The central Appalachia-focused producer said the review work for the NI 43-101 was done in tandem with Summit Engineering’s James Canterbury, and reflected a measured and indicated mineral resource of about 32.4 million tons currently leased at the site in Greenbrier County.

Of those tons, about 25.4Mt are proven and probable mineral reserve tons in seven seams: Hughes Ferry, Castle, Sewell B, Sewell A, Sewell, Beckley and Fire Creek.

Xinergy said its base-case mine plan had an estimated production commencement date of October 1, 2011, at an average 10,000 tons per month for 2011. In 2012, that will ramp up to a run rate of 500,000t per annum.

Total capital expenditure for the Greenbrier property is expected to range between $US25 million and $40 million.

"[Xinergy president] Bernie Mason and his team in West Virginia have done a tremendous job executing our vision of creating shareholder value through organic growth, as well as accretive acquisitions, with this being the most significant to date,” company chairman and chief executive officer Jon Nix said.

“We expect this property to have a substantial, positive financial impact on our company going forward."

Xinergy's other key producing assets are Straight Creek in Bell County and Harlan County, Kentucky, and the Raven Crest complex in Boone County, West Virginia.