Reuters quoted workers at Antamina as saying that contract talks with the company had broken down and that they would prepare to strike.

Labor negotiations at Antamina a JV between BHP Billiton Limited, Teck Cominco Limited and Mitsubishi Corporation are among the first to be held at a major mine since the global economic crisis hit the sector in 2008.

The union and the company were negotiating a new contract to replace a 3 year deal that expired in late July and industry analysts had been watching the talks closely for signs of what might happen with contract deals at other big mines.

Mr Francisco Marinas union leader said that the general assembly has agreed to break off direct dialogue and to go on strike. He said that 3 other workers assemblies, which are due to take place in the coming days, still need to approve the stoppage.

Mr Gonzalo Quijandria spokesman of Antamina said that contract talks have not broken down and that he expects a response from the union on the company's latest offer.

(Sourced from Reuters)