It's been a wonderful experience to gather all the information regarding the Pacquiao vs Mayweather fight. Everything comes to an end. Not all endings are happy. 

Today I bring you a sad news. I'm still waiting for this to be not true. Pacquiao vs Mayweather won't happen. Read the rest.

Pacquiao-Mayweather bout is off 

The proposed mega-fight between Manny Pacquiao and Floyd Mayweather Jr. is off after both sides couldn't agree to common ground on drug testing following a Tuesday mediation session.

Michael Koncz, Pacquiao's U.S. business advisor, commented on Pacquiao's Web site that "the whole blood testing issue that Mayweather wants from Manny is just a facade to get Mayweather out of this fight."

The bout was set for March 13 in Las Vegas and was likely to be the richest in boxing history.

Earlier, Pacquiao filed a defamation lawsuit against Mayweather and several members of Golden Boy Promotions in a Las Vegas federal court. That was in response to Mayweather's promoter releasing a statement regarding Pacquiao's refusal to undergo Olympic-style blood testing prior to their proposed bout.

The release appeared to insinuate Pacquiao, the current welterweight champion and title holder in seven different weight classes, had taken performance- enhancing drugs in order to reach the pinnacle in the sport, though Pacquiao has repeatedly said he has never tested positive for a banned substance.

"I am very disappointed that we could not make this fight for the fans and I am angered because of the false accusations from Golden Boy and the Mayweather camp that I used some type of drugs and that is why I have instructed our American lawyers to proceed with the lawsuit to clear my name," Pacquiao said in a statement on his Web site. "This is all I have to say at this time."

After the inflammatory remarks, Pacquiao immediately stated he would file suits due to false accusations. The Filipino did so, naming Mayweather, Floyd Mayweather Sr., and promoters Oscar De La Hoya and Richard Schaefer as defendants.

The 31-year-old Pacquiao stated he had difficulty taking blood and didn't want to be subjected to random testing within 30 days prior to the fight.

"Manny doesn't need to ever prove anything to his fans," Koncz said on Pacquiao's Web site. "Manny's character stands on it's own. Manny's fans understand his character. Enough is enough and Manny can not and not will bullied inside or outside the ring.

"Right now Manny is terribly disappointed. We did everything the Nevada Athletic Commission regulates. We even went above what we had to and even though it was out of their jurisdiction and we had the Olympic committee take urine samples from Manny home just last week and those samples will be in next week. Manny knows this is the fight of the century. He knows this is what the fans want. Manny will not bow down to these people who think they can just change the rules and make Manny jump through their hoops."

Koncz went out to bash Mayweather's tactics.

"I believe that Floyd did not want to tarnish his perfect record and used this blood testing as an excuse to get out of the fight, because he knew Manny would never do it," he said. "Floyd, being the coward, he found a way out and he did not care if he tarnished another man's reputation."

Pacquiao (50-3-2, 38 KOs) is coming off a 12-round TKO of Miguel Cotto, while Mayweather (40-0-0, 25 KOs), who retired for nearly two years from 2007-09, has just one fight since his return to boxing - a unanimous decision over Juan Manuel Marquez.

Mayweather could now fill the void in March by trying to fight former junior welterweight champion Paulie Malignaggi.

This a very sad news for all of us. I really wanted the fight to happen. I wish the contract be signed already without excuses and now this. How do you feel about this? What's your analysis on this? It certainly feels disappointing.