Norwegian center-right leader Erna Solberg is set to form a new government after Labor Prime Minister Jens Stoltenberg admitted election defeat, BBC News reports.

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. Breivik had previously been a member of the Progress Party.

With three quarters of the votes counted, the bloc of four center-right parties had won 96 of 169 seats in parliament.

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 Labor leader, prime minister since 2005, congratulated 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".

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."