0506 GMT - Some JGBs pare yield declines after tepid demand at the Japanese finance ministry's auction of 30-year sovereign debt. The bid-to-cover ratio, a measure of demand in bond auctions, stood at 3.79, lower than the 3.86 at August's 30-year sale. In another indication of soft appetite, the auction's tail, or gap between the average accepted price and the lowest, was at 0.28 yen, larger than 0.21 yen at the prior 30-year sale. Ten-year JGB yield is 4 bps lower at 2.970%, compared with 5 bps lower before the auction's outcome. Thirty-year yield is down 8 bps at 4.085%, versus a 9.5bp decline before the auction results.