Britain's biggest sports retailer, JJB Sports, has announced an increase in turnover and further expansion plans. Preliminary results released today reveal a positive start to the year with like-for-like turnover in the first ten weeks 5 per cent higher than last year. The results also show that the gross margin increased to 47.2 per cent from 46.5 per cent in 1999/2000 and from 46 per cent in the first six months of the year.