LJUBLJANA, Yugoslavia (AP) _ Ex-Communist Milan Kucan and conservative Joze Pucnik emerged Sunday as the top candidates for Slovenia's presidency in the Yugoslavian republic's first free multiparty elections since 1945.

According to unofficial partial results, Kucan, a candidate of the Democratic Renewal, formerly the Communists, received 40.2 percent of vote, while Pucnik, of the center-right DEMOS coalition, won 26.8 percent.

Election law requires a runoff on April 22 between the top two candidates when no one receives more than 50 percent.

''I'm confident that I will win the runoff election,'' Pucnick said. ''Many Slovenians link Kucan to Communism, and that is a disadvatge for him.''

Independent candidate Ivan Kramberger and Marko Demsar of the Liberal Party received 21.5 and 10.5 percent, respectively, of the 100,000 votes counted.

Kucan told reporters he hoped those who voted for Kramberger and Demsar will give their votes to him in the runoff.

About 75 percent of the 1.5 million registered voters, 18 years and over, also voted for 240 seats in the new multiparty parliament.

Official results from the republic's 4,130 polls were not expected until Tuesday.

Turnout was heavy, with voters lining up in front of the polling stations despite heavy rain.

Louis Sell, a U.S. Embassy spokesman who is monitoring the elections along with four members of Congress, said ''the voting seems to be extremely fair.''

High school teacher Janez Toncic said he was excited as he cast his ballot in Ljubljana. ''I never thought I would live to see the day when we bury single-party monopoly in Slovenia,'' he said.

Slovenia is the first of Yugoslavia's six republics to hold free elections.

Yugoslavia is a loose federation of six republics and two autonomous provinces. It is ruled by an eight-man collective presidency.

Communist leaders have allowed the formation of opposition parties in all of the republics, but only Croatia, the second-largest republic, has also scheduled multiparty elections. Those elections are planned for April.

Communist leaders in Serbia, the largest republic, have demanded Communist Party dominance and have harshly criticized the reforms in Slovenia.

Yugoslavian President, Janez Drnovsek, a Slovene, said after voting in Ljubljana that he hoped the country ''will have the first free elections for the federal parliament by the end of this year.''

He said elections in Slovenia ''represent a sign of the democracy drive that cannot be stopped in Yugoslavia.''

The main issue in the presidential campaign were Slovenia's future within the troubled Yugoslav federation and high inflation.

Kucan said the voting showed that Slovenia was becoming a Western European democracy.

''It is a pleasure to see people vote freely after so many years,'' Kucan said. ''Slovenia is finally joining (West) European democracy.''

Kucan's closest rival was Pucnik, a former dissident and leader of the DEMOS, a coalition of five pro-secession center-right parties.

''The main task of the DEMOS is to oust Communists from power in Slovenia and make parliamentary democracy work in the republic,'' Pucnik told reporters while voting in his native Slovenska Bistrica.

Pucnik, a professor of philosophy, spent seven years in Slovenian prisons during the 1950s for his opposition to communism. He was forced into exile after his release from prison and first returned to Yugoslavia in 1989.

The makeup of the new Slovenian parliament could decide whether the republic remains within Yugoslavia.

Most of the 17 parties taking part in the parliamentary elections urged Yugoslavia to become a loose confederation, but some rightist parties want quick secession.

Slovenians are increasingly pushing to secede from Yugoslavia because they are unhappy with the slow pace of democratic and economic reforms in the rest of the country.

Slovenian reform-minded Communists have moved quickly over the past three years to create a pluralistic system in the republic and have shown considerable popularity in the electorate.