* William Hill sees strong betting on top Olympic events
* Bookmaker sees progress on ownership of online presence
* Online, mobile help H1 profit grow by 13 pct
* Shares up 4.5 percent
By Keith Weir
LONDON, July 27 (Reuters) - William Hill raised hopes of an Olympic boost for bookmakers who have been cautious on the world's biggest sporting event, saying on the day the Games opened that the top events would attract strong interest from gamblers.
Britain's biggest bookmaker and its rivals such as UK No.2 Ladbrokes have played down the impact of the Games, which run until August 12, saying they were not a big gambling event and pointing out that the Euro 2012 soccer tournament was likely to be far more significant.
Online betting exchange Betfair has said the Games would generate the same amount of business as a typical weekend of English Premier League soccer matches.
After William Hill posted a 13 percent increase in first-half profit on Friday, Chief Executive Ralph Topping told reporters the excitement generated by the Games could only be good for business.
"I cannot see many people jumping out of bed in the morning to have a bet on the badminton but I can see lots of attraction in some of the bigger events with the bigger names," he added.
Soccer, athletics and tennis are likely to attract the most money, but William Hill has been fine-tuning its online systems to accommodate more bets on sports such as beach volleyball.
"Having the event in London is far better than having the event in Australia in betting terms," said Topping.
The group's gross win overall on Euro 2012 was 10.2 million pounds ($16 million), with the number of bets up by 61 percent on the 2008 tournament when England failed to qualify.
William Hill is best known for its chain of 2,370 betting shops in Britain, where it generates more than 90 percent of its revenue, but is expanding overseas where markets are liberalised -- such as the U.S. state of Nevada -- and like other gaming companies has a growing online and mobile business.
The bookmaker said its pretax profit for the six months to June 26 rose 13 percent to 143.3 million pounds on revenues 11 percent higher at 627.8 million pounds.
The company, which hiked the interim dividend by 17 percent to 3.40 pence per share, said revenue at its online operation rose 30 percent.
Its shares, which have risen 30 percent in the last six months, were 5 percent up at 305 pence by 1055 GMT, valuing the company at over 2 billion pounds.
"The group remains confident of its expectations for the full year ... and we increase our target price to 350 pence from 280 pence and reiterate our buy recommendation," said Panmure analyst Simon French.
The company said it hopes to resolve in the next few months the ownership of its online presence, which is a joint venture with Gaming software company Playtech.
Playtech has a 29 percent stake in the William Hill online business but the bookmaker can start the process to buy them out from the fourth quarter under a call option.
"We will be in a position to offer clarity on Playtech in a few months' time," Topping said.
Playtech has been the bookmaker's online partner since 2008 when it paid 250 million euros ($307.50 million) for its stake.