Seoul: South Korea's new president won the parliamentary majority he needs to push through promised major economic reforms but bitter squabbling in his conservative camp could hamper the ambitious plans, experts said on Thursday.

The conservative Grand National Party (GNP) won 153 seats in Wednesday's vote for the 299-seat National Assembly, short of the commanding lead President Lee Myung-bak might have hoped for after he took office in February, intent on radical change to Asia's fourth-largest economy.

"The electorate has decided it wants conservatives to place checks and balances on the other conservatives," said Kim Kwang-dong, a specialist in domestic politics at the Nara Policy Institute.

President Lee began his five-year term in February pledging to boost growth this year to six per cent from five per cent last year, end regulation that he said stifles business and open the export-driven economy more to foreign investment. But his optimistic growth targets have begun to look unrealistic as the global economic downturn starts to bite at home.

"Koreans have become more conservative. We don't trust the liberals but we also didn't want to give Lee Myung-bak too much power," said a medical researcher who voted for the GNP candidate in her central Seoul constituency.

Conservative stalwarts, unhappy with the way Lee had treated them, led a rebellion in the GNP ahead of the vote. They won 32 seats under the banner of other right-leaning parties.

Local media calculated that Lee's main opponent for last year's GNP presidential nomination, Park Geun-hye, will have more than 50 allies in the rebel and GNP camps when the new parliament sits at the end of May for a four-year term.

Newspapers said the president, who saw several of his confidants defeated in an election with the lowest voter turnout in the country's history, may have to cut back on more ambitious plans, such as a cross-country canal, because he does not have enough political capital to force them through.

"Now that we have a majority, we should try to pick up speed and produce tangible results for the people," spokesman Lee Dong-kwan quoted the president telling aides yesterday.

Left-of-centre parties which had controlled parliament suffered a stinging defeat in their first loss to the conservatives in the two decades the country has had open, democratic elections to the National Assembly.

The United Democratic Party saw its seats cut by about 40 per cent to 81 and both its leader and the liberal's candidate for the December presidential election defeated.

Financial markets generally welcomed the win by the business-friendly GNP.

"This outcome appears to be a strong mandate for the new administration to implement its 'pro-market and pro-growth' policy platforms," Goldman Sachs said in a research note.