BEIJING, Aug. 1 -- China's manufacturing sector posted a slight drop in July due to the flood season and weak demand, official data showed on Monday.

The purchasing managers' index (PMI) came in at 49.9 in July, slightly lower than June's 50, according to the National Bureau of Statistics (NBS) and the China Federation of Logistics and Purchasing.

A reading above 50 indicates expansion, while a reading below 50 reflects contraction.

NBS statistician Zhao Qinghe said floods that hit much of the country disrupted manufacturing activities and transportation.

In addition, slowing market demand and weak investment sentiment in the private sector contributed to the contraction in the manufacturing sector, he added.

The sub-index measuring production stood at 52.1, 0.4 percentage points lower than a month ago.

The sub-index for new orders settled at 50.4, 0.1 percentage points lower than the previous month, declining for a fourth month in a row.