TOKYO, April 17 (Reuters) - Japanese government bonds edged higher and the yield curve flattened on Tuesday, taking cues from an overnight climb in U.S. Treasuries and the best demand for newly auctioned 30-year debt in five years.

The favourable auction result gave some reprieve to the long end of the yield curve, which had been under pressure since late last week as traders prepared for fresh supply including the 30-year offer and next week's 20-year JGB auction.

The Finance Ministry's offer of 600 billion yen ($5 billion) in 30-year JGBs produced a bid-to-cover ratio of 4.26, the highest at a 30-year offer since 6.1 at an auction in May 2002.

"The yield curve had been steepening as traders focused on the 30-year offer, and I think the market is feeling some relief now that the auction is over," said Yasunori Kuroda, a manager for Sompo Japan Insurance Inc.'s fixed income division.

June 10-year JGB futures ended 0.05 point higher at 133.75 (2JGBv1: Quote , Profile , Research ), having trimmed some gains after rising to an intraday high of 133.90 after the auction results were announced.

Kuroda said the high bid-to-cover ratio may partly have been caused by traders who had hoped to capitalise on uncertainty stemming from a change in the 30-year auction style to a conventional, price-competitive format. Continued...

This is cache, read story here