Oct. 1 Deadline Is Urged for Soviet Reforms : Economy: Gorbachev adviser pushes for quick approval. Plan calls for putting nation’s factories into private hands within 500 days.

President Mikhail S. Gorbachev’s economic adviser said Thursday that he hopes lawmakers around the country will agree by Oct. 1 on a radical reform plan to sell off most of the Soviet economy into private hands and decentralize decision-making within 500 days.

“The time has come when we must choose,” Nikolai Y. Petrakov told a news conference he had called to explain the status of competing proposals for transition to a market-oriented economy after weeks of bickering.

Gorbachev had announced the previous day that a final draft for the reforms had been forged from the more radical proposals of a group led by Soviet economist Stanislav S. Shatalin and the centralized, more deliberate approach of Prime Minister Nikolai I. Ryzhkov.

The Shatalin plan, the intellectual offspring of an economists’ task force created by Gorbachev and Russian Federation leader Boris N. Yeltsin, was made public in its complete form Thursday for the first time. It mandates a near-total break with the top-heavy bureaucratic economics that date back to the era of Josef Stalin.

Asked if the plan means that the Soviet Union has gone capitalist, Petrakov said that what is important now is results, not labels.

“We need an effective economy in the first place,” he said. “As for the terminology, we must make the point clear: If it is the socialism which Stalin created, then we are rejecting it.”

According to a copy of the Shatalin plan obtained by The Times, it seeks within 500 days the selling or leasing into private hands of no less than 70% of the country’s factories and up to 90% of its construction enterprises, wholesale and retail trade network, restaurants and services.

Under an “economic union of sovereign republics,” the Soviet Union’s increasingly restive local territorial units are granted the “exclusive right” to regulate the ownership, use and management of all wealth in their territories.

To be full-fledged members of the new union, however, the republics would have to delegate certain powers to the central government, including defense, state security and responsibility for a single, unified monetary policy.

By Jan. 1, as part of the initial stage of the reforms, all government subsidies to enterprises are to cease, and 100 to 200 unprofitable plants are to be shut down.

The unified document, Gorbachev said, has been submitted to the Supreme Soviet, the national legislature, and to lawmakers in the country’s 15 republics for their consideration. But Petrakov indicated that there had been no genuine compromise, and he said the regional parliaments had been sent copies of the original Ryzhkov and Shatalin plans, plus a third blueprint heavily based on the Shatalin proposals but containing a “few valuable aspects” from Ryzhkov’s.

Yeltsin has said that merging the two plans would be as impossible as mating a hedgehog and a snake, and he is seeking rapid implementation for the Shatalin plan. The Russian Parliament has already heeded him and approved it in principle, with only one dissenting vote.

As debate continued over the reform plans, bad economic news continued unabated. Izvestia, the government newspaper, printed official statistics showing that in the first eight months of 1990, Soviet industrial output dropped by 0.7% compared with the same period a year earlier.