Workers at Chile's Escondida copper mine, the world's biggest, voted in favor of strike action Thursday after rejecting as insufficient a salary hike proposed by Anglo-Australian owners BHP.
The N1 union said 84 percent of its members had voted in favor of the strike, adding that 2,330 of its 2,500 members had voted, "a historic number for our union."
"We hope that this overwhelming desire to reject the company's offer... will convince the company of the need to show a willingness to build a accord that recognizes our rights," N1 said in a statement.
The union is calling for a five percent salary increase and a conflict termination bonus of four percent of dividends received by shareholders last year, or about $34,000 per worker.
The company increased its initial offer of 13.5 million Chilean pesos to 15 million ($23,000) per worker as a bonus for ending the negotiation.
BHP, a multinational mining, metals and petroleum company that posted revenues of $38 billion last year, has the right to request mediation, which could last 10 days.
If that fails, workers would go on strike.
Last year Escondida miners went on strike for 44 days, provoking a 39 percent drop in production over the first half of the year.
Some five percent of the world's copper is produced at the mine.
The government had pleaded with miners on Wednesday to be "realistic."
"Strike action is a legitimate tool, but without a doubt we hope the problems can be resolved without resorting to a strike," Finance Minister Felipe Larrain said.
The Escondida mine is located in the world's driest desert, the Atacama in northern Chile, at more than 3,000 meters (10,000 feet) in altitude.
It's the same area where eight years ago 33 men were trapped 700 meters underground for 69 days following a cave-in at the Copiapo mine.
Earlier this week, at yet another mine in Chuquicamata, workers briefly went on strike to demand the reinstatement of sacked colleagues.
The Escondida mine in Chile is the world's biggest copper producer