Thorntons has announced that its turnaround is continuing to gather pace as strong demand from supermarkets helps boost fourth quarter sales.

The retailer said chocolate sales through supermarkets increased 11.8% during the 10 weeks to 29 June, while international sales more than doubled to £900,000, helping its commercial arm lift sales 21.1% during its fourth quarter.

It also reported more progress with its high street stores’ recovery, where underlying sales edged up 0.5%, amid signs consumers are still prepared to splash out on the odd treat.

But total sales in its owned stores fell 3.8% to £13.9 million after 34 closures during the year.

The Derbyshire-based group is two years into a three-year plan that will see it halve the number of shops it has on the high street to around 200 and grow its commercial and online channels. The retailer now has 296 stores and 186 franchises across the UK.

Jonathan Hart, who took over as CEO in 2011, said he was “encouraged” by the results and that it showed the three-year turnaround strategy “was beginning to deliver”.

In April, Thorntons upgraded annual profit forecasts after Easter trading kept its turnaround on track. The retailer said trading over its key Easter, Valentine’s Day and Mother’s Day trading periods was “satisfactory”, helping it offset tough conditions on the high street.

However, analysts have cautioned that it’s a good job that Thorntons’ financial year ran to 29 June, as the hot weather since then will not have helped chocolate sales, even if some shops now sell ice-cream.