Hamburg  - World Boxing Association (WBA) middleweight champion Felix Sturm of Germany will defend his world title against Koji Sato of Japan in Germany in April, his promoters said Tuesday.

The bout will take place on April 25 in Krefeld, the Hamburg-based promoters Universum said.

Sturm has won 31 of his 34 professional fights, while Sato steps down from super middleweight where he is unbeaten in 14 bouts.

Sturm's management late last year rejected a unification bout with the International Boxing Federation (IBF) champion Arthur Abraham, an Armenian-born German who is represented by Berlin-based promoters Sauerland.

Kelly Pavlik of the United States is the World Boxing Council (WBC) and World Boxing Organization (WBO) champion and is listed as number one in Ring magazine's rankings. (dpa)