Next has been Britain's most successful clothing retailer of the last decade but warned in March that 2016 could be its toughest year since 2008. Its shares have fallen by over a quarter so far this year.

"In March we predicted a challenging year and this has been reflected in our first-half results," the group said, after sales from full-priced goods fell by 0.3 percent. The firm, which trades from more than 500 shops in Britain and Ireland, some 200 mainly franchised stores overseas and online, said it made a pretax profit of 342 million pounds in the six months to the end of July.

It retained its full-year sales guidance but said it expected to have a clearer picture of trading conditions at the beginning of November when it reports its third-quarter sales.

"There has been some talk of a general retail bounce in July and whilst Next did enjoy very strong sales in July, this was driven by a much larger end-of-season sale," the company said.

"Full price sales in July remained subdued, so we do not believe that July trading represented any change in underlying consumer spending patterns. Trading since July ...has remained challenging and volatile."

(Reporting by Kate Holton, editing by James Davey and Jason Neely)