Silver Standard Resources Inc said it resumed silver concentrate sales on a spot basis at its Pirquitas mill in Argentina, which was shut down in September due to a gearbox failure.

The mill shutdown had prompted the Canadian miner to cut its 2011 silver production outlook to 7.3-7.6 million ounces, from 8.5 million ounces.

Silver Standard, which has a pipeline of 15 projects in Argentina, Peru, Mexico, Canada, Chile and the United States, said spot silver concentrate sales are expected to continue through the second quarter of 2012.

Talks on long-term contracts are expected to conclude in the second quarter of next year, the company said, adding that zinc concentrate sales too have continued.

The Pirquitas mine, in the Jujuy province, began commercial production in December 2009. The silver and zinc concentrates produced from the plant are shipped to smelters.

The company decided to rebuild the gearbox with new parts received from Siemens AG (SIEGn.DE: Quote). The work is scheduled to be complete in mid-November, the company said.

A spare gearbox is scheduled for delivery in January, it added.

Shares of the company closed at C$17.08 on Friday on the Toronto Stock Exchange.