NBC is looking to social media to help it rise from its bottom place among the big four U.S. television networks.

NBC on Thursday unveiled a new program called Fan It that will offer prizes to fans of its shows, and encourage them to earn points by using websites Twitter or Facebook to create online buzz for programs such as The Office and Chuck.

The network's new twist on efforts by media companies to engage viewers on the Web comes as studies show that TV watching and Web surfing are increasingly going together.

The Nielsen Company reports Americans spend about 3.5 hours each month simultaneously gazing at their TV sets and the Internet, which is a 35 percent increase from a year before.

Broadcasters and advertisers are seeking to exploit that phenomenon, and NBC, while seeing its ratings up six percent this season, is still trailing rivals CBS, News Corp's Fox and Walt Disney Co's ABC in total viewership.

NBC's Fan It program will launch on Monday as the TV networks present their new seasons to advertisers in New York. It will be tied to all of NBC's programs in the 2010-11 season.

Fans earn points by watching episodes of shows at NBC.com, chatting about the network's programs on social media websites and by hitting the Like icon on Facebook to show their approval of certain shows that will be visible on the website.

Underlying the whole effort is NBC's desire to see participants get their friends and followers to click on NBC-related Web links, and ultimately watch more of the network's programs.

Fans can exchange their points for rewards such as access to early previews of new shows, NBC merchandise, discounts at the NBC store and the virtual goods that are a big part of the online experience on Websites like Facebook.

James Poniewozik, a TV critic for Time magazine, said the challenge for NBC will be to make the online buzz-generating program seem authentic to fans and not have it seem like the impersonal spam messages that flood e-mail boxes.

There's a fair amount of potential in social media for television, as we've seen Twitter has very much been a boon for live TV, Poniewozik said.

It makes watching communal and people are more likely to watch things live and discuss it with their friends, he said.

Aside from Twitter and Facebook, the NBC Fan It program will also link with the websites MySpace and MyNBC, a social network the company launched in 2007. Users can sign up at NBC.com/FanIt.

NBC is owned by General Electric Co, but it is expected to be folded into a $30 billion joint venture with No. 1 U.S. cable operator Comcast Corp in a deal awaiting U.S. federal government approval.

(Reporting by Alex Dobuzinskis: Editing by Jill Serjeant)