The transfer of a minority stake will see the co-founders, Steve Lane and David Moutrie, retain a majority stake and their operational roles as the chief executive and managing director of the agency respectively.
Lane, 50, said the move is designed to keep Brilliant's senior talent on board, while getting them more involved in the running of the business.
Brilliant, which was founded in 1999 following the merger of DMS and Media Lane, is looking to grow through acquisition. The directors taking an equity stake are Steve Empson, Daniel Ward, Cathy Burns, Rachel Empson, Simon Price, Sarah Mills and Craig Megretton.
The agency, ranked 15th in Campaign's Top 50 Media Agencies with billings of £99.62 million, employs 100 people across two offices in Leeds and Manchester. Key clients include Asda, DFS, the DVLA and Subaru.
Lane said: "The move secures our senior team and the future independence of our business, which is central to our culture and a key differentiator in our sector."
Brilliant is projecting a 13 per cent growth in turnover this year on the back of recent wins including Asda's regional account and the HomeForm business.