By Kantaro Komiya

TOKYO (Reuters) - Business confidence at big Japanese manufacturers sank to a seven-month low in September, with managers across a wide range of sectors citing soft Chinese demand as a concern, a Reuters monthly poll showed on Wednesday.

The mood at non-manufacturers fell for a third consecutive month, to a one-year-low, according to the Reuters Tankan survey, suggesting a gloomy sentiment after the Bank of Japan (BOJ) raised interest rates in July.

The Reuters Tankan, which closely tracks the BOJ quarterly business survey, showed the sentiment index for manufacturers was at plus 4 in September, down sharply from August's plus 10 and the lowest since February's minus 1.

Manufacturers expect their business confidence to drop further to plus 3 over the next three months, the survey showed.