Columnist Robert Novak said publicly for the first time Tuesday that White House political adviser Karl Rove was a source for his story outing the identity of CIA officer Valerie Plame.

In a column, Novak also says his recollection of his conversation with Rove differs from what the Rove camp has said.

"I have revealed Rove's name because his attorney has divulged the substance of our conversation, though in a form different from my recollection," Novak wrote. Novak did not elaborate.

Watch FOX News at 6 p.m. ET for an exclusive interview with Novak on Special Report with Brit Hume. Novak will also appear on Hannity & Colmes at 9 p.m. ET.

A spokesman for Rove's legal team, Mark Corallo, said that Rove did not even know Plame's name at the time he spoke with Novak, that the columnist called Rove, not the other way around, and that Rove simply said he had heard the same information that Novak passed along to him regarding Plame.

"There was not much of a difference" between the recollections of Rove and Novak, said Corallo.

Novak said he is talking now because Special Counsel Patrick Fitzgerald told the columnist's lawyer that after 2 1/2 years his investigation of the CIA leak case concerning matters directly relating to Novak has been concluded.

Triggering the criminal investigation, Novak revealed Plame's CIA employment on July 14, 2003, eight days after her husband, White House critic and former U.S. Ambassador Joseph Wilson, accused the administration of manipulating prewar intelligence to exaggerate the Iraqi threat from weapons of mass destruction.

Novak's secret cooperation with prosecutors while maintaining a public silence about his role kept him out of legal danger and had the effect of providing protection for the Bush White House during the 2004 presidential campaign.

The White House denied Rove played any role in the leak of Plame's CIA identity and Novak, with his decision to talk to prosecutors, steered clear of potentially being held in contempt of court and jailed. Novak said he had declined to go public at Fitzgerald's request.

In a syndicated column to be released Wednesday, Novak says he told Fitzgerald in early 2004 that Rove and then-CIA spokesman Bill Harlow had confirmed information about Plame.

Contacted Tuesday night, Harlow declined to comment. But a U.S. intelligence official familiar with the matter denied that Harlow had been a confirming source for Novak on the story. The official, speaking on condition of anonymity, said Harlow repeatedly tried to talk Novak out of running the information about Plame and that Harlow's efforts did not in any way constitute confirming Plame's CIA identity. The official spoke on condition of anonymity because Harlow may end up being a witness in a separate part of Fitzgerald's investigation, the upcoming criminal trial of Vice President Dick Cheney's former chief of staff, I. Lewis Libby, on charges of perjury, obstruction and lying to the FBI.

In his column, Novak said he also told Fitzgerald about another senior administration official who originally provided him with information about Plame. Novak said he cannot publicly reveal the identity of that source even now.

"I have cooperated in the investigation while trying to protect journalistic privileges under the First Amendment and shield sources who have not revealed themselves," Novak said in his statement. "I have been subpoenaed by and testified to a federal grand jury. Published reports that I took the Fifth Amendment, made a plea bargain with the prosecutors or was a prosecutorial target were all untrue."

Rove's role in the scandal wasn't revealed until last summer when Time magazine reporter Matthew Cooper disclosed that Rove had leaked him the CIA identity of Wilson's wife. Cooper cooperated with prosecutors only after all his legal appeals were exhausted and he faced jail.

While Rove escaped indictment, Libby has been charged with lying about how he learned of the covert CIA officer's identity and what he told reporters about it.