World number one Henin retires at 25

BRUSSELS (Reuters) - World number one Justine Henin announced she was retiring from professional tennis with immediate effect on Wednesday.

"It's the end of a wonderful adventure but it's something I have been thinking about for a long time," the Belgian told a news conference.

Henin, the winner of seven grand slam titles, had been expected to defend her French Open crown later this month but instead opted to turn her back on the sport at the age of just 25.

"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.

She also became the first woman to quit the sport while ranked number one.

"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," said Henin, whose final match turned out to be a third-round defeat by Dinara Safina in Berlin last week.

"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."

FIRST BELGIAN

Henin became the first Belgian to win a grand slam title with her triumph at the French Open in 2003 and despite suffering numerous turmoils throughout her career, 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 1.67 meter 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 realized 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 realize their dream of an Olympic medal and I have realized that goal.

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

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

'FIGHTING SPIRIT'

"It's obviously a shock for the tennis world," Federer said at a news conference 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."

WTA chief Larry Scott paid tribute to Henin.

"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," he said in a statement.

"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.

"History will remember Justine for not only her seven grand slam titles and three years finishing as the WTA Tour's world number one but for one of the most graceful backhands the sport has ever seen and an ability to overcome any and all obstacles placed in her way on the tennis court and off."

(Writing by Pritha Sarkar in London, editing by Miles Evans)