CNN president Jeff Zucker abruptly resigned on Wednesday for failing to disclose a romantic relationship with a colleague at the U.S. cable television network.
"I certainly wish my tenure here had ended differently," Zucker said in a message to the network's employees. "But it was an amazing run. And I loved every minute."
Zucker, 56, said his resignation was effective immediately.
As head of the cable network since 2013, Zucker was one of the most powerful media executives in the United States and a frequent target of the ire of former president Donald Trump.
In his message, Zucker said that as part of an investigation into a CNN anchor, he was "asked about a consensual relationship with my closest colleague, someone I have worked with for more than 20 years."
"I acknowledged the relationship evolved in recent years," he said. "I was required to disclose it when it began but I didn't. I was wrong."
CNN identified the colleague as chief marketing officer Allison Gollust, who said she would remain at the network.
"Jeff and I have been close friends and professional partners for over 20 years," Gollust said in a statement published by CNN.
"Recently, our relationship changed during COVID," she said. "I regret that we didn't disclose it at the right time.
"I'm incredibly proud of my time at CNN and look forward to continuing the great work we do everyday."
Zucker and Gollust are both divorced, according to The New York Times.
Zucker joined CNN from NBC, where he served as president and chief executive officer of the NBC Universal Television Group.
While at NBC, Zucker launched the reality TV show "The Apprentice" that rocketed Trump to stardom.
The two fell out after New York real estate mogul entered politics and CNN became a favorite target of Trump's diatribes against the media while in the White House.
In a statement published by CNN, Jason Kilar, the CEO of WarnerMedia, CNN's parent company, said he will be "announcing an interim leadership plan shortly."
"We thank Jeff for his contributions over the past 9 years," Kilar said.
WarnerMedia is currently engaged in merger talks with Discovery Inc.