According to two people familiar with Mr. Zucker’s departure from CNN, a company investigation into his conduct by the law firm Cravath, Swaine and Moore found multiple violations of CNN’s standards and practices, including taking part in advising former New York Gov. Andrew M. Cuomo.

Ms. Heller, Mr. Zucker’s spokeswoman, said Mr. Zucker did not advise Mr. Cuomo.

“As we have said numerous times, Mr. Zucker never advised Andrew Cuomo, directly or indirectly,” she said. “He was asked to resign for one reason only, failure to disclose his relationship.”

For Mr. Zucker, who has been in senior management ranks since his 20s, when he became executive producer of “Today,” his abrupt exit from CNN represented a marked change of pace. He soon began to explore his options, gravitating to the familiar territories of sports and media. Years ago, Mr. Zucker told a writer for the Harvard Crimson, the campus newspaper he worked on as an undergraduate, that he hadn’t taken a day off since finishing college.

Shortly after his ouster from CNN, Mr. Zucker began plotting his next move, meeting with advisers, former colleagues and industry stalwarts at upscale watering holes like the Core Club in New York and the Four Seasons in Los Angeles. But even as he planned for the future, Mr. Zucker was thinking about his past.

In the summer, he traveled to Jackson Hole, in Wyoming, for an off-the-record gathering of media executives. In a fireside chat at the event, he was asked for his view on the current direction of CNN and in his answer criticized Mr. Kilar for the way the executive handled his exit, according to two people familiar with his remarks.