Melbourne, Nov 18 Australia's swimming sensation Stephanie Rice has taken control of her business affairs at just 21 and will manage the endorsements and personally negotiate all deals with the help of a friend.

In a move which has surprised many, Rice walked away from her management company, International Quarterback three weeks ago after deciding its industry-standard 20 per cent commission was too much, The Herald Sun reports.

It was believed her mother, Raelene Clark, would take over the management role, but yesterday she said her daughter would instead be self-managing her career and earnings, estimated at 800,000 dollars a year.

But the move has surprised those she has already had dealings with.

"She looked at the figures and saw 20 per cent of her earnings going to her management company and she felt it was a lot of money and decided to manage herself, which is her prerogative," the paper quoted a source close to Rice, as saying.

"If she thinks she can maintain her existing relationships with sponsors and employers and also develop new ones, then good luck to her. Whether she can do so without the back-up of an organisation dedicated to such work day in, day out will be a test - but good luck to her."

An executive with an organisation Rice already had a relationship with said her decision was intriguing. (ANI)