Investors are set to face the largest supply of Japanese sovereign bonds in at least a decade as the central bank plans to shrink its balance sheet, adding to debtholders’ woes from rising interest rates.

The Finance Ministry typically releases a plan in late December on the amount of debt it will sell in the fiscal year starting April 1.

Should it be roughly the same as the current year, supply will increase 64% to ¥61 trillion ($390 billion) if redemptions and Bank of Japan purchases are taken into account, according to a Bloomberg analysis of official data.