* Revenue falls 12 pct to $825.2 mln
* Thermal coal business margin falls 21 pct
* Gas division's margin down 31 pct
Jan 31 (Reuters) - Consol Energy Inc's adjusted core earnings declined 20 percent in the fourth quarter as weak realized prices for coal and natural gas squeezed margins.
Consol Energy, which plans to transition into an exploration and production company with a coal subsidiary, said adjusted EBITDA fell to $179 million for the quarter ended Dec. 31, from $224 million a year earlier.
Average margin per ton of thermal coal sold fell 21 percent, while margin fell 31 percent in the gas business.
Natural gas business accounts for about a quarter of Consol's total revenue.
The company said earlier this month it would spend three-quarters of its $1.5 billion capital budget on natural gas production in 2014 as the U.S. coal industry comes under increased regulatory pressure.
Net income attributable to shareholders rose nearly five times to $738.2 million, or $3.20 per share, including earnings of $591 million from discontinued operations.
The company sold five coal mines in West Virginia during the quarter.
Revenue fell 12 percent to $825.2 million.
Consol shares, which have risen 22 percent in the last six months, closed at $37.90 on the New York Stock Exchange on Thursday.