TORONTO, May 11 (Reuters) - Ivanhoe Mines' Oyu Tolgoi project in Mongolia will be one of the world's top three copper-gold mines when it goes into full production, the Canadian exploration company said on Tuesday.

Ivanhoe forecast the mine's average annual production at 1.2 billion pounds of copper (544,000 tonnes) and 650,000 ounces of gold in its first 10 years, with operations set to begin in 2013.