The key institutions are the Serbian presidency and parliament, not the federal ones, and Mr. Kostunica has fought to get early Serbian elections, now expected in late December.

Belgrade is awash with rumors that Mr. Milosevic may give up the Serbian presidency, either by resigning before his term ends or declining to run in the fall elections.

Mr. Milosevic's hand-picked successor for the Serbian presidency, a colorless bureaucrat and former Yugoslav President, Zoran Lilic, is expected to win today.

Elections for the Serbian presidency scheduled for Sept. 21 are likely to be boycotted by the opposition parties, according to Slobodan Vuksanovic, spokesman for the Democratic Party.

One candidate for the Serbian presidency will be the opposition leader, Vuk Draskovic.

In 1997, Milošević was termed out of the Serbian presidency, and was elected to the federal presidency.

Milošević's Socialist Party of Serbia still wanted to retain the Serbian presidency, and their first candidate in the Serbian presidential elections in 1997 was Zoran Lilić.

The re-election of Milosevic to the Serbian presidency disappointed Western hopes for the election of a leader more disposed to compromise over Bosnia-Hercegovina.

If Yugoslavia disappeared, Mr. Kostunica would almost surely run for and win the Serbian presidency.

President Vojislav Kostunica of Yugoslavia, a moderate nationalist, came out ahead today in the first round of the election for the Serbian presidency, preliminary results indicated.