TOKYO — Japanese voters yesterday handed a humiliating defeat to the Liberal Democratic Party after its half-century of nearly unbroken rule, opting for an untested opposition party that pledged to revive the nation's ailing economy.

Signaling frustration over a declining quality of life, a record-high unemployment rate, unraveling social services and political scandals, voters rebuked Prime Minister Taro Aso and a party that had dominated national politics here since the 1950s.

In landslide numbers, they turned to Democratic Party of Japan leader Yukio Hatoyama, a wealthy 62-year-old grandson of a former prime minister, who 13 years ago abandoned the Liberal Democratic Party to help co-found a now-thriving opposition movement. His party won 308 seats in parliament's 480-member lower house, according to the final tally reported by Japanese media, assuring that he will be elected prime minister in the coming weeks.

The Kyodo News Agency reported that Hatoyama began talks early today on forming a new government.

Still, questions remain about how Hatoyama and his Democratic Party will accomplish their campaign promises in the face of an entrenched and often unwieldy bureaucracy and a stagnant economy. The strength of the party's mandate also is unclear, despite the numbers — some experts believe that many voters were more intent on defeating the Liberal Democrats than putting the opposition party in power.

Despite his campaign assertions that his government would re-examine Japan's policies toward the United States, few expected any major changes between the two allies.

In a speech carried nationwide, Hatoyama said he would form a coalition government with the Social Democratic Party and People's New Party, acknowledging that he rode a sentiment of public anger against Liberal Democrats.

"We have felt this great need to change things to make life better for the public," he said. "We have been vowing to change the government in this election. It feels very likely that that is the situation that is unraveling."

Aso announced that he would resign as prime minister and party leader, taking responsibility for the defeat. "The outcome of this election has been a very tough one. I am taking what the Japanese public is saying sincerely," he said. Later today, Aso indeed did step down as party leader.

PROMISE OF CHANGE

Throughout the campaign, the Democratic Party of Japan echoed the promise of change that Barack Obama last year rode to the U.S. presidency. Although experts say there was jubilation among many voters yesterday, they believed that those high spirits were tempered.

"People feel better and lighter because the LDP is gone, but there is not the same jubilation felt in America after Obama's election," said Masaru Tamamoto, a senior fellow at the World Policy Institute. "Obama told America where he was going. But the Democratic Party really hasn't told us where it and we are going."

The Democratic Party's campaign platform pledged to wrest control of government from bureaucrats they say have failed to fix the nation's ailing pension system. Hatoyama said he would form a National Strategy Bureau composed from both the public and private sectors to advise the government.

The platform included child allowances for middle-class families and assistance for struggling farmers. The party promised to bolster an economy that is suffering its worst recession in six decades and in July saw a record 5.7 percent jobless rate.

In the past, Hatoyama has also stressed that Japan must develop a more "independent" stance from U.S. policy. But as prime minister, many believe he will not immediately risk upsetting the status quo with his nation's most crucial security ally.

"He's not going to rupture the relationship, but I do think he will try to have a somewhat more Asia-centered than U.S.-centered policy," said Ellis Krauss, a professor of Japanese politics and policymaking at the University of California, San Diego.

One stumbling block will be Japan's role refueling U.S. ships in the Indian Ocean carrying war materiel to Afghanistan, a mission Hatoyama opposes.

"He's going to pretty quickly confront some realities of Japan's situation and find it might be a little difficult at times," Krauss said. "He's in a hard place. This isn't a great way to start off a relationship with the Obama administration."

Under Hatoyama, Japan probably will shift toward friendlier relations with China, he added.

The Democratic Party leader has already indicated that, unlike some past prime ministers, he will not visit the Yasukuni war shrine where many of the nation's veterans are buried — including convicted war criminals. Such visits have angered Japan's Asian neighbors.

"All the bad-memory stuff will go away," Krauss said. "It will be an immediate improvement."