Independent News and Media has bought 2.5m of its own shares at a total cost of €9.1m.
The move is unrelated to the stand-off between Tony O'Reilly and Denis O'Brien over the future direction of the newspaper group.
The share buy back will have the effect of very marginally lifting the stakes of existing shareholders.
The company is preparing for some shareholders to convert preference shares into ordinary shares later this year, which would have the effect of diluting existing shareholders.
A spokesperson said today's repurchase would mitigate against existing shareholders being diluted when the conversion happens in November.
