Prime Minister Junichiro Koizumi reshuffled his cabinet on Monday, replacing several top ministers in an effort to boost his popularity, consolidate political support and quicken the pace of reforms in the world's second-largest economy.

Among those replaced was Foreign Minister Yoriko Kawaguchi, who had come under fire from some members of Koizumi's Liberal Democratic Party, or LDP. Koizumi named a former education minister, Nobutaka Machimura, as her replacement.

Koizumi also named Yoshinori Ono as defense minister. In addition, the prime minister boosted the political clout of his ally in the LDP, Taku Yamasaki -- a former defense minister who faced a sex scandal two years ago and was voted out of office last November -- by naming him as a special adviser. Yamasaki and Ono are close associates.

Some analysts, however, expressed skepticism that the new lineup would improve Koizumi's public image. The prime minister's approval ratings in opinion polls have reached record lows as he forges ahead with unpopular efforts to overhaul Japan's near-bankrupt pension system and continues to support the presence of Japanese noncombat troops in Iraq.

None of his appointments on Monday, which also included a new justice minister, indicated a change in political direction, analysts said.

But Koizumi did appear to focus on his troubled effort to reform Japan's economy, which has begun to emerge from a 13-year slump. Most notably, Koizumi retained Heizo Takenaka -- considered the key architect of Koizumi's reform program -- as head of economic policy. The finance minister, Sadakazu Tanigaki, and trade minister, Shoichi Nakagawa, also kept their posts.

Koizumi in effect boosted Takenaka's power by also giving him control over the planned reform of Japan's national postal system. Privatization of the postal system is now seen as a litmus test of Koizumi's ability to enact real reform, trimming the large government bureaucracy that many economists say contributed to Japan's protracted recession.

The move to privatize, however, is opposed by powerful conservatives within the LDP who have traditionally used post office branch managers to mobilize rural voters.

"We can call this the cabinet that will realize postal privatization and reform," Koizumi said in a nationally televised news conference Monday.

With his reshuffle, analysts said, Koizumi was also moving to keep in check his opponents within the LDP, the party that has ruled Japan for most of the post-World War II era. He gave top jobs to close allies, some with blemished political pasts.

Tsutomu Takebe, a former agriculture minister who stepped down in late 2002 after an outbreak of mad cow disease in Japan, was named the new secretary general of the LDP. Takebe, a staunch supporter of Koizumi's plan to privatize the postal service, replaced Shinzo Abe, who resigned to take responsibility for the LDP's poor showing in upper house elections in July.

"It's an unchallenging cabinet in the sense that Mr. Koizumi selected people who supported his position on policies and excluded those with different views," said Yoshiaki Kobayashi, professor of political science at Tokyo's Keio University. "There are no fresh surprises here that the public will welcome. If Mr. Koizumi really cared about pushing through postal reform, he could have chosen bolder people."

Special correspondent Sachiko Sakamaki contributed to this report.