* Oscar audience up from 2011, retains 18-49 year-olds
* Host Billy Crystal seen as old-fashioned
* Angelina Jolie's leg gets own Twitter account (Adds more Web traffic information, paras 11-12)
LOS ANGELES, Feb 27 (Reuters) - Billy Crystal, Angelina Jolie's leg and French silent film "The Artist" brought the Oscars bouncing back from recent slack viewership, drawing a larger-than-expected 39 million TV viewers and setting social media abuzz.
Some 39.3 million Americans watched the Oscars ceremony on television on Sunday, up from the 37.6 million audience in 2011, according to preliminary ratings data.
Broadcaster ABC said it was the second largest TV audience for the Academy Awards since 2007.
The bigger audience came and stayed tuned-in despite criticism that host Billy Crystal, 63, put on an old-fashioned show, and that the big awards went to "The Artist", a film that few people have seen.
The Academy Awards also retained all of its 2011 audience in the 18-49 year-old age group prized by advertisers, and drew more women in that viewer category than last year.
The annual Oscars ceremony show is traditionally one of the most watched events on U.S. television but audiences have fallen away in the past few years, especially when blockbuster films like "Avatar" are not in the running for the biggest honors in the movie industry.
"The Artist", which has made only about $30 million at the North American box office, was the big winner on Sunday with five Oscars including best picture, best director and best actor for Frenchman Jean Dujardin.
Crystal, making his 9th appearance as Oscar host, got mixed reviews. Alessandra Stanley at the New York Times said "the whole night looked like an AARP pep rally," while Tim Goodman at the Hollywood Reporter called Crystal's efforts a "safe unfunny retro-disaster."
But the news was not all bad for Crystal. Entertainment Weekly's Ken Tucker said it was a "jolly good show," and the New York Daily News said that Crystal "recaptured smartly the formula that worked for him in the past: quick-hit opening monologue, a song-and-dance number, then a sprinkling of jokes that had an edge but never drew blood."
Despite the jibes from critics about being old-fashioned, the Internet was abuzz with Oscar talk as millions of people watched and chatted online before and after the telecast. ABC said four million people visited website Oscar.com or used an Oscar smartphone app on Sunday alone.
Social media tracker Trendrr said social activity during the show - ranging from online buzz to Twitter comments and Facebook 'likes' - doubled from 2011 to 4.2 million hits on Sunday. Red Carpet coverage brought 3.9 million hits.
Meryl Streep, who was a surprise best actress winner over presumed front-runner Viola Davis, attracted the most mentions on social media, Trendrr said. The most-mentioned actor was "The Artist" star Jean Dujardin.
Angelina Jolie set the online world alight when she thrust her leg out of her thigh-high slit dress while presenting an award. Within minutes, a Twitter account had been set up with the handle "angiesrightleg," and by Monday it had some 17,000 followers.
Sunday's Academy Awards TV audience was on a par with February's Grammy Awards show, which was watched by a bumper 39.9 million Americans and fueled by the sudden death of singer Whitney Houston. (Reporting By Jill Serjeant; Editing by Bob Tourtellotte)