TOKYO, May 22 (Reuters) - Japanese government bond prices were mostly firmer on Wednesday, paring earlier modest losses after a well-received 20-year debt auction improved market sentiment.
The 10-year JGB futures rose 0.03 points to 152.68, with a trading volume of 23,229 lots by late afternoon trade.
The futures contract pared modest losses after the 20-year auction attracted ample investor demand.
The bid-to-cover ratio, a gauge of demand, at the 900 billion yen ($8.2 billion) 20-year auction rose to 5.47 from 5.10 at the previous sale in April.
The benchmark 10-year cash JGB yield fell half basis point to minus 0.055 percent.
The 20-year JGB yield dropped 1 basis point to 0.350 percent while 30-year and 40-year yields fell 1.5 basis point each 0.520 percent and 0.550 percent, respectively. ($1 = 110.4200 yen) (Reporting by the Tokyo markets team; editing by Rashmi Aich)