* Canada and Slovenia claim French 1-2-3 came with illegal suits

* CAS to rule on Sunday, final day of the Games (Adds detail, background)

By Mitch Phillips

SOCHI, Russia, Feb 22 (Reuters) - The Court of Arbitration for Sport (CAS) was meeting on Saturday night to decide whether three French skiers who swept the podium in the men's ski cross finals at the Winter Olympics wore illegal suits.

Jean Frederic Chapuis, who formerly competed in Alpine skiing for Switzerland, Arnaud Bovolenta and Jonathan Midol swept the medals in Thursday's final but Canadian and Slovenian officials protested to the International Ski Federation (FIS), claiming they changed their suits to gain an illegal aerodynamic effect.

FIS said that it could not consider the complaint because it had not been made in time so the protest was escalated to CAS, sporting law's highest court.

"The Canadian Freestyle Ski Association (CFSA), the Canadian Olympic Committee (COC) and the Slovenian Olympic Committee (SOC) ask for the disqualification of all of the French competitors from the 20 February 2014 ski cross Big Final competition and for the correction of the final rankings," CAS said in a statement.

"They allege that, just before the Big Final, French support staff changed the shaping of the lower leg suits of the riders creating an aerodynamic effect that the appellants submit is contrary to the International Freestyle Skiing Competition Rules."

A panel of CAS's ad hoc division will hear the case later on Saturday and will publish its results before 1000 GMT, 1400 Sochi time, on Sunday, the final day of the Games.

Canada's Brady Leman finished fourth in the "Big" final while Egor Korotkov of Russia and Filip Flisar of Slovenia led the way in the "Small" final and would be promoted to the medal positions should the French trio be disqualified.

The clean sweep helped France to their current tally of 15 medals, their highest in a Winter Olympics. (Editing by Julian Linden and Pritha Sarkar)