Olympic gold medallist James DeGale (11-1, 8KOs) is to split from manager Frank Warren.
The 24-year-old shot to prominence four years ago by winning middleweight gold at the Beijing Games.
DeGale turned pro later that year and joined Warren's promotional stable along with fellow Olympians Billy Joe Saunders and Frankie Gavin. He suffered his first loss as a pro last May, when rival George Groves won a majority decision. Groves later signed with Warren.
DeGale confirmed his split from Warren on Friday in a statement released to Press Association Sport by the boxer's solicitors, Blick & Co.
The European super-middleweight champion from Harlesden, London, said in the short statement: "I think it is time for both of us to move on."