Business confidence among major manufacturers improved on a quarterly basis for the first time in 2 1/2 years, but not as much as the market expected, the Bank of Japan said Wednesday.

The central bank's closely watched "tankan" survey indicated that big manufacturers are still reluctant to invest and that sentiment at small companies is deteriorating, highlighting the severity of the deepest recession since the war.

The confidence index for big makers rose to minus 48 in the quarter through June, up 10 points from minus 58 in the previous survey, a record low since the survey's start in May 1974.