New Delhi, Sept. 23 -- India's business activity hit a three-month high in September due to strengthening demand in both manufacturing and services, although growth in export orders slowed, a preliminary private survey released on Wednesday showed.

The HSBC Flash India PMI Composite Output Index, a seasonally adjusted index that measures the month-on-month change in the combined output of India's manufacturing and service sectors, touched 56.5 in September up from 54.3 in August.

The HSBC Flash India Manufacturing PMI hit 55.7 in September, a seven-month high, compared to 52.8 in August. HSBC Flash India Services PMI Business Activity Index inched up to 55.8 in September from 54.1 in August.

Business confidence over the year-ahead outp...