Tennis great Roger Federer, long all but synonymous with Nike Inc., has parted ways with the swoosh to join casual clothing brand Uniqlo.

The eight-time Wimbledon champion surprised many fans when he walked onto Centre Court for his first-round match Monday afternoon in an outfit by Fast Retailing Co.'s Uniqlo. The Swiss star's apparel contract with Nike expired March 1.

"Our partnership will be about innovation on and off court," Fast Retailing Chief Executive Officer Tadashi Yanai said in a statement Monday.