William Hill
Britain's biggest bookmaker William Hill has seen its revenues lifted by its website and mobile app (Reuters)

William Hill, the UK's largest bookie, reported strong first quarter revenue and profit rises, driven by significant growth in customers betting on its Sportsbook.

A new mobile phone app helped attract a large number of fresh customers to the William Hill brand, as the bookmaker's online business continued to rapidly expand.

"I am pleased by our strong performance in the first quarter. With positive underlying trends at this relatively early stage in the year, the Board remains confident in its expectations for the full year," Ralph Topping, William Hill chief executive, said.

Shares in the group were around 3 percent higher in early London trading, the biggest advancer on the benchmark FTSE 250 index. The stock has rise more than 35 percent this year.

Group operating profit was up 19 percent year-on-year in the first quarter of 2012 for William Hill, which employs over 15,000 people across its 2,370 licensed betting offices.

Net revenue for the group was up 12 percent, while net online revenue for the online side of the business saw a big 33 percent increase.

Around 190,000 dowlnloads of William Hill's new Sportsbook mobile app helped boost Sportsbook wagering by 31 percent in the quarter - pushing Sportsbook net revenue up 58 percent higher than in the first quarter of 2011.

Of the mobile app downloads 30 percent were new customers for the bookie.

"Our mobile performance is now benefiting from our Sportsbook app being available in the Apple App Store, giving us access to thousands of new customers who have never bet with William Hill before, highlighting the growth potential of these new channels and their importance to our multi-channel offering," Topping said.

Sportsbook surpassed £50m in turnover in a single week for the first time ever, while mobile turnover hit almost £11m in a single week.

However over the counter bets fell 2 percent in the quarter, as bad weather led to fewer horse racing fixtures, the company said.

William Hill still maintains a positive outlook for the full year.

London FTSE