More than 340 employees will be laid off as multiple coal operations are idled in West Virginia.

Tuesday, Blackhawk Mining LLC announced the layoffs in Mingo and Logan Counties.

The company sent WARN notices to 342 employees, saying they will be out of work in early December.

The affected operations are:

1. Washington Underground Mine, Logan County, WV

2. Muddy Bridge Underground Mine, Logan County, WV

3. Buffalo Underground Mine, Logan County, WV

4. Fanco Preparation Plant and Loadout, Logan County, WV

5. Mingo 1 Preparation Plant and Mingo 2 (Scaggs) Loadout, Mingo County, WV

Blackhawk is also idling operations at the No. 8 Underground Mine, a contract mine in Mingo County.

The company cited "recent weakness in global coal markets, and the corresponding drop in prices to three-year lows" as the reason for the closures.