Laurel Creek, made up of three underground mines and a preparation plant, are slated for immediate closure due to high costs, difficult mining conditions and an unfavourable market, officials said.

“The decision to idle the Laurel Creek complex is a necessary step in order to optimise the financial performance of our affiliates in Central Appalachia and will further our position as a low-cost producer in the region," Foundation Coal chairman James Roberts said.

“Our highly skilled workforce is our most valuable resource, and the workers at Laurel Creek will be considered for employment opportunities at other affiliates within our organisation."

About 200 of Foundation’s 3000-plus staff work at the complex.

Laurel Creek’s operations produced about 1 million tons of output last year. Its affiliates anticipate writing down up to $US36.5 million due to the idling.

Foundation’s operations – located in Pennsylvania, West Virginia and Wyoming – produce more than 70Mt of coal per year.

Laurel Creek’s closure is the latest in a string of producer announcements citing market conditions for temporary or permanent idling of mines.

Last week, Peabody Energy spin-off Patriot Coal said it would let 400 workers go as it shuts the doors on its Remington complex and Black Oak mine and reduces activity at its Rocklick preparation facility in Central Appalachia.