(Adds Garrison Keillor, details, updates share price)
NEW YORK, Nov 29 (Reuters) - NBC News fired popular "Today" show host Matt Lauer after a colleague accused him of inappropriate sexual behavior, the network said on Wednesday, making him yet another rich and powerful man to be felled this year by accusations of harassment.
His termination sent shockwaves through U.S. morning television, where Lauer has been a fixture since becoming a "Today" anchor in 1997, going on to reportedly earn $20 million a year.
The married 59-year-old news star was the latest public figure to be embroiled in allegations of sexual misconduct that have recently struck down high-profile men in entertainment, politics and media.
Just hours later, U.S. radio host Garrison Keillor said he had been fired by Minnesota Public Radio over an accusation of inappropriate behavior.
The complaint made by an unnamed female colleague on Monday night was a "clear violation" by Lauer of the company's standards, NBC News chairman Andrew Lack said in a statement.
"While it is the first complaint about his behavior in the over twenty years he's been at NBC News, we were also presented with reason to believe this may not have been an isolated incident," Lack said.
Lauer's agent Ken Lindner did not respond to requests for comment.
The news was announced by "Today" co-anchors Savannah Guthrie and Hoda Kotb at the start of the talk show, a staple of U.S. morning television for more than six decades that, NBC says, averages more than 4 million viewers.
"We just learned this moments ago just this morning," Guthrie said, visibly shaken. "As I'm sure you can imagine we are devastated."
Lack's statement did not say who made the accusation, but promised that NBC News would cover Lauer's firing in "as transparent a manner as we can."
The woman had met with New York Times reporters on Monday before meeting with NBC's human resources and legal departments that evening to share her allegation, the Times reported, saying that she said she was not ready then to publicly identify herself.
The woman's Washington-based lawyer, Ari Wilkenfeld, said the meeting with NBC officials lasted several hours.
"In fewer than 35 hours, NBC investigated and removed Mr. Lauer," Wilkenfeld wrote in a statement. "Our impression at this point is that NBC acted quickly, as all companies should, when confronted with credible allegations of sexual misconduct in the workplace."
The complaint said the sexual misconduct occurred while Lauer and the female colleague were covering the 2014 Sochi winter Olympics in Russia, NBC News reporter Stephanie Gosk said on air.
The misconduct continued after the Games, Gosk said. An NBC representative did not respond to a request for more details.
Comcast Corp, the largest U.S. cable television company, owns NBCUniversal. Its shares rose 2.4 percent to $37.13.
"Today" earned $509 million in advertising revenue last year, more than any of its competitors, New York-based analysts Kantar Media said.
Lauer joined "Today" in 1994 and has interviewed presidents George Bush and Barack Obama and broadcast from seven Olympic Games. He had been due to join his co-hosts for the nationally-televised lighting of the giant Christmas tree at New York City's Rockefeller Center on Wednesday night.
According to Fortune Magazine, he signed a two-year deal in 2016 that would pay him $20 million per year.
U.S. President Donald Trump responded with messages on Twitter calling for some of Lauer's colleagues to be fired too, and adding to his recent attacks against U.S. news outlets for their reporting on his administration.
"Wow," Trump wrote about Lauer. "But when will the top executives at NBC & Comcast be fired for putting out so much Fake News."
During the 2016 presidential campaign, then-Republican candidate Trump was accused by 13 women who publicly said that in the past he had physically touched them inappropriately in some way, the Washington Post reported.
Trump denied the accusations, accused rival Democrats and the media of a smear campaign, and went on to win the election.
(Reporting by Gina Cherelus and Jonathan Allen; Additional reporting by Susan Heavey in Washington, Jessica Toonkel in New York and Supantha Mukherjee in Bengaluru; Editing by Alden Bentley, Howard Goller and Nick Zieminski)