The Bank of Japan's Policy Board decided Thursday to maintain its benchmark interest rate at 0.5 percent despite a dissenting vote by one member to raise the rate to 0.75 percent.

But the market could see the 8-to-1 vote as a sign the central bank will raise the rate at the Aug. 22-23 Policy Board meeting.

Recently, the board has been voting unanimously to keep the rate the same.

However, in January, the month before the board voted 8-1 to double the rate to 0.5 percent, three members voted for the hike.

BOJ Deputy Gov. Kazumasa Iwata was the member who voted against the rate hike in February.

Policy Board member Atsushi Mizuno, a former chief strategist at Credit Suisse First Boston Securities, proposed raising the unsecured short-term interest rate to 0.75 percent at this month's two-day meeting.

BOJ Gov. Toshihiko Fukui said Mizuno made the proposal because he had "stronger confidence" than other board members that the economy will expand in a sustainable manner.

"The other members wanted to be more certain about the probability" that the nation's economy will grow in the long term, Fukui said. "They were not convinced enough to change the monetary policy."

Fukui said the central bank will continue to monitor the economy and will increase the interest rate as the economy and pricing improved.

In its monthly economic report released the same day, the BOJ kept its upbeat assessment of the economy unchanged, but downgraded its view on housing investment and production.