BEIJING - China's non-manufacturing activity expanded strongly in December, indicating a bigger role for the service sector in supporting the slowing economy, a monthly survey showed Friday.

The purchasing managers' index (PMI) for the non-manufacturing sector came in at 54.4 in December, up from 53.6 in November and also the highest in 2015, according to a report released jointly by the National Bureau of Statistics (NBS) and the China Federation of Logistics and Purchasing.

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

Industries related to household consumption, such as retail, postal and express delivery services, storage and distribution services, as well as Internet software, all expanded due to a holiday and year-end promotion sales boom, NBS statistician Zhao Qinghe said.

Financial activities including banking, securities trading and insurance also posted strong expansion.

The sub-index for new orders in services climbed to 51.2, up 0.9 percentage point from November, showing demand rallied in the service market, Zhao said.

The non-manufacturing PMI tracks business activities of both the service sector and the construction industry.

The sub-index for the service sector rose to 53.7 in December from 52.8 in November. The sub-index for the construction industry increased 0.2 percentage point from November to 58.3.