CHARLESTON, W.Va. (AP) - Alpha Natural Resources expects to lay off 1,100 workers at 11 West Virginia surface coal mines by mid-October, with the company citing dismal markets and federal regulation.

CHARLESTON, W.Va. (AP) Alpha Natural Resources expects to lay off 1,100 workers at 11 West Virginia surface coal mines by mid-October, with the company citing dismal markets and federal regulation.

An Alpha news release says the company notified employees Thursday afternoon that it expects to idle mines and related facilities.

Alpha says the mines produce about 75 percent thermal coal for power generation, and 25 percent metallurgical coal for steel production.

The company cited weak domestic and international coal markets and federal limits on carbon emissions from coal-fired power plants.

In the past three years, the Bristol, Virginia-based company says it has laid off 4,000 employees and idled 60 mines and 35 million tons of production.

Alpha is one of the country's biggest coal suppliers. It also has mines in Virginia, Kentucky, Pennsylvania and Wyoming.