In a move expected to push the Bank of Japan to start specific debate on ending its ultraeasy monetary policy next week, the government said Friday the January core consumer price index rose 0.5 percent from a year before, marking the third consecutive year-on-year increase and the biggest jump since March 1998.

The core CPI -- which excludes volatile prices on perishables -- rose to 97.7 against the 100-point benchmark for 2000, due largely to increases in the price of such items as kerosene and gasoline following a jump in crude oil prices, the Internal Affairs and Communications Ministry said in a preliminary report.

The January increase was larger than the market estimate of 0.4 percent and comes on the heels of increases of 0.1 percent last November and December.