A federal judge in New York has been asked to investigate charges that the office of Manhattan U.S. Attorney Rudolph W. Giuliani improperly leaked details of a secret grand jury probe into alleged insider stock trading by three leading Wall Street executives.

The request was made by attorneys representing Robert M. Freeman, a partner at Goldman, Sachs & Co., and Timothy L. Tabor, a former stock trader at Kidder, Peabody & Co. The two men, along with Richard B. Wigton, a suspended Kidder executive, were arrested in February on insider trading charges.

In a motion made public yesterday, the defense lawyers asked Judge Shirley Kram to investigate whether government prosecutors were the source for a May 22 article in The Wall Street Journal that reported on the scope of the government's grand jury investigation into alleged wrongdoing by Freeman, Wigton and Tabor.

"We have no objection to an investigation of the source of the May 22 article because we're quite convinced that it could not have come from anybody in this office," Giuliani said in an interview today. "There are several erroneous facts {in the article} that indicate they did not come from anyone in this office."

Charges against Freeman, Wigton and Tabor were dismissed last month at the request of prosecutors, who said they needed time to pursue a broadened grand jury investigation into alleged wrongdoing by the executives and possibly others. In court papers, prosecutors referred to the charges they dismissed as merely "the tip of an iceberg."

At the time, defense lawyers accused the prosecutors of using dismissal as a ploy to avoid federal speedy trial rules. They also complained that, in their "tip of an iceberg" remarks and other disclosures, prosecutors had violated federal rules governing grand jury secrecy.

The motion made public yesterday was filed under seal last week by Freeman's attorney, Paul Curran, and Tabor's attorney, Andrew Lawler. Wigton's lawyer, Stanley Arkin, declined to join the motion, which was made public after attorneys for the Journal asked Judge Kram to lift the seal.

At a conference yesterday, prosecutors and defense lawyers agreed to disclose the motion and Judge Kram set a hearing today to consider the motion, which asks her to order prosecutors to "cease immediately" their improper leaks and to investigate defense charges.