Former Massey Energy CEO Don Blankenship is finishing up a one-year federal prison sentence related to the deadliest U.S. mine explosion in four decades.

According to the U.S. Bureau of Prisons website, Blankenship is set to be released Wednesday from a halfway house in Phoenix, Arizona. He must serve one year of supervised release.

Blankenship was sentenced last year for a misdemeanor conviction of conspiring to violate federal mine safety standards at Massey's Upper Big Branch Mine in southern West Virginia, where 29 workers died in a 2010 explosion.

In January, a three-judge appeals panel affirmed Blankenship's 2015 conviction.

Blankenship, who's 67, served most of his sentence at Correctional Institute Taft near Bakersfield, California.

(Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)