Geraldo Rivera says he's 'filled with regret' after defending Roger Ailes

Geraldo Rivera says he regrets coming to the defense of Roger Ailes after the former Fox News CEO was accused of sexual harassment by network host Gretchen Carlson.

In a lengthy Facebook post, Rivera says that he is "filled with regret" for his actions (though later concedes that "news is a flirty business") and apologizes to all of the "purported victims" of sexual harassment at Fox News and elsewhere.

"The man we knew as the blustering genius who invented our mighty Fox News Channel is a deceitful, selfish misogynist, if the charges against him are true. And if they are true, then his shame and banishment are well earned," he writes. "I was totally blindsided by his sexual harassment scandal, which is why I responded to Gretchen Carlson's initial filing of her lawsuit with extreme skepticism. The man she described in her pleadings was unknown even to those of us who thought we knew him well."

Read more: Gretchen Carlson Lawsuit Against Roger Ailes Ends in Settlement

Rivera, who says he has known Ailes for decades, says he still thinks the former exec is a "hail-fellow well met, a corporate barroom brawler, more likely to tear your throat out than engage in sweet talk," when defending a tweet from July in which he defended Ailes ("I've known him 40 years. He's about as flirty as the grizzly in #TheRevenant. I stand with Roger Ailes").

In Carlson's complaint filed in July, she claimed she was let go from Fox News as retaliation for rebuffing Ailes' sexual advances. She said that she had met with Ailes to discuss treatment and was told, "I think you and I should have had a sexual relationship a long time ago and then you'd be good and better and I'd be good and better." On Tuesday, Carlson filed paperwork to dismiss her lawsuit against the former Fox News chief, walking away with a $20 million settlement, according to a source. This week, Greta Van Susteren revealed that she would be leaving the network, weeks after Ailes resigned.

Rivera outlines his professional career with Ailes in his Facebook post, from working with him at CNBC to reuniting after 9/11 at Fox News. "He had my back through thick and thin," he says about Ailes at the time.

PHOTOS: Roger Ailes through the years

After more women came forward with allegations against the former CEO and Ailes resigned, Rivera says that he became convinced there was something wrong. "Now I am filled with regret for stubbornly discounting their various allegations. The Murdoch's would not have turned the world upside down but for good cause. Moreover, I apologize for my skepticism. Like victims of sexual assault, those alleging harassment deserve the presumption of credibility."

He also reveals in the post that because of his defense of Ailes, HarperCollins decided against publishing his upcoming book, Geraldo of Arabia, From Tora Bora to Trump.

In his post, Rivera also apologizes to Gabriel Sherman, who Rivera once called a "nerd with a grudge," saying that Sherman "is on the right side of history. Might does not mean right. I was wrong, and am paying the price."

PHOTOS: Geraldo Rivera through the years

But he did manage to get in a dig at his television competitors: "The Ailes scandal will continue to percolate at least in part because of the fear and loathing by competitors for Fox News, the ratings leader. Because it suits their perceived competitive advantage, CNN and other news networks will continue to report, repeat and regurgitate every detail in this melancholy saga."

Read more: Michael Wolff: Roger Ailes' Stunning Fall Marks the End of a Murdoch Era