Solidarity leader Lech Walesa predicted Saturday that his newly legalized labor movement will dwindle as it gives rise to splinter groups during the growing political pluralism in Poland.

Speaking at a news conference at the end of a three-day visit to Italy, he also praised President Bush's proposed aid for Poland and voiced his support for economic reforms in the Soviet Union."From Solidarity, other economic and political organizations will be born," said Walesa, a strong proponent of pluralism. "Solidarity for the moment is huge, but it will become smaller with the growth of other organizations. This is the logical course of events."

Poland's Communist government last week lifted the ban on Solidarity and agreed to free elections for a new chamber of Parliament. Solidarity was crushed in martial law in 1981 and later outlawed.

The government is now seeking support from Solidarity and aid from the West to restore Poland's shattered economy. In its heyday, the union claimed 10 million members of the 18 million-member Polish work force.

Coinciding with the official recognition of Solidarity, the Bush administration announced a $1 billion economic aid program for Poland.

Speaking through an interpreter, Walesa called the program "a great step forward taken by Mr. Bush."

"We ask Europe and the world to help Poland travel the road of development. We have laid the foundations, and if we don't succeed, the responsibility will also be yours," he said.

The union leader reiterated his support for the liberal reforms of Soviet leader Mikhail Gorbachev.

Asked about Solidarity's contacts with opposition in other East bloc countries, Walesa said his labor movement was open to ties with other groups. But he added, "We don't want to disturb anyone and above all create obstacles for perestroika."

Walesa, who won the 1983 Nobel Peace Prize, indicated he planned to visit other countries as an "ambassador of Solidarity."