World heavyweight champion Wladimir Klitschko has led the tributes to Hall of Fame boxing trainer Emanuel Steward, who died on Thursday at the age of 68.

Steward, the mainstay behind the legendary Kronk Gym in Detroit, passed away having recently undergone surgery for a stomach illness, according to his sister, Diane Steward-Jones.

"Boxing has suffered a tremendous loss with the passing of Emanuel Steward," Wladimir said in a statement posted on the Klitschko brothers' official website.

"Vitali and I, along with the entire Team Klitschko, send our deepest and most heartfelt condolences to Emanuel's family and friends.

"It is not often that a person in any line of work gets a chance to work with a legend. Well, I was privileged enough to work with one for almost a decade.

"I will miss our time together. The long talks about boxing, the world, and life itself. Most of all I will miss our friendship.

"My team and I will carry on with the goals we had set while Emanuel was with us because that is exactly what Emanuel would have wanted. I know he will be with us in spirit along the way and we will accomplish these goals in his honour."

Steward, who was inducted to the International Boxing Hall of Fame in 1996, trained or was involved in the careers of more than 40 world champions, but first found fame with Detroit fighter Thomas Hearns in the 1980s.

Hearns, who became Steward's first professional fighter along with another Detroit native, Hilmer Kenty, in 1977, won his first world title in 1980 and went on to engage in a series of all-time classics with Sugar Ray Leonard, Roberto Duran and Marvin Hagler.

In later years, Steward went on to help shape the careers of Naseem Hamed and Lennox Lewis, among others, before turning his attention to the younger of the Klitschko brothers, whom he had always admired.