SANTIAGO (AFP) -- Workers at the world's biggest copper mine, Chile's Escondida, have approved a strike after rejecting the latest offer proposed by Anglo-Australian owners BHP.

Following the results of a vote that lasted until Saturday night, the union reported in a statement that there were 2,164 votes in favor of starting the strike against 11 for accepting the employer's offer.

Chile is the world's top producer of copper, making up 28 percent of global output. The mineral accounts for 10-15 percent of the South American country's GDP, with much of it exported to China, the world's biggest consumer.

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 is the same area where in 2010 some 33 men were trapped 700 meters underground for 69 days following a cave-in at the Copiapo mine.