Sports Direct has revealed a 51.1 per cent slump in full-year underlying pre-tax profits to £85 million, during what it called the most difficult trading period in its history.

Group revenues in the 52 weeks to April 27 fell 6.5 per cent to£1.26 billion, driven by a fall in UK retail sales, which plunged 10.5 per cent to£957.7 million.

Underlying group EBITDA dropped 29.9 per cent to£150 million. Group margins were down 70 per cent to 43.6 per cent.

Sports Direct chief executive David Forsey said: “The trading environment in Sports Direct’s first year as a listed company has been the hardest we have faced in our history, inevitably impacting our results.”

Forsey said that while the results were “disappointing”, the retailer has delivered ahead of its expectations.

He said: “We are targeting 2009 group underlying EBITDA to be at a similar level to the period just reported.”

Sports Direct acting non-executive chairman Simon Bentley said the retailer’s performance had been hit by last year’s wet summer and the failure of England to qualify for Euro 2008.

He added that Sports Direct was well placed for growth, particularly internationally following the acquisition of Everlast – allowing a platform for growth in the US – its strategic alliance in China with ITAT and the continued development of the group’s headquarters at Shirebrook in Derbyshire during the year.

International retail sales climbed 20.8 per cent to£77.3 million. Brands wholesale sales were up 11 per cent to£171.5 million and licensing revenues rose 21.3 per cent to£21.1 million.

The retailer added a net 42 stores in the UK to its store portfolio including a further 50 Sports Direct stores in the UK operating under the Sportsdirect.com fascia. It plans to open an additional 20 stores in the UK this year. At the year end, it operated 375 stores in the UK. Internationally, it opened 39 stores in Belgium, 14 in Slovenia, four in Holland and one in Luxembourg.