The board of the Broadcasting Authority of Ireland is to write to Communicorp on the issue of media ownership and control.
The BAI Board held its monthly meeting today and its ownership and control policy was one of the items on the agenda.
A spokeswoman said the board would be writing to Communicorp on the matter later this week.
Communicorp's holding in the Irish radio market includes the national stations Today FM and Newstalk, and the Dublin stations 98FM, Spin 1038 and Phantom.
Its founder Denis O'Brien increased his share in the Independent News and Media newspaper group to 29.9% in May.
The BAI published an updated Ownership and Control policy in April.
It set out the regulatory approach it will take and the rules that will be enforced regarding the ownership and control of broadcasting services.
Its stated strategy is the maintenance of plurality of ownership, content and viewpoint.