China's factory activity saw a notable rebound in December, returning to expansion territory above the 50-point mark for the first time since April, according to official data released on Wednesday.

Data from the National Bureau of Statistics showed that China's official purchasing managers index (PMI) for the manufacturing sector stood at 50.1 in December, up from 49.2 in November.

Huo Lihui, an NBS statistician, said the improvement was underpinned by a clear recovery in both supply and demand, with gauges for new orders rising above the critical threshold for the first time in the second half of the year.

The sub-index for production stood at 51.7 in December, up from 50 in November, while the gauge for new orders came in at 50.8, up 1.6 percentage points from the previous month, the NBS reported.

Meanwhile, the PMI readings for major industries all improved from November. High-tech manufacturing, for instance, recorded a PMI of 52.5, up 2.4 percentage points, pointing to a solid improvement in growth momentum.

Market expectations strengthened further with a notable upward trend. The sub-index for production and operation activity expectations stood at 55.5, up 2.4 percentage points from November, reflecting rising confidence among manufacturing enterprises in market prospects.

China's non-manufacturing PMI, which includes sub-indexes for service sector activity and construction, came in at 50.2 in December, up 0.7 percentage points month-on-month. The services sector also saw a mild improvement, as the business activity index rose to 49.7, up 0.2 percentage points.

The country's official composite PMI, which encompasses both manufacturing and non-manufacturing activities, stood at 50.7 in December, up 1.0 percentage point from the previous month, NBS data showed.