Japan's core consumer price growth picked up slightly in October, after easing the previous month, reinforcing investors' views that stubborn inflation may push the Bank of Japan to roll back monetary stimulus before long.

The nationwide core consumer price index, which excludes volatile fresh food costs, rose 2.9% year-on-year in October, government data showed today, compared to the 3% expected by economists in a Reuters poll.

Core inflation had slowed to 2.8% in September from 3.1% in August, the first time it was below 3% since August 2022.

The rate of inflation has hovered above the central bank's 2% inflation target for 19 consecutive months, but the Bank of Japan has insisted the cost pressures are largely driven by higher global commodity prices and the weaker yen, not a sign of sustainable price gains led by stronger domestic demand and wage growth.

"I expect the central bank to end negative interest rates and remove yield control as early as in April when they see the results of labour-management wages talks and the ongoing move among companies towards passing on costs," said Yoshimasa Maruyama, chief market economist at SMBC Nikko Securities.

The narrower gauge of inflation, or core-core index, which strips away fresh food and fuel costs, rose 4% in the year to October, slowing from a 4.2% gain in September but staying above 4% for the seventh month in a row.

Many analysts see the yield control policy as becoming obsolete as the Bank of Japan has made the 10-year yield target more and more flexible, sending the JGB yield closer towards 1%.

With inflationary pressures appearing to be more stubborn than expected, speculation is growing that the Bank of Japan may soon have to ditch its negative interest rate policy as well as yield curve control, which sets a 0% cap for the 10-year bond yield.

The Bank of Japan has brushed aside such speculation, saying that the current global cost-push inflation is not sustainable. It says healthy wage growth is needed to spur domestic demand and prices in a stable and sustainable manner.

The latest inflation data is among indicators the Bank of Japan will eye at its two-day policy meeting ending on December 19, its last scheduled review this year.

The government for its part is pressuring companies to raise wages to help employees overcome higher living costs.