Zagreb, Jan 11 (DPA) Croatia's opposition Social Democratic Party (SDP) candidate Ivo Josipovic has swept the country's presidential election run-off Sunday to become the next head of state, exit surveys said.

Television channels Nova and RTL said Josipovic with 64.6 percent of the vote defeated his rival, the populist Zagreb Mayor Milan Bandic, who garnered 35.3 percent.

"We knew the difference would be vast," Igor Dragovan from Josipovic's campaign headquarters said. The margin projected by exit polls is in line with the last-minute popularity surveys.

Josipovic, 52, also clearly dominated the first round of the vote, Dec 27, but did not win the 50 per cent required for an immediate victory and was forced into the run-off.

The turnout in the first round was only 44 percent, lower than in any of the four previous presidential elections, won twice by the late nationalist Franjo Tudjman in the 1990s and twice by the outgoing leftist Stjepan Mesic in 2001 and 2005.

The turnout Sunday was stronger, reaching 38 percent with three hours still to go in the vote, or four percent more than at the corresponding time Dec 27.

Official Croatian election results are often delayed due to the additional time needed to count the votes of the 400,000 voters who live abroad, mostly in neighbouring Bosnia.