Business activity across China's private sector expanded in September, with the headline RatingDog China Composite Output Index, compiled by S&P Global, coming in at 52.4, according to data released on Wednesday.

The latest print, which aggregates combined performance figures across both the manufacturing and service sectors, compared with the 52.1 recorded in the previous month.

A reading above 50 indicates an overall expansion in private-sector activity, while a figure below 50 signals a contraction.

The reading was higher than the official government composite PMI, which stood at 50.7.

The monthly momentum reflected broad-based growth across both sectors, with the RatingDog Manufacturing PMI coming in at 52.1, down from 51.5 in August, while the RatingDog Services PMI rose to 51.6 from 51.4.

Growth in new business, new export business, output and employment was recorded across both sectors, while business confidence strengthened to a four-month high at the composite level.