Heavyweight boxing title holder Wladimir Klitschko (R) of Ukraine exchanges punches with Jean-Marc Mormeck of France during their IBF/WBO, WBA and IBO world heavyweight championship title fight in Duesseldorf Saturday. — Reuters Vitali announces Haye fight DUESSELDORF – Wladimir Klitschko knocked out Jean-Marc Mormeck of France with a stinging left-right combination in the fourth round to retain his world heavyweight titles at the Esprit Arena Saturday. The Ukrainian, who holds the IBF, IBO, WBO and WBA versions of the championship while his older brother Vitali has the WBC crown, took his career tally to 50 knockouts from 60 fights with just three losses. Klitschko, 35, had knocked down former cruiserweight world champion Mormeck, who at 1.81 meters is 17 centimeters shorter than the Ukrainian, in the second round with a huge right that sent the Frenchman sprawling. Klitschko, whose last defeat stretches back to 2004, inflicted more punishment in the next two rounds, his left working to open his opponent up as Mormeck ducked low to avoid his wider reach, before finishing him off in the fourth. “I have been doing this for 15 years and now I have my 50th knockout,” Klitschko said in a ringside interview. Meanwhile, Vitali a much-awaited fight with Briton David Haye for the WBC crown without specifying a date or location. “I can announce that my next fight will be with David Haye,” Klitschko told immediately after Wladimir knocked out Mormeck. Haye, who retired in October, had been wanting to fight Klitschko after losing his WBA belt to Wladimir last July. He was also involved in a post-fight brawl with Dereck Chisora after the former Commonwealth champion had lost his fight to Vitali on Feb 19 on points and is wanted by German police for questioning. The British boxer said on Twitter: “Vitali has just finally agreed to fight me in a live RTL (television) interview. He told me I will be his next fight. Let's get ready to rumble.” The Klitschkos twice had fights with Haye called off in the past years after they failed to agree on the details for a unification fight before the ‘Hayemaker' lost to Vladimir in July 2011. Should the fight go ahead it could be 40-year-old Vitali's last after announcing before taking on Chisora that he planned to fight “a couples of times more” before retiring. Haye, who turned heavyweight in 2008 after a cruiserweight career that started in 2002, could face problems fighting in Germany – the Ukrainian brothers' base – after leaving the country following the brawl with Chisora, who was briefly detained and questioned by police.