SHIPROCK, N.M. (AP) – A Navajo Nation enterprise has named the new operator for a coal mine it owns in northwestern New Mexico.

Bitsi Fuels Co. LLC signed a contract Wednesday with the Navajo Transitional Energy Company, LLC. to run the mine for 15 years. Bitsi is a subsidiary of the North American Coal Corp.

The tribe purchased the Navajo Mine near Farmington in 2013 from BHP Billiton. The mine is the sole supplier to the Four Corners Power Plant and employs about 320 people, mostly Navajos.

BHP’s contract as mine operator expires at the end of 2016.

Navajo spokesman Erny Zah says the financial details of Bitsi’s contract are confidential.