H&M is following Zara by opening a UK online store in autumn 2010.
High street fashion chain H&M revealed the shift to e-commerce as it posted a rise in profits to £427m for its third quarter.
The group, which boasts more than 1,800 shops in over 30 countries, already has online sales in Scandinavia, the Netherlands, Germany and Austria.
Its latest plans signal an escalation in the battle for web customers, with Zara saying last week it will launch internet sales this time next year.
H&M, the world’s third-biggest clothing retailer, saw sales increase by 13% in the three months to the end of August.
But sales fell 11% as the warmer than usual weather across Europe failed demand for clothes.
The fashion giant also blamed increased price competition and a general tightening of discretionary spending among consumers.
The company said: “During the recession the customers have become more attracted to markdowns.
But H&M and Zara owner Inditex have so far weathered the downturn better than mid-market rivals such as Marks & Spencer and Next, helped by a focus on low-cost, fast-moving fashions.
Kate Moss