MIAMI: Shaquille O'Neal, a dominant center who played on four NBA championship teams, announced Wednesday he was planning to retire after a professional career spanning nearly two decades. One of the most accomplished players in the game, the 39-year-old O'Neal made the announcement by posting a video on the social media website Twitter. “We did it. Nineteen years baby. I want to thank you very much, that's why I'm telling you first, I'm about to retire. Thank you, talk to you soon,” he said in the message. The physically imposing O'Neal, who stood 7 feet one inch (2.16 meters) and weighed 325 pounds (147kg), was taken as the first overall pick in the 1992 NBA Draft by the Orlando Magic. After moving to the Los Angeles Lakers in 1996, O'Neal became part of a championship run with the young Kobe Bryant that produced three successive NBA titles from the 1999-2000 season. O'Neal was named NBA Finals MVP in each of those triumphs and earned the league's Most Valuable Player award in 2000. In 2004, O'Neal signed on with the Miami Heat and teamed up with Dwyane Wade to win the 2006 NBA championship. He later played for the Phoenix Suns and Cleveland Cavaliers before spending an injury-marred campaign this season with the Boston Celtics. O'Neal averaged 23.7 points a game over his long career along with 10.9 rebounds.