UK supermarket chain Asda has pipped retail rivals to the post with the £700m (US$1bn) signing of the European rights to the fashion empire of Mary-Kate and Ashley Olsen. The 15-year old twin sisters will plug shoes, fashion and underwear at 150 Asda outlets from March. Two names virtually unknown to anyone out of their teens, Mary-Kate and Ashley Olsen have won a following amongst children the world over. Staring in films since they were seven months old, the sisters have developed their own "un-Britney" style, which has turned into a multi-million dollar fashion empire.