UPDATE: Peru's Cerro Verde Mine Union Ends Strike, Threatens New One

Unionized workers at copper mining company Sociedad Minera Cerro Verde SAA (CVERDEC1.VL), controlled by U.S.-based Freeport-McMoRan Copper & Gold Inc. (FCX), ended their strike over the weekend, a union official said.

Union General Secretary Leoncio Amudio said in a telephone interview Monday that the workers went back to work on Saturday due to a legal technicality, but that they may go out again on strike on Sept. 27.

Amudio said that clashes with police had injured several union members and that the union doesn't plan to negotiate anymore with the company.

"We don't plan to hold any more talks" with the company, he said.

More than a thousand workers walked out last Wednesday to back demands for higher pay. Their contract expired Aug. 31. Workers had previously walked out for two days earlier in September to back their demands.

The company has used other workers in the absence of the striking workers.

"Production of copper and molybdenum concentrates were not materially affected by the three-day strike," Freeport's Director of External Communications Eric Kinneberg said in an email. Kinneberg said the company will continue negotiating a new labor contract with the union.

Compania de Minas Buenaventura SA (BVN, BUENAVC1.VL) and a subsidiary of Sumitomo Corp. (SSUMY, 8053.TO) also have stakes in the company.

Cerro Verde is one of Peru's biggest copper mining companies. In the second quarter of this year, it turned out 170 million pounds of copper, compared with 166 million pounds in the same period last year.

Peru is the world's second biggest copper producer.

-By Robert Kozak, Dow Jones Newswires; 511-221-7050; [e-mail]