Collahuasi, or to give it its full name Compañía Minera Dona Inés de Collahuasi SCM, is a joint venture owned by two equal mining majors, AngloAmerican and Xstrata, with 44 percent of the shares apiece. The remaining equity is in the hands of a group of Japanese interests led by Mitsui & Co Ltd, one of Japan’s largest trading companies and including Nippon Mining & Metals and Mitsui Mining & Smelting.