George Groves has failed in his appeal to the International Boxing Federation over the purse split for a world title rematch with Carl Froch.
Because Groves is not considered a top challenger, 85% of the money will go to WBA and IBF champion Froch.
The IBF board voted unanimously to maintain the 85%-15% split.
Froch, 36, released a statement last Friday claiming that his rival had turned down a seven-figure offer to fight again.
Fellow Briton Groves, 25, said he was unhappy with several clauses in the offer.