MOSCOW, SEPT. 14 -- President Mikhail Gorbachev has revised a radical plan for the Soviet Union's transition to a market economy to retain more power in Moscow over such issues as monetary policy and taxation, in an apparent attempt to settle major differences among his advisers over the pace and scope of reform.

The latest economic reform document, which was handed to Soviet legislators today, calls for rapid dismantling of the system of central planning under which the Soviet Union has been run for the last six decades. It draws heavily on a "500 Days" economic recovery plan already adopted by the Russian federation, the largest and most powerful of the 15 Soviet republics, and accepted in broad outline by Gorbachev.

There are, however, significant differences between the original "500 Days" plan and Gorbachev's revised version. The new document, which Gorbachev has recommended to the Supreme Soviet, or standing legislature, as a basis for discussion, includes several clauses designed to prevent the dispersal of economic and political power from the capital to the republics.

The original plan, which was drawn up by a panel of radical economists appointed by Gorbachev and Russian President Boris Yeltsin, vests "supreme" economic and political power in the republics. Gorbachev's latest proposal attempts to take back some of this power for the central government, putting the federal authorities in charge of monetary and foreign exchange policy and giving them the right to raise taxes.

By seeking to preserve the Kremlin's prerogatives, Gorbachev appears to be attempting to prevent his presidential authority from being undercut by a rush of sovereignty declarations by the republics. He is also meeting one of the principal objections of his embattled prime minister, Nikolai Ryzhkov, to the "500 Days" plan.

At a press conference this week, Ryzhkov said a refusal to allow the central authorities to raise taxes could lead to the breakup of the Soviet Union. The Russian legislature insists that the federal budget should be made up entirely of contributions from the republics.

Although much of the argument has been couched in dry economic terms, what is ultimately at stake is the nature of the Soviet Union itself. Yeltsin and other Russian leaders favor transforming the country into an "economic union" of sovereign states, along the lines of the 12-nation European Community. Gorbachev's proposals delete all references to an "economic union," referring instead to the existing federal state.

The latest document suggests that the president has sided with his prime minister on this key point, although he has endorsed Russian proposals for rapid denationalization and privatization of huge chunks of the Soviet economy. It remains to be seen whether this will be sufficient to satisfy Ryzhkov, who has indicated that he will resign if he does not get the backing of the Supreme Soviet.

Ryzhkov's closest economic aide, Deputy Prime Minister Leonid Abalkin, suggested in a legislative debate today that there are still big and probably insurmountable differences between the two camps. He described the "500 Days" plan as unworkable, saying that proposals for the immediate sale of state assets would harm future generations and Soviet citizens without financial reserves.

Another leading economist, Abel Agenbegyan, told the Supreme Soviet today that it was impossible to find common ground between the Russian plan and the Ryzhkov approach. He predicted that the country would have to choose between the rival proposals.

The draft sent by Gorbachev to the Supreme Soviet includes a new clause reserving "monetary and foreign exchange policy" for the central authorities and describes the ruble as the only legal currency within the Soviet Union.

The original "500 Days" plan, by contrast, allows individual republics to launch their own currencies and set up their own banking systems.

Several republics, including the Ukraine, the second-largest republic after Russia, already have passed legislation to establish their own currencies. The Baltic republics of Lithuania and Estonia plan to launch their own currencies at the beginning of next year.

The principal author of the "500 Days" plan, Stanislav Shatalin, told today's legislative session that the independence of the republics is an objective reality. "We are accused of tearing the Soviet Union apart. What we are really doing is attempting to keep a renovated union together through economic methods," he said.