An official survey shows China's factory activity eked out an expansion for the third straight month, in a possible sign that the downturn in the world's second biggest economy might be stabilizing.

The index released Wednesday by the Chinese Federation of Logistics & Purchasing came in at 50.1, level with April's reading.

It is based on a survey of factory purchasing managers. The index uses a 100-point scale on which numbers below 50 indicate contraction.

Data released by China's national statistics agency also showed production expanded while new export orders were flat, in a sign of weak global demand.

The federation's index for China's service industry, meanwhile, slipped to 53.1 last month from 53.5 in March.