Shares in Hornby were down on the FTSE All Share after the hobby group said it had a poor trading period from 1 October 2010 until the present.
In the first half of the year ended 30 September 2010 Hornby said that its sales growth had been good.
However Hornby said that inclement weather in the month of December had noticeably impacted its sales in the pre-Christmas period.
Hornby said that as a result of its difficult Christmas period it was now predicting pre-tax profit for the full year to 31 March 2011 to be "below current market expectations".
The group said that net debt at the end of 2010 was £10.3 million, down slightly from £10.5 million at the same time in the previous year.
Neil Johnson, Chairman of Hornby, said, "The negative impact on the Group caused by the unusually adverse weather in December is almost certainly a one-off event. Coming on top of the previously reported supply chain issues the result for the year will clearly be impacted. Nonetheless, due to its diverse product and geographic spread Hornby continues to occupy a position of strength amongst its peers. We continue to see significant growth potential in many of our markets. The further positive progress on our supply chain issues will enable us to capture this potential as the business grows."
By 10:40 shares in Hornby were down 12.73 per cent on the FTSE All Share to 120.00 pence per share.