Spokane Valley-based mining company Revett Minerals Inc. says suspended underground mining at its Troy Mine in Montana since December led to its second-quarter net loss of $4.1 million, compared with a loss of $2.2 million for the year-earlier quarter.

The company says operations at the copper-silver mine were suspended because of unstable conditions and a rockfall along the main hauling route. Revett says in a press release that it hopes to return to production in the fourth quarter following efforts to regain access along its lower quartzite route, pending further inspections.

"We remain cautiously optimistic that the remainder of this access route will meet our standards of safety, but we cannot be categorically sure until all inspections are complete," says John Shanahan, Revett president and CEO, in the press release.

Currently, the mine employs about 75 people, down from more than 200 working there before the December mining activity halted. The company laid off nearly 100 miners there in late May, says company spokeswoman Monique Hayes.

Meanwhile, Revett reported expenses of $3.9 million related to ongoing redevelopment at the Troy Mine, "which reflects wages and costs for monitoring, preventative maintenance, and mine development associated with establishing alternative access."

Revett reported its cash and short-term investments at $15 million as of June 30, compared with $28.3 million as of Dec. 31.

The company also plans to develop the Rock Creek mining project, near Noxon, Mont. The U.S. Forest Service, as the lead agency for certain regulatory approvals, is working to complete a supplemental environmental impact statement for the project, Revett says. A draft for public comment is expected for release during the second quarter of 2014.