Warne moves up from her role as managing director of the group.
In her new post she will oversee healthcare comms agency Red Door Communications (RDC) and sister agency Rock Medical Communications.
Warne co-founded RDC ten years ago and it has grown into one of the largest healthcare PR agencies in the UK. It was sold to Creston Health in 2005.
In her new role, Warne will also be responsible for exploring new offerings, either as start-ups or acquisitions.
'We believe there are other opportunities out there for our group to diversify and adapt to the evolving and dynamic marketplace,' said Warne. 'My new role is to help us to realise these opportunities.'
Catherine Oliver will take over Warne's previous role as MD of RDC from 1 April.
Oliver has worked with RDC founders Catherine Warne and Julia Harries for 13 years. Harries is also expected to return from maternity leave to her role as client strategy director in May.
In addition, Nicola Walsby has been promoted to the board from her role as associate director and becomes a director of RDC.
Rock associate director Joanne Neave has also been promoted to director and will report to Warne.
Finally, RDC's finance director Paul Turnbull has been promoted to the newly formed position of divisional finance director for the Creston Health group of companies.