MOSCOW, OCT. 31 -- In what many described as a bellwether ballot, voters in a Moscow suburb rejected a swastika-wearing ultranationalist and a free-market democrat and elected to parliament a controversial businessman who is under investigation for tax fraud.

The Sunday election in a dreary industrial district north of Moscow, made necessary by the gangland-style shooting of the incumbent last spring, reflected the disillusion and disgust many voters feel for the government, analysts said.

Sergei Mavrodi, head of an investment firm that collapsed last summer in the most spectacular financial failure of Russia's young capitalist era, won his seat with the support of Vladimir Zhirinovsky, the ultranationalist whose party garnered the most votes in parliamentary elections last December. Mavrodi, 39, spent much of the three-month campaign in jail while police investigated allegations of wrongdoing against him.

Dogged by antisemitism and jackbooted neo-fascists, democratic reformists were soundly defeated in the election, which came a little more than a year before a nationwide general election. Most reform parties did not even field a candidate.

The candidate most closely identified with free-market economics, businessman Konstantin Borovoi, came in third, according to preliminary results. Some analysts suggested that Borovoi lost votes because his middle name, Natanovich, has a Jewish ring to Russian ears.

The tone of the campaign was set by a neo-fascist candidate, whose jackbooted supporters filled every election forum even though Zhirinovsky backed Mavrodi. Although their candidate ended up far back in the pack, his swastika-blazoned followers put ethnicity on the agenda of every electoral debate, with many candidates proudly declaring they were "Russian" -- meaning not Jewish or Georgian or a member of some other ethnic minority.

The early results showed Mavrodi collecting 28 percent of the vote. A local bureaucrat and longtime Communist Party functionary came in second with 15 percent, while Borovoi received 14 percent. Nine other candidates, including a leader of the antisemitic group Russian National Unity, split the remainder. Only 30 percent of eligible voters took part.

Mavrodi began the campaign in prison and did not make a single appearance in the election district, even after a judge ordered him freed Oct. 12. But he promised to spend as much as $10 million of his own money to bring telephones and other improvements to his downtrodden constituents.

By portraying himself as a victim of arrogant government investigators, Mavrodi also tapped voter resentment of official corruption, high-handedness and incompetence in this nation's young democracy, analysts said.

"People feel victimized," said Sarah Mendelson, a program officer with the National Democratic Institute who followed the campaign closely. She said a common view among voters was: "The government had no right to do that to him, and they have no right to do all this to us."

Mavrodi's MMM company collected billions of rubles from Russians in what critics called a classic pyramid scheme. The company used the money it collected for television advertising, promising huge returns at no risk and bought back shares at ever increasing prices until the pyramid collapsed this summer, leaving the shares virtually worthless.

MMM said the collapse was triggered by jealous bureaucrats. Many bankrupted shareholders believed that only Mavrodi's election could rescue their investments, a sentiment Mavrodi encouraged. He said in interviews that if he lost, he could be returned to prison and MMM shares would never recover their value. If he won, he said, the MMM shares would soon soar above their pre-collapse level.

In the wake of his victory today, an MMM spokesmen said the company would again begin selling shares at 48 Moscow outlets and 49 other places across Russia and other former Soviet republics.

"It's so cynical, it's really depressing," Mendelson said.

Mavrodi's opponents in the race accused the financier of running mostly to win the legal immunity that members of parliament enjoy. Moscow's chief prosecutor said today that his investigation of Mavrodi's alleged tax fraud will continue but that he would have to appeal to parliament to lift Mavrodi's immunity if and when formal charges are filed.