House of Fraser is rolling out new designer brands including Anya Hindmarch and Lauren and pushing ahead with an extensive makeover of its stores, despite "difficult" trading conditions.

New brands include Anya Hindmarch, whose 'I'm not a plastic bag' cotton bag costing a fiver was a must-have accessory last year, alongside Episode, Kenneth Cole and The White Company. Next year the 61-department store group, which is owned by Icelandic retail investor Baugur, will start selling Lauren, the new womenswear line from Ralph Lauren.

It has also developed its own brands, including Linea which has been extended into handbags, accessories and products for the home, and is about to launch Criminal - a fashion brand for younger men.

The chain is on track to spend £150m on an overhaul of its stores and its brand portfolio by the end of the year, as part of a £250m investment programme annnounced 18 months ago when it was taken private. Chief executive John King, who took the helm at that time, is positioning the company at the higher end of the retail market.

House of Fraser reported 2.9% sales growth for the six months to July 26, but did not release like-for-like figures. Sales at refurbished stores are 8% ahead of the rest of the chain, including 18.7% growth at Lakeside shopping centre. Sales at the two new stores in Belfast and High Wycombe beat management expectations by 15%.

Earnings before interest, tax and depreciation climbed by more than 30% from last year.

The company has revamped 13 stores so far this year, with eight more to follow including Glasgow, London's Oxford Street and Manchester.

Don McCarthy, the chairman, said the management team had done a "great job in repositioning House of Fraser in what can only be described as difficult trading times".