* Operating profit rises 20 pct, beats forecasts
* Bookmaker is expanding online and overseas
LONDON, Jan 29 (Reuters) - William Hill, Britain's largest bookmaker, said that operating profit increased by 20 percent in 2012, boosted by continued strong revenue growth from its expanding online business.
The company forecast operating profit of 330 million pounds ($518 million) in the 53-week period to Jan. 1, 2013, generated from revenues that had grown by 12 percent. Analysts had pencilled in a profit of about 309 million pounds.
Set up in 1934, William Hill is a familiar name in Britain, where it has more than 2,300 betting shops.
The company has been expanding its overseas and online activities to reduce reliance on its traditional market.
"Q4 delivered a strong end to an already good year in 2012," Chief Executive Ralph Topping said in a trading statement on Tuesday.
"Performance was robust in retail, and profits continued to grow strongly in online, with sporting results going in our favour in both channels."
Over the year, online revenue grew by 27 percent, while revenue from its retail arm - essentially the high street shops - was up by 6 percent.
The company is spending 454 million pounds to acquire the Australian arm of online gambling company Sportingbet, as well an option to take over the company's Spanish operation.
A further deal is in the works, with William Hill looking at buying out online joint venture partner Playtech.
Bankers are assessing a valuation for the 29 percent stake held by Playtech. Analysts have said it could be worth up to 400 million pounds.
William Hill said the valuation process would be concluded next month, after which it would have a short time to decide whether to exercise its option.