MSNBC host Keith Olbermann announced unexpectedly Friday that he is leaving the network and has taped his last "Countdown" show.
MSNBC issued a statement that it had ended its contract with the controversial host, with no further explanation. Olbermann hosted the network's most popular show, but his combative liberal opinions often made him a target of critics.
Olbermann did not explain why he was leaving.
"MSNBC thanks Keith for his integral role in MSNBC's success and we wish him well in his future endeavors," the network said. A spokesman said Phil Griffin, MSNBC's president, would not comment on Olbermann's exit. 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.
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 -- but not to the network.
Olbermann, before leaving the show with a final signature toss of his script toward the camera, thanked his audience for sticking with him.
He thanked several people, including the late Tim Russert, but pointedly not Griffin or NBC News President Steve Capus.
Beginning Monday, "The Last Word With Lawrence O'Donnell" will move to 8 p.m. from 10 p.m., MSNBC said and "The Ed Show," hosted by Ed Schultz, will move to 10 p.m., MSNBC said. "The Rachel Maddow Show" will stay at 9 p.m.