Greek Socialist party supporters react as they watch exit poll results from the parliamentary elections on a display in AthensGreece's ruling conservative party has conceded defeat in Sunday's national election.

Prime Minister Costas Karmanlis acknowledged a Socialist victory after early results showed the opposition Socialist (PASOK) party more than seven percent ahead of his New Democracy Party.

With a fifth of the ballots counted, an official projection put the Socialists at about 43 percent of the vote and the conservatives at about 36 percent. Final results are expected Monday.

The interior ministry says the Socialists could win up to 160 seats in the 300-member parliament, a decisive victory over the New Democracy party, which before the election held a meager one-seat margin.

A senior member of the Socialist party (Evangelos Venizelos) called the expected win "historic."

Prime Minister Karamanlis ordered the snap polls halfway through his term, saying Greece needs a government with a clear mandate to deal with its economic woes.

Socialist leader George Papandreou is now poised to become the new prime minister.

The ruling party in Greece has been stung by corruption scandals and voter discontent with the economy.  

Conservatives once loyal to Mr. Karamanlis have also criticized the government's handling of riots late last year, triggered by the fatal police shooting of an Athens teenager.

Mr. Karamanlis held his final campaign rallies Friday, promising voters an economic turnaround by 2011.