President Mikhail S. Gorbachev's vision of a renewed Soviet federation won the approval of more than three-quarters of voters in the country's first referendum, the national legislature was told Tuesday.

Vladimir Orlov, chairman of the Supreme Soviet's referendum committee, said 82 percent of eligible voters cast ballots Sunday in the districts that had reported results by today. He said 77 percent of those voted "yes," although the total was higher in some republics."According to official information . . . an absolute majority of our citizens has voted for preserving the union," Orlov told lawmakers. He said 436 of the nation's 1,059 districts have reported results.

Six small separatist republics boycotted the referendum.

Gorbachev appeared to have won strong backing in rural and eastern republics but much weaker support in key cities such as Moscow and Leningrad. Early returns showed 53 percent of voters opposed the referendum in Kiev, the Ukrainian capital.

Voters in the large Russian and Ukrainian republics endorsed both the union and measures favoring local autonomy.

Neither Gorbachev nor his chief political rival, Russian Federation leader Boris N. Yeltsin, have commented publicly on the preliminary referendum results. Final results are not expected for days.

Gorbachev proposed the referendum to pressure leaders of the 15 republics into signing a new Union Treaty to preserve central control in the nation of more than 100 ethnic groups. All republics have declared some form of autonomy and seek primarily to cast off the yoke of central control of their economies and administration.

Orlov told lawmakers of alleged voting abuses in some republics.

He singled out Moldavian President Alexandru Mosanu for calling for a boycott of the vote and trying to block polling stations in the capital Kishinev and elsewhere. However, by day's end, Orlov said, "practically everyone in Kishinev who wanted to vote had voted."

Despite the problems, Orlov said 650,000 people cast ballots in Moldavia.

Moldavia was among the republics that refused to take part in the referendum, prompting Communist Party and military officials to set up balloting on their own.

Preliminary results indicated the referendum won approval by margins of 70 to 95 percent in seven republics: the Ukraine, Byelorussia, and the five Central Asian republics of Kazakhstan, Uzbekistan, Tadzhikistan, Turkmenia and Kirghizia.

In the ad hoc voting in the Baltic republics, Orlov said 250,000 people cast ballots in Estonia, nearly 500,000 in Latvia and slightly more than 500,000 in Lithuania. Officials earlier said 96 percent voted "yes" in Estonia and 97 percent in Lithuania.