Conor McGregor announced on his website, TheMacLife, that he has struck a deal with the
"It is an honor to sign this record-breaking deal alongside my partners," McGregor wrote of UFC's parent company and his own agency.
"The first and most important part of this historic contract has now been officially signed off on. Congratulations to all parties involved. We now await [Mayweather manager] Al Haymon and his boxer's signature in the coming days."
UFC President Dana White confirmed the deal with McGregor, according to the Associated Press.
"I'm not saying the fight will happen, but I've got one side done," he said. "Now it's time to work on the other."
White did not respond to questions about how McGregor and the UFC would split money on their side. McGregor's agent, Audie Attar, didn't comment, either, but The Times was forwarded TheMacLife story from a representative of McGregor's agency.
Mayweather, 40, and his associates have remained quiet on the subject in recent days after the unbeaten (49-0) boxer previously announced he would end a retirement dating to September 2015 only for a fight against the talkative McGregor.
A boxing match between the pair could become the best-selling pay-per-view of the year even if McGregor is considered a massive underdog against the skilled boxer.
A gifted striker in mixed martial arts who ended featherweight champion Jose Aldo’s 10-year unbeaten run with a knockout punch in a title-fight-record 13 seconds, McGregor also repeatedly knocked down Nate Diaz and Eddie
Ireland's McGregor on St. Patrick's Day reaffirmed his confidence in faring well in a stand-up fight against Mayweather while attending countryman Michael Conlan's pro debut at Madison Square Garden.
"I'm the boxing guy!" McGregor roared to reporters at ringside.
He took a break earlier this month to await the birth of his son.
While White said a planned Sept. 16 date was lost when Canelo Alvarez and Gennady Golovkin sealed that date earlier this month, Mayweather-Alvarez could happen a week earlier, with McGregor reportedly telling White he plans to fight twice this calendar year.
May 18, 9 a.m.: This article was updated with UFC President Dana White confirming the deal with Conor McGregor.