BLM spokesperson Mary Apple told the Associated Press Wednesday that no new date has been set for the lease sale.

In November, the agency rejected a $US5.3 million offer for the 35.5 million ton reserve block near Roundup, calling the figure insufficient.

The leases are in the part of the 300-worker Signal Peak longwall operation, the state’s only underground coal mine.

Mining has been idle at Signal Peak since December 1, when crews discovered high carbon monoxide levels.

Shortly after the mining freeze, federal officials told ILN that it and the company were working together on the issue.

“A nitrogen generator has been injecting nitrogen into the area where the CO was discovered,” US Mine Safety and Health Administration spokesperson Amy Louviere said, adding that a second drill hole was being cased at that time for the purpose of dropping a camera to look for evidence of heating and possibly also for nitrogen injection.

Signal Peak spokesperson Mike Dawson told the AP just after the accident and again this week that work above ground at the mine continues, and no layoffs of the mine’s workers are anticipated.

He also said there is no timetable for the resumption of mining.

Signal Peak and its operating subsidiary, Bull Mountain, are owned by Boich and First Energy as well as the Gunvor Group.