Kate Bostock has quit Asos as an executive director just six months after her appointment at the online fashion retailer.The former Marks & Spencer (M&S) employee was recruited by Asos after almost a year of courting by the company. She said she was leaving the board with immediate effect on Tuesday. Her role will be taken over by the group's retailing team.In a statement, Bostock said she has "concluded that Asos isn't the right place for me".Nick Robertson, Chief Executive and Co-Founder of Asos, said: "Kate and I have agreed that Asos is not the right platform for her talent. Of course we are disappointed that things haven't worked out and Kate leaves with our very best wishes. In the meantime, we have a very strong team in place and the business continues to fire on all cylinders." Bostock joined Asos after stepping down as M&S's Head of General Merchandise, including clothing, last July following eight years at the retailer. Her decision to leave Asos marks the third high-profile board director departure at the firm during the past year. International Director Jon Kamaluddin left in April after nine years and Product Director Robert Bready departed in October.Shares in Asos declined 0.85% to 4,442p at 12:41 on Tuesday.RD