Conservative Vojislav Kostunica emerged as the front-runner in Serbia's presidential election after Sunday's first round of voting. He will face free-market economic reformer Miroljub Labus in a runoff next month. The election is unlikely to resolve a bitter power struggle among the pro-democracy groups that toppled former Yugoslav president Slobodan Milosevic.

These were Serbia's first presidential elections since the fall of Mr. Milosevic.

Mr. Kostunica, who defeated the former strongman in the 2000 elections and became president of Yugoslavia, is Serbia's most popular politician.

But his current job is likely to disappear in the months ahead when the Yugoslav federation is disbanded and recast as a looser union between Serbia and the smaller republic of Montenegro. That is why he is running for the Serbian presidency.

Unofficial returns show Mr. Kostunica winning the first round balloting with more than 31 percent of the vote. Mr. Labus, who is backed by powerful Serbian Prime Minister Zoran Djindjic, came in second with just under 28 percent.

Though the two rivals are both strong believers in democracy, they have conflicting visions of Serbia's future.

Mr. Labus, a technocrat who is considered the architect of Yugoslavia's economic reform program, wants Serbia to become part of the West and attract foreign investment. He says Serbia needs to speed up the pace of change, no matter how painful it might be in the short term for ordinary citizens.

"That means to continue with economic reforms that everybody would benefit from and to continue on the path to accession to the European Union," he said.

While most voters agree that reforms are necessary, many have lost their jobs during the last two years of transition from a state-run economy. Reform, therefore, is proving difficult to stomach. Mr. Kostunica has focused his campaign on Serbs' unhappiness with low living standards and job losses.

Mr. Kostunica, a constitutional lawyer and self-described moderate nationalist, is intent on building up the rule of law in Serbia. But, as pollster Srdjan Bogosavljevic found out during the campaign, many voters had their own idea of what was meant by the rule of law.

"So we were trying to understand what rule of law means for the average Serb and, in fact, they are thinking about protection from unemployment. That is, for them, rule of law," he said.

Mr. Kostunica has been engaged in a fierce battle with the free-market economic reformers around Mr. Labus and his patron, Prime Minister Djindjic. He has accused them of bending over backwards to please the West. He has also insisted that suspected Serb war criminals be tried at home rather than at the international tribunal in The Hague, which he regards as being biased against Serbs.

Experts say Mr. Kostunica is in line to win the runoff because he can count on the votes of those who supported radical nationalist Vojislav Seselj and other fringe candidates in Sunday's balloting. Mr. Seselj, who was endorsed by Mr. Milosevic, made a surprisingly strong showing, getting more than 22 percent of the votes.

Political analyst Bratislav Grubacic says Mr. Seselj, like French extreme right-winger Jean-Marie Le Pen, can always count on getting 10 to 15 percent of the vote in Serbia by capitalizing on resentment of the West and the frustration of Serb refugees from such places as Bosnia, Croatia, and Kosovo.

"When Seselj gets more than 15 percent, then it indicates that there is something wrong in our social and economic environment," he said. "That there is still a huge frustration among Serbs, not only national but also social and economic, and I think it played a very big role in Seselj's success in yesterday's election."

But what worries Mr. Grubacic is more than the ultra-nationalist vote. Citing Sunday's turnout of barely 55 percent of registered voters, he says voter participation in the second round could drop below 50 percent. If that happens, he says the election would be declared null and void.

And that, says Mr. Grubacic, would only prolong the political infighting between supporters of Mr. Kostunica and backers of Mr. Djindjic and Mr. Labus.

In his view, such an outcome would paralyze lawmaking and the reform process, and scare investors away.