Duke Energy and Progress Energy who plan to merge, asked on Friday for mining company proposals to supply coal, with bids specifying how much coal would come from mountaintop removal.

Political pressure is mounting to stop mountaintop mining, which is economical for miners but widely criticized for its environmental impact, analysts said.

Mr Jim Thompson editor of the industry newsletter Coal & Energy Price Report that "They've had a lot of pressure from various groups to abandon mountaintop removal coal, so what they did was to say they'd court offers.”

Mr Tom Williams Duke director of external relations said that it is the second time Duke, the acquiring party in the merger, has requested information about mountaintop coal. Progress has not made such requests. Duke's first was last year.

Mr Williams said that "It's just another component of being prudent. We would certainly buy non-MTR coal when it is not at a price premium, and that is a policy of our company."

Mr Williams added that the practice also helps Duke coal buyers understand how much it would cost to meet its fuel needs if mountaintop removal is stopped. Industrywide, mountaintop coal is about 25% of power company supply.

Duke and Progress operate in mostly regulated markets and must defend operating costs, including the cost of coal, in rate requests to government officials.

(Sourced from Thomson Reuters)