MANCHESTER, United Kingdom — Fashion chain Boohoo defied weak consumer confidence and reported a jump in its first-half pretax profit on Wednesday because of strong demand for brands such as PrettyLittleThing and Nasty Gal, and helped by celebrity campaigns.

Manchester-based Boohoo has been an online success story with millions of active customer accounts across brands, drawing in more younger consumers who shop on their mobile phones and share fashion tips through social media.

The social media-friendly company, which has teamed up with television celebrities and models, said it has 6 million followers on Instagram and 3 million Facebook likes.

The online retailer, which raised its full-year revenue forecast earlier this month, said pre-tax profit rose 83 percent to £45.2 million ($56.24 million) for the six months ended August 31.

"Other retailers may suffer from weak consumer confidence and hot weather, but Boohoo has posted an acceleration in total sales growth... but the surprise came from UK multi-brand sales growth," Jefferies analysts said of the first half, which beat the brokerage's expectations.

Revenue rose 43 percent to £564.9 million, with PrettyLittleThing growing in France and the United States while Nasty Gal, whose revenue more than doubled, performed well in the US.

AIM-listed Boohoo's shares, which are up nearly 60 percent for the year, were down 1.9 percent at 0803 GMT, in what one trader said was due to profit-taking.

By Tanishaa Nadkar and Pushkala Aripaka; editor: Uttaresh V.