Actors Robert Pattinson, Kristen Stewart and Taylor Lautner pose during a photocall to promote their latest film The Twilight Saga: New Moon in Madrid, November 12, 2009. REUTERS/Sergio Perez

Hollywood watchers think vampire romance The Twilight Saga: New Moon could take a nearly $100 million bite from movie theater box offices when it debuts this weekend, and score one of the biggest openings ever for a non-summer film.

New Moon, which debuts in the United States and Canada on Friday, is independent studio Summit Entertainment's sequel to last year's Twilight, which surpassed expectations by making $69.6 million in its first weekend.

Exactly one year later, no one will be surprised if New Moon has a blockbuster opening in domestic markets, but the question is just how big it will be.

The film follows the romance between high school student Bella Swan and vampire Edward Cullen, and her friendship with Jacob Black, a werewolf. It has a built-in audience from the first movie and from millions of readers of the Twilight books by Stephenie Meyer on which the movies are based.

I have huge expectations for the movie, said Paul Dergarabedian, president of the box office division of film website I'm not going to say it's going to exceed it, but a $100 million opening weekend I think is totally in the cards for this one.

Jeff Bock, box office analyst with tracking firm Exhibitor Relations Co Inc, also believes the film could make nearly $100 million, and a source close to Summit said it could rake in nearly $85 million.

The film is slated to debut in 4,024 theaters in the U.S. and Canada, which is not a record but is far more than the roughly 3,500 theaters in which major releases normally open.

If New Moon reaches the $100 million mark, it will approach the record $102 million for Harry Potter and the Goblet of Fire, which debuted in November 2005 and sits atop the charts as the biggest opening weekends outside Hollywood's blockbuster-heavy summer season of May to August.

Online ticket sellers and reported this week that New Moon is their biggest advance ticket seller of all time.

The film is unusual for an expected blockbuster because of its heavy romance and appeal to young women, elements not typically seen in other mega-hits like the Spider-Man or Transformer aimed mostly at teenage boys and filled with action and special effects.

In an informal survey, 66 percent of respondents said New Moon's love story is its biggest draw.

Summit has sought to increase New Moon's appeal to boys by featuring action sequences from the film in TV commercials.

Bock said last year's Twilight opened to an audience that was 75 percent female, and if New Moon reaches just slightly more males it will exceed Twilight's success -- something other box office watchers said is likely.

Girls are going to drag their boyfriends to it, Dergarabedian said.