BEIJING, June 1 (Reuters) - Activity in China's factory sector picked up in May, a government survey showed, adding to signs of stabilisation in the world's second-largest economy.

China's official Purchasing Managers' Index rose to 50.8 in May from April's 50.4, the National Bureau of Statistics said on Sunday.

Economists had expected the reading to rise to 50.6 in May, climbing further above the 50-point threshold that separates growth from contraction.

(Reporting by Aileen Wang)