TOKYO, July 7 (Reuters) - Japanese government bond (JGB)

yields held near multi-decade highs on Tuesday as fiscal and

inflation concerns loomed before a sale of super-long-term debt.

Here are a few details:

* The benchmark 10-year JGB yield was

unchanged at 2.830%, holding at the highest level since October

1996. Yields move inversely to bond prices.

* The yield on the 30-year JGB climbed 1

basis point (bp) to 4.085%, the highest since May 20.

* The Ministry of Finance will sell about 600 billion yen

($3.70 billion) in 30-year securities later in the session.

* JGB yields have been on the rise this month, particularly

in the long and super-long end, driven by inflation concerns, a

sharply weaker yen and worries about fiscal expansion.

* "This auction is therefore closely watched as a key

indicator for gauging where the market will stabilise in the

near term," Keisuke Tsuruta, a senior bond strategist at

Mitsubishi UFJ Morgan Stanley Securities, wrote in a note.

* The yield on the 20-year JGB was unchanged

at 3.805%, the highest in data going back to 1999.

* The two-year yield, the one most sensitive

to Bank of Japan policy rates, held steady, while the five-year

yield was unchanged at 1.940%.

($1 = 162.1500 yen)