One of the nation’s largest coal companies has announced it will be closing several mines and preparation plants in Eastern Kentucky.Alpha Natural Resources will stop mining coal at four mines in Martin and Pike counties and idle two preparation plants. The company has enough jobs at other locations to reassign 286 employees, but about 150 will lose their jobs.Alpha spokesman Ted Pile says the move is necessary.“The Kentucky coal mines unfortunately are just uncompetitive in the current market,” he said. “There’s a lot of market factors at work, there’s a lot of regulatory actions that are dampening the need for coal from Kentucky.”Most of the coal mined in Kentucky is thermal coal, which is burned in power plants for electricity. A warm winter, cheap natural gas and increased environmental regulations have all combined to decrease the demand for coal. Pile says the company has no long-term plans to resume production at the mines.