Yukio Hatoyama, who led his opposition party to a landslide win in Japan's weekend elections Monday promised to build consensus and avoid "arrogance" in pursuing his party's political programme.

Media projections show that Hatoyama's centre-left Democratic Party of Japan won 308 seats in the powerful 480-member lower house of parliament in the Sunday poll, ending more than 50 years of almost unbroken conservative rule.

"It is an incredible number," Hatoyama told a live televised interview with public broadcaster NHK.

"We will not just bulldoze our policies.

"We must exercise patience and seek people's understanding because we are given such latitude," said Hatoyama, who is expected to replace Prime Minister Taro Aso by mid-September.

"We must shed ourselves of arrogance that might come from such a number," said the 62-year-old US-trained engineering scholar.

Hatoyama is set to lead Japan as the world's number two economy emerges from its worst recession in recent decades.

Hatoyama campaigned on a promise of change and people-centred politics against the business-friendly Liberal Democratic Party (LDP), headed by Aso.

Aso told reporters Sunday night that he would step down as LDP president to take responsibility for the huge defeat.

In the NHK interview, Hatoyama also confirmed he would form a coalition with smaller partners such as the Social Democratic Party and the People's New Party, despite policy differences on security and other issues.

The LDP was ousted from government for 10 months in the early 1990s, as smaller parties formed a fragile coalition to take power. But even then, the LDP, as a single party, held the most seats in the parliament.

(Agencies)