TOKYO, April 15 (Reuters) - Yields on benchmark 10-year Japanese government bonds were unchanged on Thursday even as an auction drew healthy demand, while overnight gains in U.S. Treasury yields weighed on investor sentiment. Earlier on Thursday, a liquidity auction at the Ministry of Finance received bids worth 4.7 times the amount available, higher than a bid-cover ratio of 3.66 at the previous auction. The 10-year JGB yield was unchanged at 0.085% and the 20-year JGB yield was also flat at 0.455%. The 30-year JGB yield rose 0.5 basis point to 0.650% and the 40-year JGB yield rose 0.5 basis point to 0.690%. The five-year yield rose 0.5 basis point to minus 0.100%. Benchmark 10-year JGB futures fell 0.03 point to 151.36, with a trading volume of 15,183 lots. (Reporting by Tokyo markets team; Editing by Shailesh Kuber)