Fox News anchor Megyn Kelly leaving to join NBC

Megyn Kelly in a January 2016 file photo awaiting the start of a Republican Presidential debate.
Megyn Kelly in a January 2016 file photo awaiting the start of a Republican Presidential debate.PHOTO: EPA

(REUTERS) - Fox News Channel anchor Megyn Kelly, a star of the US cable network's highly rated prime-time lineup, has decided to leave to join NBC News in a broad role that includes hosting a one-hour daytime news show, NBC announced on Tuesday (Jan 3).

Kelly also will anchor a Sunday night news show and take part in the network's special political programming and other big-event coverage, NBC News said in a statement.

Kelly's departure is a potential blow to Fox News, the top-rated cable news network owned by Rupert Murdoch's 21st Century Fox.

Just months ago, its founding chairman, Roger Ailes, left following sexual harassment allegations by several women.

Kelly was one of the accusers and detailed Ailes' behaviour in her best-selling book, Settle For More.

Ailes has denied the allegations.

Fox News, which is known for a roster of conservative commentators such as Bill O'Reilly, remained at the top of cable news ratings amid the Ailes turmoil. The network delivered its highest annual viewership in its 20-year history in 2016.

Kelly, 46, played a large role in that success, with 2.7 million viewers on average for her prime-time show, The Kelly File, second on Fox only to O'Reilly's programme, The O'Reilly Factor.

"I have decided to end my time at FNC, incredibly enriched for the experiences I've had," Kelly wrote on Facebook.

She became a subject of news stories after then-Republican presidential candidate Donald Trump attacked her as unfair for her questioning of him at a primary debate during the 2016 election campaign.

While Kelly's departure leaves a hole in the Fox News lineup, it comes at a time when the network needs to reinvent itself to appeal to younger viewers, said Pivotal Research analyst Brian Wieser.

Fox News, like many of its peers, has an older audience, with a median age of over 65, higher than MSNBC and CNN, whose viewers' median ages are 64 and 60 respectively, according to Nielsen data.

Advertisers generally seek out a much younger market.

"Their audience is ageing," Wieser said. "The question now for investors is 'What will Fox put in Kelly's place?'"

A Fox News spokeswoman did not respond to requests for comment.

Some media buyers said they expected Fox to maintain strong ratings given interest in the White House transition and its other popular hosts.

Barry Lowenthal, president of agency The Media Kitchen, called Kelly's departure "neutral" for the network.

"Given Fox's ratings dominance, they've shown that they're bigger than any one anchor," he said.

Kelly joined Fox in 2004 as a Washington-based correspondent before rising to host her prime-time show. Her decision to move to NBC News, a unit of Comcast Corp, was first reported by The New York Times.

While details about Kelly's daytime and evening shows were scarce, she will be trying to succeed where high-profile news anchors have struggled. In recent years, Katie Couric and Anderson Cooper lasted just two seasons with syndicated daytime talk shows.

Kelly's new NBC News colleague Brian Williams, meanwhile, saw his low-rated prime-time news magazine show, Rock Centre, end after only two years as well.