China's manufacturing activity continued to contract in September but the rate of deterioration eased slightly compared with the previous month, official data showed.

The official purchasing managers' index (PMI), released on October 1 by the National Bureau of Statistics and the China Federation of Logistics and Purchasing, rose to 49.8 percent last month from 49.2 percent in August. However, it remained below the 50-percent threshold that divides expansion from contraction.

The September index ended the manufacturing PMI's continuous decline for four straight months. The index fell below the boom-bust line in August for the first time since November 2011.