LOS ANGELES — Jeff Robinov, president of the Warner Brothers Pictures Group, arrived at the fashionable Tower Bar here on a recent weekend. Other members of Hollywood’s A-list were quickly ushered to tables in the dining room, but Robinov had to wait — and wait. He finally ordered off the bar menu.

The Tower Bar may want to have a talk with its headwaiter. While little known outside of the clubby film industry, Robinov, 51, has become one of the most powerful people in moviedom over the last two years and is becoming even more so. He is the heir apparent for the company’s top movie job when Alan Horn, chief operating officer of Warner Brothers Entertainment and overlord of film production, retires next year.

With its corporate gentility and stability in a highly unstable business, Warner has long been Hollywood’s gold standard. By sticking to “the Warner way” — star-driven pictures, effective marketing — and keeping executive churn to a minimum, the studio of “Batman” and “Harry Potter” has sold more than $1 billion in tickets at the domestic box office for an unparalleled nine years running.

But Robinov, taking notice of changing industry economics and shifting consumer tastes, has been modifying that blueprint.

His strategy involves making fewer but more ambitious movies, cutting back on sweetheart producer deals and at long last integrating its corporate sibling DC Comics more tightly into the movie division.

Robinov, in close alliance with his president of worldwide marketing, Sue Kroll, is also moving Warner out of its stately comfort zone by pursuing more provocative advertising campaigns (“Rock Out With Your Glock Out” is the slogan for a forthcoming title) and raunchy comedies like “The Hangover.” Robinov pressed to make “The Hangover” over Horn’s objections. The $35 million movie, co-produced with Legendary Pictures, has sold about $467 million in tickets.

“There are movies that don’t necessarily speak to my generation,” Horn, 66, said, “but Warner needs to speak to all audiences.”

Big expectations

Robinov has more on his hands than just continuing to show Hollywood who’s boss. The studio’s slimmed-down corporate parent, Time Warner, is relying more than ever on its motion picture arm to mint profits that will impress investors. And he must accomplish that without the “Harry Potter” franchise, which ends next year.

Operating income for the studio rose 61 percent to $436 million in the fourth quarter. Even so, Wall Street’s attention is currently focused elsewhere, namely on 20th Century Fox’s “Avatar,” which has become the top-grossing movie of all time (in dollars not adjusted for inflation).

Premium-price 3-D tickets are one reason “Avatar” has attracted over $2 billion at the global box office, and Warner is hopping on the 3-D bandwagon in a big way. Last week it announced plans to release “Clash of the Titans” and the final two “Harry Potter” films in 3-D. Warner will have as many as nine 3-D releases next year, according to Dan Fellman, president of domestic distribution.

Driven by its need to replace “Harry Potter,” not to mention the continued appeal of superheroes, Warner recently announced a major reorganization of DC Comics. The goal is to quickly and more fully exploit its characters, something Time Warner’s corporate bureaucracy has hampered in the past.

The Walt Disney Co.’s $4 billion purchase of Marvel Entertainment just over a month ago has increased the pressure on Warner to succeed this time. Warner is expected to announce a DC slate in the coming months populated by characters like the Flash and Wonder Woman.

Central to Robinov’s approach to DC is to avoid cookie-cutter representations and take risks when it comes to hiring directors and choosing a cast. Fully backing a filmmaker’s vision has become a hallmark of his style, ranging from the odd “Watchmen,” which was a modest success, to the candy-colored “Speed Racer,” which was a flaming disaster, to “The Dark Knight,” a home run.

“He is trying not to cling to the things that have worked in the past,” said Christopher Nolan, who directed “The Dark Knight” and is working on another “Batman” sequel.

Succession

Another part of Robinov’s vision for the studio involves Kroll, his hard-driving marketing chief, who has been charged with instilling electricity and nimbleness in campaigns.

She was behind the arresting visuals for “Where the Wild Things Are,” which opened at No. 1 at the box office despite its art house aura. For the forthcoming comedy “Valentine’s Day,” which is showing such strong advance interest that producers are already racing to put together a similar movie built around New Year’s Eve, Kroll found an elegant way to showcase 18 stars on one billboard.

“She’s a monster: creative, brilliant, tireless,” Robinov said.

While it tinkers with its formula, Warner Brothers Entertainment, the studio’s umbrella company, is also confronting the distracting issue of corporate succession for only the fifth time since 1967, when the Warner family ceded control. Speculating about who will replace Horn and Barry Meyer, the company’s departing chairman, has become one of Hollywood’s favorite parlor games.

While Robinov is widely seen as Horn’s successor, it is less clear what the corporation might do with Meyer’s post — with speculation running the gamut from simply replacing him to splitting his job among a handful of executives.

There are three princes vying for the roles: Robinov; Bruce Rosenblum, president of the television group; and Kevin Tsujihara, president of home entertainment. The uncertainty has set off political maneuvering inside the studio.

Time Warner’s chairman, Jeffrey Bewkes, declined to comment about succession except to say, “We have a real preference for our own people.”

He added: “We’ve shown that it is possible to be consistently successful in a business that is supposed to be enormously volatile.”

Meyer, 66, said slow succession — the opposite of what Walt Disney Studios has recently set in motion — was the proper course for a business that has long lead times for its products and turns on subjective decisions. “If you inject jolting management changes into that process, it’s a recipe for destruction,” he said. “We are trying to evolve the system.”