Bauer is rebranding Wave 105 as Greatest Hits Radio South Coast and Greatest Hits Radio Cornwall will replace Pirate FM.
The move, once complete in the coming weeks, means the Hits Radio and Greatest Hits Radio networks will have taken over all heritage local radio brands owned by Bauer.
In a change from other regional Greatest Hits Radio stations in England, Wave 105 will include its own regional breakfast show hosted by the current breakfast presenter, Rick Jackson, in addition to a regional mid-afternoon show hosted by Mark Collins.
Pirate FM will rebrand to Hits Radio Cornwall with the station being digital only with Neil and Saffy presenting the Breakfast show.
Greatest Hits Radio Cornwall will announce details of its new local afternoon show soon.
Some jobs will be put at risk as a result of the move and freelance contracts reviewed.
All stations will continue to provide local news and information, including traffic and travel as well as commercials and charity initiatives.
Gary Stein, Group Programme Director for the Hits Radio Portfolio said: “Pirate FM and Wave 105 are both well-loved and recognised station identities in their own areas, and we want to build on their fantastic success and secure their future by transforming them into these nationally recognised brands.
“This will mean that alongside their locally produced shows, and local news and information, they will be able to offer audiences access to programmes from some big name broadcasters, all while being bolstered through national marketing campaigns, giving them even more opportunity to grow.”