Strike at Chile copper mine could expand - union

SANTIAGO, Chile, Oct 30 - Striking workers at Chile's Spence copper mine said on Friday pressure was growing on owner BHP Billiton to resolve the 18-day labor dispute as contractors mull joining the work stoppage.

Production at Spence has been reduced to a minimum due to the strike, company officials have said, adding to supply concerns in global metals markets.

The mine produced 165,000 tonnes of copper cathodes last year.

"We're firm in our stance, so we're just waiting for the company to show a willingness to negotiate," said Andres Ramirez, president of the 560-member union at the mine.

BHP officials have declined to comment on production levels or the status of negotiations throughout the conflict.

Ramirez said more than 1,000 indirect employees of the mine, working for contractors, have also threatened to strike if the company does not pay them in full even though the miners' strike has reduced the need for their services.

"I believe that between now and Monday there should be a pronouncement by the company on the situation of the contractors," he said.

According to BHP, the mine employs 954 people directly and just over 1,000 contractors.

The contract talks at Spence are seen as an indicator of negotiations set to begin at other mines in Chile this year and next, equivalent to one quarter of Chile's total annual copper output.