Former three-division champion Shane Mosley will take on WBO welterweight champion Manny Pacquiao on May 7 at the MGM Grand Garden Arena in Las Vegas, Top Rank promoter Bob Arum told

The fight will be promoted by Top Rank and be at the welterweight limit of 147 pounds.

Mosley, 39, had been considered the favorite of a three-candidate field to fight Pacquiao that included lightweight champion Juan Manuel Marquez and welterweight champion Andre Berto. Arum said he presented Pacquiao with these options after consulting with Pacquiao's trainer, Freddie Roach, and Top Rank matchmaker Bruce Trampler.

Roach has been vocal in his opposition of a fight with Mosley, telling in November that he "didn't see much of a point" in a Mosley fight and that he preferred a third fight with Marquez to "shut Marquez up." According to Arum, Roach's opinion changed after spending a week with Arum and Pacquiao in the Philippines.

"He turned around," Arum said. "He was an advocate [for the fight]."

Arum has taken some criticism over his preference for a fight with Mosley. Mosley has struggled in his last two fights, a one-sided loss to Floyd Mayweather last May and a draw against Sergio Mora in September. Many in the boxing industry believed a fight with Marquez, who battled Pacquiao to a draw in 2004 and lost a narrow decision to the Filipino in 2008, was the better choice.

"I try to take the pulse of people who are non-boxing fans," Arum said. "And to them, without question Shane Mosley is at the head of the pack. I know there were some issues within the boxing community that maybe Marquez was more deserving. But people don't know Marquez, and even fewer know Berto. Their Q rating doesn't resonate. To everyone I talk to around the world, it's always Mosley."

As for Mayweather, Arum said he would have waited to make a deal with the former pound-for-pound champion if Mayweather had given him any indication he was interested in the fight. Mayweather is due in court next month to face four felony charges stemming from a domestic incident in September.

"We put it off as long as we could," Arum said. "He has been totally incommunicado. All he had to do was pick up a phone and say, 'Hey Bob, wait a week, two weeks' and we would have waited. He could have given us a signal. No one knows how to get a hold of him. The only ones who know how to get a hold of him are the police."

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