WARN notices were issued at the Wells mining complex near Wharton and the Corridor G mining complex near Danville.

The Wells complex includes the Black Stallion mine, CC10 mine and Wells preparation plant.

It employs 450 people and produced 1.4 million short tons of metallurgical coal in 2013.

The Corridor G complex, which includes the Hobet 21 mine and Beth Station preparation plant, employs 397 people and produced 2.3Mt of thermal coal in 2013.

During the 60-day period, mine management at both locations will have to evaluate operations and staffing to assess their ability to produce coal at a cost below projected sales prices.

The scope of the anticipated downsizing will be communicated at the conclusion of that process.

"These actions are an unfortunate but necessary step to align Patriot's production with expected sales," Patriot president and CEO Bennett Hatfield said.

"Both metallurgical and thermal coal markets continue to be challenging, with pricing at levels well below production costs at many Central Appalachian mines.

“Despite the savings we achieved in our reorganisation, the production costs of these mines exceed today's depressed prices, necessitating these actions.”