(Recasts with confirmation of Salvador strike, adds union comment)
By Fabian Cambero
SANTIAGO, Sept 1 (Reuters) - Workers at Codelco's small Salvador deposit will go on strike next week after failing to reach agreement in contract talks with the Chilean state-owned company, the union told Reuters on Thursday.
The strike is set to start on Monday after workers rejected Codelco's latest offer and the company said it had opted not to request a five-day mediation process.
It could herald the start of tricky times ahead for mining companies in the world's no.1 copper producer, as a sharp fall in the price of the metal slimmed margins and forced cost cuts.
Salvador, which produced 49,000 tonnes of copper in 2015, has been battling to keep a lid on high production costs and make progress on a plan to extend the mine's life.
"As the company was not disposed to dialogue, we will make effective the strike from Monday 5 September," union spokesman Waldo Gomez told Reuters.
The union has rejected a deal offered by Codelco for a $3,730 per worker bonus, and no salary increase, although another Salvador union has accepted the deal.
Separately, Anglo American Plc's flagship Los Bronces copper mine also inched closer to a strike after most unionized workers rejected the company's collective wage deal on Thursday. However, the government-sponsored mediation process could still avert a stoppage.
Anglo American offered the nearly 1,700 workers a bonus of some $13,000 each, plus other benefits.
Los Bronces is part of the Anglo American Sur complex, which produced 437,800 tonnes of copper in 2015. That's about 8 percent of the total output of Chile. (Reporting by Fabian Cambero; Writing by Anthony Esposito and Rosalba O'Brien; Editing by Andrew Hay)