(Adds union chief's president, production data)
SANTIAGO, Jan 8 (Reuters) - The union at global miner BHP Billiton's BHP.AX BLT.L Cerro Colorado copper mine in Chile said on Friday that it will go on strike on Monday over failed contract negotiations.
"If the company doesn't offer anything better we will go on strike on Monday," said Leoncio Parra, president of Union 1 at the mine.
The union, which represents 682 workers at Cerro Colorado, said the strike is set to begin at 07:35 am Chile time (10:35 GMT) on Monday.
"Unfortunately, the latest proposal by Cerro Colorado only considered a real (wage) increase of 1 percent, which we consider to be a mockery of the workers, whose efforts are the lifeline of the company's profits," said Parra.
Cerro Colorado produced 55,600 tonnes of copper in January to September 2015, according to Chilean state copper commission Cochilco.
BHP Billiton was not immediately available to comment.