Mayweather Jr. to fight again

LAS VEGAS -- Floyd Mayweather Jr., the welterweight champ and pound-for-pound king until retiring last June, officially ended his retirement Saturday at an afternoon news conference to announce a fight with lightweight champion Juan Manuel Marquez.

Mayweather, who hasn't boxed since knocking out Ricky Hatton in a December 2007 welterweight title defense, will fight Marquez on July 18 on HBO PPV at the MGM Grand, the same venue hosting Saturday night's fight between junior welterweight champion Hatton and Manny Pacquiao, the man who succeeded Mayweather as the pound-for-pound king.

The sides have been close to a deal for several days but the one hang up had been the exact weight. In the end, they settled on a maximum weight of 144 pounds, a source involved with the fight told ESPN.com.

Mayweather had wanted the fight to be at 145 pounds, but Marquez (50-4-1, 37 KOs), the smaller man coming up from the 135-pound division where he is champion, wanted the weight as low as possible.

The deal was finalized Friday afternoon following a flurry of conversations over a six-hour period, another source said.

Besides the weight issue, the fight was delayed when Mayweather, a former five-division champion, visited promoter Don King last week at his Florida home, where they discussed a possible deal. But King couldn't get him to sign.

The seeds to a Mayweather comeback had been planted months ago when he began working out and sparring at his Las Vegas gym. Mayweather has also been dogged by IRS problems.

Mayweather (39-0, 25 KOs), who turned 32 on Feb. 24, told his advisers, Al Haymon and Leonard Ellerbe, in December that they were free to listen to fight offers.

Also, Mayweather's father, Floyd Mayweather Sr., who trains Hatton, told media members during the promotion of Hatton-Pacquiao that his son's ring return was imminent.

The winner of Mayweather-Marquez clearly looms as the most attractive opponent for the winner of Hatton-Pacquiao. Marquez and Pacquiao have already fought two very close, exciting fights, a draw in the first fight and a split decision win for Pacquiao in the second bout.

Dan Rafael is ESPN.com's boxing writer. Information from The Associated Press was used in this report.