O'Reilly's behavior has been under scrutiny since an April 1 report in the New York Times that said he and Fox News have paid $13 million in settlements against women who have accused him of sexual harassment or abusive behavior going back to 2002.
21st Century Fox stock dropped following the announcement of O'Reilly's departure from Fox News, closing at $30.39 a share, down 0.88 percent for the day.
"It is tremendously disheartening that we part ways due to completely unfounded claims", he added.
Fox News Channel says "Tucker Carlson Tonight" will begin airing an hour earlier to fill the time slot vacated by Bill O'Reilly, who lost his job Wednesday after allegations that he sexually harassed women.
Yet the allegations against O'Reilly fit into an uncomfortable narrative for the cable news network.
He had initially planned to return to his The O'Reilly Factor show on April 24, but as outrage mounted and new allegations of inappropriate behaviour surfaced, it became clear the company could no longer afford to back the star who helped bring Fox News to prominence almost 20 years ago.
O'Reilly has lost his job following reports that five women had been paid millions of dollars to keep quiet about harassment allegations.
A security guard looks out of the the News Corp. headquarters in Midtown Manhattan, Wednesday, April 19, 2017.
Charles Herring, the president of Herring Networks, which owns OANN, said he expected Fox would replace O'Reilly with a highly capable host, but he's hopeful that "viewers migrate to One America News".
Some analysts believe that James and Lachlan Murdoch - the sons of 21st Century Fox executive chairman Rupert Murdoch - made the call on O'Reilly to change the Ailesian culture at the network and to cement their control following his departure.
Wendy Walsh, a regular guest on O'Reilly's show, told the Times the cable TV anchor retracted a lucrative role as a Fox contributor after she rebuffed his sexual advances in 2013.
It might take a while for the heated reactions to die down, but however you feel about the news, O'Reilly is out. He thanked his viewers and noted the success Fox had achieved. "Bill has been the undisputed king of cable news, and for good reason". Bustle has reached out to Fox News for comment. "The O'Reilly Factor" has generated a huge ad bonanza for Fox, one that yielded more than $178 million in 2015.
"That's bigger than O'Reilly", he said.
OANN, for example, is available in about 35 million households in the USA, while Fox News is available in nearly 100 million. With a profit center gone, 21st Century Fox stock fell nearly 1 percent Wednesday in heavy trading. "It speaks to a company that has recognized that the best business decision for them is to end their relationship with Bill O'Reilly".
There was no immediate response from Bill O'Reilly's bosses Wednesday to escalating reports that the Fox News Channel personality will lose his job following accusations he had harassed women.