Mayweather, who won the belt with a unanimous points victory against the Filipino fighter in Las Vegas in May, earned at least $180 million for the fight.
The 38-year old American also failed to vacate his World Boxing Association (WBA) and World Boxing Council (WBC) titles at junior middleweight — an issue as WBO rules state a boxer can only hold titles in one weight division.
“Despite affording Mr. Mayweather Jr. the courtesy of an extension to advise us of his position within the WBO Welterweight Division and to vacate the two 154-pound world titles he holds, the WBO World Championship Committee received no response from him or his legal representatives on this matter,” the WBO said on its website.
“The WBO World Championship Committee is allowed no other alternative but to cease to recognize Mr. Floyd Mayweather, Jr. as the WBO Welterweight Champion of the World and vacate his title, for failing to comply with our WBO Regulations of World Championship Contests.”
Undefeated in 48 fights, “Money” Mayweather told a press conference after the Pacquiao fight that he’d consider relinquishing his WBO, WBA and WBC welterweight belts to give “younger guys an opportunity.”
“I’m not greedy. The other guys need a chance. It is time they fight for the belts,” he said.
The fighter has 14 days to appeal the WBO’s decision. The title is expected to go to Timothy Bradley, who beat Jessie Vargas in an interim title bout last month, if the Mayweather issue is not resolved by then.