TOKYO, May 14 (Reuters) - Japan's 30-year government

bond (JGB) yield rose on Wednesday after investors sold the

bonds to book profits amid concerns about weak demand for the

super-long bonds.

The 30-year JGB yield rose 3.5 basis points

(bps) to 2.91%, reversing the early declines.

Earlier in the day, investors bought the 30-year bonds

following a better-than-expected auction outcome on Tuesday.

However, a handful of investors sold them probably to book

profits, said Miki Den, a senior Japan rate strategist at SMBC

Nikko Securities.

Demand for the 30-year bonds is weak as most life insurers,

major investors in super-long bonds, have already completed

their asset-liability duration matching to comply with the

Financial Services Agency's regulations.

"But the new issue of the 30-year bonds by the Ministry of

Finance remains the same this fiscal year. That also hurt the

demand for the bonds," said Den.

The gap between the 10-year JGB yield and the 30-year bonds

hovered at a record level, signalling ongoing

concerns about demand, Den said.

The finance ministry's auction for the 30-year bonds in the

previous session was better than expected, with the lowest bid

price within the market expectations, said strategists.

The 10-year JGB yield inched up 0.5 bp to

1.45%. The 20-year JGB yield rose 1.5 bp to

2.355%.

The yields on shorter-dated bonds fell, with the two-year

JGB yield down 0.5 bp to 0.71%. The five-year

yield fell 1.5 bps to 0.965%.