NEW YORK – Dan Rather admitted he was hoodwinked by a shaky source and apologized Monday for pinning a story questioning President Bush’s service in the Texas Air National Guard on dubious documents.

“I’ve been humbled by this experience,” the CBS anchorman told the New York Daily News in an interview. “If I had known then what I know now, I wouldn’t have used them. I did it; it was a mistake.

“I’m looking deep within myself, about what I did and didn’t do. However, my job is to ask tough questions and not be afraid to ask tough questions, not to be fearful of taking on the tough stories.

“I’m sorry I wasn’t better, quicker, smarter,” he said.

Rather’s stunning admission capped weeks of furor during which CBS’ credibility was questioned and the White House accused the newsman of smearing Bush during a presidential election with a story based on bogus memos.

In a prepared statement, a series of interviews and later on his own national news show, Rather insisted he was “misled” by Bill Burkett, a retired Texas Guardsman with a well-known grudge against Bush who said he got the documents from another Guardsman.

“I misled you on the one individual,” Burkett told Rather on CBS News on Monday night. “You know your staff pressured me to a point to reveal that source. … I simply threw out a name that was basically, I guess, to take a little pressure off for a moment.”

Burkett also denied forging the documents but would not say where he got the memos, which purportedly were written by Bush’s former commanding officer, Lt. Col. Jerry Killian.

“Before I gave up any documents, I wanted to know what you were gonna do with them,” Burkett said. “And I insisted that they be authenticated.”

Rather admitted to a national audience that CBS could not authenticate the memos and told viewers last night, “I’m sorry.”

But in his interview with the Daily News, Rather did not retract the premise of his “60 Minutes” expose, which was that Bush pulled strings during the Vietnam War to get into the Guard and was grounded in 1972 after disobeying an order to take a required physical.

“We did not go in this on blind faith, but on the preponderance of evidence,” Rather told The News. “We checked our source out, but we didn’t check him out enough; we didn’t check the documents enough.”

White House spokesman Scott McClellan said Rather and CBS are not off the hook. “We appreciate that they deeply regret it, but there’s still serious questions that need to be answered,” he said.

One question quickly arose. John Kerry aide Joe Lockhart said he called Burkett at the request of CBS shortly before the documents were released, but Lockhart insisted Monday that the call to Burkett had nothing to do with documents.

CBS News President Andrew Heyward said outside investigators are being brought in to find out what went wrong. But one of Rather’s most prominent colleagues said the anchorman’s job is not in jeopardy.

“Everybody makes mistakes; there’s no talk of resigning,” John Roberts said. “Dan is the face of CBS News. We’re all behind him 100 percent.”

CBS curmudgeon Andy Rooney, who said earlier he believes the Killian memos are fake, closed ranks behind Rather. “We made a mistake, we admitted it, it’s fine,” he said.

Rather told The News he was not thinking about his future.

“I care passionately, deeply about the credibility and integrity of CBS News,” he said. “I think people understand fully what’s happened here and I think they have it in context.”

As for his enemies, Rather said, “Everybody has them if you do what I do as long as I have.”

Citing the disputed documents, CBS reported on Sept. 8 that Killian, who died in 1984, was being pressured to “sugarcoat” Bush’s performance ratings.

Almost immediately, document experts and Internet bloggers questioned the veracity of the memos, saying they appeared to have been created on a computer and not a typewriter that was in use in 1972.

Rather steadfastly defended the story, even as experts CBS hired to vouch for the memos’ veracity defected to the doubters. But after first lady Laura Bush suggested the memos were forgeries, CBS interviewed Killian’s secretary, Marian Carr Knox, who also called them fakes.