WASHINGTON — W. Mark Felt wanted to become FBI director. President Nixon and his closest aides thought that ambition might make Felt the ideal person to sidetrack an FBI investigation into the Watergate burglary.

They couldn't have been more wrong.

Rather than helping shield Nixon, Felt became the best-known anonymous source in history. As "Deep Throat," he was a key figure in the scandal that eventually led to Nixon's resignation.

Information was traveling from Felt, the No. 2 official at the FBI, to the news columns of the Washington Post via reporter Bob Woodward, snippets from a criminal investigation that led ultimately to the president.

The Post on its Web site Tuesday quoted Woodward as saying that Felt helped the newspaper at a time of tense relations between the White House and much of the FBI hierarchy.

FBI Director J. Edgar Hoover died shortly before the Watergate break-in. Felt himself had hopes that he would be the next FBI director, according to the Post, but Nixon instead appointed an administration insider, assistant attorney general L. Patrick Gray, to the post.

Felt's ambition was no secret, as White House tape recordings from the Watergate scandal show.

Six days after the break-in at the offices of the Democratic National Committee, Nixon and his co-conspirators discussed ordering the FBI to shut down its probe on grounds that the investigation would interfere with a CIA operation.

"Mark Felt wants to cooperate because he's ambitious," White House chief of staff H.R. Haldeman said.

"Yeah," the president replied.

Months later on the Watergate tapes, Nixon and his aides discussed Felt as a possible leaker.

"We know who leaked it," Haldeman said on Oct. 19, 1972.

"Somebody in the FBI?" Nixon asked.

"Yes, sir, Mark Felt," Haldeman replied.

The Post's executive editor during Watergate, Ben Bradlee, said Tuesday it's a good thing for the country that Felt's identity has finally been revealed.

Bradlee has never met Felt, but "I would thank him" if the two men ever did get together, Bradlee said.

Although scholars and journalists frequently speculated about Felt's role in exposing the scandal that brought down the Nixon administration, Felt had consistently denied he was the unnamed source until Tuesday.

"I would not leak any information," Felt told the Twin Falls Times-News in a 1974 interview after a Washingtonian Magazine article named him as the likely Deep Throat. The magazine, which has a long tradition of probing Deep Throat's identity, based its speculation on Felt's high-level position with the FBI, his friendliness with reporters and his possible irritation at the Nixon White House for overhauling the structure of the agency that had been established by Hoover.

Only days before Nixon resigned the presidency, Felt told the Times-News that he was considering suing the Washingtonian for being labeled Deep Throat and that secretly feeding information to the news media about the White House went against his principles.

"I did not and would not," Felt said. "I don't operate that way."