Copper futures traded in London, New York and Shanghai rallied to the highest level in 14 months as the dollar's decline boosted the appeal of raw materials as alternative investments.

The metal used in construction and automobiles has more than doubled this year as the global economy recovers from its worst recession since World War II and a weaker dollar encourages investment in physical assets.

The US currency fell yesterday for a third time in four days against a basket of six major currencies.