Former world number one Lindsay Davenport is thinking about quitting tennis after dropping "off the radar" in recent years.

The American lost to current number one Justine Henin-Hardenne in the Australian Open quarter-finals last week, a result which has prompted her to consider retirement.

"Definitely, I think about it a lot more now than I ever have," said Davenport after thrashing Venezuelan Maria Vento-Kabchi 6-2, 6-1 at the Pan Pacific Open in Tokyo on Wednesday.

"Also, the last two years I don't really feel like I've been that competitive in the top four or five. I don't want to be like a perennial quarter-finalist for the rest of my career."

The 27-year-old Californian won the 1998 U.S. Open, 1999 Wimbledon and 2000 Australian Open titles but has endured a barren spell since that Melbourne triumph.

"I haven't had one of those really big wins in a Grand Slam situation and I've stopped winning as many titles as I used to," said Davenport.

"Definitely, it just gets a little bit more frustrating because for a few years, from 1997 until I had my knee surgery (in January 2002), I don't think I was out of the top three or four."

HAPPY MARRIAGE

Davenport, who joked in Australia that she had fallen "off the radar," admitted that her Grand Slam drought, combined with a happy marriage, had made her consider her future plans.

"You know, as well as being married, not being as successful also weighs a little bit on that decision," said Davenport, who married investment banker Jon Leach in April 2003.

"But at the end of the day, every time I think about it, I still like to play and I still think at this stage of my life I would be a little bit lost without tennis."

However, a decision does not appear too far away for Davenport, who has won 38 WTA Tour singles titles, a gold medal at the 1996 Atlanta Olympics and more than $16 million in prize money.

"As soon as I feel like I've put absolutely everything into it, then I'll probably walk away," she said.

"I don't know when that will be but certainly last year, I thought about it an awful lot."