PARIS, NOV. 20 -- East European leaders warned today that growing economic conflict between rich and poor nations is endangering the continent's newfound unity and could spawn divisions as serious as those of the Cold War unless the West accelerates aid to the East.

West European help may be on the way, at least for the beleaguered Soviet Union. Italian Foreign Minister Gianni De Michelis today predicted the 12-nation European Community will adopt an urgent $1 billion financial aid package next month to enable the Soviet Union "to put goods in the shops," and Germany announced it will send $480 million in stockpiled food and other supplies to its former adversary.

The economic plight that has plagued Eastern Europe's newly democratized nations in the year since their Communist governments were overthrown took center stage during today's sessions of 34-nation Conference on Security and Cooperation in Europe (CSCE).

Hungarian Prime Minister Jozsef Antall, who announced that the Warsaw Pact military structure probably would be completely dissolved in early 1992, said that a new wall dividing rich and poor may rise in the place of the Iron Curtain.

His words were echoed by his Polish counterpart, Tadeusz Mazowiecki, who said that unless Western economic aid and debt relief are expedited to bridge the gap between the rich West and impoverished East, "our common future may be darkened by the sinister clouds of the resurging conflicts of bygone days."

With travel restrictions lifted in the East and borders now open, West European countries are starting to recognize that their own security interests may be affected by the economic refugees from the East, whose already steady emigration could turn into a flood if hunger and political turmoil spread in the former Soviet Bloc.

Germany recently tightened its asylum laws to restrict the number of foreigners seeking to settle there, but its laws require it to accept the hundreds of thousands of ethnic Germans living in the Soviet Union and other East European countries.

Austria has stationed troops on its border with Hungary to stem a tide of Romanians fleeing West, and even Norway has expressed concern about a possible surge of desperate Russians crossing the Kola Peninsula if food shortages worsen this winter in the Soviet Union.

German Chancellor Helmut Kohl, expressing gratitude to the people of Central and Eastern Europe whose revolutions helped clear the way to German unity, said "there must now be no borders that perpetuate the prosperity divide. The ideological gulfs that have been overcome must not be torn open again by social gaps."

Kohl advocated urgent action showing "pan-European responsibility" that would help achieve "a successful outcome to the far-reaching political, economic and social reforms" in Eastern Europe.

Germany, acknowledging a special debt to Soviet President Mikhail Gorbachev for his role in the recent transformation of Europe, has vowed to send new deliveries of food assistance to Moscow.

The first shipments will be stocks of milk, baby food, grain and meat that were stored in Berlin by the Western allies to provide against an East-West confrontation, Berlin city officials announced today.

Kohl said he intends to dispatch a delegation headed by Economics Minister Helmut Haussmann to Moscow next week to determine the extent of Soviet needs. Kohl said he expressed concern in a meeting with Gorbachev here about Soviet transport and customs inefficiencies holding up German supplies but was assured that the problems would be resolved.

De Michaelis's prediction that the EC would come to Gorbachev's aid is bolstered by the Italian's stature within the organization. He played a key role in crafting a surprise compromise on economic and political union that emerged from the EC's October summit. Italy holds the EC presidency and will host the organization's December summit meeting.

"I expect a green light from the European Community next month for financial aid to the Soviet Union," De Michaelis said, adding that there will be proposals for an EC contribution to a currency stablization fund for the Soviet ruble as well as immediate financial aid.

The EC Commission, the community's executive arm, is due to submit a report on the Soviet economy that will be the basis of the decision on aid at the December summit.

A move by the EC to provide substantial financial aid to the Soviet Union now would put it at odds with the United States and Japan, which have called for in-depth studies of the Soviet economy. Those studies are due to be completed at the end of the year for consideration next summer by the Group of Seven industrial democracies.

Antall, Mazowiecki and Czechoslovak President Vaclav Havel agreed today to establish a common front pushing for "the closest possible links" with the EC and other Western institutions.

Mazowiecki, whose Polish government has been eager to win Western support for debt relief, met with President Bush and was promised that the United States "will be addressing {Poland's debt problem} seriously," according to White House Press Secretary Marlin Fitzwater. The United States has urged the World Bank and the International Monetary Fund to come up with $5 billion in new loans for Eastern Europe.

Antall's statement that the complete dissolution of the Warsaw Pact will occur over the coming year was the first time that a leader from one of the pact's six member states has spoken about a timetable for its eradication. A summit conference that could spell out plans to dismantle the alliance, which Havel described as "a remnant of the past" in his speech here, is expected to take place in Budapest next month.

Gorbachev said Monday that the Warsaw Pact members "are likely to make important decisions before the end of the year on transforming the organization and changing its character."

A prominent role for Eastern Europe within new CSCE institutions is considered important, U.S. and other Western officials said, particularly in light of the Warsaw Pact's impending dissolution. The collapse of the organization will leave the former East Bloc nations without security guarantees, creating a need for them to establish tangible political links with the West.

The CSCE has agreed to establish a small political secretariat in Prague and a "free elections" bureau in Warsaw. A third new organ, a conflict-prevention center that Gorbachev proposes to turn into a pan-European security institution, will be based in Vienna.