* Escondida copper workers reject final wage offer
* Strike looms
* BHP says wants to keep door open to talk (Adds comment from BHP Billiton)
By Fabian Cambero
SANTIAGO, Feb 1 (Reuters) - Workers at BHP Billiton's BLT.L BHP.AX Escondida mine in Chile, the world's biggest copper mine, have voted to reject a company wage offer and go on strike, the union told Reuters in the early hours of Wednesday.
The strike is due to begin in 48 hours but the union said the company will likely request government mediation to attempt a resolution, which would delay any strike action for about another week.
BHP in a statement emailed to Reuters said it regretted the rejection of its final offer.
"We want to keep an open door to continue negotiations so that we can reach an agreement that allows us to face future challenges together," the company said.
The vote had been expected after union leaders last week called BHP's latest wage offer "absurd" and recommended its 2,500 workers reject it and prepare for an extended conflict. have been offered a $12,000 bonus.
In the last contract talks four years ago, when the copper price was higher, workers received a $49,000 bonus after a two-week strike.
The failure of the contract negotiations has already triggered a rise in the global price of copper CMCU3 on expectations of a potential stoppage at the mine.
Escondida produced 1.15 million tonnes of the metal in 2015, about 6 percent of the world's total. It is majority controlled by BHP, with Rio Tinto RIO.L RIO.AX and Japan's JECO 7768.T also owning stakes.