Chris Wallace moderates a debate in September 2020 between then-President Trump and Democratic challenger Joe Biden.

Chris Wallace, the longtime Washington journalist, announced his departure from Fox News Channel at the end of his weekly program Sunday, and will head to CNN’s upcoming streaming service.

Wallace, whose contract at Fox News ends this month, was considered the most evenhanded journalist at the conservative-leaning Fox News. An 18-year veteran of the channel, he was the anchor of its Sunday roundtable show “Fox News Sunday.”

“Eighteen years ago, the bosses here at Fox promised me they would never interfere with a guest I booked or a question I asked,” Wallace said on his program. “And they kept that promise. I have been free to report to the best of my ability, to cover the stories I think are important, to hold our country’s leaders to account. It’s been a great ride.”

The surprising departure makes Wallace the latest in a series of high-profile cable news stars to leave their long-standing posts.

Brian Williams signed off from MSNBC’s “The 11th Hour” on Thursday, ending a 28-year run at NBC News. Rachel Maddow is expected to end her daily prime-time program hosting duties on the same channel in 2022, although she will remain with parent company NBCUniversal.

CNN fired prime-time host Chris Cuomo on Dec. 4, following the release of a New York state attorney general’s report detailing his heavy involvement in defending his brother, Andrew, the former governor who resigned after sexual harassment allegations.

Wallace was not the most popular of Fox News personalities, as he never had a daily program. But his tough-on-both-sides approach gave the channel a patina of journalistic respectability often used to deflect criticism of its opinion hosts who draw the largest audiences.

Wallace brought gravitas to special event and election coverage on Fox News. He is the only anchor from the network to moderate a presidential debate, taking on the role in 2016 and 2020.

Wallace has long said he was immune to the right-wing rhetoric of Fox News commentators and never publicly criticized the organization. There have been reports that he was among the journalists in the Washington bureau who expressed concerns about Tucker Carlson’s Jan. 6 insurrection documentary series, which pushed a conspiracy theory that suggested government involvement.

Two Washington-based contributors, Jonah Goldberg and Stephen Hayes, quit Fox News over the Carlson programs, which streamed on Fox Nation.

But according to a Fox News representative, Wallace is leaving because he has the desire to try something new.

A CNN representative confirmed that Wallace is joining the streaming service CNN+. He will be a Washington-based anchor and have a daily program on the service, which is scheduled to launch in the first quarter of 2022.

Wallace, 74, may occasionally appear on the cable channel CNN to offer political analysis, but his main role will be on CNN+, where he is the biggest name hire so far. He will not be a candidate or even a fill-in for the prime-time hour vacancy created by Cuomo’s termination, according to a CNN executive familiar with the plans who was not authorized to speak publicly.

Earlier this year, CNN+ also hired Kasie Hunt, a longtime Washington-based NBC News correspondent.

Wallace is the son of legendary CBS News journalist Mike Wallace. He had stints at NBC News and ABC News before joining Fox News in 2003. He worked as an intern at his father’s network and served as a correspondent for WBBM, the CBS station in Chicago.

Wallace was known as the Fox News journalist who would push back hard against conservative guests who came in with an expectation of friendly treatment, often generating viral moments on social media.

Wallace has told associates that while reports of his concerns over Carlson’s Jan. 6 documentary were accurate, he was treated well at Fox News and was generally happy during his tenure there. Insiders at the company said management did not want him to leave.

But his exit does add to a narrative that Fox News is losing journalists who are troubled by the network’s direction.

Shepard Smith, a popular figure inside Fox News, walked away from one of the biggest salaries in TV news ($15 million annually) in 2019, after becoming increasingly unhappy with the intensity of the pro-Donald Trump rhetoric of Carlson and host Sean Hannity. Smith joined CNBC in 2020 to anchor a nightly newscast.

This year Fox News terminated its political director, Chris Stirewalt, following the backlash among conservative viewers — and Trump — over its coverage of the 2020 election, when it called the state of Arizona for Joe Biden, a win that put the Democrat on a path to victory.

Fox News said Stirewalt’s job was eliminated in a company restructuring. But the veteran political analyst indicated in a Los Angeles Times op-ed piece that pressure from viewers unhappy over the Trump loss was a factor.

“When I defended the call for Biden in the Arizona election, I became a target of murderous rage from consumers who were furious at not having their views confirmed,” Stirewalt said.

Cherie Grzech, a longtime executive at the Fox News Washington bureau, left in June to join NewsNation, the cable news channel launched last year by Nexstar Media Group.

As for Wallace’s replacement, “Fox News Sunday” will turn to a rotating group of in-house names including Shannon Bream, Harris Faulkner, Bill Hemmer, Bret Baier, Jennifer Griffin, Dana Perino, John Roberts and Martha MacCallum, until a permanent moderator is named. Roberts, a former White House correspondent who co-anchors a daily two-hour block, is considered a leading candidate by insiders.

Fox News Media Chief Executive Suzanne Scott has demonstrated an ability to develop opinion hosts and shows that have strong appeal to the channel’s loyal audience, keeping it in first place in the ratings among all cable networks. But filling Wallace’s role with an outside hire would be a test of the network’s ability to attract a solid, big-name journalist with no partisan political baggage.

One factor in Scott’s favor is the company’s willingness to pay well. Wallace was earning at least $5 million a year, putting him in the higher income bracket among Washington journalists.