(Adds statement from worker union official)
By Wilda Asmarini
JAKARTA, Oct 3 (Reuters) - Mining operations at Freeport-McMoRan Inc.'s giant Grasberg open pit site in the Indonesian province of Papua have stopped as a result of a labour dispute, company and union officials said on Monday.
Any disruption to supplies from one of the world's biggest copper and gold mines could support benchmark metal prices.
The dispute involving around 1,000 workers began on Sept. 28, but has not yet affected output of copper and gold concentrate, Freeport Indonesia spokesman Riza Pratama said.
"The company is working to address the issues and to restore open pit mining operations as soon as possible," Pratama said.
"Underground mining operations have not been impacted and milling operations continue at a reduced rate."
Abraham Tandi, deputy secretary of the Freeport workers union, said mining operations at Grasberg had been stopped for the past three days, as workers demanded better conditions including bonus payments.
"We've been complaining for about eight months," Tandi told Reuters by telephone, adding that management had been "slow" to respond to the complaints but were now discussing the issues directly with the union.
"Hopefully they'll find a solution today," Tandi said.
Freeport Indonesia, which employs around 24,000 workers, aims to produce 180,000-200,000 tonnes of copper ore per day this year.
Relations between Freeport and worker unions have been strained in recent years. Production was brought to a halt in 2015 after workers blocked access to Grasberg for five days. (Writing by Fergus Jensen; Editing by Tom Hogue)