2ND UPDATE, SATURDAY AM: An MSNBC insider told this to Deadline today about Keith Olbermann’s departure Friday:

“This was all Keith’s choice. He has several times over the years said that he wants out of his contract. He never meant it until this year. He started lawyers negotiating twice this year. He stopped them in the spring. Then, about a month ago with the guidance of his new ICM team and a new LA manager (who were making zero $ on his current deal), he once again said he wanted to leave and this time they negotiated the full package. “Because of all the false threats in the past, it was impossible for the network to know if he was really going to sign the final document yesterday. That’s why promos for his show were still running after he quit on the air. The network couldn’t really believe it or act on it until he said it on TV. They couldn’t tell the promo people to pull Keith’s show out of the cycle until they were sure. His staff learned he was quitting when they heard him say it on TV. “Comcast has had no impact at all on MSNBC [yet]. Phil Griffin has complete authority. He makes deals without having to consult with anyone. He has made proposals over the years on the fly and in high-speed contexts where he is acting alone and with full authority. MSNBC is Phil Griffin’s network and no one at NBC thinks they have a better idea than Phil about what to do next.”

Rachel Maddow & Bill Maher React To Keith Olbermann’s Ouster

Adam Green, co-founder, Progressive Change Campaign Committee at BoldProgressives.org who “saved” Olbermann’s job the last go-round with MSNBC, had this to say: “The newly announced line up, including the addition of Cenk Uygur, consists of people who will undoubtedly continue Keith Olbermann’s legacy of holding power to account. But there’s a gnawing feeling among many MSNBC viewers that Keith blazed the trail for these other good hosts, Keith wasn’t ready to leave yet, and an important leader is now being sidelined involuntarily.” In his goodbye last night, Keith thanked the 300,000 folks who signed the PCCC’s Olbermann petition last November.

UPDATE FRIDAY PM: The word inside MSNBC is that Keith Olbermann, who’d been negotiating his out with one year left on his contract, can’t move to another cable/broadcast news channel right away, so he may be “on ice” for some time. On the other hand, he could go back into sports talk.

—

FRIDAY 6 PM: The statement (below) about Keith Olbermann’s exit came without warning. The Last Word With Lawrence O’Donnell will move to 8 PM weekdays on MSNBC, and The Rachel Maddow Show remaining at 9 PM, with The Ed Show starring Ed Schultz moving to 10 PM. Cenk Uyger of the liberal “Young Turks” will be taking over Ed’s 6 PM slot. The moves are simultaneous with new owner Comcast starting to show its hand over the broadcast network and cable NBCU after receiving FCC approval. “He’s been very problematic,” an NBCU source told Deadline about Comcast’s attitude to Olbermann. Officially, the Comcast takeover is next week. But word has been circulating for months now that the new owners have wanted to “tinker” with MSNBC and had many changes in store, including a right turn for the left-wing cable channel so that it represents both political points of view more evenly. It is well known that both Comcast chief Brian Roberts and NBCU chief Steve Burke have donated heavily to the Republican party with Burke more recently donating money to a few Democrats as well as heavily to Republicans. Roberts was a co-chairman of the host committee at the 2000 Republican Convention while Burke raised at least $200,000 for George W Bush’s re-election campaign.

Olbermann hosts the highest-rated program on MSNBC, which isn’t saying much since that channel’s ratings lag those of Fox News by a big margin. His Countdown averaged 1 million viewers, down a modest 10% from 2009. However, he’s known as a very polarizing figure and a loose cannon, and became more and more of a liability for MSNBC. In November, he was briefly suspended for making Democratic campaign contributions — and then reinstated. Olbermann’s exit follows yesterday’s departure of NBC primetime president Angela Bromstad in a housecleaning there.

: