By Rick Reeno

Top Rank's CEO Bob Arum advised BoxingScene.com that WBA/WBO lightweight champion Juan Manuel Marquez (52-5-1, 38KOs) would be a leading candidate to fight Manny Pacquiao (52-3-2, 38KOs) in the fall for the WBO welterweight title. Pacquiao is scheduled to defend his belt against Shane Mosley on May 7 at the MGM Grand in Las Vegas.

If Pacquiao beats Mosley, Arum's first goal is to finalize a deal with Floyd Mayweather Jr. If Mayweather is unavailable, or a deal can't be reached, then Arum would focus on a Marquez trilogy. Pacquiao and Marquez fought to a controversial twelve round draw in 2004, and then Pacquiao won a controversial twelve round split decision over Marquez in their 2008 rematch.

The recent headlines certainly help Marquez's cause. According to reports in Mexico, and elsewhere, Marquez is looking to become a free agent once his contract expires with Top Rank's promotional rival, Golden Boy Promotions. The contract reportedly expires at the end of this month.

It's not clear if Mosley, who recently left Golden Boy to secure a Pacquiao deal, inspired the move by Marquez. The ongoing cold war between Golden Boy and Top Rank has certainly prevented their respective boxers from facing each other since mid-2009.

"Marquez would be one of the leading candidates, if not the leading candidate, to fight Pacquiao if he beats Mosley," Arum said to BoxingScene.com.