MOSCOW, FEB. 4 -- The Soviet Supreme Court today began its review of the case against Nikolai Bukharin, 50 years after the leading Bolshevik theoretician was executed in Stalin's purges, Soviet sources said.

The process is expected to lead to Bukharin's legal and possible political rehabilitation, the sources said. Other Bolsheviks who were convicted with Bukharin at a 1938 show trial, including onetime premier Alexei Rykov, are also expected to be rehabilitated in coming days.

The rehabilitation of Bukharin, which has been expected for several months, is regarded as an event of major political significance with implications for the policies being pursued by Soviet leader Mikhail Gorbachev.

Bukharin was a leading advocate of the New Economic Policy, a program adopted by Lenin that allowed limited private enterprise in the 1920s.

Now, as Gorbachev pursues reforms that also create opportunities for private initiative, the New Economic Policy and its theoretical underpinnings have gained importance. The publication last weekend of a report by Bukharin in the Communist Party's theoretical journal Communist signaled the pending rehabilitation not only of the man, but also of his theories.

Bukharin defended the New Economic Policy as a gradualist approach to socialism and, in the field of agricultural policy, argued for an alliance with the "middle" peasantry and against forced collectivization. These views pitted him against Stalin who, by 1929, turned the party's theoretical debates into the battleground of a vicious, bloody power struggle.

Bukharin, a popular leader whom Lenin dubbed the "favorite of the party," was arrested in 1938 and accused of treason, sabotage and even attempting to assassinate Lenin. The grotesque charges, part of Stalin's attempt to crush the party's moderate wing, were echoed by the Kremlin's top prosecutor, Andrei Vyshinsky, who said of Bukharin: "The hypocrisy and perfidy of this man exceed the most perfidious and monstrous crimes known to the history of mankind."

Until recently, the official view of Bukharin remained much as it was in 1938. Although he was one of the leading figures in the Bolshevik revolution and a close associate of Lenin, Bukharin's name was omitted in history books and encyclopedias, and his legal and political status was one of a criminal.

Attempts to rehabilitate him during the leadership of Nikita Khrushchev got caught in the backlash against de-Stalinization. Bukharin's widow, Anna Larina, whom he had married when she was 19, was denied her full pension as the wife of one of the Soviet state's founding fathers.

For years, Bukharin's name has been associated with reform moves inside and outside the Soviet Union, as communist theoreticians looked for historical precedents in their arguments for attempts to break up centralized bureaucracies and for a limited market economy.

In the last year, after Gorbachev's invitation to fill in the "blank pages" of Soviet history, journalists, historians, film makers and writers have rediscovered Bukharin and other old Bolsheviks. For the first time since his death, Bukharin's name appeared in the encyclopedia devoted to the 1917 revolution.

The key turning point in the official view of Bukharin came on Nov. 2 when Gorbachev, in a speech on the 70th anniversary of the revolution, quoted Lenin's favorable comments about Bukharin, while also noting his failings.

Since then, Bukharin has been the focus of a number of articles, including a long interview with his widow in the weekly magazine Ogonyok. For the first time in a Soviet publication, Anna Larina, now 72, recounted how Bukharin, on the eve of his arrest, asked her to pledge herself to the task of his exoneration.

Now as in the past, Bukharin's rehabilitation is seen as a symbol of liberalization, especially among the intelligentsia. Thus, he has emerged as the hero of several recent literary productions, including a poem by Yevgeny Yevtushenko and a new play by Mikhail Shatrov.

The rehabilitation was expected in December. Soviet and western analysts link the delay to the continuing sensitivity over the subject, particularly among the generation of leaders who began their careers under Stalin.

In recent weeks, the tempo of historical revelations has picked up, touching not only the purges of the 1930s but also repressions of the 1950s, the last years of Stalin's life.

The rehabilitation process is part of a larger review of the consequences of the Stalin era. Some Soviet sources have said that it will continue at the next session of the Supreme Court, perhaps including such figures as Lev Kamenev and Grigori Zinoviev, who were executed in 1937.

The case of Leon Trotsky, still the most controversial of the Bolsheviks, is likely to be the last one reviewed, although some liberal historians here argue that the process will be complete only when all those convicted of political crimes in Stalin's courts are exonerated.