Striking workers at the Chile Spence copper mine have restarted wage negotiations with BHP Billiton.

On 13 October workers at the mine began a strike after union members vetoed BHP’s offer following a government-assisted mediation period.

The new negotiations are seen as an attempt to stop the strike, which has triggered supply concerns and lowered output.

Union leader Andres Ramirez said that BHP has yet to propose a new contract offer to the workers in the negotiations, which are being conducted under a government-appointed mediator.

“The government is very interested in both sides reaching a good agreement,” Ramirez said.

“We continue in conversations with the company today but there is nothing concrete yet.”

BHP said earlier that the strike was affecting production at the mine but did not disclose details.

The Spence mine generated nearly 165,000t of copper in 2008.

Spence’s prolonged strike, coupled with the commencement of bargaining at state-owned Codelco’s Andina division and a series of other wage contracts that are soon to terminate, have aggravated supply troubles in the global metals market.

The problems have been further exacerbated by BHP’s announcement of force majeure at its Olympic Dam mine in Australia.

A rise in copper and other metals prices have increased labour unrest in Peru and Chile mining powerhouses, as workers demand a larger portion of industry profits.