It is curtailing production at its Willow Creek mine in northeast British Colombia, citing weak metallurgical coal prices in the US energy market.

In addition to Willow Creek the company had earlier idled operations at the Aberpergwm mine in South Wales as well as the Gauley Eagle underground and surface mines in West Virginia.

The Maple underground mine in West Virginia also experienced production cuts.

Walter did not provide details about the degree of curtailment, aside from saying that 250 of the mine's 350 employees would be affected.

The company said Willow Creek would continue with limited operations to support the company's nearby Brule mine, which sends its coal to Willow Creek for processing.

“Over the past 18 months, since I became CEO, one of my key priorities has been aggressive operational management,” Walter chief executive officer Walter J Scheller III said.

“While it is never easy to curtail operations at a facility, our commitment to idle operations where necessary is central to the company’s operating plan.

“This plan has been developed with the full support of our board.

“We greatly regret the impact this decision will have on many of our dedicated employees.

“I would like to commend them for their work in significantly improving our productivity and costs at the mine over the past year.

“The current price environment for met coal dictated that we curtail production at Willow Creek in order to ensure we generate a sufficient economic return in mining the high quality met coal reserves at the site.

“Given the tremendous progress that has been made in the cost structure at the mine, when we see signs of sustainable market pricing conditions we would expect to ramp up production.”

The curtailments come amid Walter’s battle with UK investment group Audley Capital for control of the Walter boardroom.

Audley says it feels Walter Energy has “failed to deliver shareholder value” since the company’s takeover of Western Coal, accusing the miner of mismanagement and proposing new members for the company’s board.

Shareholders will have a chance to vote for or against Audley's nominees at Walter’s annual general meeting on April 25.