The pace at which the Bank of Japan is expanding its massive hoard of bonds will continue to slow in 2018, according to the majority of economists surveyed by Bloomberg.

The central bank will increase its Japanese government bond holdings by about ¥44 trillion ($392 billion) next year, according to the average estimate in the survey. That's well below the BOJ's ¥80 trillion annual guideline and a considerable drop from the ¥61 trillion increase that was seen in the 12 months through the end of November, according to calculations by the outlet.

Under Gov. Haruhiko Kuroda the BOJ has come to dominate the government bond market in Japan, owning more than 40 percent of outstanding debt and depressing volatility and interest rates. But the pace of its purchases has decelerated after switching emphasis in 2016 from the volume of asset purchases to targeting interest rates.