Canada's Primero Mining Corp said quarterly gold production fell about 7 percent, hurt by lower ore grades and lack of grade predictability.
For the fourth quarter, the company produced 23,100 ounces of gold equivalent, down from 24,800 ounces a year ago.
Full-year 2011 production rose by about 2 percent to 102,224 ounces of gold equivalent.
The precious metals producer's average daily throughput rose to 2,050 tonnes per day in the fourth quarter and 1,950 tonnes per day for 2011, Primero said in a statement.
Throughput is the total amount of raw materials processed by a refinery of a plant in a given period.
In 2012, Primero, which owns the San Dimas gold-silver mine in Mexico, expects to produce between 100,000 and 110,000 ounces of gold equivalent.
Primero expects 2012 cash costs in the range of $630 to $660 per gold equivalent ounce. In 2011, it had forecast cash costs to be in the range of $610 to $630 per gold equivalent ounce.
Shares of the company closed at C$3.74 on Monday on the Toronto Stock Exchange.