The British-born TV host tweeted Tuesday morning that he has officially left the cable network after turning down CNN boss Jeff Zucker's offer to present 40 news specials over two years.
"After considerable thought, I decided not to accept it -- and to try pastures new," Morgan wrote.
A CNN spokeswoman did not respond to an email seeking comment.
"His deal is now over as of yesterday," John Ferriter, Morgan's manager, wrote in an email. "It is all amicable."
"Piers Morgan Live" ended its run on CNN back in March and it was unclear what he might do next. The show -- then named "Piers Morgan Tonight" -- premiered in January 2011 with heavy promotion and a parade of A-list celebrity guests such as Oprah Winfrey.
But ratings subsequently eroded sharply and Morgan's show became an emblem of the overall troubles afflicting CNN's primetime lineup, which has struggled against Fox News and MSNBC. His departure comes as CNN is wrestling with budget cuts and staff downsizing.
Morgan's staunch support for stricter gun laws made him a frequent target online, where he seemed to take delight in baiting his critics.
When one journalist wryly suggested on Twitter that Morgan was leaving to spend more time with Internet trolls, he replied: "That's just a hobby."
What do you think of Morgan?