Yancoal has redeployed the majority of its 205 workforce from its Austar coal mine in NSW as the ASX-listed miner waits for regulators to say whether it can reopen following a rock blast mid-May.
Yancoal says most of Austar's staff are now working at the nearby Ashton, Abel and Moolarben underground mines in the Hunter Region, with skeleton crews of between 40 and 60 people retained to maintain the Austar operation.
About 25 Austar employees are on voluntary or forced annual leave.
The NSW Resources Regulator announced on May 18 that it had prohibited all underground production activities at Austar and commenced an investigation following "another significant coal burst" the previous day.
The mine had gained permission to undertake controlled cutting at the longwall under strict conditions following a coal burst on March 16.
But the regulator said the second blast reportedly caused significant damage to the longwall shearer, which is used to cut coal underground.
Yancoal had commenced legal proceedings to have the regulator's most recent investigation reviewed in the Industrial Relations Commission, and is awaiting a decision.
"Unfortunately, as this matter is the subject of legal proceedings, an estimated date for a return to production is currently unavailable," Yancoal said in a statement on Monday.