MOSCOW, NOV. 18 -- The erosion of central power in the Soviet Union will be apparent to the 34 world leaders gathering for the European summit in Paris Monday, as representatives from the Ukraine, Armenia and the Baltic states try to make their presence felt as observers and separate, unofficial delegations.

Three leaders of the Ukraine, a republic of 53 million people that has been pressing for independence, said Soviet Foreign Minister Eduard Shevardnadze refused their request to come to the summit on European security as a delegation separate from that of the Soviet Union.

Dmitri Pavlichko, the chairman of the Ukrainian legislature's foreign affairs committee, said, "After Russia and Germany, we are the biggest entity in all of Europe. We have a separate delegation in the United Nations. We have a right to our own representation."

Bogdan Horyn, a former political prisoner and now a leading member of the Ukrainian legislature, said he, Pavlichko and Ivan Drach, the leader of the Rukh independence movement, would distribute letters of protest to all leaders at the summit.

"Frankly, we understand that this is not going to make us independent overnight, but the point is that we must assert our aspirations on the world stage," Horyn said. "Step by step, the Ukraine intends to become a genuine presence in the world."

While Moscow seems prepared to give independence to the Baltic states, it is far more reluctant to let go of the Ukraine, a vast territory that provides much of the country's industrial and agricultural base. A year and a half ago, the Ukrainian independence movement seemed limited mainly to western Ukrainian cities, but now it has gained strength even in the east, which is heavily populated with ethnic Russians.

Horyn said Shevardnadze had told him in a private meeting this month that neither Moscow nor other states were prepared to allow the Ukraine to participate in the 34-nation summit. He said the United States, especially, was "reluctant to embarrass" Soviet leader Mikhail Gorbachev. Shevardnadze did say he would "study" the Ukrainians' request to exchange embassies with Canada, which has nearly a million citizens of Ukrainian descent.

Nearly every republic in the Soviet Union has declared its independence or sovereignty, and Gorbachev has been trying to forge a new treaty to prevent the union's dissolution.

Armenian president Levon Ter-Petrossian said the Baltic states and Armenia were "invited observers."