TOKYO, July 9 (Reuters) - Japan's Nikkei share average

surrendered early gains to trade flat on Wednesday, as investors

sold chip-related heavyweights to book profits from a recent

rally.

The Nikkei was down 0.03% at 39,677.42 by the midday

break, after rising 0.7% earlier in the day to 39,971.06. The

index swung between marginal gains and losses during the

session.

The broader Topix was up 0.3% at 2,824.93.

"The Nikkei opened higher, supported by the yen's weakness

against the dollar. But as soon as the Nikkei rose closer to the

40,000 level, investors sold stocks to book profits," said

Shuutarou Yasuda, a market analyst at Tokai Tokyo Intelligence

Laboratory.

"Overall, the market is firm, with the Topix rising.

Investors are rotating their targets day to day."

Chip-related heavyweights Advantest ( ADTTF ) and Tokyo

Electron ( TOELF ) gave up early gains and were trading down

1.87% and 0.92%, respectively.

Uniqlo-brand owner Fast Retailing ( FRCOF ) lost 1.18%.

Automakers rose on the back of a weaker yen, with Toyota

Motor ( TM ) and Honda Motor ( HMC ) up 1.36% and 2.83%,

respectively.

The yen weakened 0.2% to 146.91 against the dollar.

The greenback extended gains as U.S. President Donald Trump

pledged more trade-related proclamations after announcing 25%

tariffs on Japan and other trade partners.

A weaker Japanese currency tends to boost shares of

exporters, as it increases the value of overseas profits in yen

terms when firms repatriate them to Japan.

Energy-related shares rose after oil prices hit a two-week

high overnight. An index for oil refiners jumped 3%

to become the top performer among the Tokyo Stock Exchange's 33

industry sub-indexes.

Yoshinoya Holdings ( YNOYF ) jumped 6.56% after the fast-food

chain known for "gyudon" beef bowls reported a 9% gain in

quarterly net profit, supported by strong sales of its new ramen

business.

Of the more than 1,600 stocks trading on the TSE's prime

market, 82% rose, 15% fell, and 2% traded flat.