financial assets play an efficient role, that could well boost the economic growth rate," Fukui said in a Tokyo lecture.

His remarks came after the central bank raised its key short-term interest rate to 0.5 percent from 0.25 percent Wednesday to reflect the stable economy, the first rate increase since July.

"Thanks to growth in the past and savings, the amount (of Japan's household financial assets) has reached a huge figure of about 1.5 quadrillion yen," Fukui said.

He added that the economy can see further expansion by shifting the money to investments.