VANCOUVER, May 12 -- In a first quarter results announcement Vancouver-based Silver Standard Resources cut its estimate of 2010 tin-in-concentrate production at its Pirquitas mine in Argentina to under 400 tonnes, compared to 900 tonnes previously forecast and a planned annual capacity of 2,500 tpy. Commercial silver production at the mine began late last year and is on target to reach 7 million ounces this year, but start up of the by-product tin circuit has been temporarily deferred.

In a statement the company said that "the tin circuit is commissioned and will be operated when suitable material is available. Due to the lower tin grades in the initial levels of the mine, tin production is now estimated at 800,000 pounds (approx 360 tonnes) for 2010 compared to the previous estimate of two million pounds." The company is ramping up open pit mine production and also reports significant zinc values in the ore. It now plans to start producing zinc concentrates in the current quarter.