French Olympic swimming champion Clement Lefert is to retire from the sport to concentrate on his studies, the 24-year-old told Nice Matin daily in an interview published on Friday. Lefert, who won the 4×100m freestyle relay to see off a US quartet which included Michael Phelps and added a silver medal in the 4x200 meters freestyle relay, wants to concentrate on finance studies. \"I really want to land a job which I like and not something chosen by default after my (swimming) career,\" said Lefert, who turns 25 on September 26. He dubbed his Olympic achievements \"the culmination of a sporting career\" and it was time to move on, his medals meaning he can go out \"on a high.\"