The heavyweight title clash between Anthony Joshua and Wladimir Klitschko at Wembley on April 29 is expected to match the British attendance record with a crowd of 90,000 spectators.
Joshua's IBF belt and the vacant IBO and WBA Super crowns will be up for grabs when the pair go toe to toe in London.
Matchroom Boxing promoter Eddie Hearn has revealed that a deal has been reached with mayor Sadiq Khan to increase capacity from 80,000 after he agreed with Network Rail and Transport for London to put on additional services.
"Sadiq urged me to bring the biggest fights to the city and I'm delighted to have the biggest fight in British boxing history at Wembley," BBC Sport quotes Hearn as saying.
Attendance of the fight will equal the British record set in 1939 by Len Harvey and Jock McAvoy at White City Stadium.