Bolstered by strong overseas and information technology-related demand, optimism among large manufacturers overcame fears over a rising yen and soared to a 6 1/2 year high, according to a key business survey released Friday.

According to the Bank of Japan's quarterly "tankan" survey, the business confidence index for large manufacturers hit 11 points, up 10 points from three months earlier, when the confidence index stood at one.

Optimism among large manufacturers rose for the third consecutive quarter, surpassing levels during the IT bubble three years ago, when the confidence index hit a high of 10.