Aluminum giant Chinalco may buy a stake in the massive Oyu Tolgoi copper-gold project in Mongolia, according to a regulatory filing to the U.S. Securities and Exchange Commission. The document, submitted by Ivanhoe Mines, one of the owners of the deposit , says Rio Tinto, its partner in the venture, plans to sell part of its stake to Chinalco, which has a 9% stake in Rio – it's the largest shareholder in the British-Australian giant.

The paper reads, "Chinalco has indicated an interest in acquiring a minority equity stake in the company or acquiring, from the company, a direct minority ownership interest in the OT project (...) Rio Tinto's ongoing discussions with Aluminum Corporation of China (Chinalco) also continue". The end result of talks could be a two-way or three-way agreement between Rio, Chinalco and Ivanhoe – the first has a 29.6% stake at the last.