The Soviet Parliament gave preliminary approval Friday to President Mikhail Gorbachev's economic reform plan, after he accused his key rival of shirking responsibility for the transformation to a free market system.

The Supreme Soviet voted 356 to 12 in favor of the plan, with 26 abstentions, and began debating possible amendments.Gorbachev, selling his plan as "the only rational course of action," said the huge Russian Federation wants faster, more radical changes but is afraid of the social and economic disruptions they would cause.

In a 50-minute speech, Gorbachev also dismissed concerns that the switch from a centrally planned system was a retreat from socialism.

Russian President Boris N. Yeltsin has lambasted Gorbachev's program as a "catastrophe" that is "doomed to fail" within months after touching off inflation and unemployment.

He said the largest and richest of the 15 Soviet republics may proceed with a more radical 500-day plan as early as Nov. 1.

Gorbachev said he shared Yeltsin's concern and alarm about the country's deteriorating economy, and his fears of inflation. But he noted the Russian parliament recently raised the wholesale prices of meat, and said this touched off a wave of inflation.

"Comrade Yeltsin's assertions are strange, to say the least," Gorbachev said. "I'm under the impression that the Russian leadership is afraid of difficulties and wants to pass on responsibility for possible difficulties and consequences . . . onto central organs of power."

Leaders of the republics were invited to join the 542 national lawmakers in listening to Gorbachev's speech in the Supreme Soviet's beige marble hall, but Yeltsin was not present. The speech received only five seconds of lukewarm applause.

The 59-year-old Gorbachev, in a low-key address, appealed to the Soviet people and lawmakers at all levels of government to approve his plan, stressing "we cannot delay any longer."

Some parts of Gorbachev's plan will require legislative changes approved by the Supreme Soviet, but large sections are to be implemented by the republics. Gorbachev also has sweeping powers, valid until next spring, to unilterally impose changes need to overhaul the economy.

Gorbachev's plan, distributed to parliamentary committees for study on Tuesday, would transform the moribund Soviet economy in four stages. It sets no deadline for the switch from a centrally planned economy, but says other countries have achieved similar goals in 18 months to two years.

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(Additional information)

4 stages of Gorbachev's plan

Stage 1: Calls for reduction of the national budget deficit, controls on the money supply, higher bank interest rates on savings accounts, increased production of consumer goods and land reform.

Stage 2: Provides for freeing the prices of 70 percent to 80 percent of goods from state control, encouraging small private businesses and a social welfare net for workers who lose their jobs.

Stage 3: Establishes a minimum wage and the lifting of restrictions on the size of earnings, as well as a free market for housing and a modern banking system.

Stage 4: Ends the government monopoly of many industries and makes the ruble a convertible currency.