A former president of Massey Energy's White Buck Coal Company says he will enter a plea on conspiracy charges in January.

David Hughart is set to appear January 16 in US District court. Hughart is cooperating in an investigation of the Upper Big Branch mine disaster in April 2010. That explosion killed 29 men.

Prosecutors say Hughart worked with unnamed co-conspirators to ensure miners got advance warnings about surprise federal inspections many times between 2000 and March 2010.

Prosecutors say that gave workers time to conceal life-threatening violations that could have led to citations and shutdowns.

Hughart faces up to six years behind bars.