The talks at Collahuasi – a partnership between Glencore and Anglo American with Japanese firms – were widely seen as the most sensitive of 2020 in top copper producer Chile, both because of the size of the union involved and the mine’s importance to the country’s total output.

“There is a good atmosphere… the issue has been settled,” the source, who requested anonymity because the talks are confidential, told Reuters.

He added that the deal would “surely” be announced ahead of the legal deadline for the negotiations of Oct. 30 and that the new contract would take effect November 1.

Copper prices have been supported recently by concern about potential strikes in Chile.

A union of workers at Lundin Mining’s much smaller Candelaria copper mine in Chile walked off the job on Thursday after talks broke down earlier this week. BHP’s Escondida copper mine, the world’s largest, is also looking to cement a deal with a union of supervisors.

Collahuasi is one of Chile’s largest mines. It produced 565,400 tonnes of copper in 2019.