Maltesers’ sales grew by £2.6M over the 52 weeks to September 13 2015, while Cadbury Dairy Milk’s dropped by £9.8M over the same period.
The chocolate-coated honeycomb treat had grown its sales partly because of seasonal products, such as Malteser Bunny and white chocolate Maltsers, on top of its traditional sharing range.
To find out what other brands made the top 10 and how sales have grown and decreased, view our gallery.
Unsurprisingly, the list is dominated by brands owned by Mondelēz and Mars UK, although Ferrero’s Kinder Surprise did make this list.
Chocolate sales are worth £1bn a year to the convenience channel, a decline of 2.1% from the previous year, IRI claimed.
The convenience sector accounts for 29% of all chocolate sold in the UK, it added. It costs shoppers 32% more (price per kg) than it does if they bought it in supermarkets, at £12.22 per kg.
This is partly because impulse outlets can command higher prices, and partly due to the higher sales of multipacks and bigger promotions in the supermarkets.
IRI UK’s head of strategic insight – Retail Martin Wood said: “Premium consumers are willing to pay for convenience. So even after allowing for the higher costs of distribution within this sector, there is still ample opportunity for bigger margins and profits for manufacturers.”