Commentator Keith Olbermann signed off his msnbc cable television show Friday night after nearly eight years.
"Msnbc and Keith Olbermann have ended our contract," Phil Griffin, president of msnbc, said Friday.
"Msnbc thanks Keith for his integral role in msnbc's success and we wish him well in his future endeavors," Griffin said.
(Msnbc.com, a joint venture of NBC Universal and Microsoft, is the online home for msnbc TV programming.)
Olbermann announced his departure before closing his show with a reading from a James Thurber novel, a Friday night tradition.
Recounting his move to msnbc after departing ESPN, Olbermann said, "I was supposed to fill in for the late Jerry Nachman for exactly three days. 49 days later there was a four-year contract for me to return to this nightly 8 PM time slot which I had fled four years earlier."
He noted that the show gradually established an anti-establishment position.
"The program grew thanks entirely to your support with great rewards for me and I hope for you," Olbermann told viewers.
"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. But your support and loyalty and if I may use the word insistence ultimately required that I keep going."
Olbermann did not explain why he was leaving.
"Starting Monday, “The Last Word with Lawrence O’Donnell” will move to 8 p.m. ET/PT and “The Ed Show,” hosted by Ed Schultz, will move to 10 p.m. ET/PT on msnbc, Griffin said. "The Rachel Maddow Show” will continue to air live at 9 p.m. ET/PT.
Also starting Monday, Cenk Uygur, msnbc contributor and host of the popular web show “The Young Turks,” will be filling in as host of the 6 p.m. ET hour.
Msnbc spokesman Jeremy Gaines would say only that the acquisition of NBC Universal by Comcast, which received regulatory approval this week, had nothing to do with the decision.
Comcast said in a statement it did not yet have operational control of msnbc.
"We pledged from the day the deal was announced that we would not interfere with NBC Universal's news operations," Comcast said. "We have not and we will not."
Olbermann was suspended without pay from the network for two days in November for donating to three Democratic candidates, which violated NBC News' policy on political donations. Olbermann complained that he was being punished for mistakenly violating an inconsistently applied rule that he had known nothing about.
The host apologized to fans.
On Friday, Olbermann thanked viewers for donating $2 million to the National Association of Free Clinics, supporting other causes and for showing his dying father that there is good in people.