Pinnacle Mining located at Pineville, West Virginia, will loose about 182 employees, whilst at Oak Grove Resources, located near Birmingham, Alabama, 171 employees will be dismissed.
"Today's decision is difficult for each affected employee, their families and the local communities where PinnOak operates. Our goal is to focus on and resolve current staffing issues, longwall development timing and inventory considerations," PinnOak CEO Benjamin Statler told Associated Press (AP).
Statler said PinnOak hoped to resolve most of the issues within six months, when they will then assess bringing some of the employees dismissed back to the mines.
Pinnacle longwall produced 3.5 million tons of coking coal in 2002, whilst the Oak Grove mine produced 2.0 million tons of coking coal last year.
AP said approximately 85 percent of production is under contract, mainly with domestic and international steel buyers.
PinnOak Resources LLC was formed this year by Questor Management Company and current CEO Benjamin Statler. PinnOak purchased Pineville and Oak Grove mines from United States Steel Corporation in June.
Questor specialises in acquiring significant positions in companies that are underperforming or have not met their owners' expectations, but offer the potential for superior returns with the application of appropriate levels of capital and management expertise.