NEW YORK, JAN. 14 -- U.S. District Court Judge Kevin Thomas Duffy removed himself today from the Bess Myerson divorce-fixing case and sharply criticized the office of U.S. Attorney Rudolph W. Giuliani for, among other things, allegedly leaking grand jury information.

Giuliani, who is on the verge of deciding whether to resign to run for the U.S. Senate, responded by calling the judge's assertions "baseless and dishonest."

The unusual exchange came after repeated requests by Giuliani's office for Duffy to recuse himself.

Myerson, a former Miss America and former top aide to Mayor Edward I. Koch, was indicted in October on charges that she illegally influenced a state judge, Hortense W. Gabel, to reduce alimony payments made by Myerson's boyfriend to his ex-wife.

Gabel, now retired, and Myerson's millionaire boyfriend, Carl A. (Andy) Capasso, now serving a four-year prison term for tax evasion, were also charged in the case. All three denied wrongdoing.

The indictment charged that Myerson, while serving as Koch's cultural affairs commissioner, hired Gabel's daughter as a $19,000-a-year aide in exchange for having Capasso's divorce case fixed. Gabel later slashed Capasso's alimony payments.

In a 20-page opinion, Duffy denied prosecutors' assertions that he is "a close personal friend" of Gabel, saying he had met her twice some years ago. Duffy also denied that his wife, Irene, a state judge, was a close friend of Gabel.

Duffy said he was recusing himself to ensure "the appearance of impartiality." But, he added, "I resent the unsupported assertions of the United States attorney and his tactics in attempting to disqualify me."

Defense lawyers have asked that Giuliani's office be punished for leaking grand jury information about the case to the news media. While he has not ruled on that request, Duffy noted that NBC News reported last January that Myerson had invoked the Fifth Amendment before a grand jury.

"At least at first blush, it appears that these leaks can be attributed only to the government," Duffy wrote. Duffy also appeared to criticize Giuliani for asking another judge to urge Duffy to get off the case.

"The assertions that Judge Duffy has made in his opinion about me and my office are baseless and dishonest," Giuliani said. He urged Duffy to unseal the government's motions in the case so that "everyone will be able to find out the actual reasons for Judge Duffy's having to disqualify himself in this case."