Asos has lowered its full-year expectations for the second time this year after its US and European arms suffered ongoing “operational issues”.

Total group revenue was up 12% to £919.8m for the four months to June 30 with sales in the UK up 16% to £334.1m for the same period.

Despite the increase in sales, the online fashion retailer expects its full-year profits to be in the region of £30-£35m. This is the second profit warning the struggling retailer has issued since December.

Asos has been struggling with ongoing issues with its European and American parts of the business with growth in those two markets “lower than expected”.

Chief executive Nick Beighton said: “While we are making good progress in improving customer engagement, our recent performance in the EU and US was held back by operational issues associated with our transformational warehouse programmes.

“Embedding the change from the major overhaul of infrastructure and technology in our US and European warehouses has taken longer than we had anticipated, impacting our stock availability, sales and cost base in these regions.

“We are clear on the root causes of the operational challenges we have had, are making progress on resolving them and now expect to complete these projects by the end of September.

“Despite these short-term challenges, the move to a multi-site logistics infrastructure will enable us to offer customers across the world our market-leading proposition, facilitate our future growth, as well as leading to longer-term efficiency benefits.”