(Adds Escondida comment)
By Fabian Cambero
SANTIAGO, March 10 (Reuters) - Chile's Escondida copper mine, the largest in the world, has invited its union to resume talks as a first step towards ending a month-long strike, it said Friday.
The strike, which began Feb.9 and has lasted for 30 days, is the longest in Escondida's history. With stoppages also in place at other important copper mines worldwide, global copper prices CMCU3 have risen on tighter supply expectations.
"The company is insistent in its call to the union to restart talks, in order to arrive at a deal that will allow the strike to end as soon as possible," Escondida said in a statement late Friday.
Escondida, controlled by BHP Billiton BLT.L BHP.AX , has spoken to the union and is preparing a new contract offer that seeks to address some of their concerns, a source with knowledge of the situation told Reuters, without giving details on the fresh offer.
The union did not give an immediate response to Escondida's statement. Union spokesman Carlos Allendes said earlier Friday that the company had not been in contact with the union.
The company has the right to use temporary replacement workers, but has previously said it would not exercise that right for the first 30 days, as it seeks to keep a lid on simmering tensions.
It said Friday it "would evaluate day by day" whether it may begin to use temporary workers. However, there were no immediate plans to do so, the source said.
After 30 days, workers can also break from the union and individually agree to accept the company offer. But the strikers remained determined to push for a good deal, Allendes said, and were unlikely to take the bait.
When Escondida does restart, the initial focus will be on maintenance and projects such as the construction of a desalination plant and concentrator expansion, Escondida said. "We are not thinking of producing from day one," said corporate affairs head Patricio Vilaplana.
Escondida produced over 1 million tonnes of copper last year, around 5 percent of the world's total, and economists are expecting an impact to Chile's economy in February as a result of the strike, which has meant that no copper is leaving the site.
Contract talks collapsed after the union and company disagreed on a number of points, including the treatment of new workers, changes to shift patterns, and the level of a one-off bonus. Tinto RIO.AX RIO.L and Japanese companies including Mitsubishi Corp 8058.T hold minority interests in the mine.