Tyson Fury wants half a billion pounds to finalise a unification fight with Oleksandr Usyk.
Usyk retained his WBA (Super), IBF, WBO and IBO belts after winning his rematch with Anthony Joshua on Saturday while Fury, who retired after beating Dillian Whyte in April, holds the WBC belt.
Promoter Frank Warren has said a bout with Fury is "the only fight" Usyk wants and Fury has given until September 1 for it to be arranged.