(Updates prices ahead of midday trading recess)

By Kevin Buckland

TOKYO, Aug 13 (Reuters) - Japan's Nikkei share average

rose above 43,000 for the first time on Wednesday, with the

broader Topix index also marking a fresh all-time high, tracking

Wall Street's overnight gains and extending the rally into a

sixth straight session.

The Nikkei gained as much as 1.4% by 0140 GMT to

touch a record 43,309.62 and extend its winning run to 7.5%

since August 4. Monday of this week was a national holiday in

Japan.

The broader Topix advanced 1% to an unprecedented

3,097.94, also rising for the sixth straight session.

Overnight, the S&P 500 and Nasdaq closed at

record highs as a moderate reading of July inflation bolstered

bets for a Federal Reserve interest rate cut next month.

"A sense of relief is permeating through markets" following

the U.S. Consumer Price Index (CPI) data, leading Japanese

stocks "to take a step higher," said Maki Sawada, an equities

strategist at Nomura Securities.

At the same time, "there are signs that the Nikkei is

overheated after its extremely steep rally, and a steep drop at

any time wouldn't come as any surprise," she added.

The Nikkei's relative strength index (RSI) rose above 75,

well beyond the 70 line that many analysts consider indicative

of an overheated market. The RSI was at a similar level on July

24, and the Nikkei fell in the following four sessions.

A stronger yen exchange rate, after Fed easing expectations

hurt the dollar, also limited Japanese stock gains in the latest

session, Sawada said.

A strong yen reduces the value of overseas revenues at

Japan's heavyweight exporters.

Of the Nikkei's 225 components, 183 rose, 41 fell and one

traded flat.

Tech shares stood out, with chipmaker Renesas Electronics ( RNECF )

jumping more than 7%, chip-testing equipment maker

Advantest ( ADTTF ) rising more than 2% and Sony Group ( SONY )

gaining 4.6%.