But Governor Toshihiko Fukui, introducing the central bank's semi-annual report, said the national bank still forecasts gradually rising prices.

The Bank of Japan said it will not eliminate the possibility of a second key interest rate hike by the year's end. Fukui repeated the central bank "will leave options open" on the timing of changes in its monetary policy.

"We do not have a preset view on the timing of policy change and I am sure we will be able to learn about the right timing -- neither too late, nor too early -- eventually," Fukui said.

The BoJ expects 0.5 percent inflation in terms of the consumer price index in fiscal 2007, down from a 0.8 percent year-on-year CPI rise forecast in the previous April report.