Workers at the world’s largest copper mine in Chile are striking after pay talks with Australian resources giant BHP fell apart, casting a shadow of uncertainty Wednesday over the market for the commodity. The Escondida mine in northern Chile yearly digs up around five percent of the world’s copper, a coveted metal used in everything from electrical wiring to rechargeable batteries. A global glut in copper stockpiles should blunt the immediate impact of the strike, analysts said, although there are fears it could start to bite if production is slowed for more than a week or two. Australian-based BHP, which owns a majority stake in the vast open-air mine, said scaled-back operations would continue as non-union staff put contingency plans into action. Production ground to a halt at the Escondida mine when workers downed tools for 44 days in 2017, costing BHP $740 million and wiping 1.3 percent off Chile’s annual economic output. Encouraged by surging global prices earlier this year, union representatives have sought a bigger slice of profits for the 2,400 workers they reportedly represent at Escondida. The union said it launched a “legal strike” over unmet demands that included bigger bonuses, shorter work days, and compensation tied to total years worked at the mine.