The San Antonio Spurs and all-start power forward Tim Duncan agreed on a two-year, $40 million (U.S.) contract extension, a source familiar with the club said Tuesday.

The 6'11" (2.11 m), 260-pound (118 kg) power forward had already signed a three-year contract with the Spurs and with this extension agreed upon, he is set to play with San Antonio at least through the 2011-12 season. He will be 36 when the deal expires.

By signing the extension, which will probably be finalized within the next few days, Duncan forfeits his option to become a free agent after this season.

The 31-year-old NBA veteran has become a San Antonio icon after spending all his eleven seasons in the league at the Texan club. During his career he managed to lead the Spurs to four NBA titles in the past nine seasons and was designated the finals MVP for the first three. The fourth went to his French team mate Tony Parker after they won the NBA Finals last season over the very talented but un-experienced Cleveland Cavaliers

Duncan, San Antonio’ No.1 pick in 1997, also won back-to-back league MVP titles in 2002-03, two years before the Spurs won their first title.

He was selected to play in the All-Star Game nine times and throughout his NBA career he averaged 21.8 points and 11.9 rebounds per game.

Timothy Theodore Duncan is also known for his off-court activities. He is well known for his quiet and unpretentious ways and very appreciated for his philanthropy efforts.

He created the Tim Duncan Foundation with the goal of raising the general health awareness, fund education and youth sports in various parts of the United States. Duncan also holds a degree in psychology.