BEIJING (AFP) - China's manufacturing activity expanded in December at the same pace as November, official data showed on Tuesday, adding to signs the world's number two economy is emerging from a recent slumber.

The official purchasing managers' index (PMI) reached 50.6 in December, unchanged from the previous month, according to the China Federation of Logistics and Purchasing and the National Bureau of Statistics.

The PMI is a widely watched barometer of the health of China's economy, and a reading above 50 indicates expansion while anything below points to contraction.

The result, the highest since April, marked the third straight month the index has shown growth but it fell short of the the median 51.0 forecast of five economists polled by Dow Jones Newswires.

The data came a day after a survey by banking giant HSBC showed manufacturing activity surged to a 19-month high of 51.5 from 50.5 in November.

A steady strengthening in China's manufacturing sector, and improvements in areas including broader industrial production and retail sales, have spurred optimism that the country's economic slowdown has bottomed out.

Growth hit a more than three-year low of 7.4 per cent in the third quarter to September, though data for the October-December fourth quarter has led to expectations of a pick-up.

Beijing is expected to release gross domestic product data for the past three months later in January.