President Bush said yesterday that he plans to personally cooperate with the investigation into the leak of an undercover CIA officer's name, and said he consulted an outside lawyer because he realizes the case is a serious criminal matter.

The White House announced Wednesday night that Bush had recent discussions with Jim Sharp, a white-collar defense attorney in Washington, in case FBI agents or a grand jury want to question Bush about the blown cover of the officer, Valerie Plame.

White House reporters were given the chance to ask Bush two questions during a Rose Garden appearance yesterday. The first was whether he had any indication prosecutors plan to call him, and what he would tell them.

"I've told our administration that we'll fully cooperate with their investigation. I want to know the truth, and I'm willing to cooperate myself," he said.

Bush said questions about the case should go to the prosecutors, who have refused to discuss the matter.

"In terms of whether or not I need advice from my counsel, this is a criminal matter, it's a serious matter, I have met with an attorney to determine whether or not I need his advice," Bush said. "And if I deem I need his advice, I'll probably hire him."

A federal grand jury meeting in Washington is investigating whether administration officials illegally disclosed Plame's identity to Robert D. Novak, who named her in a newspaper column published July 14. Plame's husband, former ambassador Joseph C. Wilson IV, was one of the most prominent critics of the White House case for war in Iraq, and he has accused Bush's aides of abetting the disclosure.

White House officials involved in the case maintain they are not concerned about the outcome. They said they do not believe Bush was in any jeopardy, but said they had been forbidden to discuss the case for quotation.

Vice President Cheney's office would not say whether he has consulted a lawyer about the Plame case. A statement said Terrence O'Donnell, partner at Williams & Connelly, has been Cheney's personal attorney for several years.

"He has consulted Mr. O'Donnell on many matters since coming to the White House," the statement said. "Were the Vice President to seek legal counsel on any issue, Mr. O'Donnell is the man he would go to." The statement said Cheney's office could not comment further because of the probe.

Sharp, a low-profile lawyer, was a member of the firm that represented Richard V. Secord in the Iran-contra affair, in which Reagan administration officials were accused of arranging secret arms shipments to Nicaraguan rebels and to Iran.