China's production of 10 major non-ferrous metals expanded 4 percent year-on-year to 23.41 million tonnes in the first five months of the year, according to an industry group.

The pace of growth slowed from a rise of 5.2 percent registered in the January-April period, according to data from the China Non-ferrous Metals Industry Association.

The 10 major non-ferrous metals are copper, aluminum, lead, zinc, nickel, tin, antimony, mercury, magnesium and titanium.

Production of electrolytic aluminum, which accounts for nearly two-thirds of the total output, climbed 2.7 percent from one year earlier to 14.45 million tonnes for January-May.

The output of copper and lead rose 4.4 percent and 15.8 percent to 3.7 million tonnes and 2.38 million tonnes respectively during the period.

In May alone, the combined output of the 10 metals reached 4.74 million tonnes, unchanged from April and up 4.2 percent from one year earlier.