Georgians have voted overwhelmingly for independence in the strongest rebuff by a Soviet republic to President Mikhail Gorbachev's efforts to hold the union together, preliminary results showed Monday.

With 38 of the republic's 71 districts reporting, 99.3 percent of voters in Sunday's referendum favored secession, said Valerian Khukhunashvili, a Georgian government spokesman in Moscow.Nearly 90 percent of the 3.3 million eligible voters in the fractious southern republic cast ballots, the independent Interfax news agency quoted Vakhtang Khmaladze, chairman of Georgia's electoral commission, as saying. Complete results were expected late Monday.

Because of its near-unanimity and high turnout, the vote dealt an even stronger blow to Gorbachev's campaign to unite the 15 diverse republics in a new Union Treaty than similar referendums in the three Baltic republics.

In February, 91 percent of Lithuanian voters endorsed independence, followed in March by 74 percent of Latvians and 78 percent of Estonians. Armenia has scheduled a vote for Sept. 21.

The Georgian referendum asked: "Do you agree that the state independence of Georgia should be restored on the basis of the independence act of May 26, 1918?"

Georgia, a multiethnic republic of 5.3 million wedged between the Caucasus Mountains and the Black Sea, proclaimed independence from the Russian empire near the end of World War I. It was forcibly absorbed into the Soviet Union nearly three years later and incorporated under a 1924 treaty.

Georgia, Lithuania, Latvia, Estonia and Armenia - plus Moldavia - refused to take part in the March 17 nationwide referendum on preserving the union for which Gorbachev vigorously campaigned.

Nine republics, representing three-quarters of the country's population, approved the referendum by 76 percent. Gorbachev has used the results to bolster support for his proposed new Union Treaty.

He says he considers anti-Kremlin polls to be invalid, but he has not tried to stop them.

Fifteen countries, including the United States, sent election observers to Georgia to monitor the voting.