Former world heavyweight champion Evander Holyfield's exhibition match in Ethiopia has been postponed for September, his opponent Sammy Retta told selfnews on Monday. The fight, to raise funds for AIDS, was set to take place in Addis Ababa on July 26, but organisers had to reschedule after a request from the government. 'The government wanted the match to correspond with Ethiopia's new year celebrations on September 11, so we both agreed,' Retta said in a phone interview. Retta, an Ethiopian-born American, is a 35-year-old with a record of 18 wins and three losses in super-middleweight bouts. At 230 pounds, he now outweighs his more illustrious rival. The bout was also meant to serve as a warm-up for four-time world champion Holyfield, who targeted another crack at the world title in September. Retta however, claimed that the 46-year-old's managers had also postponed that match for an undisclosed date in December. Holyfield failed to clinch a fifth title during his last attempt late last year when he lost to Russian Valuev. Valuev, the tallest and heaviest champion of all-time according to experts, is currently the holder of the World Boxing Association title. The September fight will rank as one of the highest-profile all-American boxing bouts on African soil since the legendary 1974 'Rumble in the Jungle' that pitted Muhammad Ali against George Foreman in the former Zaire. 