Spitzer, who resigned in March 2008, 14 months into his term as New York governor amid a prostitution scandal, began his nightly show on CNN in October.
CNN reshuffled its schedule move Anderson Cooper's flagship newscast into the tough 8 p.m. time slot and eliminate Spitzer's "In the Arena" program.
Spitzer signed off his show Wednesday, saying it would be his last. He ended with a quotation from President Theodore Roosevelt praising people who get "in the arena" to try to improve society, a passage he said inspired the name for his show. CNN talked to Spitzer about staying with the network as a commentator, but he decided not to.
"We engaged serious people in conversations about national and global issues in a way that was informative and challenging," Spitzer said. "I believe that we provided diverse and valuable perspectives during the show's tenure. I thoroughly enjoyed my time at CNN."
At first Spitzer was paired on "Parker/Spitzer" with conservative columnist Kathleen Parker, who left in February. The show was then renamed "In the Arena" with Spitzer the lead personality.
It's in a tough time slot, where Campbell Brown, Connie Chung and Paula Zahn all found rough going before him at CNN. Spitzer's show averaged 595,000 viewers for the first six months of the year, compared to conservative competitor Bill O'Reilly at Fox News Channel, who averaged just under 3 million viewers. MSNBC, first with Keith Olbermann and then with Lawrence O'Donnell, averaged 984,000, the Nielsen Co. said.
Spitzer has never ruled out a return to politics, and by helming a prime-time television show, the former governor maintained a level of visibility that could have helped relaunch his electoral career. But friends saidSpitzer had until now been focused on his work at CNN.
Cooper's 10 p.m. newscast has been CNN's most successful evening program, so it will now get the test at 8 p.m.