Boxing legend Muhammad Ali has been released froma US hospital were he had been treated for a urinary tract infection since last month, US media quoted his spokesman, Bob Gunnell, as saying Wednesday, dpa reported. The name of the hospital that Ali left late Tuesday has been keptsecret. "He's in great spirits and enjoying being back home," Gunnell said. "He's back in his daily routine. "The three-time world heavyweight champion, who suffers fromParkinson's disease, is set to celebrate his 73rd birthday at home onJanuary 17, Gunnell said. The retired boxer was hospitalized on December 20 for what wasoriginally believed to be pneumonia. But doctors established laterthat he was suffering from a urinary tract infection. Ali was born Cassius Marcellus Clay in 1942 in Louisville, Kentucky. He won a gold medal in the light heavyweight boxing competition atthe 1960 Olympic Games in Mexico. In 1964 he beat Sonny Liston tobecome world heavyweight champion at age 22. Soon after the victory, he converted to Islam and adopted the nameMuhammad Ali. Ali retired from boxing in 1981. In 1984, he disclosed hisParkinson's disease diagnosis.