LONDON: Copper prices soared to 10-year highs on Monday as Chile supply concerns, sliding inventories, a weaker dollar and expected strong demand from top consumer China triggered fresh buying. Benchmark copper on the London Metal Exchange (LME) was up 2.1% at $9,754 a tonne at 1600 GMT. Prices of the industrial metal earlier hit $9,765 a tonne, the highest since August 2011.

Mining unions in Chile have threatened to protest if the government does not drop a bid to block Chileans from drawing down more of their pensions savings early. Port workers, meanwhile, have called for a general strike. Stocks of copper in LME-registered warehouses at 155,100 tonnes have fallen about 10% over the past couple of weeks. Aluminium was up 1.7% at $2,404.5 a tonne, zinc rose 2.5% to $2,924.5, lead gained 1% to $2,078, tin was up 1.3% at $27,130 and nickel added 1.7% to $16,675.