Indonesia's thermal coal production could reach between 480 million tonnes and 500 million tonnes in 2019, remaining flat over an estimated 500 million tonnes in 2018, Reuters reported, citing a statement from the Indonesian Coal Mining Association.

Association Chairman Pandu Sjahrir attributed a possible dip in coal output to "uncertainties" in transferring coal contract mining rights to new permit structures, according to the report.

The Indonesian government is set to decide on domestic market supply requirements for coal miners in January 2019, Sjahrir said.