TOKYO, July 4 (Reuters) - Japanese government bond

yields declined on Thursday, tracking a steep fall in U.S.

Treasury yields overnight as a slew of weak economic data

boosted bets for Federal Reserve interest rate cuts this year.

An auction of some 680 billion yen ($4.21 billion) of

30-year JGBs was smoothly digested by the market, but analysts

said some investors took the opportunity to sell off-the-run

bonds for new issues, which led to a slight rise in that sector

of the yield curve.

The 10-year JGB yield fell 1.5 basis points

(bps) to 1.08% by 0635 GMT, while the 30-year yield

rose 0.5 bp to 2.275%, reversing earlier

declines.

Benchmark 10-year JGB futures closed 0.27 yen

higher at 142.76 yen.

The 10-year yield reached 1.1% on Wednesday for the second

time since the end of May. Prior to that, the yield hadn't been

that high since 2011.

"I don't think people see 1.1% as a barrier - there's no

reason it wouldn't break above that," with a potential catalyst

coming on Friday in the form of U.S. nonfarm payrolls data, said

Shoki Omori, chief Japan desk strategist at Mizuho Securities.

The rise in JGB yields has been spurred by overseas bond

moves and growing expectations for near-term Bank of Japan

policy tightening, partly to help support the yen as it slumps

to 38-year lows to the dollar.

On Thursday, the five-year JGB yield sank 1.5

bps to 0.575%, and the two-year yield fell 0.5 bp

to 0.34%.

The 20-year yield was flat at 1.935%.

The 10-year Treasury yield sank close to 9 bps

to 4.347% on Wednesday. There was no trading in Treasuries on

Thursday due to a U.S. holiday.

($1 = 161.3600 yen)

(Reporting by Kevin Buckland; Editing by Subhranshu Sahu)