Amir Khan's manager announced the Briton was turning professional after the teenager avenged last year's Olympic lightweight final defeat by beating Cuban veteran Mario Kindelan on Saturday.
Khan, 18, appearing in front of his hometown crowd in Bolton, was awarded a 19-13 points victory at the end of the four-round fight.
Frank Warren, who believes Khan is the best boxer to come out of the Olympics since Sugar Ray Leonard, said he would now act as the youngster's promoter and manager in the professional ranks.
"That will be his (Khan's) last amateur fight," Warren told ITV Sport.
"He's beaten (in Kindelan) the number one, the two-time Olympic champion, the three times world amateur champion.
"What else can you do after that? You can only go for new challenges.
"He will make his professional debut in July," added Warren, who predicted Khan could be world champion by the time he is 21.
Khan, who had lost to 33-year-old Kindelan twice previously, dominated his opponent after taking a 2-1 lead at the end of the opening round.
The fleet-footed Briton staggered Kindelan in the final round when he caught the Cuban with a venomous left hand.
Kindelan, who suffered only 22 defeats in a 360-bout amateur career, will now retire.
