William Hill reported a decline in revenue in the four months to the end of April, as the bookmaker was left reeling after heavy payouts at the Cheltenham Festival in March had a negative impact on its earnings.
In the 17 weeks to the end of April, the FTSE 250 group posted a 3% year-on-year decline in total revenue, dragged lower by an 11% slump in online revenue. The sharp decline in online revenue was attributed to a slower-than-expected growth in wagering in online markets, which saw the group's Australian business post a 22% year-on-year drop in net revenue.
In March, British bookmakers nursed collective losses to the tune of £60m ($86.1m, €76.2m) as a number of favourites repeatedly stormed to victory during the four-day festival extravaganza at Cheltenham.
Earlier this month, William Hill revealed it lost £2.2m as it paid out the biggest ever odds on the Premier League market, after Chelsea's 2-2 draw against Tottenham Hotspur on 2 May mathematically confirmed Leicester City as this season's Premier League winners.
The bookmaker said the loss was ten times worse than the previous worst result and that was despite taking only 25 bets on Leicester to win the league at the start of the season, when the odds on Claudio Ranieri's men going on to lift the trophy were as long as 5,000/1.
"It has been a tough start to the year in online, which is being impacted by both regulatory change and a gross win margin below normalised levels for the period due to a disappointing Cheltenham festival and unfavourable European football results," said group chief executive James Henderson.
"Trends in recent weeks remain in line with the guidance we gave in March."
The bookmaker suffered its worst one-day decline since the financial crisis in March, as shares plunged 13% after the group downgraded its full-year profit guidance on the back of shrinking margins.