TOKYO, Aug 20 (Reuters) - Japanese government bond yields edged higher across the curve on Tuesday due to a calmer tone in world markets and continued expectations for fresh stimulus measures in major economies.
The benchmark 10-year JGB yield added half a basis point to minus 0.230%, while the 20-year and the 30-year yields rose one basis point each to 0.105% and 0.210%, respectively.
Key 10-year JGB futures dropped 0.02 point to 154.83, with a trading volume of 17,345 lots by late afternoon trade.
Tuesday's 0.9 trillion yen ($8.5 billion) 20-year JGB auction attracted moderate investor interest. The auction bid-to-cover ratio, a gauge of demand, dropped to 3.81 from 4.89 at the previous sale last month.
On Monday, Treasury bond yields gained as risk sentiment improved and after the U.S. government said it was gauging market interest in ultra-long debt, with benchmark 10-year yield rising to 1.598%, moving further away from Thursday's three-year low.
Hopes for additional stimulus were rising after reports that Germany is prepared to increase fiscal spending, and after the People's Bank of China (PBOC) took steps to lower corporate borrowing costs. ($1 = 106.5800 yen) (Reporting by the Tokyo markets team; editing by Uttaresh.V)