Workers at BHP Billiton's Spence mine in Chile go on 24-hour strike

SANTIAGO, May 13 (Reuters) - Workers at BHP Billiton (NYSE: BBL - news) 's Spence mine in northern Chile have entered a 24-hour strike, a union representative said on Friday, citing slow progress in labor talks.

The action follows another one-day protest at Spence starting on May 3, in which the union also cited slow progress in ongoing negotiations.

"Starting first thing this Friday, workers at the Spence mine returned to strike after non-existent advances regarding the solutions that were demanded to a series of problems that are affecting them," Pedro Valdivia, director of conflicts at the Chile Mining Federation, said in a statement.

"It (Other OTC: ITGL - news) must be mentioned additionally that Spence recently fired around 7 percent of its personnel, which has meant a considerable increase in labor load and, subsequently, deficient security conditions."

Sources at BHP Billiton confirmed the strike.

In April, the company laid off about 7 percent of its 1,060 workers, following a trend among copper mines in Chile who have been squeezed by low prices and light demand in key importer China.

Spence produced 175,600 tonnes of copper last year.

(Reporting by Gram Slattery and Fabian Cambero; Editing by Meredith Mazzilli)