A total of 2 330 members voted on strike action, with 1 955 supporting it and 370 accepting the company`s final offer, with four blank votes and one spoiled ballot, according to the statement.

We hope that given this clear wish to reject the company`s offer, which has been expressed in a mature and democratic way by our bases, the company will see the need to find an agreement that recognizes our rights," it added.

BHP, which told Reuters earlier on Wednesday that it would not comment on the vote overnight, is expected to request government mediation to attempt a resolution, which could delay any strike action for as many as 10 days.

A looming strike at Escondida comes a little more than a year after a 44-day walk-off at the mine jolted global copper markets and docked economic growth in the South American country, which is the world`s top copper producer.

The decision to strike had been widely expected as a partial count of votes circulated by the union on Tuesday suggested an overwhelming majority of its workers favored the strike.

The Anglo-Australian miner`s final offer, presented to workers last week, included an approximately $18 000 signing bonus, and a 1.5% boost to salaries, with increases for inflation.

But the union had asked for a signing bonus around twice that offered by the company, and had requested a salary increase of 5%, leaving a wide gap between the two parties ahead of the vote.