Over the past 16 years, Working Title has made Britain’s biggest-ever movies including Notting Hill, Bridget Jones’s Diary, and Bean. The company headed by Tim Bevan and Eric Fellner is responsible for 96 films grossing $4.8 billion worldwide, 60% of which came from Universal’s 46 Working Title releases. (Working Title started off indie until 1992 when it was acquired by Polygram until 1999 when Universal bought Polygram and with it, Working Title.) Its movies have won six Oscars, 26 Baftas and prizes at Cannes and Berlin. Forget Korda. Ignore Puttnam. Bevan and Fellner are easily Britain’s most successful cinema magnates. Yet something almost always goes wrong every time they veer away from Richard Curtis and Rowan Atkinson, who are responsible for nine out of the top 10 highest-grossing Working Title films. There also has been a succession of political films and expensive thrillers. When it comes to deciding what to make, Bevan says everything starts with passion. So A Serious ManUnited 93, Elizabeth:The Golden Age, Burn After Reading, and The Interpreter put him in business with big stars or big directors or both. “These are A-list people that most producers would kill to work with. More than that, they feed your mind,” Bevan told me in a recent interview. It was Fellner and Bevan who gave Joe Wright a huge break and $28 million to direct Keira Knightley in 2005′s Pride and Prejudice, which made $121 million in worldwide box office gross and resulted in 4 Oscar nods for Focus Features/Universal. But Universal lost $50 million on Paul Greengrass directing Matt Damon in 2010′s underperforming Green Zone after its gross budget swelled from $80 million to $130 million (not including tax incentives).

“The last batch of movies represented them breaking free of the Working Title formula,” says one producer who’s worked with them. “In Hollywood, you’re judged by how you’ve just done, not what you’ve made over the years. So they’ve gone back to the formulaic stuff. It’s depressing.” Still, retreating “back in their wheelhouse”, as the American phrase goes, is also smart business. For now, Working Title is playing it safer. Indian Summer, a big budget movie about the last days of Britain’s colonial rule of India in 1947, has been dry-docked even though Joe Wright (Atonement) was set to direct Cate Blanchett as Lady Edwina Mountbatten. As Bevan says in an interview with me, “You don’t produce a misfire and then not take heed from it.” Fellner adds: “It’s a consolidation period for us. A retrenchment period.” To that end, Working Title made six staff redundant in July last year, reducing headcount to around 40, which is historically what it’s always been.

Working Title’s latest release is the sequel to Emma Thompson’s Nanny McPhee Returns which Universal releases August 20th. Upcoming projects include Johnny English Reborn starring Rowan Atkinson and Gillian Anderson, as well as the Richard Curtis comedy Lost For Words, and a third Bridget Jones movie. The first Johnny English, which cost $40 million to make, earned just $28 million in America but did enormous business internationally grossing $132 million overseas. That’s typical: Working Title movies routinely make 2/3s of their gross outside of North America. Bevan tells me, “The thing that always sets us apart is that we’ve always done so well in the international marketplace. If there’s going to be any growth in this business, it’s going to be outside of North America.” And yet, waiting for Bevan and Fellner in their office building, I realize that Working Title has always struck me as being intensely London — as much a part of the city as red double-decker buses, Trafalgar Square, and pigeons. Even its logo used to look like the symbol for London Underground.

When Bevan and Fellner first sat down with then Universal CEO Edgar Bronfman Jr in 1998, he told them what he didn’t need was another supplier making studio movies. Bevan recalls: “Bronfman told us, ‘You guys have found a market for non-studio movies.’” Since then, Universal pays Working Title’s overhead and production costs. Working Title’s legal, accounting and production staff work hand in hand with Universal City Plaza each step of the way. “It’s a day-to-day relationship,” Bevan says. “Sure there have been ups and downs. We’ve had successes and flops. But what’s constant is mutual respect.”

Despite last year’s bump in the road, the relationship has been very successful for Universal. Working Title has fed Universal and/or Focus Features a lot of relatively inexpensive movies that have been consistently – and in some cases hugely – profitable. Universal Pictures chairman Adam Fogelson tells me, “Working Title is one of the most extraordinarily consistently profitable companies in the business. And there is a particular area of expertise that they can do better than anyone, and that primarily is the international marketplace. The Beans, Billy Elliot, Bridget Jones, Johnny English films don’t always do a whole heck of a lot domestically, but do astronomically overseas. They are some of the most profitable pics for us. It’s a relationship that’s been mutually beneficial.”

