TOKYO, Aug 18 (Reuters) - The yield on superlong Japanese government bonds (JGBs) ticked up to six-week highs on Tuesday after an auction of 30-year bonds drew tepid investor demand but yields on shorter maturities dropped on firmer U.S. Treasuries.
The auction of 30-year JGBs attracted bids 3.44 times the offer of 900 billion yen ($8.52 billion), down from bid-to-cover ratio of 3.92 at the previous auction in July.
It produced tail, the gap between lowest and average prices, of 0.22, way above 0.08 in July auction, in another sign of weaker demand.
The 30-year JGB yield rose 0.5 basis point to 0.620%, having hit a six-week high of 0.625%.
But other maturities hold firmer, thanks in large part to rebound in U.S. Treasuries prices overnight.
The benchmark 10-year JGB yield fell 0.5 basis point to 0.035% and the 20-year JGB yield slipped 0.5 basis point to 0.425%. The five-year JGB yield fell 1 basis point to minus 0.090% and the two-year yield dipped 0.5 basis point to minus 0.125%.
Benchmark 10-year JGB futures rose 0.15 point to 151.89. ($1 = 105.6100 yen) (Reporting by Tokyo Markets Team; Editing by Rashmi Aich)
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