Hallador Energy, the owner of Sunrise Coal Mine has axed 175 jobs from the mine in Carlisle, Indiana, US.
Sunrise Coal Mine is a 230MM ton complex, which produces high-quality bituminous, low-chlorine coal.
Located in Indiana-Illinois boarder, the Carlisle Mine has capacity to produce 65Mt, Oaktown 1 has capacity to produce 65Mt and Oaktown 2 has a production capacity of 100Mt.
The company said in a statement: "2015 brought mild weather and a glut of low priced natural gas.
"Most of our customers were surprised by these conditions and purchased too much coal for 2015. In an effort to assist our customers balance their current needs and to secure long-term fuel supply, we agreed to modify several of our contracts."
As part of contract modification, the company will reduce production at its Carlisle Mine while production will be increased at Oaktown Complex.
The company said that Oaktown Complex will be account for 90% of the production for next few years.