Total sales for the company in the 53 weeks to June this year, fell by 5.9 per cent - a drop from £187.7m (€274.5m) to £176.6m (€258.3m).
In February the chocolate producers reported worrying sales figures and blamed the overall poor performance of the UK confectionery market.
Now company retail sales have continued the downward trend with a decrease of 5.3 per cent, down from £134.1m (€196.2) to £127m (€158.8) after the closure of two stores.
Totals in the commercial sales sector decreased from £35m (€51.2m) to £31.2m (€45.6m), a 10.7 per cent drop, caused in part by the restructuring of the brand in Marks and Spencers retail outlets and a decision earlier in the year to withdraw from High Street stores.
Sales to supermarkets however grew by an encouraging 11.2 per cent over the year.
There was good news as well with the subsidiary online shopping service, Thorntons Direct, reporting a rise in sales of 6.4 per cent from £5.2m (€7.6m) to £5.5m (€8m).
The company cited better marketing spend and an improved delivery system as being the main reasons for Thorntons Direct's growth in popularity. They remain optimistic that the rise will continue on the back of a new website, relaunch of customer offers and a greater degree of advertising to promote awareness of the service.
In addition, the company plan to increase the number of franchise outlets later in the year to combat the 4.4 per cent fall to £12.9m (€1.9m) in that area.
In terms of like for like sales, there was a slight halt in the downward trend when the 4.8 per cent drop in the first half of the year gave way to an improved 1.8 per cent fall - leading to an overall decrease for the year of 3.7 per cent
Management attributed this fluctuation to seasonal Easter investment in packaging and products.
Following the release of the trading statement, Thorntons' shares dropped 4.5p to 127.75p