Japan's Koizumi backs female PM candidate Koike

TOKYO (Reuters) - Former prime minister Junichiro Koizumi backed Yuriko Koike on Friday in her bid to become Japan's first female leader, although analysts said the backing of the popular politician was unlikely to lift her to victory.

Outspoken former foreign minister Taro Aso is the frontrunner among five candidates seeking to replace Prime Minister Yasuo Fukuda who quit suddenly last week, and media polls show he has enough support among ruling party lawmakers and branches to win.

But Koizumi, one of Japan's most popular prime ministers, told Koike's supporters on Friday morning that he would vote for her in the ruling Liberal Democratic Party's (LDP) leadership contest, a party lawmaker said.

"Former prime minister Junichiro Koizumi told me this: 'I will support Koike'," Seishiro Eto, who leads her campaign office, told a gathering of supporters.

Koizumi believed Koike as prime minister would mean a well-matched competition against the main opposition Democratic Party, Eto said.

Aso, 67, has regularly topped voter polls for the job, with his public popularity an important factor ahead of a general election, which must be held in the next year and analysts say could come as soon as November.

Whoever wins the LDP leadership contest on September 22 is assured the Japanese premiership by virtue of the party's grip on parliament.

Koike, a former TV announcer and defense minister, has staked out a claim as the candidate most likely to pursue market-friendly reforms pushed by the charismatic Koizumi during his 2001-2006 tenure.

"Carrying out reforms will lead to the creation of new industry and employment," Koike, 56, told a news conference with her rivals.

"I still strongly believe Japan needs to press ahead with reform."

But while Koizumi remains popular with the public, many LDP lawmakers are skeptical of pursuing reforms while the economy is faltering, leading analysts to doubt Koizumi's support would alter the momentum for an Aso victory.

"She might get a few more votes ... but there is no change in the overall outlook," said Yasunori Sone, a political science professor at Keio University.

A survey in the Yomiuri newspaper showed that Aso would get almost 60 percent support in a face-off with Democratic Party leader Ichiro Ozawa, while Koike would get only 36 percent.

(Additional reporting by Linda Sieg and Chisa Fujioka; Editing by Rodney Joyce)