Last week several major copper concentrate producers based in London and the US were raided by Europ

Last week several major copper concentrate producers based in London and the US were raided by European Commission officers and US Justice Department representatives, probing an alleged price-fixing cartel. The targeted companies included BHP Billiton, the world's single largest producer of copper concentrates, Freeport McMoran (see below) and Rio Tinto, which is not only a copper producer in its own right but also owns 49% of Portugal's Somincor and is partnered with Freeport at its Grasberg copper/gold mine in West Papua.