There are not enough older women on TV, the head of the BBC has admitted.
Mark Thompson, director-general of the BBC, said that there are "manifestly" too few older women appearing in television's top programmes and presenting roles.
He noted that although the BBC had undergone a "revolution" in recent years, with more women taking top leadership roles, the publicly-funded broadcaster still had "a case to answer" about the way it treats older women in broadcasting.
The landmark age-discrimination employment tribunal brought by ex-Countryfile presenter Miriam O'Reilly case was an "important wake-up for the whole BBC" he conceded, and writing in the Daily Mail, he said it marked a turning point of its handling of the issue,
Mr Thompson said: "Let's not mince words: those who say that the BBC has a case to answer about the way it treats older women on the air are right. We do.
He added: "The BBC is in a different class from everyone else, and that the public have every right to expect it to deliver to a higher standard of fairness and open-mindedness in its treatment both of its broadcasters and its audiences.
"If the BBC isn't prepared to take this issue more seriously, what hope is there that others will start to do so?"
Mr Thompson said a growing number of older women held top executive roles at the corporation, but admitted it has "too few women in key news and current affairs presenting roles, especially when it comes to the big political interviews".
He continued: "Of the 12 members of our Executive Board, five are female, all of them (and no, there isn't a completely satisfactory way of saying this) 'older' women.
"Critical BBC services - including both Radio 4 and BBC Two - are in the hands of exceptional women controllers. BBC News, once an almost entirely male management domain, is largely led by women.
"But we've yet to see the same rate or scale of change on the air."
The long-serving head, who is tipped to step down from his role in the near future, said other broadcasters, newspapers and advertisers were guilty of ageism at a "far more pronounced and disturbing" level "than anything you'll ever see or hear on the BBC".
He added: "I don't believe for a moment that the BBC is riven by sexism or ageism."
"The public would be alarmed if the BBC did anything other than choosing presenters strictly on merit and regardless of sex or age.
"Nonetheless, the Miriam O'Reilly case was an important wake-up for the whole BBC, one which I hope will mark a turning-point on our handling of this issue."
Mr Thompson admitted Ms O'Reilly had been mistreated by the BBC, which now had "a duty to ensure that no one has to go through a similar experience in the future".
The broadcasting chief, who is also chairman of Creative Diversity Network, the industry body that looks at fairness and representation of every kind both on and off screen, has commissioned a report into ageism on British TV as a whole.
He said the survey, called, Serving All Ages, found that most people were more concerned with quality of output rather than issues of age and that it was the young rather than old who felt discriminated against.
But there were also a minority of people who felt older women were "invisible" on the airwaves.
Mr Thompson said the BBC needed to cherish the "outstanding women broadcasters" it already had while bringing great female talent back to the corporation.
But he warned it should not "turf out other much loved and respected presenters and reporters in an attempt to achieve an instant fix" to the issue.