"Consol Energy, the largest coal producer in the eastern United States, said on Monday that it was selling five highly automated mines -- about half of its production capacity -- to focus instead on natural gas and on mines that produce coal for export."

"Domestic coal producers are facing stiff challenges. Low natural gas prices have made gas-fired electricity cheaper than electricity from coal plants, and ever-stricter air pollution regulations have led to a wave of coal plant retirements. In addition, the Environmental Protection Agency recently proposed limits on carbon emissions for new plants, which could doom conventional coal-fired power.

Nicholas J. DeIuliis, president of the company, which is based in Pittsburgh, said in a conference call with reporters that the five mines being sold to the privately held Murray Energy in the transaction, worth $3.5 billion to $4.4 billion, were 'a very profitable business, a very stable business.'

But although they historically represent the center of the 150-year-old company’s business, they have limited growth potential, he said."

Matthew L. Wald reports for the New York Times October 28, 2013. [2]