BEIJING - The Purchasing Managers Index (PMI) of China's non-manufacturing sector, a key economic indicator, dropped 0.9 percentage points to 55.2 percent in May, according to an official survey.

The figure fell for a second consecutive month as the non-manufacturing sector growth slowed, according to data released by the China Federation of Logistics and Purchasing (CFLP) on Sunday.

A PMI reading above 50 percent indicates expansion from the previous month, while readings below this mark indicate a contraction.

"The non-manufacturing economy has maintained steady and strong growth as the PMI in May remained on a high level despite a small retreat," said CFLP Vice Chairman Cai Jin.