
Japan's public pension fund GPIF, the largest of its kind in the world, is an important source of demand for the country's government bonds.
Meanwhile, the Bank of Japan plans to limit purchases of government debt, media group Bloomberg reported on Thursday.
The GPIF fund's holdings of Japanese government bonds rose 25 percent to 50.3 trillion yen ($311 billion) in the fiscal year ended March 31. Meanwhile, the share of domestic treasury bills, non-governmental and foreign debts decreased.
Japan's state pension fund GPIF holds less than a tenth of Japanese government bonds, but the fund's tendency to buy on the cheap helps limit losses in the fixed-income market.
At the end of March, Japanese government bonds made up 89 percent of domestic debt held by the GPIF fund, worth ¥56.5 trillion, up from 81.3 percent three years ago.