The 25-year-old Belgian, the first woman to quit the sport while ranked No1, made the announcement less than two weeks before the start of the French Open.

She has won that clay-court Grand Slam four times, including each of the past three years.

'This is the end of a child's dream,' she said. 'It is a new beginning for me. I feel like I already lived three lives.

'I gave the sport all I could and took everything it could give me.

'I take this decision without the least bit of regret. It is my life as a woman that starts now.'

And then, ruling out any chance of a comeback, she added: 'This is a definitive decision.'

Henin won 10 tournaments last year, but has been in one of the worst slumps of her career this season. Last week, she lost in the third round of the German Open and pulled out of this week's Italian Open, citing fatigue.

'I thought long about this,' Henin said, her voice cracking and eyes watering. 'I started thinking about it late last year.

'I was at the end of the road. I leave with my head held high.'

Her agent, Ken Meyerson, said Henin told him on Sunday evening: 'I've won everything I need to win, I have more money than I can use in three lifetimes, and I don't have the will to play one day more.'

He added that Henin had been thinking about the decision for five or six months. Her play over that period has been flat, partly because of a troublesome knee that required cortisone treatment.

But Meyerson said the reason behind Henin's retirement is all emotional.

'She's simply burnt out and has no more juice to go on,' he said.

Henin had an outstanding season last year, winning two Grand Slams, eight other Women's Tennis Association Tour titles and more than US$5 million (S$6.9 million).

However, after winning her home tournament in Antwerp in February, she has been on one of the worst skids of her career, failing to go beyond the quarter-finals at any event.

Henin's year began with a 4-6, 0-6 loss to Maria Sharapova in the Australian Open quarter-finals in January. That was followed by a 2-6, 0-6 drubbing by Serena Williams at the Sony Ericsson Open last month, the worst loss for a top-ranked player in nine years.

At last week's German Open, Henin lost to Dinara Safina, against whom she had never dropped a set previously.

'At the end of the Berlin match, retirement all of a sudden was there as something evident,' Henin said. 'I decided to stop fooling myself and accept it.'

Dressed in a simple white T-shirt and her brown hair in a pony-tail, she never lost her composure and held the microphone firmly.

But her coach, Carlos Rodriguez, broke down in tears, saying: 'Because of her, I am somebody.'

In addition to her four French Open titles, Henin also won the Australian Open in 2004, and the US Open in 2003 and 2007. The only Grand Slam title to elude her is Wimbledon, where she was runner-up in 2001 and 2006.

'Winning Wimbledon would not make me happier than I am,' she said. 'I could never dream of Wimbledon. It was destiny.

'I didn't feel myself capable. It was too much for me.'

Throughout her career, she has had to beat the odds.

With her slight, 1.66-metre, 57-kg frame, she had to battle the giants of the game. Some, like Lindsay Davenport, Venus Williams and Sharapova, are about 30cm taller.

But, with a superb one-handed backhand - considered the best in the game - footwork and balance in the class of a Roger Federer or John McEnroe, and endless determination, she rose to the top.

Life, rather than merely tennis, has been a battle. Aside from a desperately weak immune system that renders her susceptible to numerous illnesses and constant fatigue, a chronicle of sadness has been the backdrop to her success.

Her mother Fran�oise, who annually took a young Justine to Paris to marvel at the magnificence of Steffi Graf playing the French Open, died when her daughter was just 12 years old.

Later, Henin took the decision to split from the rest of her family, refusing to have anything to do with her father, Jose. And a five-year marriage to Pierre-Yves Hardenne ended in divorce.

Through all this torment, tennis was her salvation, particularly on the red clay of Roland Garros, where she once famously informed her late mother: 'One day, I will play here and I will win.'

Now that she has ended her tennis career, Henin said: 'It's a relief.'

ASSOCIATED PRESS