A robot works on a production line of an electrical equipment company in Liuzhou City, south China's Guangxi Zhuang Autonomous Region, Sept. 21, 2023. (Xinhua/Huang Xiaobang)

China's producer price index (PPI), which measures the costs for goods at the factory gate, went down 2.5 percent year on year in September, the National Bureau of Statistics (NBS) said Friday.

The decrease narrowed from a 3-percent decline in August and a 4.4-percent drop registered in July. On a monthly basis, the September PPI edged up 0.4 percent, compared with an increase of 0.2 percent registered in August, the data showed.

NBS statistician Dong Lijuan said the improvement of September's PPI came as a result of multiple factors, including recovering demand for industrial products and higher international crude oil prices.

Due to price increases in the international market for crude oil, the September PPI for the oil and gas extraction industry grew 4.1 percent month on month, Dong said.

The September PPI for the non-ferrous metals smelting and rolling industry increased by 1.2 percent month on month, while that for coal mining and beneficiation expanded by 1.1 percent, she said.

Meanwhile, the September PPI for computer manufacturing went up 0.7 percent from that in August, while that for the agricultural and sideline food processing industry rose 0.6 percent. The prices of the textile, clothing, and apparel industries increased 0.2 percent. The manufacturing prices of the lithium-ion batteries and new energy vehicles went down 1.5 percent and 0.1 percent, respectively, the NBS data showed.

The average PPI in the first nine months of 2023 went down 3.1 percent year on year.