Lawyers for the plaintiff, Harry J. Diduck, said they expected a judgment of $1 million to $2 million, which will be deposited in the union pension and welfare funds. No awards will be made to individual workers.

Mr. Diduck charged that Mr. Trump, who was desperate to meet both the deadlines for the project and for his complex financing requirements, overlooked the use of the undocumented workers, who put in 12-hour days, 7 days a week and in some cases even slept at the site. Mr. Trump was named as a defendant in the lawsuit, along with the Trump-Equitable Fifth Avenue Company, a partnership he formed with the Equitable Life Assurance Society of the United States, which was also named. William Kaszycki, a contractor who supplied the Polish workers, and his company, Kaszycki and Sons Contractors, were also named. Trial Took Place Last Summer

A 16-day trial took place last summer in which Mr. Trump testified that he did not know that undocumented workers were on the job and that Kaszycki and Sons did all the hiring. But in his ruling, Judge Stewart wrote that the Trump employee overseeing the demolition, Thomas Macari, was well aware of their existence.

"The Polish workers were obvious not only in numbers but also in appearance," the judge wrote in his decision. "In contrast to the union workers, the nonunion Polish workers were distinguished by the fact that most of them did not wear hard hats." Mr. Macari would appear on the site with cash to pay the Polish workers, the judge's decision said, and at times the Polish workers staged "very visible work stoppages because they were not being paid their wages," which at $4 or $5 an hour were at least less than half what union workers were paid.

The union's shop steward on the job, in charge of submitting reports showing how many workers were there, reported 12 to 16 union workers a week when there were "considerable numbers of Polish workers doing demolition covered by the contract," sometimes as many as 150, the judge wrote. Pension fund administrators were dependent on those reports to cross-check what was being reported by the Trump contractors. Mr. Trump's lawyer, Fran Jacobs, did not respond to two telephone messages left for her at her office yesterday.