Outdoor clothing and footwear retailer Blacks Leisure Group Plc on Friday posted a 44 per cent rise in first half pre-tax profit but said recent sales were slow due to unseasonal warmer weather. The company posted a pre-tax profit before goodwill amortisation for the six months ended August 31 of £5.6 million from £3.9m last year, as sales rose 15 per cent to £117.9m from £103.5m in the year-ago period.