Speaking at a press conference at the Amsterdam ArenA on Monday, the 35-year-old former club captain revealed that he had taken the decision to quit due to a lack of motivation.

"This decision was not taken overnight," said Stam, who retired from international football with Holland three years ago having won 67 caps.

"A while ago, I told [technical director] Martin van Geel and [managing director] Maarten Fontein that I could no longer motivate myself enough. Physically, I was no longer 100 percent.

"During matches, I was more busy with myself than with the opponent. That's not right. Especially for someone who relies on his strength.

"I want to give myself for the full 100 percent and not 60 percent or 70 percent."

Stam began his career in the 1992/93 season at FC Zwolle, and later represented Cambuur Leeuwarden, Willem II and PSV Eindhoven, where he played for three seasons.

In 1998 he signed for Manchester United, going on to win three league titles, the FA Cup and the Champions League under Sir Alex Ferguson.

He left United in acrimonious circumstances in 2001 after falling out with Ferguson following the publication of the Dutchman's autobiography.

Stam subsequently spent five years in Italy with Lazio and AC Milan before returning to his homeland to sign for Ajax in the summer of 2006.

Ajax technical director Van Geel paid tribute to Stam during the press conference.

"With Jaap, we acquired absolute quality one and a half years ago," he said.

"Not only because of his football ability, but also because of his mentality.

"We are proud that Jaap has played for us and we are very sad to see him go."

Stam added: "Ajax is the best club in Holland. I am grateful to the club and to Martin van Geel that they got me back to Holland a year and a half ago.

"I also want to thank the supporters. They made me feel right at home in the ArenA."