The HSBC China Manufacturing PMI -- a seasonally adjusted index designed to measure the performance of the manufacturing economy -- rose in September to 52.9. That compared with 51.9 in August and was the highest level since April. Numbers above 50 show manufacturing activity expanding.

"A pick up in new orders means that domestic demand is still strong. Despite uncertainties in global demand, we expect China to rely on continued investment in ongoing infrastructure projects and resilient consumption to grow by around 9 percent in the rest of the year," Hongbin Qu, chief economist for China at HSBC, said in the report.

China's economic growth slowed to 10.3 percent over a year earlier in the second quarter, down from its blistering 11.9 percent first quarter pace. But recent indicators have assuaged worries that the economy might be headed into a more severe slowdown.

Despite the positive trends in September, the survey's findings were not entirely upbeat.

New export activity rose after declining for three straight months, but the growth rate was marginal, the report said.

It also said that average costs, especially for raw materials, rose substantially, with inflation sharply higher.

China's overall inflation edged higher in August as the nation's worst flooding in a decade drove an increase in food costs and industrial growth continued to quicken. The 2.8 percent inflation rate for the first eight months of 2010 was close to the government's ceiling of 3 percent.

The HSBC survey was released several days early, due to an upcoming public holiday beginning Friday.

The state-affiliated China Federation of Logistics and Purchasing, which also issues a monthly purchasing managers index, or PMI, has not yet released data for September.