Japanese leader Junichiro Koizumi has insisted he has a mandate to reform, despite his party's disappointing showing in elections on Sunday.
Mr Koizumi is standing firm on his economic reform plans
The Liberal Democratic Party retained its majority in the important lower house, but only after agreeing to merge with a smaller coalition ally.
Tokyo's stock market fell amid fears the results weakened Mr Koizumi's hand against anti-reformist LDP members.
"We have managed to secure a stable majority," Mr Koizumi said.
Mr Koizumi insisted he could still push ahead with the reforms, which he began two years ago when he came to power, and which Japan badly needs to revive its sluggish economy and reduce its ballooning debt.
"I believe such support from a great many people has laid the foundations for our system to carry on reforms. I want to nurture the bud of reform into a big tree," he told a news conference at LDP headquarters.
It was Mr Koizumi's first election since he took power, and LDP strategists had hoped that his flamboyant personality might be a major vote-winner.
But instead, of the 480 seats in the lower house of parliament, the LDP won 237, down from 247. With its coalition partners, the smaller New Komeito party and the New Conservative Party, it won 275 seats, down from the 287 the three-way partnership had held.
In contrast, the DPJ took 177, up from 137.
On Monday, three independents said they would join the LDP, bringing its total to 240.
The LDP then announced it would merge with the New Conservative party, to give it a simple majority of 244.
In the last election, in 2000, the LDP also failed to win a simple majority - securing only 233 seats, but independents who later joined the party gave it a majority.
Mr Koizumi's main challenger, Naoto Kan, had argued that the LDP was too closely tied to vested interests in the banking, construction and agricultural sectors to carry out real reform.
Mr Kan was delighted with the early results.
The BBC's Jonathan Head in Tokyo says both parties campaigned on a platform of economic and political reform, and many people found it hard to distinguish between the policies on offer.
He says the opposition DPJ will take encouragement from their improved performance, which suggests a growing number of voters see them as a credible alternative to the governing party.
The LDP has governed almost without interruption for the last 50 years, but this election shows Japan moving towards a two-party system which could herald an end to the LDP's long monopoly on power.
An estimated 40% of voters were undecided and turnout at the polling booth was low - not helped by grey skies and light rain.
The final turnout was just under 60%, only slightly above the record low in the 1996 election.