The company has also sued MSHA in federal court, alleging the agency "indirectly forces mine operators to design a ventilation plan the way MSHA wants by refusing to approve the operator's plan.''

But Wagner's memo blames Massey for its "inability to properly manage the air it had and to follow its approved ventilation plan.'' He claims Massey had "serious problems'' following its ventilation plan, resulting in MSHA citing the Upper Big Branch mine 23 times between September 2009 and April 5, 2010.

The memo says Massey submitted many changes to the plan -- many of which were denied -- because the company failed to provide basic information such as air flow readings that are required under the law. During one conversation in December 2009 about meeting regulatory requirements, the Massey engineer drafting the ventilation plan "remarkably'' didn't even have a copy of the regulations. Wagner says MSHA later provided him a "courtesy copy.''

On Jan. 7, 2010, Massey proposed to dramatically reduce the amount of air on the longwall face by using air from the existing ventilation plan to ventilate an older section of the mine, allowing it to produce more coal, the memo says. MSHA denied this request because it was not clear that the system would work as planned.

"Massey's recent professed concern with the amount of air at the longwall and on the headgate is entirely at odds with the fact that Massey proposed to reduce the volume of air in those sections,'' Wager states in the memo.

The memo concludes that if at any point Massey determined there was an inadequate amount of air flowing to any working section, the company was required by law to stop mining operations until the problem was solved.

"Prior to the explosion at UBB, Massey did not indicate a belief that this mine required extraordinary steps,'' the memo says. "Its mine ventilation plan and mine ventilation practices are not reflective of a company showing extraordinary concern about the safety of the miners working underground.''

The depiction -- in an internal memo from a top official at the Mine Safety and Health Administration -- is part of a lengthy rebuttal to Massey's claims that the government forced it to make changes that would reduce the volume of fresh air in the mine before the blast.

A copy of the memo from deputy assistant secretary Gregory Wagner to the Labor Department's top lawyer was obtained by The Associated Press.

The memo adds to the bitter public feud that has played out between Massey and MSHA in the months since the Upper Big Branch mine tragedy in Montcoal, W.Va. Government officials have said Massey has a lax attitude toward safety, while Massey Chief Executive Don Blankenship insists he does not put profits ahead of safety.

The memo accuses Massey of making the claims about ventilation as part of a public relations strategy to deflect blame for the accident from the company. Wagner's memo states that Massey proposed in January to reduce the amount of air flowing to the working sections of the mine so it could redirect air to another area where it wanted to produce more coal.

Massey was "a company that routinely submitted plans that did not meet regulatory requirements and a company that had serious problems following its plans and managing the air flowing underground,'' the memo states.

Massey's conduct is the subject of state and federal investigations, as well as a criminal investigation launched by the Justice Department.

Jeff Gillenwater, a Massey spokesman, said the company "stands behind its previous statement about the role MSHA has and continues to have in the approval and changes in mine ventilation plans.''

Blankenship is to address the National Press Club in Washington on Thursday. Since the accident, he has contended that MSHA imposed a plan that reduced the volume of fresh air to the face of the longwall section of the mine where the blast occurred -- despite vigorous objections from Massey engineers. Mines rely on ventilation to remove methane gas and coal dust.

The company has also sued MSHA in federal court, alleging the agency "indirectly forces mine operators to design a ventilation plan the way MSHA wants by refusing to approve the operator's plan.''

But Wagner's memo blames Massey for its "inability to properly manage the air it had and to follow its approved ventilation plan.'' He claims Massey had "serious problems'' following its ventilation plan, resulting in MSHA citing the Upper Big Branch mine 23 times between September 2009 and April 5, 2010.

The memo says Massey submitted many changes to the plan -- many of which were denied -- because the company failed to provide basic information such as air flow readings that are required under the law. During one conversation in December 2009 about meeting regulatory requirements, the Massey engineer drafting the ventilation plan "remarkably'' didn't even have a copy of the regulations. Wagner says MSHA later provided him a "courtesy copy.''

On Jan. 7, 2010, Massey proposed to dramatically reduce the amount of air on the longwall face by using air from the existing ventilation plan to ventilate an older section of the mine, allowing it to produce more coal, the memo says. MSHA denied this request because it was not clear that the system would work as planned.

"Massey's recent professed concern with the amount of air at the longwall and on the headgate is entirely at odds with the fact that Massey proposed to reduce the volume of air in those sections,'' Wager states in the memo.

The memo concludes that if at any point Massey determined there was an inadequate amount of air flowing to any working section, the company was required by law to stop mining operations until the problem was solved.

"Prior to the explosion at UBB, Massey did not indicate a belief that this mine required extraordinary steps,'' the memo says. "Its mine ventilation plan and mine ventilation practices are not reflective of a company showing extraordinary concern about the safety of the miners working underground.''