By Shannon McCaffrey,Knight Ridder Newspapers

WASHINGTON – President Bush’s closest political adviser, Karl Rove, will appear for a fourth time before the federal grand jury investigating the leak of a CIA officer’s name as the politically charged probe draws to close.

Rove’s lawyer, Robert Luskin, said Thursday that he’d been told by Special Prosecutor Patrick Fitzgerald that no decisions had been made on charges in the case and that Rove hadn’t been informed that he’s a target.

Luskin said Fitzgerald had taken Rove up on his offer to appear before the grand jury again.

“He is continuing to cooperate voluntarily,” Luskin said.

Luskin said Rove never asked for or received any assurances that he wouldn’t be indicted.

Rove’s appearance could come as soon as today. It would come on the heels of testimony by New York Times reporter Judith Miller, who spent nearly three months in jail before agreeing to talk about her conversations with Vice President Dick Cheney’s chief of staff, I. Lewis “Scooter” Libby.

Eric Holder, deputy attorney general during the Clinton administration, said such a repeat appearance by a top White House aide was “somewhat unusual.” But he said because of secrecy surrounding grand jury proceedings, it was hard to know whether Fitzgerald was building a case against Rove or using his testimony to indict someone else.

Holder said it appeared that Fitzgerald was wrapping up the case before the grand jury expires on Oct. 28.

Following Miller’s testimony last week, all eyes turned to Libby. His lawyer, Joseph Tate, identified him as the source whom Miller went to prison to protect. Tate said his client did nothing wrong and believed it was always clear that he’d given Miller his permission to testify.

But Thursday’s developments renewed attention on one of Bush’s close confidants.

Rove, 54, was the chief strategist behind Bush’s rise from baseball executive to Texas governor to president. He wields enormous influence on all aspects of administration policy and is the president’s liaison to business groups, conservative activists and other organizations.

Bush, who once said that he’d fire anyone involved in the leak, is standing by Rove. The president and his aides have rebuffed questions about the case.

“The special prosecutor made it very clear early in the process that those of us in the White House should not discuss the case, publicly or privately,” Bush said Tuesday.

Time magazine reporter Matt Cooper testified to the grand jury in July that Rove told him that former U.S. Ambassador Joseph Wilson’s wife worked at the CIA without mentioning her maiden name, which she used as a clandestine service officer.

“This was the first time I had heard anything about Wilson’s wife,” Cooper wrote after this grand jury appearance. “Rove never once indicated to me that she had any kind of covert status.”

He said Rove ended the conversation by telling him, “I’ve already said too much.”

Cooper agreed to appear before the grand jury after Rove released him from a confidentiality pledge.

The leak probe began about two years ago after Wilson wrote an op-ed piece that cast doubt on part of the Bush administration’s rationale for going to war in Iraq. Shortly after that piece appeared in the New York Times, Wilson’s wife, Valerie Plame, was named in a syndicated column by Robert Novak. Plame is a former undercover CIA officer, and the intentional disclosure of her identity is a crime. Wilson alleges that the administration leaked her name to retaliate against him.