Luxury etail group Yoox Net-a-Porter’s sales jumped 11.8% (16.9% based on constant currency) to €2.1bn in 2017.

Mobile accounted for more than half of group sales over the year.

UK sales rose 6.2% (13.7% in constant currency) to €286.8m across the year.

However, global growth slowed to 6.9% (13.2% in constant currency) in the golden quarter, which the group said was due to lower product availability on off-price website The Outnet following the migration of its logistics centres.

The ecommerce giant said that the issue had been rectified. Chief executive Federico Marchetti said: “This is behind us now and product availability has been fully restored.”

Over 2017, net sales at Yoox Net-a-Porter’s in-season etailers Net-a-Porter and Mr Porter surged 18.3%, and by 14.9% at off-season specialists The Outnet and Yoox.

Gross merchandise value of its online flagship store division – websites that Yoox Net-a-Porter designs and manages for fashion brands including Armani, Chloe and Karl Lagerfeld – soared 20.8%.

Marchetti said: “We’ve had a very good year. Performance in the fourth quarter was strong across the business. Net-a-Porter, Mr Porter and Yoox did particularly well.”

Yoox Net-a-Porter: 2017 vs 2016

2017: 842.2 million visits – 2016: 715.5 million visits

2017: 9.5 million orders – 2016: 8.4 million orders

2017: €328 average order value – 2016: €334 average order value

2017: 3.1 million active customers – 2016: 2.9 million active customers