Frank Cronin has resigned as chief executive of Newstalk 106-108 FM, the national radio station owned by Denis O’Brien.

In a statement, Newstalk said Mr Cronin had decided to “decided to pursue a new business venture”.

It was not clear last night what this new venture was and Mr Cronin could not be reached for comment.

In a note to colleagues yesterday, Mr Cronin said: “I am writing to inform you that I have resigned my position as CEO of Newstalk. I plan to pursue a new venture.

“I have discussed this with the board over the last couple of months and they have been very supportive.

“Newstalk is a great station and it is lucky to have strong, intelligent, hard-working staff like you. I am very proud of what we achieved and I wish you and Newstalk the very best for the future.”

JNLR radio listenership figures published this week showed that Newstalk’s share of the national radio market has declined to 4.4 per cent from 4.6 per cent.