Victor Grishin, former Communist Party boss of the Soviet capital and by reputation one of the staunchest holdovers of the Kremlin's old guard, was retired from the ruling Politburo today in a meeting of the Central Committee, the official news agency Tass reported.

Boris Yeltsin, who two months ago replaced Grishin as leader of Moscow's Communist Party, was elected a candidate, or nonvoting, Politburo member, Tass said.

Yeltsin, 55, raised a citywide furor last month with a hard-hitting speech criticizing corruption and calling the city's management inept. He is widely regarded here as a senior-level recruit brought in to rid Moscow of some of the inefficiencies that have stifled its growth in recent years.

Tass said the Central Committee relieved Grishin, 71, of his duties "in connection with his retirement on pension." The fact that Grishin would receive a pension after being cast as head of a party machine rife with corruption affirmed the view among some western analysts here that old guard members would be retired gracefully, rather than fired under a cloud.

Like Nikolai Ryzhkov, who was named premier last fall, and several others in the inner circle of new economic advisers, Yeltsin comes from Sverdlovsk, in the Urals.

In its final session before the 27th party congress begins next Tuesday, the Central Committee also approved several documents to be presented to the 5,000 delegates, including a revised Communist Party program, the new five-year economic plan, and proposed rule changes in the party charter.

Western analysts and Soviet officials said they expect that at least half of the 300 members of the Central Committee will be replaced at the congress.

One of the first acts of the Central Committee at the end of the congress will be to elect the Politburo.

Grishin had been a candidate member of the Politburo since 1961 and a full member since 1971, under the late Soviet leader Leonid Brezhnev. In the shuffle for power before Mikhail Gorbachev became party leader last year, Grishin had been widely regarded as a possible successor to the Kremlin leadership.

Several western analysts have included him in the group of opponents to Gorbachev.

Under Gorbachev, Grishin's fortunes faded. A press campaign against corruption scandals involving city officials climaxed on Dec. 24 when he was stripped of his duties as head of the biggest local Communist Party in the Soviet Union.

Grishin is the third member of the Politburo to lose his seat in the 11 months since Gorbachev came to office. Previously, Grigori Romanov, the former Leningrad party leader, and Nikolai Tikhonov, then premier, were dropped.

The Central Committee also retired one of its secretaries, K.V. Rusakov, who headed the department on relations with East Bloc countries. Rusakov, 77, had been ailing and inactive for some time, according to Soviet sources. Tass said he was removed "in connection with his retirement on pension for health reasons."