As the “Twilight” franchise draws to an end, Summit will need some eternal vampire blood to keep in the game. It’s counting on spawning new franchises like “Highlander” and “Red” to fill the looming void when the fifth “Twilight” leaves theaters in early 2013.

Until “Twilight” No. 4 opens Nov. 18, there’s a mixed bag of titles filling Summit’s slate: Sci-fi pic “Source Code,” starring Jake Gyllenhaal, opens April 1, while controversy still swirls around Mel Gibson, who stars in “The Beaver” due May 8.

By the time the “The Twilight Saga: Breaking Dawn — Part 2” opens in Nov. 2012, the franchise — initially picked up four years ago after Paramount passed — will have grossed well over $3 billion worldwide thanks to the global fascination with vampires, Kristen Stewart and Robert Pattinson.

Summit co-chief Rob Friedman thinks that a sequel to “Red,” the adventures of retired and extremely dangerous CIA agents; and a reboot of “Highlander,” a fantasy-adventure set in Scotland, which has the avantage of having been a popular TV series, have what it takes to follow in the footsteps of “Twilight.”

Summit hopes to start shooting “Highlander,” with Justin Lin directing and Neal Moritz and Peter Davis producing, this summer, probably in England. “We’re very hopeful with ‘Highlander,’ that it can be re-imagined like ‘Batman’ or ‘Star Trek,’ ” Friedman says.

Summit is also hoping to shoot a second “Red” in the first quarter of 2012, with an eye toward replicating last year’s success. And it has high hopes for starting a franchise with Constantin’s 3D “The Three Musketeers,” directed by Paul W.S. Anderson, opening Oct. 14.

“We think ‘Musketeers’ is a home run that will have huge international appeal,” says Summit production president Erik Feig.

The “Twilight” series has made Summit the town’s biggest success story in recent years, proving there’s still box office gold beyond the majors, despite a Hollywood landscape littered with minimajors that have vanished (such as Overture Films) or have been forced to slash operations (such as New Line).

Proceeds from “Twilight” enabled Summit to pay off the $1 billion raised in 2007 via Merrill Lynch. At that time, it made the risky move to launch a full-service production and distribution studio, tapping Friedman to join longtime Summit chief Patrick Wachsberger.

On March 8, Summit announced a $750 million debt refinancing and a cash distribution to investors including Participant Media, private equity fund Rizvi Traverse Management and Summit’s own management.

But the “Twilight” success has also raised expectations significantly. Summit received its first debt ratings from Moody’s Investors Service and Standard & Poors in January when the refinancing was unveiled, with both agencies expressing a mix of optimism and caution due to concerns over the end of the “Twilight” franchise next year and the volatile nature of the feature biz.

Over the past four years, Friedman and Wachsberger have transformed Summit from a foreign sales company into a full-service production and distribution studio, and their timing has been fortunate. When Friedman, who had been vice chairman at Paramount, came aboard in April 2007, Summit announced the $1 billion financing deal — a transaction that would not have been possible a few months later as the financial markets began melting down.

The Summit toppers remain a study in contrasts. Wachsberger’s a soft-spoken Frenchman with a well-regarded expertise in the international market. Friedman, who exudes caution, is very much a product of the buttoned-down studio culture he learned at Warner Bros. as chief of marketing under Terry Semel and Robert Daly and at Paramount as part of Sherry Lansing’s regime.

Wachsberger notes that Summit’s foreign sales clout is key, with the company handling recent titles such as “Source Code,” “Something Borrowed” and “Larry Crowne.”

“It’s a real advantage that we have because distributors know that they can rely on us to have the film to them on time with the materials they need,” he says.

Despite the success of “Twilight,” the Summit development slate has remained relatively sparse by design. The ratio of development to production is about three or four to one — far lower than the Big Six studios.

We tell people right away if we’re interested (in developing a film),” Friedman notes. “People who come to us want an answer because if a project stays in limbo too long, it gets stale.”

Summit execs have no illusions about becoming the seventh studio.

“The community knows what Summit is,” Freidman says. “We have 175 employees, the same number as in the business plan.”

In a recent interview, Wachsberger stressed that the success of “The King’s Speech” — which has grossed nearly $340 million wordlwide — reflects well on the nonstudio sector.

“‘The King’s Speech’ is great for us and all the independents,” he says. “It made a lot of money for distributors.”

The ministudio is sticking to its original strategy of releasing and distributing 10-12 films per year, with a focus on the midrange films that the majors are less likely to greenlight. It’s not willing to pay studio-tentpole prices for its tentpoles. But an increasing number of competitors have entered the same space recently, with Relativity, AMC-Regal’s Open Road, FilmDistrict and established minimajor Lionsgate.

“We’re willing to go to $100 million cautiously,” Friedman notes. “We’re very comfortable in the $35 to $60 million range, and we’re fine in the $15 to $25 million range.”

Wachsberger believes that Summit’s bread and butter continues to be broad-based fare at moderate prices with recognizable stars in a pair of thrillers now in post-production: “Man on a Ledge” with Sam Worthington and “Cold Light of Day” with Henry Cavill, Sigourney Weaver and Bruce Willis.

“Our films really look and feel like studio movies,” Wachsberger notes. “And we are very strong in international markets.”

Besides the next “Twilight,” “Source Code” and ‘The Beaver,” Summit’s 2011 release slate includes sci-fi (“The Darkest Hour”), a comedy-drama about surviving cancer (“50/50”) and a Chris Weitz’ drama about Mexican immigrants in Los Angeles (“A Better Life”).

Summit recently wrapped “The Impossible,” a tsunami disaster film shot in Thailand by Juan Antonio Bayona with Naomi Watts and Ewan McGregor starring. It’s going into production this spring on “Perks of Being a Wallflower,” with Emma Watson and Logan Lerman, and is aiming to get vampire romancer “Warm Bodies” shot later this year, along with dance pic “Step Up 4.”

Feig notes that Summit began development of “Warm Bodies” before the Isaac Marion’s tale was even published. It’s tapped Nicholas Hoult to star, with Jonathan Levine (“The Wackness”) directing.

“We’re proud that we’re finding filmmakers with unique voices,” Feig notes. “And I love being able to point to repeat customers like Melissa Rosenberg on all the ‘Twilight’ films and Robert Schwentke (“Red”) coming back for ‘The Osterman Weekend.’ ”

Still, Summit’s not throwing buckets of money at talent to get their movies made. It’s staying singular as the town’s sole studio without any first-look term deals with producers.

“We love them all, but we love them as independents,” Friedman says.

Summit’s also planning to expand into television some time soon, though Friedman and Wachsberger are sparse on details at this point. “We’re looking for the right executive but we won’t be like a studio,” Friedman adds.

There have been missteps (“Furry Vengeance,” “Remember Me” are the most recent) but Summit reaped prestige, if not B.O. rewards, with Oscar-winner “The Hurt Locker.”

Its 2010 foray into awards season didn’t gain much traction: “Fair Game” bowed at Cannes, but didn’t hold up in the crucial fourth quarter, while “The Ghost Writer” performed strongly at the worldwide B.O., and nabbed kudos from overseas orgs but couldn’t translate into U.S. honors.

Summit may be trying again with “A Better Life,” which it has slotted for late June — the same weekend it opened “Hurt Locker” as a counterprogrammer two years ago. “Life” centers on the problems faced by a hard-working illegal immigrant in Los Angeles when his truck is stolen and the subsequent efforts by him and his son to recover the vehicle.

“We think people will want to see something with great characters during the summer blockbuster season,” Feig says.