Newmont Mining Corp will start cutting back production at its Batu Hijau copper and gold mine in Indonesia from around June 1, the U.S. miner said in a statement on Wednesday, if talks with the government remain unresolved over export taxes.
Indonesia in January levied an escalating tax on copper concentrate exports, but both Newmont and rival copper miner Freeport-McMoRan Copper & Gold Inc - who together account for 97 percent of Indonesia's copper output - said the rule conflicts with contracts they signed with Indonesia that exempt them from new taxes and duties.
"Batu Hijau's copper concentrate storage facilities will reach capacity in late May, requiring an orderly ramp down of operations," the firm said in its statement.
"Once the mine's copper concentrate storage is filled, PTNNT (PT Newmont Nusa Tenggara) will move to cease mining and milling."
Before the new export rules, Newmont forecast copper concentrate output for 2014 at 110,000-125,000 tonnes.
Newmont usually supplies around 30 percent of its Indonesian output to the country's only copper smelter, PT Smelting at Gresik.