World number one Justine Henin has announced her retirement from professional tennis with immediate effect.

More Stories

• The life and times of Justine Henin
• Henin's career in photos

"It's the end of a wonderful adventure but it's something I have been thinking about for a long time," the 25-year-old Belgian said.

Winner of seven Grand Slam singles crowns, Henin suffered a surprise defeat in the third round of the German Open last week. She then withdrew from this week's Italian Open, citing fatigue.

"I am leaving as the world number one and that is important and it is always better to go out at the top," said Henin, who won 41 titles since turning professional in 1999.

"I have been driving my career based on an emotion but I didn't feel that emotion anymore since (last year's season-ending championships in) Madrid.

"At Madrid I felt I had reached the climax of my career. I had thought about taking a break, but in the end I didn't think this was the right decision."

"I decided on returning from (last week's tournament in) Berlin to stop now.

"I leave without any regrets and I know it is the right decision."

Henin became the first Belgian to win a Grand Slam title with her triumph at the French Open in 2003 and despite suffering numerous personal tribulations - including the death of her mother when she was just 12-years-old - she did not let it affect her form on court.

Credited with owning the best backhand in the game, she bucked the trend of the power players on the tour by climbing to the top of the world rankings despite her slight five-foot-three frame.

A winner of four Roland Garros crowns, two U.S. Open titles and one at the Australian Open, Henin admitted the lure of completing her collection at Wimbledon was not enough to prolong her career.

"Winning Wimbledon would not have made me any happier," said Henin, who also captured Olympic gold in Athens four years ago.

"I didn't feel I was capable of winning there (Wimbledon). I stopped before Roland Garros because I asked myself if I could produce a better Roland Garros than last year and I realised I couldn't.

"I wanted to play in the Olympics for my country and would have been proud to do so despite the current problems. Some people never realise their dream of an Olympic medal and I have realised that goal.

"But I couldn't go to Beijing and do my country proud. It's time for a change."

Only last week Henin wrote on her website that she had been training without any problems and was injury free.

"Justine Henin will be remembered as one of the all-time great champions in women's tennis, and a woman who made up for her lack of size with a will to win and fighting spirit that was second to none," said WTA chief Larry Scott.

"It is rare that an athlete leaves at the very top of her game in this day and age, but Justine has always played by her own rules, in the very best sense of those words."

Despite her patchy form this season, Henin would have been a favourite heading into this month's Roland Garros to win a fifth French Open crown.

Men's world number one Roger Federer, to whom she has often been compared with, was surprised by the timing of her announcement.

"It's obviously a shock for the tennis world," Federer said after his first match at the Hamburg Masters.

"It's a particular surprise before Roland Garros and Wimbledon, which she's never won. It's quite surprising and unfortunate that she's out of the game but she will have her reasons."

Henin's retirement comes a year after compatriot and fellow former world number one Kim Clijsters walked away from the sport to start a family.

"Pound for pound Justine is the greatest player of her generation," said WTA founder and American great Billie Jean King.