By Brigid Riley and Kevin Buckland
TOKYO, Sept 7 (Reuters) - Japanese 30-year government bond (JGB) yields ticked higher on Thursday as an auction for the bond saw poor response. The 30-year JGB yield rose 0.5 basis point (bp) to 1.645% following the auction, after hitting a one-week low of 1.635% earlier in the Asian hours.
The benchmark 10-year JGB yield rose 0.5 bp to 0.655%.
The Ministry of Finance said it sold nearly 725 billion yen ($4.91 billion) of the 30-year bond on Thursday. The yield for the lowest accepted price was at 1.656%, while the yield at the average price was 1.64%.
The tail - the difference between the lowest bid and average bid at the auction - came in at 0.28 yen, compared with last month's 0.04 yen, signaling poor demand.
"People were expecting a weak auction, but the result was even weaker than their forecast," said Shoki Omori, chief Japan desk strategist at Mizuho Securities.
"Nobody wants to go long the 30-year at these levels."
Analysts also pointed to the fact that investors bought ahead of Thursday's auction as a factor in the lacklustre showing.
The 30-year JGB auction on Thursday capped an entire month of weak results across all tenors, raising concerns over demand at the 20-year JGB sale scheduled for Sept. 14. The 20-year yield rose 1.5 bps to 1.385% after dipping down as low as 1.37% on Thursday.
The 40-year JGB yield fell to 1.795%, the lowest since Aug. 18, before last being flat at 1.81%.
The two-year JGB yield was unchanged at 0.015%, while the five-year yield ticked down 0.5 bp to 0.22%.
($1 = 147.61 yen) (Reporting by Brigid Riley and Kevin Buckland)