Tennis star Kim Clijsters has threatened to boycott the Athens Olympics in 2004 if she is not allowed to wear Fila apparel.

The former world number one, who has a sponsorship deal with the Sport Brands International-owned apparel and footwear company, is refusing to wear gear from Belgian Olympic team sponsor Adidas.

"As long as my clothing remains an issue, it is impossible for me to go to the Olympics, even though I would like to go and even though I would be able to fit it into my schedule," she said.

Clijsters was overtaken in world tennis ranking this year by fellow Belgian Justine Henin-Hardenne, an Adidas-sponsored player who has already committed to Athens.