A CNN Switcheroo

There's no time for Paula Zahn now.

The CNN anchor announced Tuesday that she is leaving the cable news network, a day after the Atlanta-based outfit said that it had hired former NBC News personality Campbell Brown to host a nightly talk show.

Zahn, who has been at CNN for six years, currently hosts the prime-time program Paula Zahn Now, whose last episode will be Aug. 2. Brown is expected to start sometime in November, per an agreement with NBC that keeps her off the airwaves until then.

A series of fill-in hosts will take over during Zahn's 8 p.m. timeslot until Brown's arrival, which will be interrupted once again in late December when she's scheduled to go on maternity leave to await the birth of her first child with husband Dan Senor.

After her stint hosting the two-hour Live from the Headlines, Paula Zahn Now premiered in 2003 and has faced an uphill ratings climb ever since. The 51-year-old newswoman's show has pulled in only 558,000 viewers a night this past year, barely a quarter of the audience the more explosive O'Reilly Factor over on Fox News gets and about 100,000 viewers less than Countdown with Keith Olbermann on MSNBC.

Brown, 39, was with NBC for 11 years, most recently as host of Weekend Today and as a fill-in for Brian Williams on NBC Nightly News.

But although the timing is suspect, Zahn says that the decision to leave CNN was a mutual one between her and management, and that her contract was going to up at the end of this year anyway.

"We worked so hard to maintain a high quality of objective reporting on the air," she told the New York Times Tuesday, discussing a recent series of special reports on her show that dealt with various forms of intolerance, including racial bias. "Yet what has become clear when you look at the landscape, particularly in the 8 o’clock hour, it seems pretty obvious the audience is drawn to opinion-driven shows. That is not what I do."

CNN signed Zahn after she was fired by Fox News in 2001. She at one time anchored the FOX Report and then her own show, The Edge with Paula Zahn.

Zahn was originally hired by the network Ted Turner built to host a morning show, but then was rushed into duty on Sept. 11, 2001, to help lead CNN's coverage of the terrorist attacks. After American Morning with Paula Zahn posted some good numbers for the network, she was promoted to prime-time.

"We are grateful for her dedication, professionalism and class over the last six years, as she has presided over our coverage of such significant news stories as 9/11, the launch of the war in Iraq, national elections and natural disasters, among many others," CNN U.S. president Jon Klein wrote in a note to staffers.

Zahn told the Atlanta Journal-Constitution that her prime-time show always had good support from Klein and that she was leaving the network with "very positive feelings."

"The sadness I feel is that I'm leaving friends and colleagues who have been a very important part of my life," she said. "I'm going to take a break and actually think about, for longer than a day, what I'm going to do next."

As for Brown, the decision to make a major move after more than a decade did not come easy, but she thinks she has made the right choice.

"There's no question leaving NBC was an emotional decision for me and a bittersweet one," she told the Washington Post, which reported that CNN offered the newswoman a big raise, and then NBC matched the offer. "I get that what I'm doing carries risk. I made a choice…I wanted the challenge."

Brown said that, after her maternity leave, she hopes to be back on TV by February, in time for the presidential primaries.

"As soon as I feel okay, I'm going back to work," she said.