• CNN President Jeff Zucker resigned Wednesday after revealing he failed to disclose a romantic relationship with a top-ranking colleague.
• Zucker said in a statement that shocked CNN employees that he should have admitted to that relationship with CNN executive Allison Gollust during a recent probe by the network of Chris Cuomo.
• Gollust previously served as communications director for former New York Gov. Andrew Cuomo, the older brother of Chris.
• Andrew Cuomo resigned last summer after nearly a dozen women accused him of sexual harassment.

CNN President Jeff Zucker resigned Wednesday for failing to disclose a romantic relationship with a high-ranking colleague who once served as communications director to ex-New York Gov. Andrew Cuomo.

Zucker wanted to stay in the role temporarily, but he faced a possible firing if he did not step down, the network's journalists reported, citing two people involved in the matter.

Zucker, 56, in a memo sent to staff said that he should have admitted to his relationship with CNN executive Allison Gollust when he was asked about it during a recent probe by the network of Chris Cuomo, who at the time was a host of a prime-time show there.

Chris Cuomo was fired in early December after CNN said it had obtained new information about his controversial role in advising his brother Andrew during a sexual harassment scandal, which itself had ultimately led to the governor's resignation last summer.

"As part of the investigation into Chris Cuomo's tenure at CNN, I was asked about a consensual relationship with my closest colleague, someone I have worked with for more than 20 years," Zucker said.

"I acknowledged the relationship evolved in recent years. I was required to disclose it when it began but I didn't. I was wrong," said Zucker, who like Gollust is divorced.

"As a result, I am resigning today."

"I came to CNN on January 28, 2013. Together, we had nine great years. I certainly wish my tenure here had ended differently. But it was an amazing run. And I loved every minute," said Zucker.

CNN reported that "Zucker's resignation left staffers inside the network in shock."

Jason Kilar, CEO of CNN's parent WarnerMedia, itself a subsidiary of AT&T, in a statement to network employees, said "We thank Jeff for his contributions over the past 9 years.

Kilar later announced in a separate memo that CNN would be led for now by three long-time members of its current leadership team: Michael Bass, Amy Entelis and Ken Jautz.

Gollust, who was not identified by name in Zucker's statement, is keeping her job as CNN executive vice president and chief marketing officer.

She previously was chief of communications at NBC Universal during Zucker's tenure there, which include serving as president and CEO of NBC Universal, the parent company of CNBC.

An NBC News story last year described Gollust as "Zucker's most-trusted lieutenant for decades."

Gollust, in a statement, read on air by CNN media reporter Brian Stelter, said, "Jeff and I have been close friends and professional partners for over 20 years."

"Recently, our relationship changed during Covid. I regret that we didn't disclose it at the right time," Gollust said. "I'm incredibly proud of my time at CNN and look forward to continuing the great work we do every day."

CNN declined to comment when contacted by CNBC.

Zucker had a reputation within CNN for being a very hands-on manager who was involved in essential details of producing shows, which included decisions such as which guests to book, which chyrons to use and story selection, according to two employees.

"Jeff had an eye for talent and knew everyone in the business," one employee said. "From new producers to veterans of the industry. It's a really sad day here. I'm at a loss for words."

Gollust joined CNN as its communications director in February 2013, weeks after Zucker started there. She had spent only four months as Andrew Cuomo's communications director before quitting.

In her recent memoir, the veteran journalist Katie Couric wrote about Gollust and her then-husband moving into an apartment above that of Zucker and his then-wife.

Gollust at one time worked as senior publicist for NBC's "TODAY," show, which Couric hosted for years.

"I had to wonder why Jeff was angling so hard to bring Allison on board. She and her husband and kids had moved into the apartment right above Jeff and Caryn's—everyone who heard about their cozy arrangement thought it was super strange," Couric wrote.

"By that point, Caryn (Zucker's ex-wife) had become a close friend and it made me really uncomfortable."

AT&T last May agreed to have CNN's parent WarnerMedia merge with Discovery Communications.

Discovery CEO David Zaslav will run that combined company.

Zaslav has a long-standing professional relationship with Zucker dating their working together at NBCUniversal in the early 1990s. CNN employees, before Zucker resigned, widely assumed that he would have a larger role in the merged company.

Zaslav is not allowed to make any leadership decisions for the combined entity until regulators approve the deal, which is expected in the second quarter of this year.

Discovery declined to comment on Zucker's resignation.