Actors Daniel Radcliffe (L) and Ralph Fiennes are shown in a scene from the film "Harry Potter and the Deathly Hallows Part 2" in this undated publicity photo released to Reuters April 27, 2011.[Photo/Agencies]

If only they could wave a magic wand, studio executives at Warner Bros. would make their "Harry Potter" film franchise last forever. But movie magic takes more than a whisk of a stick to conjure up.

When "Harry Potter and the Deathly Hallows Part 2" opens on July 15, it marks the beginning of the end for the highest grossing movie series of all time -- $6 billion worldwide box office -- and one that has given Hollywood studio Warner Bros. a stable revenue source since 2001.

The end of "Harry Potter" has led financial analysts to wonder what Warner Bros., a unit of Time Warner Inc., has planned to fill the gap when the series about the young magician, his friends, and their battle against evil comes to an end.

With this eighth movie, Warner Bros. has tapped all the books in the "Harry Potter" series from author J.K. Rowling, which are the backbone of the films.

"Overall, you're not going to capture all the mojo created from 'Harry Potter,' but you've got some real potential there with reboots of existing franchises and sequels of already existing properties," said David Miller, an analyst with Caris & Company.

For summer 2012, Warner Bros can bank on "The Dark Knight Rises," the third Batman movie directed by Christopher Nolan and the follow-up to his 2008 "The Dark Knight," which topped $1 billion in world ticket sales.

Also next year, the studio looks to release its highly anticipated "The Hobbit: An Unexpected Journey," which is a prequel to its successful "The Lord of the Rings" trilogy.

Last year, the studio's then president and chief operating officer Alan Horn said at an industry event in Las Vegas that as "Harry Potter" fades away, the company would rely more on its rich source of characters and material in its DC Comics unit.

DC SUPERHEROES TO THE RESCUE?

But Hollywood observers point to missed opportunities with some previous movie adaptations using DC Comics superheroes, especially compared to the nearly flawless record of rival Marvel Entertainment, which this summer has seen its "Thor" 3-D movie earn about $440 million at worldwide box offices.

"The jury is still out on whether they've found the right combination from their DC franchise to replace 'Harry Potter,'" said James Dix, an analyst with Wedbush Securities.

One case in point is the low-wattage result for "Green Lantern," a movie based on a DC character that has earned just over $103 million in the United States and Canada since opening on June 17.

Given that some industry watchers pegged the production cost of "Green Lantern" at about $200 million -- a figure Warner Bros has disputed -- the movie is widely viewed as a box office disappointment.

Meanwhile, Warner Bros is busy on the next Superman movie, "Man of Steel," set for release in 2012. The studio hopes to reverse the mediocre performance of 2006's "Superman Returns."

Jeff Bock, an analyst with Exhibitor Relations Co, noted that the studio assigned Nolan, the Batman director with the golden touch, a producing role on the new Superman flick.

And Warner Bros is said to have plans for other DC characters, including a long anticipated Wonder Woman movie.

"That cast of DC characters is probably going to be their crown jewel for the foreseeable future," Bock said.