The undisputed heavyweight champion of the world Wladimir Klitschko said he expects to fight again at the end of the year, but does not yet have a confirmed opponent.

"I want one more fight this year, probably in December. Exactly where and against whom, I cannot say yet," he told Germany TV channel RTL.

The 35-year-old Ukrainian beat David Haye with a unanimous decision in July to add the British fighter's WBA title to his collection of IBF, WBO and IBO belts.

Elder brother Vitali Klitschko, 40, defends his WBC title against Tomasz Adamek in Wroclaw, Poland, on Saturday night and his sibling expects a win.

"Even if you do not underestimate Adamek, I expect a clear victory," said the younger Klitschko, who will be in Vitali's corner.

A future opponent of Vitali could be brash Brit Haye, who has yet to announce whether he will box on having said he will retire before his 31st birthday in October.

Wladimir Klitschko said it was nice that Adamek has not resorted to the same tactics Haye used before their title bout in Hamburg, when he constantly taunted Klitschko by calling him "Bitchko", "a fraud" and a "Ukrainian robot".

"The way Adamek has behaved is very pleasant, because it shows that he respects my brother and is very focused on the fight," said Wladimir.

"David Haye was a cruel version of a boxer who constantly hit below the belt with his statements and actions."