Corbett has been at the firm since 2001 when Corbett & Keene, the agency she set up with Sara Keene in 1988, was folded into Premier. She leaves on 29 February.
Corbett said: ‘I am very proud to have set up Corbett & Keene with Sara and have experienced a very small company growing into a big international success.
‘I feel that I now need time to complete the research on a book that I have in development and a couple of design projects, as well as undertaking some occasional work with Premier. So my ties with the company will not be entirely severed.’
Corbett is known for her skills in escorting luminaries of the film world on international red carpet events and is a veteran film and awards campaigner.
Premier PR chairman John Reiss said: ‘Ginger is one of the industry’s most experienced and well-respected PR professionals. She has been a mentor to so many across the industry. She is very much part of this company’s DNA and will be much missed by me and all her colleagues.’