Profits growth slowed sharply over the past six months at online fashion retailer ASOS, though sales continued to bound ahead.Pre-tax profits to September came in at £4.4m, up 9%, on sales 47% higher at £96.5m. ASOS blamed the reduction in margins to 44.6% (from 48.3% in H1 2008/09) on increased sourcing costs, an extra sale period during the first half and a change in the branded product/own-label mix.Sales have continued to grow strongly into the second half of the year it added, with total sales for 7 weeks to 15 November up 46% year-on-year. UK sales for the latest 7 week period were 23% ahead and international sales up by 161%. "Our outlook for the second half remains cautiously optimistic. We expect UK sales to carry on growing, underpinned by further marketing activity, and for International sales to continue providing additional momentum. Stock and costs have been controlled well, so our performance in the second half should be significantly ahead year on year, providing sales continue to grow in line with expectations," chief executive Nick Robertson said.There is no dividend.