Manny Pacquiao will begin talks about a possible fight with Mexican Antonio Margarito or Puerto Rican Miguel Cotto next week after a deadline to agree a clash with undefeated American Floyd Mayweather Jr. expired. Pacquiao's promoter Bob Arum said Saturday that exclusive negotiations with Mayweather were over and that although a fight between the pair could yet happen other opponents had to be considered for the Filipino's scheduled Nov. 13 bout. “The fight we wanted is Mayweather,” Arum said in a telephone conference call Saturday. “Floyd, for whatever reason, didn't want to commit. I am sure, without knowing, that there is a very good reason why Mayweather hasn't committed at this time.” A highly anticipated fight between WBO welterweight champion Pacquiao (51-3-2) and Mayweather (41-0), easily the sport's best two fighters, was called off earlier this year over the Filipino's failure to agree to blood and urine testing. Arum suggested that the issue over drug testing had been resolved and speculated that the pending trial of Floyd's uncle and trainer Roger Mayweather over a charge he attacked a female boxer could be why Floyd would not agree to fight this year. “I really believe this issue with the uncle has an affect,” Arum said. “If I were in his shoes I wouldn't want to go into this big fight without my trainer.” Pacquiao now faces the prospect of an unattractive clash against Cotto (35-2), who he stopped in the final round of their November clash, or Margarito (38-6), who has only just returned to the ring after being banned for a year for wearing illegal hand wraps. Arum said he expected it to take only a week to negotiate a contract with either opponent, both of whom fight in his Top Rank stable. “I have to discuss with Manny to see who he prefers. The decision falls on Manny.” However, Arum suggested that Pacquiao could fight Mayweather in 2011 in what could be the richest fight ever in the sport. “If Floyd emerged and said he wanted to do the fight there would be no objection on our part. It would be a shame if it didn't (happen).” Mayweather's camp has been silent throughout the negotiations, with Golden Boy CEO Richard Schaefer even refusing to acknowledge talks were occurring. Mayweather's official Twitter feed, which usually is overflowing with plugs for his iPhone application, music ventures and charity endeavors, hasn't been updated since Thursday afternoon, the Assocaited Press reported.