TOKYO, March 31 (Reuters) - Japanese government bond yields rose on Wednesday on speculation that the Bank of Japan (BOJ) will reduce bond purchases for its quantitative easing policy. Later on Wednesday, the BOJ is expected to announce the amount of bonds it will buy in April. The central bank earlier this month decided to slightly widen its trading range long-term yields, but some investors are uncertain how this will affect its daily bond operations. Benchmark 10-year JGB futures fell 0.09 point to 151.14, with a trading volume of 12,330 lots. The 10-year JGB yield rose 0.5 basis point to 0.090%. The 20-year JGB yield rose 1.5 basis points to 0.470%. The 30-year JGB yield rose 2 basis points to 0.660%, but the 40-year JGB yield was unchanged at 0.685%. The five-year yield gained 0.5 basis point to minus 0.095%. At the short end, the two-year JGB yield was unchanged at minus 0.125%.