Sentiment at large manufacturers rose slightly in September, with optimism for strong exports somewhat dampened by worries over soaring oil prices, according to the Bank of Japan's "tankan" quarterly business survey released Monday.

The survey is closely watched, as any clear sign of a strong recovery in the world's second-largest economy would provide support to mounting calls at the central bank that it soon end its ultraloose quantitative-easing monetary policy.

The confidence index for large manufacturers was 19, up one point from three months earlier and the second straight quarter of improvement. But the figure was lower than the recent high of 26 registered in September 2004.