Copper prices extended their recent rise after the world’s largest producer of the industrial metal reported a drop in output.

The Chilean mining company Codelco, the world’s top copper producer, said Friday that copper production had fallen to a five-year low. The announcement followed news that a strike disrupted operations at a mine run by Anglo American in Chile. Both reports have helped push copper prices up this week, said George Gero, vice president of global futures RBC Capital Markets in New York.