British supermodel Naomi Campbell refuses to retire after more than two decades on the world's catwalks because there are still too few black beauties in the fashion industry.

While many of her colleagues of the late 1980s -- like Cindy Crawford and Christy Turlington -- have moved on from the runways, the 38-year-old icon continues to turn heads at the world's top fashion shows.

"I'm very grateful for my career, but I worry for the girls after me for the opportunities they get -- the way they get treated. And this is one of the reasons I still do what I do," she told Reuters in a weekend interview in Nigeria.

Campbell, who as a teenager was the first black model to grace the covers of the French and British editions of Vogue magazine, said many fashion designers still favoured fair-skinned models over their dark-skinned counterparts.

"I don't do so many shows anymore, but I do count how many girls of colour they use in the shows. It happens to be last year New York was the worst," the British bombshell said, wearing a simple white short-sleeved top and blue jeans.

"Now at Paris Haute Couture there was only one black girl out of all the shows. It cannot be a trend."

Italian Vogue decided to use mainly black models in its July edition to highlight the problem.

"For me, it is something that is history-making. Something that I'm going to keep forever," she said about the magazine, which has a photo of her on one of four different covers.

The magazine also includes Tyra Banks, Iman, and other black actors, models and singers.