NRG Energy executive VP and Gulf Coast regional president John Ragan was quoted by Reuters as saying that the firm recently voided the air permit for Limestone 3 which was set to expire in December.

Initially proposed in 2006, Limestone 3 obtained an air permit in 2009 after an unsuccessful challenge by the Sierra Club, an American environmental organization.

The company also sought an extension of the permit, but determined later that the project did not make financial sense going forward.

"It would not be economical and would not be something our shareholders would want us to move forward with," Ragan said.

NRG Energy’s Limestone power plant is located in Jewett and consists of two lignite coal-fired units that generate about 1,690MW of power.

The firm said its diverse power generating facilities have a capacity of over 25,000MW, capable of supply power to more than 20 million homes in the nation.