Norwegian centre-right leader Erna Solberg is set to form a new government after Labour Prime Minister Jens Stoltenberg admitted election defeat.
Ms Solberg described her win as “a historic election victory for the right-wing parties”.
Her Conservative Party is widely expected to form a government with the anti-immigration Progress Party.
It was the first election in Norway since Anders Breivik killed 77 people in a bombing and shooting in 2011.
Prime Minister Jens Stoltenberg admitted defeat in front of a rapturous Labour Party. They showed their gratitude for the way he had led his party and the country through the worst terror attack in peace time when Anders Breivik killed 77 mainly young Labour supporters. Mr Stoltenberg will stand down in October after delivering his government’s last budget.
After eight years, Jens Stoltenberg’s Labour-led coalition no longer holds sway in parliament, despite steering the country safely through the economic crisis and overseeing a booming economy with very low unemployment.
Many here put this result down to voter fatigue with the current government. But the opposition says it has fresh and different plans to make sure Norway’s economy stays strong – after the current oil wealth that has made this one of the world’s wealthiest countries starts to run out.
The leader of the Conservative Party, Erna Solberg, will now start work on negotiating a coalition with other centre-right parties.
With three quarters of the votes counted, the bloc of four centre-right parties had won 96 of 169 seats in parliament.
Mr Stoltenberg said he would step down after presenting the budget next month.
“In accordance with Norwegian parliamentary tradition, I will seek the resignation of my government after the presentation of the national budget on October 14, when it’s clear that there is a parliamentary basis for a new government,” he said.
The Labour leader, prime minister since 2005, congratulated Ms Solberg.
He said his party tried “to do what almost no-one has done, to win three elections in a row, but it turned out to be tough”.
Ms Solberg, 52, will become Norway’s second female prime minister and its first Conservative prime minister since 1990.
She told supporters in Oslo: “Today the voters have produced a historic election victory for the right-wing parties. We will give this country a new government.”
Correspondents say at least the top two cabinet posts – and possibly the top three – are likely to be filled by women.
The vote was Norway’s first general election since the attacks by Breivik – a far-right extremist – killed 77 people at a Labour Party youth camp in 2011.
Breivik had previously been a member of the Progress Party.