Former M&S fashion chief joins Asos Online fashion retailer Asos today confirmed one of the worst-kept secrets in the City by appointing former Marks & Spencer director Kate Bostock. Described as one of the most influential women in British fashion, Bostock will join as executive director for product and trading from January. She said she was "very excited" to be joining the online retailer, which was launched in 2000 and now has more than five million active customers and annual sales of around £500 million. Bostock, who is the former head of general merchandise at M&S and previously held senior roles at Next and George at Asda, said: "Asos is a phenomenon and I'm in awe of the story. With its unique mix of own label and fashion forward brands delivered online and increasingly through mobile, the potential for ASOS globally is huge. Her departure from M&S was revealed in July when chief executive Marc Bolland announced plans to bring in former Debenhams chief Belinda Earl as style director to hone its fashion range. Asos product director Rob Bready, who is credited with playing a key role in the development of the firm during his seven years on the board, will leave the company. With Asos having been linked to a move for Bostock for some time, Freddie George, retail analyst at Seymour Pierce, said the appointment was "perhaps the worst kept secret in retailing." Espirito Santo analyst Caroline Gulliver said: "This is clearly a high profile appointment for Asos as it reaches a scale that requires a different skillset. It will be interesting to see how the fit works, given the very different culture and customer demographic at Asos compared with the companies at which Bostock has previously worked. Last week, Asos announced the appointment of Scots-born Brian McBride, a former managing director of Amazon in the UK, as its new chairman. He will take over from Waheed Alli next month. Glasgow-based McBride, a board member at venture capital group Scottish Equity Partners, spent almost six years heading up Amazon's UK business and prior to that held senior positions at Dell, IBM and T-Mobile.