Argentina's Nalbandian announces retirement

BUENOS AIRES (Reuters) - Argentina's 2002 Wimbledon finalist David Nalbandian announced on Tuesday that he will quit tennis next month citing physical problems that have sidelined him for most of the year. "It's not easy what's happening to me now, my shoulder is not helping me to train as I should for the circuit," the 31-year-old told a news conference. "It's a tough day to (have to) announce my retirement today," said Nalbandian, winner of 11 ATP Tour titles including the season-ending ATP Championship in Shanghai in 2005. The former world number three, who had shoulder surgery in May, said he would quit tennis after playing an exhibition match against Spanish world number two Rafael Nadal in November. (The story corrects Nalbandian's age in second para) (Reporting by Luis Ampuero; Editing by Ken Ferris)