It's done... Fox News is formally parting ways with host Bill O'Reilly amid a cascade of sexual harassment allegations.

The news channel said there's been a thorough and careful review and both the company and Mr O'Reilly have agreed he won't be coming back.

It's a dizzying turn of events for a TV veteran who has long banked on a loyal following and his stature as an influential voice in US politics.

He had been on, but had been expected back on The O'Reilly Factor on Monday.

Media Matters president Angelo Carusone told Nadine Higgins he shouldn't be allowed back on air to say goodbye after his 21-year tenure.

"If they're firing him for business reasons, which is what they're doing, it's a terrible business decision to let him come back because advertisers are concerned about Fox's posture as a whole about sexual harassment."

O'Reilly has been with the news channel almost since its start.

LISTEN ABOVE: Angelo Carsuone, president of Media Matters in New York, spoke to Nadine Higgins on Early Edition