BEIJING, June 10 (Xinhua) -- China's producer price index (PPI), which measures costs for goods at the factory gate, went up 3.9 percent year-on-year in May, an increase of 1.1 percentage points from April, the National Bureau of Statistics (NBS) said Wednesday.

Among industries with rising prices that contributed to the year-on-year PPI rise last month, the mining and processing of non-ferrous metal ores increased by 36.5 percent and the smelting and rolling of non-ferrous metals rose by 24 percent. The extraction of petroleum and natural gas, processing of petroleum, coal and other fuels, and manufacturing of chemical raw materials and chemical products also logged notable price increases, the data showed.

The manufacturing of non-metallic mineral products, the production and supply of electric power and heat, and automobile manufacturing recorded price decreases, the data showed.

On a month-on-month basis, PPI rose 0.5 percent in May, down from 1.7 percent in April, the NBS data showed.

NBS statistician Dong Lijuan, in an analysis of month-on-month changes in PPI last month, said the optimization and upgrading of the industrial structure drove up prices in some sectors, seasonal increases in demand led to price rises in certain industries, and fluctuations in international crude oil prices caused prices in some industries to either turn from increases to decreases or see their growth moderate.

From January to May, the PPI increased by an average of 1 percent year-on-year, the data showed.

Wednesday's data also showed that China's consumer price index (CPI), a main gauge of inflation, rose 1.2 percent year-on-year in May. The core CPI, which excludes food and energy prices, increased 1.1 percent year-on-year.