Kim Dae-jung went against the opinion of the opposition party and the people by appointing Mr Chang acting prime minister

Grand National Party spokesman

Chang Dae-whan, 50, is the chief executive of the Maeil Business Newspaper.

The announcement came a day after the main opposition Grand National Party (GNP) seized control of the country's National Assembly in a by-election landslide.

The prime minister is a largely ceremonial figure in South Korea, but would take over the reins of power if the president was incapacitated.

His appointment must be ratified by the National Assembly.

Reservations

President Kim's initial choice for prime minister - Chang Sang, the president of a women's university - was vetoed by parliament last week.

Local election results were a blow to the president

Ms Sang would have been the country's first female prime minister.

But the GNP had accused her of lying over property dealings and her academic background.

The party also expressed strong reservations about the new nominee.

"President Kim Dae-jung went against the opinion of the opposition party and the people by appointing Mr Chang acting prime minister," said GNP Spokesman Nam Kyong-phil.

"As we are not able to form an opinion about the nominee's suitability for the post at this stage, we will do our best to determine if he is the right man for the job through parliamentary hearings," he said.

However President Kim's Millennium Democratic Party (MDP) welcomed the appointment.

"The new nominee seems to be a man of outstanding ability who has his own views on international affairs and the economy," MDP Spokesman Lee Nak-yon said.

Presidential poll pointer

Kim Dae-jung's allies did badly in Thursday's by-elections, a bad sign for him ahead of presidential elections at the end of the year.

Mr Kim is barred from running again by the constitution.

But the pro-government candidate, Roh Moo-hyun, has been trailing in the polls.

The election results will be a further boost for the GNP's presidential hopes.

GNP leader Lee Hoi-chang, who narrowly lost a 1997 election to President Kim, is running for president again this year.

GNP candidates from won 11 of the 13 districts being contested, including all three high-profile seats fought in Seoul.

Those wins give a majority in the single-chamber parliament to the conservative GNP, which is critical of President Kim's "sunshine" engagement policy with North Korea.

The independent election commission said the turnout was just 29.7% - a new national low.

Correspondents said many voters were on holiday, put off by the country's scandal-ridden politics or busy cleaning up after torrential rains which flooded thousands of homes and killed at least five people.