Billionaire media mogul Denis O'Brien will not be investigated for excessive influence over his radio and newspaper empire.
A watchdog has looked into his ownership of two national and four local radio stations, and his large stake in Independent News & Media (IN&M), and found no reason for an inquiry.
"The authority was not obliged to review Mr O'Brien's interests in the context of an undue amount of communications media," said the Broadcasting Authority of Ireland (BAI).
Mr O'Brien's Communicorp company controls nationwide stations Newstalk and TodayFM, Dublin stations 98FM, Spin 103.8 and Phantom and local station Spin South West. It has media interests in seven other countries. Mr O'Brien is also the single largest shareholder in IN&M after building up a stake of more than a quarter.
The BAI said his interests in the newspaper group were of interest as its officers are obliged to consider "the desirability of allowing any person, or group of persons, to have control of, or substantial interests in, an undue amount of communications media".
The watchdog looked at Mr O'Brien's stake after the departure of Gavin O'Reilly as INM chief executive earlier this year. The BAI said the media mogul has a substantial interest in the newspaper business but does not control the company.
"In its deliberations, the authority considered it noteworthy that Mr O'Brien's interest in IN&M has been enhanced, that the situation regarding the company is fluid and that it is intended that further appointments be made to its board of directors," he said.
"Communicorp has been requested to ensure that it keeps the Authority fully informed of all developments in this regard."
Increasing questions have been asked over Mr O'Brien's media ownership, particularly in light of the findings of the 14-year long Moriarty tribunal.
Its investigation into the award of the State's lucrative second mobile phone licence reported last year that Mr O'Brien made a series of payments to then communications minister Michael Lowry after his company won the hugely lucrative bidding process. Mr O'Brien, who also owns the Caribbean mobile phone firm Digicel, fought long-running battles against the tribunal during its inquiry. He has rejected the findings against him.