TOKYO, June 26 (Reuters) - Japanese government bond

yields rose for a fifth straight session on Wednesday as the

uncertain outlooks for monetary policy and future bond issuance

deterred buying.

Yields on the longest-tenor securities again rose the most,

causing a further steepening of the yield curve.

The 20-year and 30-year JGB

yields each rose 2 basis points (bps) as of 0505 GMT to 1.860%

and 2.210%, respectively.

The 10-year yield added 1 bp to 1.005%.

Reports from Reuters and other media last week suggesting

the finance ministry might shorten the average maturity of bond

issuance in future had seen so-called superlong yields drop

sharply, according to Shinichiro Kadota, head of Japan FX and

rates strategy at Barclays.

However, a lack of clarity on the timing and extent of any

change caused the effect to be short-lived, he added.

Meanwhile, the yen's continued slide to the cusp of 160 per

dollar for the first time since late April, when

Japanese authorities were forced to step in with massive dollar

selling intervention, has raised expectations that the BOJ "will

have to do more" in terms of policy changes to help stem the

currency's decline, Kadota said.

"As a trend, we expect a gradual grind higher in yields this

year," with that on the 10-year note rising to 1.05%, he said.

The BOJ announced earlier this month that it would outline

its plan for a tapering of its bond-buying programme at its next

policy meeting on July 30-31, while leaving the door open to an

interest-rate hike at the same gathering.

Benchmark 10-year JGB futures fell 0.2 yen to

143.28.

The two-year and five-year

yields were both unchanged at 0.3% and 0.545%, respectively.

(Reporting by Kevin Buckland; Editing by Janane Venkatraman

)