ELAINE GERAGHTY has stepped down as chief executive of the Denis O’Brien-owned Newstalk FM national radio station.

In a surprise move, Ms Geraghty has been succeeded by Frank Cronin, a Newstalk board member who most recently was an executive with Irish pay TV broadcaster Setanta Sports. He is also a former managing director of the Sunday Tribunenewspaper.

Ms Geraghty declined to comment to The Irish Times, but it is understood that she plans to further her academic career. She has joined the boards of Mr O'Brien's Dublin 98 and Spin South West stations in a non-executive capacity.

Rumours of Ms Geraghty’s departure had circulated in media circles here for some time, with the Newstalk boss linked with a number of media roles.

Newstalk has struggled for ratings since going on air in 2002 and racked up millions in losses. It began life as a Dublin local radio station but went national about three years ago. This change failed to boost its listenership and its market share is just 3.6 per cent.

Ms Geraghty was a personal assistant to Vincent Browne in the mid-1980s at the Sunday Tribune. In 1989 she joined 98FM, which had yet to hit the airwaves, in an administrative role.

She was then chosen by the station, without having any previous on-air experience, to co-host a successful breakfast show with New Zealander Pat Courtenay.

In 2004 she went to work for Mr O’Brien’s Communicorp group, working on his radio investments in central and eastern Europe.