David Haye could earn a share of $120million by fighting one of the Klitschko brothers in the United States, according to American promoter Richard Schaefer.

Britain's newest heavyweight world champion was nursing a broken hand today after winning the World Boxing Association (WBA) title against giant Russian Nikolai Valuev in Germany last Saturday night.

But while there is already talk of a fight with either Wladimir or Vitali Klitschko at Wembley Stadium next summer, Schaefer says the big bucks could be in the US.

"He could be massive," said Schaefer.

"If he comes and fights in the United States against one of the Klitschkos, I have no doubt that the total global receipts could be close to $120million for one fight.

"We will see how far his talent, willpower and charisma will carry him but I have a feeling, given the current landscape of the heavyweight division, that he will clean it up and become the undisputed heavyweight champion."

Adam Booth, Haye's trainer, revealed that discussions with Wembley Stadium are already under way following his 12-round, majority-points victory over 7ft 2ins Valuev.

"Wembley have already been on to me," said Booth.

"Haye against a Klitschko, Wladimir or Vitali, would be one of the biggest fights in heavyweight history."

The sheer scale of the gate receipts from a sell-out 100,000 Wembley crowd, combined with his percentage of the pay-per-view TV subscriptions, could earn the London-born champion an estimated £20million.

In America, the financial rewards would be even greater and Haye admits he has always wanted to fight in Las Vegas.

But the 29-year-old must first make a mandatory defence against John Ruiz, who was paid to step aside and let Haye have the chance of taking the WBA belt from Valuev.

"If I don't fight him they'll take the title from me, and I don't fancy giving it up after winning it," said Haye.

His fight against Ruiz will almost certainly be held at London's O2 Arena with victory setting up a lucrative unifying heavyweight division fight against one of the Klitschko brothers, with Wladimir the WBO, IBF and IBO heavyweight champion and Vitali the WBC champion.

The Haye-Ruiz contest is unlikely to take place before next May - despite Haye's hopes - as he allows his broken hand, sustained in the second round against Valuev, to heal completely.

However, Ruiz is also facing a period out after suffering a bad cut on the way to stopping German-based Turk Adnan Serin in the seventh round of a non-title bout on the under card of the Haye-Valuev contest in Nuremberg.

"March, April sort of time would be ideal to get it on with him," Haye told Sky Sports News.

"Get it on with him, knock him out and make it look spectacular, and then my schedule's free to unify the titles later on in the year.

"Definitely after this fight, a unification fight with one of the Klitschko brothers will be higher up on my agenda - number one.

"Either Wladimir or Vitali, I rate them both the same - I believe I should be sitting right above them, so it's up to me to prove that in the ring."