The former Massey Energy chief was given a one-year prison term for his role in a deadly 2010 mine blast that was one of the worst in US history, prosecutors announced Wednesday.

Don Blankenship, convicted by a jury in December 2015 of conspiracy to willfully violate mine safety standards, will also be fined $250,000, the Justice Department said.

The sentence was imposed the day after the six-year anniversary of the Upper Big Branch mine disaster in West Virginia in which 29 men died.

It "lets companies and their executives know that you can't take chances with the lives of coal miners and get away with it," acting US attorney Carol Casto said.

"Putting the former chief executive officer of a major corporation in prison sends a message that violating mine safety laws is a serious crime and those who break those laws will be held accountable."

The government, in a sentencing document to the court, described Blankenship's indifference to safety violations as "monstrous" and said he "made a conscious, cold-blooded decision to gamble with the lives of the men and women who worked for him."

In 2011, an independent investigation found that Blankenship had failed to implement proper safety standards at the mine and concluded the accident "was the result of failures of basic safety systems."

The investigation found that an inadequate ventilation system allowed explosive gases to build up, while water sprays were not properly maintained and failed to extinguish a spark that caused the blast 1,000 feet (305 meters) beneath the surface.

Blankenship's team had argued he was portrayed unfairly by prosecutors and had a commitment to mine safety. He was expected to appeal, according to US media reports.

The government had also charged Blankenship with lying to regulators and investors, but he was acquitted by the jury on those counts.

Massey Energy was acquired by Alpha Natural Resources in 2011. In December that year, the US Justice Department announced that Alpha had agreed to pay a record $209 million to settle a criminal probe into safety violations at the Upper Big Branch mine.

The Massey mine accident was the worst US coal mine disaster since an explosion killed 38 workers in Kentucky in 1970.