The company which produces coke used in steelmaking, is expected to minimise its annual coal production to 500,000 tons from 1.1 million tons.
However, it will continue to mine about 500 thousand tons of coal.
SunCoke Energy chairman and chief executive officer Fritz Henderson said, "While we plan to continue pursuing opportunities to sell all or a portion of our Coal Mining business, the challenging coal price environment has led us to make these hard decisions.
"However, idling a significant portion of the Coal Mining business is the right step going forward and allows us to focus on our core competencies of processing and handling raw materials for industrial customers."
For SunCoke Energy, which currently operates mines in Virginia and West Virginia, and this decision will make one-time cash costs of $25m to $35m.
Meanwhile, the company is also planning to sell it business completely or partially. It now seeks to hire contractors to mine coal or acquiring coal for its 720,000-tons Virginia Jewell Coke facility.
As per the records of 2013, the company employed about 1,344 people in US and around 233 employees at its cokemaking facility in Vitoria, Brazil.
