China's manufacturing unexpectedly accelerated in May, indicating that a slowdown in economic growth in the first quarter may be stabilizing.

The Purchasing Managers' Index rose to 50.8 from 50.6 in April, the National Bureau of Statistics and China Federation of Logistics and Purchasing said in Beijing on June 1. That was higher than all estimates in a Bloomberg News survey of 30 analysts and compares with the median projection of 50, which marks the dividing line between expansion and contraction.

The report may provide some comfort to policy makers after the preliminary reading of a private manufacturing survey pointed to the first contraction in seven months.