Months of negotiations for the rematch ended with both fighters signing contracts over the weekend that will pay them $15m (pounds 9.4m) each .
Holyfield reiterated his view that he did not lose the first fight at Madison Square Garden, New York, in March, when the verdict was a draw. He said he suffered from cramp during the fight.
Lewis also stuck by his opinion that the scoring went awry. "The judging definitely was suspect. I believe there was some influence there," Lewis said. "But I'm bringing my own two judges to this fight."
Holyfield holds the IBF and WBA titles and Lewis the WBC crown. The title has not been unified since Riddick Bowe threw the WBC belt into a rubbish bin after beating Holyfield in November, 1992.