Director Christopher Nolan, shown with the cast of "The Dark Knight Rises," has declined Warner Bros.' entreaties to produce a "Justice League" film.

Warner Bros. will need a new hero to invigorate its DC Comics brand on the big screen, now that director Christopher Nolan’s successful Batman trilogy comes to an end with next week's "The Dark Knight Rises."

Home to such superheroes as Superman, Batman and Wonder Woman, DC has struggled to find the same success on the big screen as its Walt Disney Co.-owned rival Marvel Entertainment — despite having a better known collection of characters.

Nolan's Batman movies have been its only hits of the past decade, surrounded by modest flops such as 2006's "Superman Returns" and 2009's "Watchmen" and such major money-losers as 2010's "Jonah Hex" and last year's "Green Lantern."

As a result, top Warner executives had hoped that Nolan, who is producing next summer’s Superman reboot "Man of Steel," would agree to serve the same role on the studio's "Justice League," which may hit theaters in 2015.

"It was a conversation we had," Warner Bros. film group President Jeff Robinov said. "Obviously anything you can get Chris involved in is great."

However, Nolan has declined the studio's overtures, the filmmaker confirmed last weekend in interviews promoting the release of his final Batman installment. He also doesn’t plan to produce Robinov's hoped-for Batman reboot.

The news will likely come as a disappointment to the thousands of people in San Diego this week for Comic-Con International, the annual gathering of genre entertainment aficionados. Fans have been eagerly awaiting news of a next DC movie since "Man of Steel" was announced in 2010.

Like all the Hollywood studios, Warner craves new film franchises, which tend to perform best overseas, generate sequels and drive sales of DVDs, toys and other ancillary products.

Warner's most successful franchise, "Harry Potter," came to a close last year. While the studio has a pair of "Hobbit" films kicking off in December, it's on the hunt for more. The comic book library is the most obvious source of material, given the success Marvel has had over the last few years with movies based on Iron Man, Thor, and Captain America, culminating in May’s $1.5-billion box-office blockbuster "The Avengers."

But none of the DC movies currently in the works has a producer, director or cast, save for Zack Snyder’s $200-million-plus "Man of Steel."

As a result, it will likely be at least three years before a new DC title hits the big screen, according to several knowledgeable people close to Warner Bros. who were not authorized to speak publicly.

Marvel, by contrast, has four new films coming out between now and 2014 — new sequels to "Iron Man," "Thor" and "Captain America," along with the debut of the interstellar team "Guardians of the Galaxy."

In 2009, Warner reorganized its 78-year-old comic book subsidiary under the name DC Entertainment. The new unit was supposed to serve as a guiding force for projects throughout the company. Over the last three years, under former "Harry Potter" brand manager Diane Nelson, DCE has relaunched its line of comics and grown publishing revenue 10%, shepherded a new lineup of animated shows and video games, and helped bring a new TV series based on Green Arrow to the CW Network this fall.

But DC Entertainment has not been able to accelerate the movie slate overseen by Robinov, even though its chief creative officer, veteran comic book writer Geoff Johns, has consulted on some of the projects. Johns played no role in Nolan’s Batman movies or "Man of Steel," said people close to both pictures.

Indeed, one of the people described Nolan's creative process as a "black-box operation" into which outsiders have little input.

Despite the studio’s desire to make the most of its DC library, Warner's creative approach to its DC movies is very different from Marvel's.

First, it has attempted to keep a single filmmaker involved in numerous pictures, as evidenced by the attempt to attract Nolan to "Justice League."

Marvel, by contrast, typically hires filmmakers with little experience on big-budget tentpoles who can be had at a low price, such as "Lethal Weapon" screenwriter Shane Black, who is directing "Iron Man 3," and TV comedy veterans Anthony and Joe Russo on "Captain America 2." They are often replaced by still-newer filmmakers for sequels.

And while Warner would put most of its DC heroes on the big screen for the first time in "Justice League" and then potentially spin them out into their own movies, Marvel introduced four of its key characters in their own movies before teaming them up in "Avengers."

But with Nolan moving on to other projects, Warner Bros. must take a leap of faith without its superhero savior. Robinov claims he’s ready to do it soon.

"My hope is that over the next month or so," he said, "we’ll be ready to lay out the plan for the next DC movies."