The project is expected to bolster thermal coal exports for Peabody, which has faced a drop in metallurgical coal production after the fire at its North Goonyella mine in Queensland in 2018.

Peabody CEO Glenn Kellow said the United Wambo project should be a long life asset for the JV.

"Within the seaborne thermal coal, the United Wambo joint venture received a key approval from the New South Wales Planning Commission in late August," he told an analysts' presentation.

"The final step is a federal permit that we expect to be granted later this [financial] year."

According to Kellow, production sharing is projected to begin by the end of 2020.

"The JV is expected to optimise mine planning and improved the strip ratios, enhanced quality and has the potential to extend the life of this mine beyond 2040," he said.

"We are also working to improve fourth quarter production volumes at Wambo open cut and Wilpinjong through the use of additional equipment from Millennium.

"Equipment was transfered to Wambo and Wilpinjong … to improve second half production volumes."