UPDATE 1-Restaurant booking service provider OpenTable expects weak profit

(Adds forecast, details, background, share movement; compares with estimates)

Feb 6 (Reuters) - OpenTable Inc, an online restaurant booking service provider, forecast a weaker-than-expected profit for the current quarter, sending its shares down as much as 10 percent in post-market trading.

The company forecast adjusted profit of 39 cents to 43 cents, way below the average analyst expectation of 54 cents.

OpenTable said it expects revenue of $53.3 million to $54.9 million, compared to analysts' average estimate of $54.3 million, according to Thomson Reuters I/B/E/S.

OpenTable said it would buy a provider of mobile personalized restaurant recommendations, Ness Computing Inc, for about $17.2 million as part of efforts to boost revenue from mobiles devices.

About 41 percent of OpenTable's seated diners booked through mobile devices in North America in the third quarter.

Application downloads on smartphones, tablets, and other mobile computing devices will jump to 187 billion in 2017 from 87.8 billion in 2013, IDC forecast in June. (http://link.reuters.com/myg79t)

OpenTable said it was working on allowing patrons to pay for a meal via their mobile phones and that it planned to launch the service in San Francisco.

If a diner makes a reservation at a restaurant through the OpenTable website or its app, the restaurant gets charged $1 per diner. If a diner makes a reservation on the restaurant's website and is directed to the OpenTable system, the restaurant is charged only 25 cents per diner.

Net income rose to $10.3 million, or 43 cents per share, in the fourth quarter, from $7.5 million, or 32 cents per share, a year earlier.

Revenue rose about 22 percent to $52.3 million.

Number of seated diners rose to 44 million.

Excluding items, the company earned 59 cents per share.

Analysts on average had expected earnings 52 cents per share on revenue of $51.5 million.

OpenTable shares were trading down at $69.50 in extended-trading. They closed at $75.41 on the Nasdaq on Thursday.

(Reporting by Chandni Doulatramani in Bangalore; Editing by Sriraj Kalluvila)