LAUSANNE, Switzerland — A court has ruled in favor of American swimmer Jessica Hardy, rejecting the World Anti-Doping Agency's appeal to extend her doping ban.

The Court of Arbitration for Sport on Friday dismissed WADA's appeal to lengthen the ban from one to two years, but offered no ruling on whether Hardy should be allowed to compete at the 2012 London Olympics.

Hardy tested positive for clenbuterol — an anabolic agent that can be used to reduce body fat — at the U.S. Olympic trials in July 2008 and missed the Beijing Games.

She served a one-year ban and set several breaststroke world records after returning to swimming last year.

The International Olympic Committee must now decide whether to apply a rule which bars athletes from the next Olympics if they serve a doping ban of at least six months.

Hardy's legal team had asked CAS to rule on her Olympic status at a hearing held in New York in March.

"The CAS Panel rejected the request to have the IOC joined in the arbitration procedure and did not issue any opinion on the applicability of Rule 45 of the Olympic Charter," the court said in a statement.

The IOC said Friday that the rule took effect on July 1, 2008 — three days before Hardy provided the sample that led to the failed test.

Friday's ruling allows Hardy to keep the world records in the 50 and 100 meter breaststroke, and the 50-meter short-course breaststroke.

Hardy also retains the $100,000 first prize she earned as the top woman swimmer on the five-meet World Cup circuit.

The CAS panel agreed with the American Arbitration Association's decision in May 2009 that Hardy should be spared a longer ban because she was not at fault for the positive test.

Hardy "had shown good faith efforts before ingesting the food supplements at stake," the court said.

"She had made the research and investigation which could reasonably be expected from an informed athlete wishing to avoid risks connected to the use of food supplements. The supplements she took were not labeled in a manner which might have raised suspicions."

Hardy used a powdered supplement called Arginine Extreme made by one of her sponsors, Advocare International of Carrollton, Texas.

WADA went to CAS to challenge the American tribunal's ruling, and wanted the 23-year-old swimmer to serve a fresh two-year suspension.