Talks on the WBC heavyweight title bout between champion Vitali Klitschko and challenger Nikolai Valuev have stalled after a promoter for the `Russian Giant` demanded a sum of $4 million for the fight, according to RIA Novosti.

Veteran promoter Don King is standing firm on his demand, while managers of Ukraine`s `Dr. Ironfist` Klitschko (39-2, 37 KOs) say they are unwilling to pay and may seek another contender for their boxer.

"This is impossible even if Valuev had four title belts and was undefeated," German`s Bild tabloid quoted Bernd Bonte, Managing Director of the Klitschko Management Group, as saying.

He added there are still two weeks to make a final decision on the bout with the Russian and if no agreement is reached the Ukrainian may face another boxer - either Russian Alexander Povetkin or the winner of the bout between WBA Heavyweight Champion David Haye and challenger John Ruiz.

The 36-year-old `Russian Giant` (50-2, 34 KOs) lost his WBA title last November to Britain`s Haye (23-1, 21 KOs).