Dan Rather, the hard-charging anchorman who dominated CBS News for more than two decades but whose final months were clouded by a discredited story on the president's military service, is leaving CBS after 44 years, the network announced Tuesday.

The 74-year-old Rather has complained of being virtually forgotten at CBS Corp. since his exit as anchor last year, six months after the story on President Bush's military service aired. He has said he is considering an offer to do a weekly show at the HDNet high-definition network.

"There will always be a part of Dan Rather at CBS News," said Sean McManus, CBS News president. "He is truly a `reporter's reporter,' and he has helped to train several generations of broadcast journalists. His legacy cannot be replicated."

Rather said that his departure before the end of his contract represented CBS' acknowledgment, "after a protracted struggle, that they had not lived up to their obligation to allow me to do substantive work there."

"It isn't in me to sit around doing nothing," he said. "So I will do the work I love elsewhere, and I look forward to sharing details about that soon."

McManus, in an interview, would not discuss details of what CBS had offered Rather. He said it had become clear that CBS and Rather would not be able to agree on a role that satisfied both parties.

"It was obviously very difficult because I have enormous respect for what Dan has brought to CBS News and what he meant to CBS News, but I had to make the tough decision of what direction in which to go, and this is what I chose," he said.

Rather, whose final CBS News report aired on "CBS Sunday Morning" last weekend, will be the subject of a prime-time special on his career next fall, CBS said.

The network also said it had made a contribution to Rather's alma mater, Sam Houston State University.

The Texan has worked at CBS News since 1962, covering stories ranging from the Kennedy assassination to the 2001 terrorist attacks. He was the "CBS Evening News" anchor who replaced Walter Cronkite in 1981 until signing off with the admonition "courage" on March 9, 2005.

Rather apparently hadn't even seen the report questioning Bush's Vietnam-era National Guard service before introducing it on the air in September 2004. When CBS News couldn't substantiate the story following questions about its sources, Rather became a symbol of the incident even as he escaped official blame.

Since then, Rather's on-air appearances have been infrequent. He contributed eight stories to "60 Minutes" this season, about half the airtime of most full-time correspondents there. His most recent "60 Minutes" story, a profile of Whole Foods Market, aired June 4.

In interviews last week, Rather made clear the professional divorce was imminent. Rather said CBS had offered him an office but no real assignments.

For more than two decades, Rather dominated broadcast news along with NBC's Tom Brokaw and the late Peter Jennings of ABC. They were the faces seen every evening and whenever big news broke.

Rather always considered himself a reporter first, and the habit of news anchors to travel to the scenes of big stories is largely his legacy. His interview with Saddam Hussein in 2003 was the last given by the Iraqi leader before he was toppled.

With his intense on-air demeanor, Rather also had his detractors, and his broadcast was a distant third in the evening news ratings at the time he stepped down. CBS News' ratings have rebounded under short-term successor Bob Schieffer; Katie Couric will take over the broadcast in September.