The Australian operations of coal giant Peabody Energy will continue to trade as normal despite the group filing for Chapter 11 bankruptcy protection in the United States.

The long-expected move comes in the wake of a sharp fall in coal prices that left the company unable to service its debt load of about $US6.3 billion ($8.2 billion), much of which was created during a debt-fuelled expansion into Australia.

The Helensburgh Colliery in the Illawarra region of NSW is a Peabody subsidiary. Credit:Michele Mossop

"Through this process, the company intends to reduce its overall debt level, lower fixed charges, improve operating cash flow and position the company for long-term success, while continuing to operate under the protection of the court process," the miner said in a statement on Wednesday.

"All of the company's mines and offices are continuing to operate in the ordinary course of business and are expected to continue doing so for the duration of the process."