REUTERS/Stringer
Five men sit on a electric bicycle as they cross a street in Changde, Hunan province.
Economists estimate the headline index slipped to 51.0 in September from 51.1 in August.
" We expect the official PMI to drop to 50.6 in September from 51.1 in August, as growth continues to lose momentum because of the ongoing property market correction, overcapacity in several upstream industries and a highly indebted economy, which has reduced the efficacy of policy easing," Nomura's Aman Mohunta said ahead of the report.