Business activity in China's non-manufacturing sector expanded in August with slightly slowed pace from June and July, official data showed on Tuesday.

The purchasing managers' index (PMI) for the non-manufacturing sector fell to 53.4 in August, down from 53.9 for July, according to a report released jointly by the National Bureau of Statistics (NBS) and the China Federation of Logistics and Purchasing.

Non-manufacturing PMI tracks business activities of the service and construction sectors. A reading above 50 indicates expansion, while a reading below 50 represents contraction.

"China's non-manufacturing sector was growing steadily," said NBS statistician Zhao Qinghe, adding that the August reading was well above the expansion-contraction line, although it was lower.

The service sector sub-index stood at 52.6 in August, down from 52.8 for July, indicating slower growth in the industry.

The sub-index for the construction sector retreated to 57.8 in August, down from 60.1 for July, suggesting waning construction activities.

Meanwhile, the new order sub-index in general slid to 49.6 last month, falling to contraction territory from 50.1 for July.