GERALD Mosse is quitting Hongkong early in order to ride for the Aga Khan in the French Oaks a week on Sunday. Mosse, whose Hongkong contract was not renewed by trainer Patrick Biancone, has been booked to partner the Nishapour filly Les Aigles. He will leave the territory after Saturday night's Sha Tin meeting. It would be no surprise to see Mosse become first jockey to the Aga Khan in France as well as renewing his association with his former trainer Francois Boutin and picking up rides from Criquette Head. Mosse said yesterday: ''Hongkong is a horse-racing paradise. Everything works so well and is so professionally run. ''But after Saturday's Sha Tin meeting I will have to face reality and do what is best for my career. ''It is very important that I re-establish myself in France. ''There is no better way of doing that than going back to ride for the Aga Khan in the Oaks. ''I don't want to let the Jockey Club down and am sure they will appreciate that I have to miss the final two meetings here as the Aga Khan wants me to ride the filly in her final piece of serious work on the Wednesday before the Oaks.'' This season Mosse has ridden 40 winners despite missing a month when his mount, King Prawn, fell at Happy Valley in late February. It forced him to miss the winning Derby ride on Helene Star which went to Eric Legrix, his long-time friend and the jockey who will succeed him at Biancone's yard. Last season Mosse took the Invitation Cup on River Verdon and his split with Biancone shocked the racing community.