The purchasing managers' index (PMI) for China's non-manufacturing sector came in at 52.8 in October, down from 53.7 in September, the National Bureau of Statistics (NBS) said Thursday.

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

The sub-index for service activity moderated to 51.4 from 53, while the business expectation reading for the sector ticked up to 60.3 from 59.3 in the previous month.

Rapid expansions were seen in industries including air and railway transport, postal and courier service, bank and insurance, with their sub-readings all staying above 65, revealing service enterprises' buoyed market confidence about future market developments, said NBS senior statistician Zhao Qinghe.

The sub-index for the construction sector's activity rallied to 60.4 in October from 57.6 in September, returning to a relatively high expansion level, according to the NBS.

Thursday's data also showed that China's manufacturing PMI fell to 49.3 in October from 49.8 in September.