SQM, the Chilean lithium giant, is exploring for copper with a US partner, a bid to diversify as lithium prices stay weak and copper demand climbs.

Chile's state-private lithium venture is filing a $3bn plan to overhaul Atacama output, a key test of its bid to lead the battery-metal market.

SQM, the Chilean lithium giant, is exploring for copper with a US partner, a bid to diversify as lithium prices stay weak and copper demand climbs.