SuperGroup, the British company behind the Superdry fashion brand, posted a 4 per cent fall in first-half profit, hit by the botched implementation of a warehouse IT system upgrade that left stores short of stock.

The firm, which issued a profit warning in October, said its warehouse system and operational issues had been resolved but will cost it about £8.8 million of profit for the full year.

SuperGroup made an underlying pretax profit of £13 million in the six months to October 30th, down from a profit of £13.5 million in the same period last year.

The firm, whose clothes are a favourite of celebrities such as David Beckham, Leonardo DiCaprio and Zac Efron, said total sales of its trademark T-shirts, hooded tops, check shirts and jogging bottoms increased 51 per cent to £136.1 million.

It said the retail business in the first six weeks of the third quarter had delivered a positive like-for-like sales performance, showing an improving trend over the second quarter.

It added that the wholesale business was peforming well.

"Whilst mindful of the widely documented challenging consumer climate and our particularly strong Christmas trading season last year, we are well positioned for this year's peak trading period," it said.

SuperGroup was one of 2010's most successful stock market flotations. After listing at 500 pence 21 months ago, its shares rocketed to a high of 1,899 pence in February this year after a procession of stellar sales figures.

But a poorly received fourth-quarter trading statement in May and October's profit alert prompted a dramatic reversal.

The stock closed at 495.4 pence yesterday, valuing the business at about £397 million.