(Updates to Europe morning, adds comments and background)

Sept 3 (Reuters) - Long-dated euro zone bond yields were

choppy on Wednesday, lingering near multi-year highs, as

investors fretted over the sustainability of government debt

levels at the start of a month of seasonally heavy debt supply.

Germany's 30-year yield rose to a 14-year high

of 3.4340% before reversing course, and was last a touch lower

on the day at 3.3979%.

While euro zone bond yields had kicked off the session

on a steady note, the U.S. 30-year Treasury yield's

fleeting rise to 5% exerted pressure that dissipated as the

long-tenor U.S. yield eased below its highest level since July.

Other regional long-dated bond yields, including in France

and Italy, tracked their German

counterpart's fitful moves and were last a little lower at 4.49%

and 4.65%, respectively.

Germany's 10-year yield, the benchmark for euro zone bonds,

also nudged down to 2.77%.

Investors are bracing for heavy bond supply in September

and October from Germany, Japan and the U.S., while also

confronting political worries in

France

and

Japan.

Societe Generale expects more than 100 billion euros ($117

billion) in European bond issuance in September and October.

French Finance Minister Eric Lombard

said

the minority government would have to compromise on plans

to cut the budget deficit if Prime Minister Francois Bayrou is

toppled in a confidence vote on September 8.

"To say that event risk for France and OATs is high in

the coming days is something of an understatement. The vote on

the 8th September appears to be a done deal in that Bayrou's

government will fall. What ensues will be key to dictating the

tone of OAT spreads," said Peter Goves, head of developed market

debt sovereign research at MFS Investment Management

Meanwhile, jitters about the UK's ability to keep its

finances under control

pushed up

its 30-year borrowing costs their highest level

since 1998.

British finance minister Rachel Reeves will

deliver

her annual budget on November 26, her department said on

Wednesday.

In the near-term, investors focus is also on key U.S. labour

market data due on Friday that is expected to influence

expectations of a rate cut by the U.S. Federal Reserve this

month.

Money markets are currently pricing in a more than 90%

chance of a 25-basis-point cut by the Fed, per CME's FedWatch

tool.