SEOUL - South Korea's liberal Uri Party appears to be heading for a significant victory over more conservative rivals in Thursday's elections for seats in the National Assembly. This may make political life easier for the country's president.

Members of the Uri Party cheer at party headquarters in Seoul Thursday, after South Korean news organizations predicted the party might win as many as 180 seats in the 299-seat legislature. It had only 49 seats in the outgoing National Assembly.

The other main contender in the race, the conservative Grand National Party, or GNP, trailed by a wide margin. Specific predictions vary widely, however, and the final result was not expected until late Thursday night Seoul time.

The Uri Party, which formed late last year, is allied with impeached President Roh Moo-hyun. In the campaign, Uri candidates focused on resentment over the impeachment, which the GNP helped drive through the legislature last month.

South Korea's Constitutional Court is widely expected to reject the impeachment, which came after the president was found to have violated an election law, and allow President Roh to return to office.

Uri Party Chairman Chung Dong-young says the vote is a historic event. He says voters have spoken out resoundingly against corruption in South Korean politics.

Uri and the GNP both made the fight against corruption the centerpiece of their platforms. The GNP, which over the past few years has faced campaign-funding scandals, says it is reinventing itself as a clean party.

Overall, sentiment in this election has been sharply divided between generations. Younger voters tend to support Uri, while older people back the GNP.

Professor Leo Sang-Min Whang of Yonsei University says the Internet played a major role in connecting younger voters politically. "In cyberspace, it becomes their foreground, so they use cyberspace to express their opinions, which are quite different from the majority group's opinions in Korean society," he said.

Mr. Roh won the presidency 18 months ago in part because of the support of younger voters. The former labor-rights lawyer has pledged to reform the political system, clean up business and continue to improve ties with communist North Korea.

It appears that this election means that for the first time, a reformist, liberal president in South Korea will have the backing of a majority in the National Assembly. Conservatives have dominated the legislature until now in Mr. Roh's term, and also controlled the assembly during the term of his liberal predecessor, Kim Dae-jung.