Beijing-based Aluminum Corp. of China made a friendly $790 million offer for the Toromocho deposit, owned by Canada's Peru Copper Corp. Additionally, Anglo American of London and a consortium led by Zijin Mining Group of China's Fujian Province concluded company-ownership deals.

Peru several years ago started trying to unload mining properties it had previously nationalized, but it had only mixed results. MarketWatch says that strong demand in recent years has boosted copper prices, and investors have responded by buying many of the remaining properties, whether owned by the government or in private hands.