TOKYO, Dec 19 (Reuters) - Benchmark Japanese government bonds inched down on Tuesday while longer maturities were slightly higher, supported by expectations that the Japanese government would trim next year's debt issuance more than some had expected.
The benchmark 10-year cash JGB yield edged half a basis point higher to 0.040 percent, while 10-year JGB futures ended down 0.02 point at 150.96.
Earlier in the session, the 10-year yield blipped up to a high of 0.060 percent, its highest since Nov. 1, on extremely low volume, before paring its rise.
"The yield level on that one issue does not appear to be indicative of market levels," said Keiko Onogi, a senior JGB strategist at Daiwa Securities.
Japan will trim its government bond issuance for most maturities to a nine-year low of 134.2 trillion yen ($1.2 trillion) in the next fiscal year, a 7 trillion yen cut from the amount planned for the current fiscal year, government sources told Reuters.
That amount was slightly bigger than the cut of 5-6 trillion yen many investors had expected.
In the superlong zone, the 20-year yield was half a basis point lower at 0.560 percent, while the 30-year yield also slipped half a basis point to 0.800 percent .
(Reporting by Tokyo markets team; Editing by Sunil Nair)