The Irish Times has agreed a deal to acquire all the publishing and media interests of Landmark Media Group which has a 75 percent stake in WLR and owns the News and Star in Waterford.
The acquisition will require separate approvals from the Competition and Consumer Protection Commission, the Minister for Communications, and the Broadcasting Authority of Ireland.
Landmarks interests include the Irish Examiner and the Evening Echo.
There are also seven regional newspaper titles including the Waterford News & Star.
Radio assets include a 75 per cent stake in both WLR and regional station Beat, and a 17.6 per cent holding in Red FM in Cork.
Liam Kavanagh, managing director of The Irish Times, said the intention was to retain the core identity and independence of the respective news titles.
The combined entities would have publishing revenues of about €100 million and employ around 900 staff.
In a note to staff, Tom Murphy, managing director of Landmark Media, said the sale of its assets to The Irish Times was in the best interest of all of our newspaper and other media companies and assets.