However, Universal passed on Working Title’s next grown-up film: Tinker Tailor Soldier Spy, a feature version of John Le Carre’s subtle spy novel already made for TV by the BBC in 1979. So Working Title is co-producing with Studio Canal of France. Swedish director Tomas Alfredson (Let the Right One In) begins directing this autumn from a script by Peter Morgan (Frost/Nixon). Says Bevan: “Alfredson’s an interesting filmmaker, so it doesn’t feel like too much of a gamble from a risk-analysis point of view.”

In November last year, U.S. cable giant Comcast announced it was buying NBC Universal from General Electric. Bevan and Fellner don’t seem perturbed by having new owners. “Being in business with an organisation already in the entertainment business has to be a good thing. Plus Comcast are entrepreneurs,” Bevan says. “But we’re right down the food chain in terms of Comcast’s priorities.” My source within Universal concurs. “Comcast shouldn’t change anything. Everything will remain exactly how it is.”

The same can be said of Bevan’s and Fellner’s working relationship. “They’re two very different men with two very different styles,” somebody who knows them well tells me. Crudely put, Fellner, 51, has almost infallible good taste in material, while Bevan, 52, has an acute business sense. Those who’ve worked with them say, “They’re very efficient in the way they split up the administration of the company.” Hugh Grant once remarked that, while most British production companies are run by awfully nice chaps who once worked for the BBC, there’s a level of professionalism about Working Title which sets it apart.  ”Tim and Eric are the definition of real producers,” said Co-Chairman of Universal Pictures Donna Langley.  “They stay close to the process and maintain their ability to hand pick and produce each of their films in a very individual way.  Their unique vision and taste has been key to their success.”

One former employee tells me that everything is meticulous, from copying in department heads on specific points of business to ensuring wrap party gifts aren’t just throwaway tat. The pair are also micro-managers, going over everything inside Working Title. And they lead from the front when it comes to hard work. As a result, they can be tough bosses. On the other hand, among Working Title staff, team members such as Debra Hayward and Liza Chasin have been there for 20 years.

Bevan founded Working Title in 1984 with Sarah Radclyffe and made My Beautiful Launderette. Like most independent producers, he spent most of his time looking for finance and just a small fraction developing projects. There was pressure to push material into production just to get the producer’s fee on the first day of principal photography. The company struggled along like this until Dutch conglomerate PolyGram bought it in 1992. Radclyffe left and Fellner joined that same year. Things didn’t go too well for the first couple of years, but PolyGram had made a conscious decision to give Working Title time to succeed or fail. Everything changed with the release of Four Weddings and a Funeral in 1994. The romantic comedy grossed $245 million worldwide.

Other British producers such as DNA Films (28 Days Later) and Marv Films (Kick-Ass) have tried to hook up with Hollywood and not succeeded. Working Title extended its deal with Universal for another seven years in 2007, after being courted by DreamWorks. Universal committed $1 billion to Working Title films. Bevan and Fellner kept creative autonomy and share in the profits. The deal means Bevan and Fellner are offered pretty much every major property in Britain, and pass on most of them. Because, broadly speaking, Working Title’s strategy is to make one risk-free movie each year, and a mainstream film, and a passion project, and one low-budget film. That way, even if their planned blo ckbuster goes down for the count, they at least have still got a shot at making winners of other fare.

Bevan and Fellner tried but failed to create their own kids’ franchise with Thunderbirds. But Working Title is now diversifying into television and doing more theatre. It’s started work on the Bridget Jones musical. Lily Allen is writing the music with author Helen Fielding. The creative team behind the stage version of Billy Elliot has reunited, including director Stephen Daldry. They plan to give it its premiere next year, hoping that lightning will strike twice. A movie version of stage musical Les Miserables is another project that brings a pre-existing audience with it.

In February, Working Title announced that it was setting up joint venture Working Title Television with NBC Universal International. Shelley McRory, a former NBC Universal executive, was named president of Working Title Television based in Los Angeles. Former BBC executive Juliette Howell was chosen to run the UK side. NBC picked up its first pilot Love Bites for broadcast in September. The series had a knockback though when creator/executive producer Cindy Chupack stepped down as day-to-day showrunner but will continue to write scripts. Former Will & Grace executive producers/showrunners Tracy Poust and Jon Kinnally have signed a two-year deal replacing her as showrunner.

And so Working Title keeps working. In this economy, that’s the biggest deal of all. Or, as Bevan likes to say, “How Big Do You Want The Bullseye?”

For all of Deadline's headlines, follow us @Deadline on Twitter.