Serbian President Boris Tadic has conceded defeat in the runoff presidential election against nationalist opposition candidate Tomislav Nikolic.

Unofficial results give Mr. Nikolic 50 percent of the vote and President Tadic 47 percent.

Turnout was less than half of all registered voters with some voters saying they did not like either candidate.

Mr. Tadic congratulated his opponent and urged him to keep Serbia on the path towards European Union membership.

Mr. Nikolic thanked the Serbian people and promised to keep EU membership a goal. But he has said he would withdraw Serbia's membership bid if giving up claims to Kosovo is one of the conditions.

President Tadic campaigned on helping Serbia emerge from its image as a pariah because of the Balkan wars in the 1990s to a pro-European nation. But with a sour economy and 24 percent unemployment, Mr. Nikolic said it is time for a change.

Mr. Nikolic was a deputy prime minister under the late Serbian President Slobodan Milosevic, who died while on trial for war crimes in 2006. But Mr. Nikolic has since backed away from his radical views and now regards himself as a populist and mainstream conservative.