(Recasts first sentence to reflect that meeting has started, adds BHP comments)
SANTIAGO, Feb 20 (Reuters) - The union representing striking workers at Chilean copper mine Escondida and mine owner BHP Billiton Plc BLT.L BHP.AX sat down to talk on Monday afternoon after the government called a meeting in hopes of ending the 12-day-old strike.
The stoppage at the world's biggest copper mine helped boost copper prices on expectations of tighter supply, although news of the pending meeting had cooled the rally. company had stipulated over the weekend that it would attend only if strikers did not interfere with nonunionized service employees on their shift change. said on Monday after the shift change it would go ahead with the meeting, but that access to the mine for the contractors had been "partial."
"Some 112 workers were stopped for more than an hour before the blockade was lifted ... and 21 contractors had to return to the city," BHP said in a statement.
Escondida, which produced about 5 percent of the world's copper last year, is located about 170 kilometers from the regional city of Antofagasta (LON:ANTO).
The union said there were no blockades and the buses with the contractors were allowed through, but that workers had checked that no strike-breakers were entering the mine.
The meeting is aimed at getting the two sides to commit to a schedule of fresh wage contract talks, after initial negotiations failed.
However, significant differences remain, including the company's wish to give new workers lower benefits. Other issues include shift pattern changes, a one-off bonus paid every four years, and other benefits. is majority-controlled by BHP with minority interests held by Rio Tinto RIO.AX RIO.L and Japanese companies including Mitsubishi Corp 8058.T .