US TV networks projections showed that Republicans would hold at least 52 of the 100 Senate seats, compared to the 51 they now have.

The Republicans were also predicted to enjoy continued majority in the 435-seat House of Representatives with likely addition of a few seats to the current 227.

The Republican capture of Democratic open seats in the states of Georgia, North Carolina and South Carolina prelude an expected widened lead over Democrats and a majority in the next Senate, which is to convene in early January.

They also kept their decade-long hold on the House of Representatives for another two years, after knocking off four veteran Texas Democrats along the way.

By winning their 218th seat, and with a dozen more likely to come, Republicans were set to control the House for a dozen consecutive years, the first time they have achieved that feat since the 12 years that ended in January 1933, US television reported.

The win could give them at least 232 seats, 14 more than the majority needed for House control.

The reelection of Senate Democratic leader Tom Daschle in SouthDakota was jeopardized and it is still unknown whether he could survive the powerful challenge from former Republican John Thune. If not, Daschle would become the first Senate leader in half a century to be voted out of office.

In Illinois, Democrat Barack Obama won the seat being vacated by a retiring Republican. He will be the only black member of the next Senate.