NBC News and MSNBC have severed ties with "Game Change" co-author and veteran journalist Mark Halperin, days after multiple women told CNN he sexually harassed or assaulted them during his time at ABC News.

An MSNBC spokesman told CNN on Monday morning that Halperin's contract with both had been terminated.

Halperin had served as an NBC News senior political analyst and MSNBC contributor, and was a frequent guest on MSNBC's "Morning Joe."

The peacock network, which had benched Halperin in the immediate wake of the sexual misconduct allegations, was the last of the media companies with which he'd had relationships going into last week to completely cut ties with him.

Showtime on Saturday announced Halperin would not be part of "The Circus," a show that chronicled the 2016 campaign cycle and the early days of the Trump presidency, should a new season be ordered. Penguin Press canceled a forthcoming book on the 2016 election that he was set to co-author last week, and HBO said it would not proceed with a project in development that would have been based on the book.

Related: Four more women accuse Mark Halperin of harassment, bringing total to at least a dozen

CNN first reported on Wednesday night about the allegations of sexual harassment and assault against Halperin. Since then, more women have come forward, bringing the total number of accusers to at least one dozen.

The accusations from the women include that Halperin, while he was clothed, placed his erect penis on the bodies of women without consent; that he masturbated in front of an ABC News employee in his office, and that he threw another woman against a restaurant window before attempting to kiss her. The alleged incidents occurred while Halperin was in a position of significant authority at ABC News, while the women were young and had little power.

Halperin has denied pressing his genitals against the women, masturbating in front of anyone, physically assaulting anyone or threatening anyone. In a lengthy statement he released Friday, Halperin said he was "profoundly sorry for the pain and anguish" he caused with what he called "outrageous conduct at ABC News," and said he felt "profound guilt."

"I fully acknowledge and apologize for conduct that was often aggressive and crude," Halperin said.

Halperin additionally said he had participated in weekly counseling sessions for several years around his departure in 2007 from ABC News to "work on understanding the personal issues and attitudes that caused me to behave in such an inappropriate manner." He said that his conduct in his subsequent jobs "has not been what it was at ABC" and that he "did not engage in improper behavior with colleagues or subordinates."

"I know I can never do enough to make up for the harm I caused," he said. "I will be spending time with my family and friends, as I work to make amends and contributions both large and small."

Before the allegations, Halperin had built an empire reporting on national politics.

Widely considered to be one of the preeminent political journalists of the past decade, Halperin, has, among other career highlights, been political director at ABC News; co-authored the bestselling book "Game Change," which was made into an HBO movie starring Julianne Moore as Sarah Palin; and anchored a television show on Bloomberg TV.