The Federal longwall operation only resumed operation in March after overcoming difficulties with its ventilation plan.

On Wednesday, the US Mine Safety and Health Administration issued an imminent danger order to the mine because of the methane levels and the longwall is expected to resume production early this week.

Continuous miner operations were not affected by the safety scare.

Both Federal and Patriot’s Panther longwall operation are also hindered by “sporadic downtime”.

Patriot said there were difficult geological conditions at its Wells and Big Mountain complexes and “continued heightened regulatory oversight”

The company’s Black Oak mine in the Rocklick complex remains on schedule for initial production this month.

The mine is expected to produce 500,000 tons of high-quality metallurgical coal when it reaches full production in the second half of 2011.

Patriot’s total September quarter sales volumes are expected to be 7.5-7.7 million tons, a 10% cut from earlier forecasts.