Mayweather said he planned to fight again in September, a short turnaround for him, as part of a six-fight deal he has with the Showtime network.

NPR: Mayweather Marvelous In Easy Win

Froch won his first fight in American network Showtime's Super Six tournament, beating American Andre Dirrell, and a victory over 31-year-old Kessler would go a long way towards assuring him a semi-final spot.

BBC: Carl Froch's bout with Mikkel Kessler to defy ash cloud

But CBS also credited higher distribution fees for CBS stations as well as cable networks such as Showtime and CBS Sports Network.

WSJ: Media companies benefit from higher network fees