The face is hardly wrinkled and the long blond locks appear unchanged, but Brad Pitt, who will turn 49 in December, is increasingly preoccupied with the passage of time and the thought that his rarefied place in movies is fleeting.

It’s now been more than 20 years since Pitt broke out as the heartthrob of “Thelma & Louise.”

While nothing has diminished his status as one of the few genuine movie stars on the planet, Pitt says he’s working as if an expiration date lurks.

“I’m definitely past halfway,” Pitt said. “I think about it very much as a father. You just want to be around to see (your children) do everything. If I have so many days left, how am I filling those days? I’ve been agonizing over that one a bit like I never have before.”

But that sense of urgency has helped fuel some of Pitt’s best, most daring work, including his new film, “Killing Them Softly.”

It’s his second with Andrew Dominik, the New Zealand-born director of “The Assassination of Jesse James by the Coward Robert Ford.”

In the adaption of George V. Higgins’ 1974 crime novel, “Cogan’s Trade,” Pitt plays a hit man operating in a shabby underworld of image-conscious gangsters.

It’s almost surprising how few blockbusters Pitt has starred in during the last decade. Instead, he’s gravitated toward working with revered directors such as Terrence Malick (“Tree of Life”) and the Coen brothers, and shaping his opportunities by producing them. His production company, Plan B, produced both “Jesse James” and “Killing Them Softly,” as well as many of his films in between.

More often than not, he’s sought to downplay his glamor, a track begun with David Fincher’s “Fight Club” and extended with ruminations on celebrity (Dominik’s “Jesse James”) and more character actor roles than most leading men would dare (his ditzy personal trainer in the Coens’ “Burn After Reading,” his Nazi-killing lieutenant in Quentin Tarantino’s “Inglourious Basterds”). “Killing Them Softly,” too, is an ensemble, with James Gandolfini, Richard Jenkins, Ray Liotta, Scoot McNairy and Ben Mendelsohn.

Even in 2011’s performance as Oakland A’s general manager Billy Beane in “Moneyball” (for which he landed his third Oscar nomination), Pitt deliberately played it low-key.

“Life is more interesting,” said the Missouri-bred Pitt. “I enjoy the fantasy; I enjoy when everyone wins. I just don’t contribute to that idea very well, for better or worse. There’s something subversive in my Christian upbringing or something, my mid-America upbringing. That irreverent urge that makes you want to yell or fart during the Benediction in church. I just can’t help it.”

And yet, Pitt has simultaneously carried the movie star mantle with seeming ease. Though his relationship with Angelina Jolie, with whom he has six children, has made him a constant tabloid target, he’s relaxed and unguarded in conversation. He said his celebrity “hasn’t bugged me since the ’90s,” but he acknowledges that he occasionally trades on it: “I mean, I play some smart ball,” he said.

“The difficulty with Brad was always: What can you cast a movie star in?” Dominik said. “You have to deal with it. You have to cast him as someone extraordinary, which I guess he is. He’s the cool guy in the movie.”

Certainly a very un-”Fight Club” thing to do was the recent Chanel ad campaign Pitt stars in, where he smolders in black-and-white and says things such as “It’s not a journey” into the camera. The spots were mocked on “Saturday Night Live,” to which Pitt says cheerfully: “Fair play, fair play.” After a reporter admitted not knowing much about fragrances, he laughed: “Apparently, neither do I.”

So why do it?

“Never done it before,” Pitt said. “Respect the company. I’m getting old. Last time I’ll probably be able to do something like that.”

It’s a line of reasoning that seems pervasive in Pitt’s choices now, including his current project: “World War Z.” It’s a zombie action film reportedly budgeted at $180 million that could give Pitt what his resume is missing: a franchise.

“I’m not a franchise guy,” he said. “They told me I should be focusing on that, as I’m getting older and cresting the precipice and heading down the other side: ‘You should really bank one of those.’ I’m just not good at it.”

It’s also a far bigger scale production for Pitt and Plan B, and things haven’t gone smoothly. The ending is being reshot — typically a bad sign for a movie — and Pitt calls the film “a total learning experience for me.” When the film finally wraps, he said, “Believe me, I’ll be celebrating.”

Dede Gardner, Pitt’s producing partner, said getting older has only made Pitt more patient.

“He’s extremely careful,” Gardner said. “I suppose that’s one thing that happens if you age with consciousness, to be vigilant.”

Their other coming productions are smaller, more director-driven. Plan B is producing the next film by Steve McQueen (“Shame”), “12 Years a Slave,” and is slated to again produce a film by Dominik: his planned Marilyn Monroe biopic “Blonde.”

Though “Jesse James” made a scant $4 million at the box office, Pitt has stuck with the director.

“Somewhere in the late ’90s, it became clear to me that there were many leading men roles that you could plug anyone of us into and virtually get the same thing,” Pitt said. “Because there’s such an investment of time and thought, I wanted to find stories that were more personal to me and that I believed I could add something that was unique.”

“Killing Them Softly,” is certainly that, a film that probably wouldn’t exist if not for Pitt. It’s an unusual mix of genre — gangsters and guns — and politics. Set in 2008, the fiscal crisis looms large, with speeches by Bush and Obama inserted as an obvious metaphor. Pitt’s character declares: “America isn’t a country. It’s a business.”

Between balletic slow-motion violence, Dominik stages Higgins’ dialogue in long scenes that give the actors theater-like room.

Gandolfini had twice previously worked with Pitt. “We were both at the beginning of our careers,” Gandolfini said. “He’s the same guy. He’s a good guy, a regular guy.”

And, despite any concerns about “cresting the precipice,” Pitt exudes contentment. His confidence as an actor is high, he said, attributing his ability to “craftsmanship.”

In his personal life, he and Jolie are planning to marry, after once saying they wouldn’t until gay marriage was legal.

“It’s an exciting prospect, even though for us, we’ve gone further than that,” Pitt said. “But to concretize it in that way. It actually means more to me than I thought it would. It means a lot to our kids.”

As he approaches 50, Pitt’s career longevity even surprises him.

“It’s amazing I’ve stuck with this this long because I’m not usually like that. I hit the road,” Pitt said. “Exploring within it has been the thing that’s kept me in it.”