Signet, which includes H Samuel and Ernest Jones among its brands, said second quarter like-for-like sales fell by 0.6% in the UK – following a 5.3% increase in the previous three months.
Total sales for the 13 weeks to August 2 fell by 4.5% following a weak performance among its US outlets.
Signet said price rises should hold profit margins steady in the US over the full year. The group has been increasing prices to counter the rising cost of gold, although the increases have been more selective in the UK.
Total first half same-store sales fell by 3.4% with the US down 5.2% and the UK up 2.3%.