Peabody had secured average prices of US$84 per tonne of coal for Wambo up until 2023. Thermal coal prices have since soared to beyond $240/t.

As a result, the company has reported about US$238 million of unrealised mark-to-market losses.

"[This] primarily related to the coal hedges contracted in the first half of 2021, which effectively locked-in the sales price on 2.1 million tonnes of expected production at the company's Wambo Underground mine with settlements of 1.4Mt in 2022 and 700,000t in 2023," it states. 

"These hedge contracts were placed to support the profitability of the mine by securing average prices of $84 per metric ton through mid-2023 as part of a strategy to extend the expected life of the mine."

Peabody CEO Jim Grech said the company was taking a disciplined approach to taking control of costs, expanding margins and reducing debt.

"Coal sales to customers were in excess of $900 million, the highest level in seven quarters," he said.

"We remain optimistic about the future given strong coal pricing and global demand fundamentals."