US radio personality Garrison Keillor, host of one of the best known shows in American public broadcasting, has been fired over allegations of "inappropriate behavior," his employer said Wednesday.

Minnesota Public Radio (MPR) did not detail the allegations, but said it learned of them last month and they related to conduct with a co-worker while Keillor was host of the long-running program "A Prairie Home Companion."The 75-year-old, who retired from the popular weekly music and comedy show last year, said in an email to the Minneapolis Star Tribune that he had "put my hand on a woman's bare back" and later offered an apology that was accepted.

"I meant to pat her back after she told me about her unhappiness and her shirt was open and my hand went up it about six inches. She recoiled. I apologized," Keillor said, according to the newspaper.

"Anyone who ever was around my show can tell you that I was the least physically affectionate person in the building," he said. "Actors hug, musicians hug, people were embracing every Saturday night left and right, and I stood off in the corner like a stone statue."

He added: "Getting fired is a real distinction in broadcasting and I've waited fifty years for the honor. All of my heroes got fired. I only wish it could've been for something more heroic."

In a separate email to MPR News, Keillor indicated that two employees had raised questions about his behavior, saying he had a different recollection of events, but respected the network's decision.

"I think the country is in the grip of a mania," he said, describing as an "absurdity" the uproar surrounding Al Franken -- the Democratic comedian-turned-senator under scrutiny over accusations of touching several women without consent.

MPR announced that it had terminated contracts with Keillor and his private media companies, through which it was broadcasting "Best of" reruns of Keillor's hosted program and other features.

"MPR retained an outside law firm to conduct an independent investigation of the allegations. Based on what we currently know, there are no similar allegations involving other staff," the network said in a statement.

The company also planned to change the name of "A Prairie Home Companion," which is now hosted by Chris Thile.

Broadcast since 1974 and recorded in front of a live audience, the program is heard by 2.6 million listeners on almost 600 public radio stations in the US, according to its website.

Keillor's firing came the same day the NBC television network announced it had fired star morning news anchor Matt Lauer over allegations of sexual misconduct.

The two joined the ranks of other giants of American film, television and journalism who have fallen amid a wave of allegations of sexual misconduct, which began weeks ago with a flood of charges against movie mogul Harvey Weinstein.