Patriot Coal Corp., the St. Louis-based coal producer spun off from Peabody Energy Corp. a year ago, will idle its Jupiter mining complex in West Virginia by year-end because of high costs.

The central Appalachian mining operations produced 1.5 million tons of coal in 2007. It consists of an underground mine, and previously also included a surface mine that was shut following a 2007 court injunction blocked the use of a mining permit.

In a statement, Patriot said several factors led to the decision to halt production, including more frequent safety inspections and “difficult geologic conditions.” Those factors, together with the closure of the surface mine, led to an “unacceptably high cost structure.”

Patriot CEO Richard M. Whiting said Patriot undertook a comprehensive review of mining operations and their cost structures following the purchase of Magnum Coal Co. in July. That transaction made Patriot the third largest coal producer in the eastern U.S.  Said Whiting:

“The idling of the Jupiter complex is one step in this process as we continue to identify synergies and optimize our combined operations.”