Carlos Allendes, leader of the 2,500-strong member union, said on Tuesday it had received and accepted an invitation from the government's labour directorate to meet with BHP.

Late Tuesday, BHP (>> BHP Billiton Limited) (>> BHP Billiton plc) confirmed in a statement that it, too, would return to the table.

News of a possible resolution of the conflict weighed on copper prices on Tuesday, traders said. Expectations of an extended stoppage at the world's biggest copper mine have helped drive copper prices to over 20-month highs since talks failed last month.

"We hope that the procedure ... allows the parties to come closer and for the strike to be resolved as soon as possible," government spokeswoman Paula Narvaez told journalists in Santiago.

A return to talks has been complicated by the company's accusations that the early days of the strike were marred by vandalism and threats.

BHP said it had filed criminal complaints over the vandalism with local prosecutors. It was also disputing whether the union had provided enough workers to ensure minimum safety requirements, as legally required.

The union has maintained that it acted in good faith and said the company was employing distraction tactics.

Although the government of the world's top copper exporter is keen for a quick resolution, the two sides were far apart when talks ended in failure earlier this month.

"The decision to begin negotiations we have taken responsibly and for the good of all, including our country, but we are capable of maintaining a strong stance and are prepared to face the longest strike in recent history," the union said in a statement on Tuesday.

The workers are demanding a significantly higher salary increase and bonus than the company has said it could offer. There also is a dispute over whether new and longtime employees should be on equal footing.

Escondida, majority-controlled by BHP with minority participations by Rio Tinto (>> Rio Tinto Limited) (>> Rio Tinto plc) and Japanese companies including Mitsubishi Corp (>> Mitsubishi Corp), produced over 1 million tonnes of copper, about 5 percent of the world's total, last year.

(Reporting by Felipe Iturrieta, Fabian Cambero and Rosalba O'Brien, Editing by Bill Trott and Richard Chang)