The acquisition of Denis O'Brien's Communicorp Group by Germany's Bauer Media Audio Holdings is now complete.
The deal received approval from The Broadcasting Authority of Ireland and the Competition and Consumer Protection Commission earlier this year.
The deal, said to be worth more than €100m, marks the end of Denis O'Brien's long and significant involvement in media ownership here.
In 2019, Mr O'Brien sold his 29% stake in Independent News and Media to Mediahuis.
Communicorp Group owns the Newstalk, Today FM, Spin 1038, Spin Southwest and 98FM radio stations here.
It also owns digital radio sport station Off The Ball, digital audio exchange audioXI and aggregated listening platform GoLoud.
Bauer Media Audio reaches over 57 million listeners weekly through its broadcast radio, online services, and podcasts across eight countries - Ireland, the UK, Sweden, Norway, Denmark, Finland, Poland and Slovakia.
Its brands include KISS, Mix Megapol, Absolute Radio, Radio Norge, Radio Expres, Radio Nova, Radio 100 and RMF.
Paul Keenan, President of Bauer Media Audio, said the company was excited to be entering the Republic of Ireland market.
Mr Keenan said Communicorp's talented teams have built a strong reputation for high quality news, entertainment, music and sport.
"From this solid foundation we are passionate about the world of radio and look forward to further exploring the audio universe," he added.