For the three months ended 30 June, revenues decreased by 7% to $714 from $766.3m in Q2 2013. Operating costs per ton dropped to $20.55 from $21.19.

Arch Coal president and CEO John Eaves said: "During the second quarter of 2014, increased shipments, higher pricing and strong cost control drove margin expansion in each of our operating regions compared with the first quarter.

"Our successful cost control efforts to date – underscored by strong operating performances at Leer in Appalachia and West Elk in Colorado – have allowed us to reduce our cost-per-ton expectations for those segments in 2014."

Arch executive vice president and COO Paul Lang said: "Looking ahead, we expect strong cost performances in our Appalachian and Bituminous Thermal segments to continue, and we plan to remain nimble in response to market."

Last week, the company said it will cease operations at its underground mines in Wise County, Virginia and Letcher County, Kentucky in response to challenged metallurgical coal markets. The move will eliminate 213 full-time positions.

For the full-year, the company expects thermal sales volumes to be in the range of 124 million to 130 million tons and metallurgical coal sales of between 6.3 million and 6.9 million tons.