MARKS and Spencer will open its sixth store in the territory in October at the Times Square shopping complex in Causeway Bay. ''This new store re-confirms our commitment to Hongkong, where shoppers seem increasingly to appreciate the quality and value of the merchandise in our stores,'' said Colin Buchanan, director of retail operations and Far East development. Hongkong turnover increased by 64 per cent to GBP40.9 million (about HK$476 million) for the year ended March 31.