Online retailer ASOS has posted a 14% fall in profits after a torrid year in which it was hit by a major warehouse fire and tough overseas trading.

The fashion site, which sells over 75,000 branded and own-brand products to almost nine million customers, racked up sales of £975 million in the year to August 31 and growth of 35% in revenues in its key UK market.

But pre-tax profits fell to £46.9 million as ASOS counted the cost of investment in its warehouses around the world and the impact of difficult trading conditions in Australia, China and Russia.

Chief executive Nick Robertson said a period of major investment had come at a short term cost but that there would be "significant" medium-term benefits.

He added: "ASOS has always been about the longer journey to a very big prize: to be the world's leading fashion destination for 20-somethings, and we are firmly focused on our next staging post of £2.5 billion sales."