NEW YORK — Revett Minerals Inc. is lowering its production outlook for the fourth quarter of 2012 due to difficult operating conditions at its Troy Mine in northwestern Montana, the company announced Monday.

Copper production will drop to an estimated 3,500 tons per day in December due to poor ground conditions at the mine and an electrical power outage, the company said. That’s down from an average of 3,788 tons per day during the third quarter of 2012.

"Rather than wait and put production numbers out in the middle of January, we felt we should let the market know that we’re struggling a bit in the fourth quarter," Revett president and chief executive officer John Shanahan told AMM.

The company has pegged year-to-date copper production through Nov. 30 at 7.55 million pounds, and now forecasts 8 million to 8.5 million pounds by the end of 2012. Revett’s third-quarter sales totaled $19.4 million.

"The last thing we want to be doing is not being transparent with the investors in the capital market or not being a good operator and pushing the limit when we shouldn’t be," Shanahan said of the company’s decision to release a revised forecast.

Although the Troy copper-silver mine is the Spokane Valley, Wash.-based company’s only operational mine, Revett is in the early stages of developing a second mine in Rock Creek, Mont., and seeks to have environmental permits issued next year.

Next year "is such a critical year for us on Rock Creek," Shanahan said. "The big picture is getting to Rock Creek. Troy just keeps us going. ... Troy is our bridge to Rock Creek."