China's manufacturing sector continued to improve in September, with expanding activities and rising expectations among firms, official data showed on Tuesday.

The purchasing managers' index (PMI) for China's manufacturing sector stood at 49.8 in September, up 0.4 percentage points from the previous month, according to the National Bureau of Statistics (NBS).

A reading above 50 indicates expansion, while a reading below 50 reflects contraction.

"The figure showed that in September, production activities in the manufacturing sector accelerated, with the overall business climate continuing to improve," said Huo Lihui, a chief statistician with the NBS.

The sub-index for production stood at 51.9, up 1.1 percentage points from August and hitting a six-month high.

On the demand side, the sub-index for new orders came in at 49.7, up from 49.5 in the previous month.

As the impact of extreme weather faded and policies to boost domestic demand took further effect, manufacturing market demand showed signs of stabilization and recovery, experts said.

"The sub-index for new export orders came in at 47.8, up 0.6 percentage points from August and rising for the second consecutive month," said Wen Tao, an analyst at the China Logistics Information Center (CLIC).

Wen attributes the gain to the robust export of "new trio" products, namely, electric vehicles, solar batteries and lithium-ion batteries, as well as the stable performance of key equipment industries and a more diversified export market.

Some key sectors maintained growth momentum, with PMI for equipment manufacturing and high-tech manufacturing standing at 51.9 and 51.6, respectively.

The sub-index for production and business activity expectations reached 54.1, up from 53.7 in August.

"This marks the third consecutive month of growth for the sub-index, indicating that manufacturing companies are upbeat on market development," Huo said.

In September, business activity in the non-manufacturing sector remained broadly stable. The non-manufacturing PMI came in at 50 in September, down 0.3 percentage points from the previous month.

The sub-index for the service sector stood at 50.1, remaining in expansion territory.

Business activity indices for postal, telecom, radio, television and satellite transmission services, as well as currency and financial services, stood above 60, indicating rapid expansion.

The monetary services and capital market services both saw solid growth, further enhancing the financial industry's support for the real economy, said Wu Wei, an expert with the CLIC.

As the policies continue to take effect, the financial sector's role in bolstering the real economy, anchoring market confidence and stimulating economic vitality will become increasingly evident.

In contrast, as the boost from the summer travel season receded, business activity indices for industries such as catering, culture, sports, and entertainment were below the boom-bust line.

Experts believe that the upcoming National Day holiday is expected to unleash a wave of pent-up demand in these sectors, driving a recovery in their business climate.

"The business expectation index for the service sector stood at a relatively high level of 56.3, showing service enterprises are optimistic about the market," Huo said.