By Rick Reeno

The negotiations for a very anticipated welterweight collision between Floyd Mayweather Jr. and WBA champion Shane Mosley are still ongoing in a positive manner, Mayweather adviser Leonard Ellerbe told on Thursday night. The rivalry between the two fighters has been brewing for over ten years.

When Mayweather was competing at super featherweight, he was calling for a fight with Mosley, who at the time was the best lightweight in the world. For several years the weight divisions kept them apart. Mosley jumped from lightweight to welterweight in 1999, and then to junior middleweight in 2003. Mayweather made a full move to lightweight in 2002, then went up to junior welterweight in 2004, and then made the welterweight jump in 2005 - which is the same year Mosley returned to 147.

Whispers of a May meeting were out there but the actual negotiations were ready to roll in full force when Andre Berto announced on Monday that he withdrawing from next Saturday's scheduled unification with Mosley. Golden Boy Promotions CEO Richard Schaefer is working day and night to finalize a deal. Golden Boy promote Mosley and have a working relationship with Mayweather. The fight will take place at the MGM Grand in Las Vegas. May 1 and May 8 have both been mentioned as possible dates.

"We are still negotiating the Mosley fight. We are having some every good discussions which is definitely a breath of fresh air. We're looking at a couple of dates in early May. Obviously we want to allow ourselves enough time to properly promote this mega, mega fight. This is a fight that fans have been talking about for ten years. Floyd has wanted this fight for over ten years," Ellerbe told

Since last January's knockout of Antonio Margarito, Mosley has called himself the best welterweight in the world and challenged both Mayweather and Manny Pacquiao to cross his path. Mosley was not successful in landing Pacquiao but a fight with Mayweather is within reach.

"Shane is a tremendous fighter and this is what these marquee matchups are all about. Shane Mosley thinks he's the best welterweight in the world. Floyd Mayweather knows he's the best fighter in the world. Both sides are working very hard to try to get it done and obviously with this being a big mega fight, there are a lot of particulars involved and these deals are not finalized overnight," Ellerbe said.