LIMA: International mining concern Antamina will spend $1.3 billion to expand its production capacity, after getting a green light for the project from government authorities, local media have reported.

The company, which mines zinc and copper, hopes the capital investment will allow it to increase its productivity in Acash province, in northern Peru, by some 40 per cent, according to published reports citing company CEO Ian Kilgour.

Anatamina is a joint venture with the Swiss mining group Xstrata, Canada's Teck, Anglo-Australian BHP Billiton, and Japan's Mitsubishi Corporation.

The capital investment will allow Antamina to continue mining at the site for an additional six years, through 2029, officials said.

The announcement in the South American country of Peru comes as another South American mining power, Chile, saw striking workers at two giant copper mines producing more than four percent of the world's copper returned to work Wednesday after a two-day strike.