TOKYO, June 18 (Reuters) - Longer-dated Japanese government bond prices dipped on Monday as the market braced for an upcoming auction of 30-year debt, although a drop in Tokyo shares helped curb losses.
The 20-year JGB yield rose half a basis point to 0.505 percent.
September 10-year JGB futures moved in a tight range and last traded at 150.77.
The finance ministry will issue 700 billion yen ($6.34 billion) of 30-year JGBs on Tuesday.
The Nikkei was down 0.9 percent as an escalating trade dispute between the United States and China stoked concerns about the impact on global demand. Also denting sentiment was a magnitude-6.1 earthquake in Osaka in western Japan on Monday, hitting the shares of utility companies headquartered in the Kansai region.
$1 = 110.4200 yen Reporting by the Tokyo markets team, Editing by Sherry Jacob-Phillips