The Associated Press quoted Chevron Mining spokesperson Margaret Lejuste as saying it was not a good strategy for the company to remain in the sector because new coal technologies, such as coal-to-liquids, were developing too slowly.

"Those technologies are so far into the future, 10 to 15 years in the future, they made the strategic decision to focus on other operations other than mining," she said.

Chevron is reportedly closing a deal with Walter Energy for its North River underground complex in western Alabama after announcing a tentative agreement with the producer last year.

The company has also just put its Kemmerer surface complex in western Wyoming on the market.

"It's my understanding there are a number of interested parties who are looking at the mine," Lejuste was quoted by the AP.

Finally, Chevron may sell its reclaimed surface mine land, McKinley, in northwestern New Mexico. She did not comment further on the operation, which closed in 2009.

The three mines together produced almost 10 million tons of coal in 2009.

Chevron reportedly will also sell its 50% stake in a proposed coal operation in northern Wyoming.