BEIJING, July 9 (Xinhua) -- China's factory-gate prices continued to pick up in June, rising 4.1 percent year on year, its fastest pace of growth in nearly four years, official data showed Thursday.

Growth of the producer price index (PPI), which measures costs for goods at the factory gate, accelerated from the 3.9-percent rise registered in May, according to the National Bureau of Statistics (NBS).

A breakdown of the data showed that stronger price gains in sectors including coal mining and washing, electrical machinery and equipment, electronics and ferrous metals contributed to the overall increase, according to NBS statistician Dong Lijuan.

On a monthly basis, the PPI dipped 0.3 percent from May.

Falling international crude oil prices weighed on the factory-gate prices in related domestic industries. Prices in the petroleum extraction industry dropped by 16 percent month on month, while refined petroleum product prices declined 3.1 percent, with the declines widening by 14.2 and 2.8 percentage points, respectively, from May.

Dong attributed higher demand and prices in some sectors to faster industrial upgrading, driven by wider AI applications, broader use of new materials and the accelerating green transition.

Manufacturing prices of virtual reality equipment, wearable smart devices and industrial robots saw monthly increases of 8.4 percent, 3.4 percent and 0.5 percent, respectively, according to the NBS.

Seasonal factors led to divergent price trends in the broad energy sector, Dong added. On a monthly basis, manufacturing prices in the coal mining and washing industry and air-conditioning equipment sector climbed 5.6 percent and 0.4 percent, respectively, while abundant rainfall, sunshine and wind resources during the summer pushed down prices of clean energy.

In the first half of the year, China's PPI increased 1.5 percent from a year earlier.

Thursday's data also showed that China's consumer price index, a key gauge of inflation, rose 1 percent year on year in June.