(Updates at 0600 GMT)

TOKYO, Oct 23 (Reuters) - Japan's Nikkei share average

fell for a third straight session on Wednesday as caution ahead

of the country's upcoming lower house election results

overshadowed any boost from a weaker yen.

The Nikkei closed 0.8% lower at 38,104.86, while the

broader Topix slid 0.55% to 2,636.96.

The losses came even as the yen weakened past the

152 per dollar level on Wednesday for the first time in nearly

three months.

A softer yen tends to help exporter shares as it increases

the value of overseas profits in yen terms when firms repatriate

them to Japan.

"With a weaker yen, investors could become more positive

about domestic stocks," said Seiichi Suzuki, chief equity market

analyst at the Tokai Tokyo Intelligence Laboratory.

"But they stayed away from making active bets as they

awaited the outcome of the general election. That capped today's

gains and this trend will continue this week."

Prime Minister Shigeru Ishiba dissolved the lower house of

parliament on Oct. 9, setting up the snap election on Oct. 27.

Local media reported that the ruling Liberal Democratic

Party (LDP) and its coalition partner Komeito may lose their

majority in the election.

Japanese stocks began the day marginally higher, but lost

steam over the course of the trading day to reverse their gains.

A bright spot was

Tokyo Metro

, whose shares shot up 44% in their market debut on

Wednesday, closing at 1,739 yen ($11.42). Japan's largest

initial public offering in six years netted it $2.3 billion with

promises of generous dividends.

Within the Topix, Toyota Motor ( TM ) rose roughly

3% to become the top gainer. Honda Motor ( HMC ) closed up

2.2%.

Automakers added 2.13% to become the best

performer among the Tokyo Stock Exchange's 33 industry

sub-indexes.

Among the Nikkei heavyweights, staffing agency Recruit

Holdings ( RCRRF ) fell 4.93% and Uniqlo-owner Fast Retailing ( FRCOF )

slipped 1.67%.

Home interior goods retailer Nitori Holdings ( NCLTF ), whose

share prices are affected by a weaker yen as it imports most

materials for its products from abroad, fell 2.81%.

($1 = 152.2800 yen)