Chile's state-run copper giant Codelco says its profit plunged by 47 percent in January to September 2015 from the same period a year before because of tumbling prices for the metal.

The world's largest copper company said Friday it earned $1.2 billion compared to $2.3 billion in the same period a year ago.

Codelco's production rose by 2.3 percent to 1.26 million metric tons despite falling ore grades.

The company has been hard hit by lower prices and demand for copper after an economic slowdown in China that has brought metal prices to a six-year low.

Codelco has been forced to scale back or delay major investments including turning the world's largest open-pit mine into an underground operation.