Floyd Mayweather revealed he will fight Andre Berto on Showtime PPV on September 12.
Mayweather insisted on the post-fight broadcast immediately after his May 2 win over Manny Pacquiao that his next fight would be the last of his career (via Sports Illustrated): "My last fight is in September, then it's time for me to hang it up. You know, I'm almost 40 years old now, I've been in the sport 19 years, I've been world champion for 18 years, and I'm truly, truly thankful and I'm blessed."
Mayweather's bout on Sept. 12 will be his last under the terms of a six-fight contract with Showtime Sports—a subsidiary of CBS. Lyle Fitzsimmons of Bleacher Report and CBS Sports reported on July 8 that Mayweather's next fight could be broadcast on CBS, which would have been unique simply because of how revenue works in boxing, with fighters collecting portions of pay-per-view buys as part of their deals; however, Mayweather's announcement confirms the fight will be done in the same format that has generated so much money in the past.
Mayweather does not seem to be in desperate need for money, as ESPN.com's Darren Rovell and Dan Rafael reported the undefeated champion walked away from his fight with Pacquiao making at least $220 million.