Shares in SuperGroup have fallen dramatically after the clothing firm issued a profit warning.

The FTSE 250 company claimed there had been a slowdown in sales in the first three weeks of January, despite a like-for-like sales increase of 4.4 per cent in the 13 weeks to 29 January 2012.

The firm now expects full-year profits to be at the lower end of the market expectations of around £50 million to £54 million.

SuperGroup’s stock has plummeted this morning, and is currently down 18.5 per cent at 570.5p at 10.15am, reversing many of the gains made this year.

The profit warning comes just four weeks after SuperGroup issued a positive Christmas trading update, boasting of a 9 per cent increase in like-for-like sales.

Julian Dunkerton, SuperGroup’s chief executive officer, commented, ‘Retail sales during the quarter have been mixed, with a challenging last three weeks of January.

‘Whilst we continue to expand our retail, wholesale and internet businesses, our focus in the coming year will be on rolling out our new ranges in the UK and internationally and making improvements to the operational side of our business.’

The stock continues to divide City analysts, as broker Seymour Pierce cut its profit forecast by £2 million to £52 million but maintained that the stock is undervalued, while Merchant Securities cut its recommendation from ‘hold’ to ‘sell’.