In the third quarter Moolarben was one of the company's star performers once again increasing production by 6% despite adverse weather events.

"The Moolarben complex continues to deliver, with run-of-mine and saleable coal volumes from both the underground and open cut operations tracking ahead of the prior quarter and 2019 volumes," it said.

"During the quarter the underground production allowed better than expected volumes to by-pass the processing plant, boosting the saleable coal volume."

The company said there were above-average rain events and unplanned maintenance events at the open cut operations, however, the processing plant performed above expectations.

"The processing throughput and yield combined with the underground by-pass volume delivered yet another strong quarter," it said.