According to New Mexico newspaper the Farmington Daily-Times, BHP New Mexico coal president Pat Risner told San Juan County commissioners on Tuesday that the operator planned to cut 100 jobs from the mine’s payroll because of Arizona Public Service’s plans to close three of five stacks at the Four Corners power plant.

APS, which operates the facility the Navajo mine feeds, said the move must be made to comply with new federal environmental regulations.

According to the paper, Risner said BHP was hoping to take 100 individuals from the staff total without furloughs, telling commissioners there were about 165 employees that had exceeded retirement age.

Those workers would be offered buyouts, he said.

At the same time, selling the Navajo mine to the tribe could save 800 plant and mine jobs paying $US75,000 to $80,000 a year, he said.

Four Corners is the Navajo operation’s sole customer and the shutdown of the units could reduce demand for the mine's coal by about 30%, according to the Daily-Times.

Unfortunately, Risner told the commissioners, the only alternative was to completely close the mine and, inevitably, the power plant.

"Our overriding concern and our overriding reason for taking this action was to preserve operations at Four Corners power plant and Navajo mine beyond 2016," Risner said.

The mine and plant’s current contract extends through 2016.

The idea to transfer ownership of the operation to the tribe came two years after stalled negotiations to extend the contract.

“The alternative was you lose the jobs and you lose the revenue in 2016," Risner said.

"That was an unacceptable outcome for BHP Billiton.”

Australia-based BHP has operated the mine for 49 years.

Risner said the company would not see any additional value from the mine's sale to the tribe.

According to the news outlet, the transaction will not affect operations at the San Juan underground mine in Farmington.

“We will continue to own San Juan mine, we will continue to operate San Juan mine as we do today," he told the local legislators.

BHP first announced in December that it would sell Navajo to the tribe.

Under the plan, BHP will continue to operate the mine, which supplies the power for one of two power facilities on the reservation, until the contract expiration in 2016.

Navajo Nation council speaker Johnny Naize told the Associated Press at the time that making the move would prevent a revenue loss for the tribe and also save their members’ jobs.

A BHP spokesman told the news service that a sale price for the surface operation had not yet been set.