Polish President Lech Walesa, finishing up a nine-day visit to the United States, appealed Tuesday to Western nations to give Eastern Europe time to convert from communism to a market economy.

"The time is coming that people will be coming not to America to make business but to Eastern Europe," he said.He warned Westerners not to be too anxious to see sweeping change in Eastern Europe.

"Leave us alone until we first come to you," he said, cautioning that if societies began to break down, "millions will be standing on your doorstep."

Earlier Tuesday, Walesa attended mass at St. Stanislaus Kostka Church in the Greenpoint area of Brooklyn, the nation's second largest Polish community after Chicago.

Hundreds of parishoners and others thronged into the church where they greeted Walesa and his wife, Danuta, with applause and a bouquet of roses.

Dozens snapped pictures as the couple sat in the front pew of the church Some even stood on back pews.

At a press conference at the Consulate General of Poland, the former electrician stood with Gov. Mario Cuomo and his wife, Matilda, and repeated his appeal to American businesses to invest in Poland's fledgling free-market economy.

"The system we are leaving was not clever," he said. "We have the proper technology and a cheap labor force.

"I would like to have an economy like the one that exists in America, even better," he said, explaining the United States had to develop its own system as it went along.

"We want to avoid the problems you had," he said.

Later, Walesa planned to visit the Ellis Island Museum and then return to Warsaw.

Walesa arrived in New York Monday after visits to Washington, Los Angeles and Chicago on his nine-day trip.

Walesa met with officials of major Jewish organizations and used the occasion to deny reports of anti-Semitism in himself and his supporters and vowed to fight religious bias among the general population of Poland.

He said he has always opposed anti-Semitism and was "framed" by a newly unrestrained press in an off-the-cuff comment made during his successful bid for the presidency to look as if he considered himself to be more Polish than Polish Jews.

Walesa, visiting the United States for the first time as president of Poland, invoked the common struggle of European Jews against Nazism and of Poles against Soviet Communism as the thread holding the two groups together.