The Moolarben coal complex - which includes an open cut and underground mine - produced 20.5 million tonnes of run-of-mine coal and 17.8Mt of saleable coal during 2019, up 8-10% over 2018.

Yancoal holds a 95% participating interest in the Moolarben Coal JV through its wholly owned subsidiaries Moolarben Coal Mines with 85% and Yancoal Moolarben with 10%.

The remaining joint venture interest is held by a consortium of Korean companies.

"The immediate benefit from the transaction will be an increase in attributable revenue from this low cost, tier-1 asset, which Yancoal will consolidate into its financial results," Yancoal said in a statement.

"In the forward years, there is the potential for the Moolarben Coal Joint Venture to increase its production profile, subject to ongoing work with external stakeholders."

During the December quarter, increased excavator productivity allowed overburden removal at Moolarben to exceed plan.

The overburden performance allowed increased run-of-mine coal output and increased feed rates at the coal handling and processing plant.

Yancoal said the operation capitalised on the good mining performance to carry the production momentum through to the end of 2019.