Thorntons has issued a profit warning after the hot weather over Easter led to a sharp drop in its chocolate sales.
The retailer said the hot weather in the Easter week contributed to a 22.8% drop in like-for-like sales compared with the same week last year.
The Easter trading period accounts for about a third of all store sales in the first four months of the year.
It now expects pre-tax profits for the year to 25 June to be £3m-£4.5m, down from the £6.1m it reported last year.
The Derbyshire-based company had previously expected profits to be about the same level as last year.
Like-for-like sales in Thorntons' own stores fell 12.6% over the 16 weeks to the end of April, compared with the same period a year ago.
Overall group sales - which includes commercial sales, franchise stores and the Thorntons Direct delivery business - fell 0.7% as commercial sales largely made up for falling store sales.
"The past quarter has been extremely challenging particularly in our own stores and for franchisees and we foresee this weakness in High Street footfall and spending continuing," said Jonathan Hart, Thorntons chief executive.
"We took steps to ensure that our ice cream was available in more stores than last year ahead of the Easter trading period.
"However, these significant additional sales were insufficient to offset the impact of the weather on those of our core chocolate items."
Shares in Thorntons closed down 12.8% at 70 pence.
In February, Thorntons had reported a fall in half-year profits after the freezing winter weather hit sales and disrupted its supply chain.