CBS is breaking the mold with its straight-to-series order for “Under the Dome,” the Amblin TV/CBS TV Studios adaptation of Stephen King’s novel.

The pact unveiled Thursday after weeks of intricate dealmaking illustrates several shifts in the primetime series marketplace, including the networks’ growing focus on alternative financing structures for series programming, the money to be made from SVOD licensing and the push by the Big Four nets to offer more high-end original scripted fare during the summer months.

CBS has ordered 13 episodes of “Dome,” the story of a New England town suddenly sealed off from the rest of the world by an enormous transparent dome. “Lost” alum Brian K. Vaughan has shepherded the TV adaptation, which was initially developed bySteven Spielberg’s TV division at CBS’ sibling cabler, Showtime. CBS TV Studios-based hyphenate Neal Baer has been recruited as showrunner and will exec produce with Vaughan, King, Amblin TV’s Justin Falvey and Darryl Frank and DreamWorks’ Stacey Snider. Niels Arden Oplev, who helmed the original Swedish version of “Girl With the Dragon Tattoo,” will direct the first seg.

“This is a great novel coming to the television screen with outstanding auspices and in-season production values to create a summer programming event,” said CBS Entertainment prexy Nina Tassler. “We’re excited to transport audiences ‘Under the Dome’ and into the extraordinary world that Stephen King has imagined.”

The straight-to-series order is an extreme rarity for the Eye, but even more unusual is the network’s plan to set an SVOD deal that will make “Dome” episodes available for streaming shortly after the segs premiere on the net. The license fee coin to be mined from an SVOD platform (think Amazon, Netflix or Hulu) will allow CBS to pay a slightly lower license fee than it would otherwise fork over for a typical drama series — figure $1 million per seg rather than $1.6 million-$1.8 million — even though the show will be a high-end production with a budget in the of about $3 million per seg.

Given its auspices, “Dome” is sure to be a strong draw for international buyers, which will also go a long way to covering production costs. And the SVOD and international contributions will help make “Dome” cost effective for CBS to run during summer, when viewing levels and advertising dollars are typically not as robust as during the regular September-May season.

“Dome” is clearly an experiment for CBS, which has kept a tight rein on the migration of its programming to other platforms lest it erode primetime ratings and future syndication value. But with so much money on the table at the moment amid growing competition among the big SVOD platforms, CBS Corp. chief Leslie Moonves said earlier this month during the Eye’s quarterly earnings call that the company was considering expanding the availability of selected CBS and Showtime skeins.

There’s also corporate synergy within CBS Corp. as its Simon and Schuster unit will cross-promote the series with the April release of a paperback and electronic edition of the book, published by its Scribner imprint in November 2009.

Spielberg and Amblin TV’s Falvey and Frank pounced on the TV rights to “Under the Dome” shortly after it was published (Daily Variety, Nov. 20, 2009). The project was set up last year at Showtime, where Vaughan went through several drafts of the pilot. When it became clear that Showtime was not prepared to greenlight the project, Amblin wound up shopping it to multiple networks including Fox and Syfy. But it was Tassler who quickly stepped up with a surprisingly big commitment, especially as the Eye has eschewed straight-to-series orders for scripted skeins. Insiders say the work Vaughan did on the script in its Showtime phase helped make Tassler comfortable with taking such a big swing.

“We’re excited that CBS is taking a chance on us in doing something that is very untraditional for them in terms of the creative as well as the business model,” Frank said.

Production on the skein is expected to begin in February, probably in a state that offers tax incentives.

The 1,000-plus page book is a sprawling saga of the fighting and chaos that ensues when the Maine vacation town is inexplicably sealed off from the rest of the world by the invisible force field. CBS plans to tubthump “Dome” as an event series, but the intention is for the show to continue for multiple seasons — with King’s blessing.

“Stephen has been incredibly supportive on the ideas that we’ve presented to him,” Falvey said. “The series is inspired by the book but it doesn’t have to be exactly the same story.”

The “Dome” pickup is also more evidence that CBS is serious about programming high-end scripted fare during the summer months. The Eye also has a second season of procedural drama “Unforgettable” on tap for a summer run.

WME shepherded the “Dome” deal with CBS on behalf of Amblin Television. Paradigm reps Baer and King. Vaughan is with Verve, while ICM reps Oplev.