Premier Foods, the firm behind Branston Pickle and Oxo stock cubes, has warned that April's hot weather "particularly impacted" its half-year sales.
In a trading update for the first six months of 2007, Premier said its like-for-like sales would be slightly lower than the same period last year.
Premier said sales were also hit by its exit from a number of low margin supermarket own label contracts.
It added that sales had improved strongly in May and June.
As a result of this, Premier, whose other brands include Hovis bread and Campbell's soup, said it remained confident of meeting its full-year targets, despite price pressures led by the rising cost of wheat.
The firm said that sales of Mr Kipling had seen a "particularly strong performance" during the first half of the year.
It added that it was on track to make cost savings of £113m from its recent acquisition of Mr Kipling firm RHM and the UK arm of Campbell's.
Premier also confirmed plans to sell off RHM's frozen foods business, which makes frozen pies, ready meals and desserts.
The firm recently announced plans to shut six factories by 2009.