WASHINGTON — Vice President Dick Cheney's chief of staff, I. Lewis "Scooter" Libby, has "a problem" in the investigation of the leak of a CIA operative's identity if his testimony conflicts with information given to the grand jury by New York Times reporter Judith Miller, her lawyer said yesterday.

Robert Bennett, speaking on the ABC program "This Week" on the day The Times disclosed new information about three conversations Miller had with Libby about the CIA employment of a White House critic's wife, said "much would depend upon what Mr. Libby said to the grand jury.

"If he said that he had not talked to Judy about these things or didn't talk about the wife, then he's got a problem," Bennett said, referring to CIA agent Valerie Plame, the woman at the center of the leak investigation. Miller told prosecutors that "to the best of her recollection she did not know of" Plame's employment at the CIA "before she spoke to Mr. Libby," he said.

Bennett would not speculate whether Libby was trying to steer Miller's eventual testimony — an action that could be considered an attempt to obstruct justice — through an alleged suggestion by his lawyer and language in a personal letter sent to her Sept. 15 that encouraged her to testify.

Libby's letter included this sentence: "The public report of every other reporter's testimony makes clear that they did not discuss Ms. Plame's name or identity with me."

Bennett said the sentence "was a very stupid thing to put in a letter," and though he would not say it was an attempt to steer Miller's testimony, "it was a close call and she was troubled by it."

Special prosecutor Patrick Fitzgerald appears to be winding up his 22-month investigation of whether any government official leaked Plame's name to retaliate for criticism of the administration by Plame's husband, former Ambassador Joseph Wilson.

Fitzgerald's investigation began as an inquiry into whether the disclosure of Plame's identity as a CIA agent to columnist Robert Novak by two senior administration officials was a violation of federal law. Novak disclosed the name of Wilson's wife, described her as a CIA "operative" and described her alleged role in arranging Wilson's trip to Niger to determine whether Iraq was seeking uranium from that country.

But over the past year, Fitzgerald's inquiry has apparently broadened. Some people familiar with the case believe he is trying to determine whether the leak of Plame's identity was part of a conspiracy within the Bush administration to discredit Wilson for his statements suggesting the White House twisted intelligence to justify invading Iraq.

Karl Rove, Bush's senior political adviser, who testified before the grand jury for the fourth time Friday, is another possible target of Fitzgerald's inquiry. Rove told Time magazine correspondent Matt Cooper about the CIA employment of Plame before Novak's column appeared, and did not tell investigators about that conversation when first interviewed, according to lawyers familiar with his testimony.

Miller, in her article in Sunday's Times, said she had conversations with Libby before Plame's identity was revealed, during which Libby spoke about Wilson's wife during all three conversations and associated her with the CIA.