Britain's largest clothing retailer, Marks & Spencer Plc, on Tuesday announced a better-than-expected rise in first half pre-tax profit on the back of a modest rise in sales. The company said pre-tax profit before items in the 26 weeks ended September 27 rose 7.4 per cent to £311.5 million from £290.1m last year, with turnover up three per cent year-on-year to just over £3.8 billion.