The CNN anchor Campbell Brown has announced that she will be leaving the ailing news network, citing poor ratings for her decision to quit.

Brown - who left NBC to join CNN in 2007 - said that she had been disappointed with the ratings for her self-titled show. She indicated that CNN would have to take the opportunity created by her departure to re-evaluate its direction for the competitive 8:00pm timeslot.

"I'm pretty sure the last time any anchor could honestly ignore ratings was well before I was born. Of course I pay attention to ratings. And simply put, the ratings for my program are not where I would like them to be. It is largely for this reason that I am stepping down as anchor of CNN's Campbell Brown.

"To be clear: this is my decision, and one that I have been thinking about for some time... The simple fact is that not enough people want to watch my program, and I owe it to myself and to CNN to get out of the way so that CNN can try something else."

Brown's programme has struggled to attract a competitive audience, finding itself easily outrated by the shows of her rivals on Fox News, MSNBC and CNN's sister station HLN. According to The New York Times, Campbell Brown has had an average audience of just 591,000 viewers this year. Fox News' Bill O'Reilly has averaged 3.34 million viewers in the same timeslot, while Keith Olbermann on MSNBC is watched on average by 1.03 million viewers. Nancy Grace's crime programme on HLN has averaged 724,000.

While professing admiration for the successes and skills of her competitors in the 8pm timeslot across other networks, Brown said that she herself would have been unable and unwilling to go down the same polarising path as polemicists such as O'Reilly or Olbermann.

"Shedding my own journalistic skin to try to inhabit the kind of persona that might co-exist in that line up is simply impossible for me. It is not who I am or who I want to be; nor is it who CNN asked me to be at any point.

"This is the right decision for me and I hope it will be a great opportunity for CNN."

In a short statement, CNN's president Jon Klein commented that "we want to wish her well as she begins the next phase of her life". He indicated that a decision about CNN's evening line-up would be made "in the coming weeks". Brown will continue at CNN in the meantime.

Mediaite, which broke the news, reported that Brown had initially asked for a review of her position earlier this year; she eventually asked to be released after CNN after the network turned down her suggestion that she be moved to the 7:00pm slot, now occupied by the former Sunday morning host John King.

CNN's future has been the subject of continuous speculation over the last year; the once-dominant network has had to contend with spiralling ratings, which have seen its popularity drop by 31 per cent year-on-year. Brown's show is only one of several which have experienced ratings troubles; both Anderson Cooper 360° and Larry King Live saw their first-quarter ratings halve compared to the same time last year, despite major continuing news stories such as the earthquake in Haiti and the US health reform debate.

Media Spy discussion: CNN