Nearly eight years after he began hosting MSNBC's top-rated show , "Countdown With Keith Olbermann," the veteran broadcaster said goodbye to his viewers Friday night.
"There were many occasions, particularly in the last two and a half years, where all that surrounded the show - but never the show itself - was just too much for me," he told viewers.
Olbermann never said why he was leaving.
During his tumultuous tenure, his liberal views became the driving force behind MSNBC's primetime shift to the political left.
But tensions with his bosses mounted.
"Keith Olbermann has been battling with MSNBC management for 2 ½ years," said Felix Gillette of Bloomberg Businessweek.
In November, Olbermann was suspended for two days for making donations to Democratic candidates - including Congresswoman Gabrielle Giffords - in violation of company ethics policies.
In a statement, MSNBC said the company and Olbermann had "...ended their contract..." adding, "... MSNBC thanks Keith for his integral role in MSNBC's success..."
"That whole primetime lineup [was] built on the quote-unquote brand that Olbermann represented for them, so he was very, very important to their primetime lineup," said Robert Thompson, a professor of television and pop culture at Syracuse University.
Olbermann's departure comes just a few days after cable giant Comcast received government approval to acquire MSNBC's parent company, NBC Universal.
An MSNBC spokesman denied the merger had anything to do with the decision.
And Comcast, which is expected to close the deal this week, said in a statement, it "…has no operational control at any of its properties including MSNBC…"
Late Friday, MSNBC host Rachel Maddow, Olbermann's liberal protege, said she knew little about what happened.
"All I know is that it was between Keith and the company," she said.
New york times media writer Brian Stelter says Maddow is now the heir apparent.
"In a way she's the next generation of MSNBC," he said. "She's still in her 30s, and she's able to carry the ball forward."
Olbermann was reportedly in the middle of a four-year, $30-million contract. It's not clear if there's a non-compete clause which would keep him from showing up elsewhere anytime soon.