BEIJING (Reuters) - China's consumer prices rose at a slower-than-expected pace in August while the rate of producer inflation hit an 18-month low, reflecting an economy plagued by weak domestic demand and leaving room for further central bank policy easing.

The consumer price index (CPI) increased 2.5% from the same month a year earlier, National Bureau of Statistics (NBS) data showed on Friday, slower than 2.7% in July and the 2.8% average forecast in a Reuters poll of analysts.

The producer price index (PPI) rose 2.3%, the slowest pace since February 2021, and slower than 4.2% a month prior and 3.1% in the poll, due to falling energy and raw materials prices.

"Factory gate inflation is set to fall further throughout the rest of the year thanks to a continued drop back in commodity prices and a higher base for comparison," Capital Economics analysts Sheana Yue and Zichun Huang said in a research note.

"We think CPI inflation will remain below the PBOC's 3% ceiling," they said, referring to the People's Bank of China (PBOC).

Official and private data indicates further lost momentum in August in the world's second-biggest economy, where property market weakness, COVID-19 containment measures and power shortages have dented consumption and factory activity.

There were 1,404 new COVID-19 infections in China on Sept. 8, 301 of which were symptomatic, the National Health Commission said, while Chengdu has extended a lockdown for the majority of its over 21 million citizens.

Slower growth in consumer prices came as food prices rose 6.1% on year in August, versus 6.3% in July, with non-food items at 1.7% from July's 1.9% rise.

Core CPI, which excludes volatile food and energy prices, rose 0.8%, matching the previous month.

On a month-on-month basis, the CPI fell 0.1% from July, after rising 0.5% in July from June, and compared with 0.2% forecast in the Reuters poll.

Overall industrial products prices maintained a downward trend due to falling prices in global crude oil and non-ferrous metals, NBS said separately.

Producer price inflation in oil and natural gas extraction slowed to 35.0% on year in August from 43.9%.

On month, the PPI fell 1.2% in August from July, when it declined 1.3% from June.

While consumer inflation was approaching the government's target of around 3.0%, it was still lower than seen in other major economies.

The PBOC in August said China faces rising structural inflation pressure and consumer inflation might exceed 3% in some months in the second half of the year.