BEIJING, April 30 -- The purchasing managers' index (PMI) for China's non-manufacturing sector came in at 50.4 in April, down from 50.8 in March, official data showed Wednesday.

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

According to the National Bureau of Statistics (NBS), the service sector continued to expand, with its sub-index standing at 50.1 in April.

Business activity indices in sectors related to air transport, telecommunications, radio, television and satellite transmission services, internet software and information technology services, and insurance remained above 55, indicating robust growth in overall business volume.

Meanwhile, business activity indices in sectors such as water transport and capital market services have fallen below the expansion point.

In April, the construction sub-index came in at 51.9, down 1.5 percentage points from the previous month, according to NBS data.

Data also showed that the country's manufacturing PMI came in at 49 in April.