PARIS (REUTERS) - Former France defender William Gallas has announced his retirement, bringing to an end a decorated 19-year professional career, he said on Thursday.

"You tell yourself you can always continue but I think that today I can't," the 37-year-old centre-back told TV channel L'Equipe 21 in an interview to be aired later on Thursday.

Gallas, who started his professional career at Caen in 1995, won 84 caps for France and scored five goals, including the controversial strike in Les Bleus's 2-1 play-off win against Republic of Ireland that earned the side a 2010 World Cup berth.

After playing for Olympique Marseille from 1997-2001, Gallas left for Chelsea, where he won back-to-back English Premier League titles in 2005 and 2006.

He moved to Arsenal in 2006 before joining another North London club, Tottenham Hotspur, in 2010.

Last October, Gallas signed a one-year deal with Perth Glory in Australia's A-League.