However, the retailer said the introduction of Adidas and Nike in-store areas within its superstores is proceeding well, with 83 Adidas and 53 Nike areas in operation. It plans to have more than 200 Adidas and about 100 Nike areas by the end of the year.
The group said trading in its shops with these areas is better than average for its retail shops, in terms of both revenue and gross margin.
JJB non-executive chairman Roger Lane-Smith said: 'Trading results for the first 18 weeks of the present accounting period is in line with our expectations and I remain confident that our policies of product differentiation within our retail stores will provide future growth.'
Seymour Pierce analyst Richard Ratner said: 'It would appear that replica sales for the World Cup last year kicked in earlier in the comparative numbers than we had calculated. Taking out replica sales, overall retail growth would have been up 2.6 per cent. Overall, it is unlikely that we will change our estimates, as we had catered for a£20 million decline in replica sales this year.'