|Bookmaker Ladbrokes has warned that trading was worse than expected in the first three months of 2013.
The firm blamed a drop in profits from the Cheltenham races and lower revenues from high value gaming customers.
It said that full-year profits were now likely "to be at the bottom" of analysts' forecasts, sending Ladbrokes' shares down 8% in early trading.
But chief executive Richard Glynn said Ladbrokes was making progress on its "reinvigoration strategy".
In an early release of its first quarter trading statement, Ladbrokes said operating profit fell to £37.4m in the three months to March, down £13m.
The Cheltenham festival generated about £6m less in revenues.
Ladbrokes said it had always expected the first period of the year to be slower.
But the company added this had been exacerbated by "a significant reduction in profit from Cheltenham, lower revenues from high value gaming customers and a proportionately higher impact from horseracing cancellations".
Mr Glynn added: "The trading environment and economic conditions since the start of the year have remained challenging, which when combined with a number of specific one off factors in the latter part of the period, have driven a softer first quarter than expected."