Billiton BLT.L , Rio Tinto RIO.L and Glencore GLEN.L , as well as U.S. private equity firm Apollo APO.N , have all signed non-disclosure agreements as part of the sale process, which is now entering its second round, the sources said.
Anglo American said in February that discussions were underway about divesting its Moranbah and Grosvenor assets, as part of its plans to sell $3-4 billion of assets this year in order to cut debt. The process is being run by Bank of America Merrill Lynch (NYSE:BAC) BAC.N , the sources said.
Anglo, BHP, Glencore and BofA Merrill Lynch declined to comment. Apollo and Rio were not immediately available to comment.
The assets could be valued at around $1.5 billion, one of the sources said, cautioning that valuation was difficult in the current commodity price environment and that no deal was certain.
Metallurgical or coking coal is used in steelmaking. Some industry players have expressed caution at the future of coking coal assets given their increasing unpopularity from an environmental standpoint and their exposure to the troubled steelmaking industry.
"They're good-quality assets but it's a challenged commodity," a sector banker said.
Several mining bankers said that BHP was a likely frontrunner for the assets through its BHP Billiton Mitsubishi Alliance (BMA), which operates seven mines in Australia's Bowen Basin, close to Moranbah and Grosvenor, a $1.95 billion mine development project.
Earlier this month Anglo said it had sold its stake in Australia's Foxleigh metallurgical coal mine to a consortium led by Taurus fund management. reported on Tuesday that Apollo had teamed up with Brazilian miner Vale VALE5.SA on a joint bid for Anglo's niobium and phosphates business in Brazil.