20th Century Fox is gearing up to continue its “X-Men” franchise with a younger set of mutants. The studio has tapped “Gossip Girl” creator Josh Schwartz to write “X-Men: First Class.” He’d also been offered a chance to direct the film, but declined. Schwartz, the creator and exec producer of the CW’s teen soap opera hit as well as Fox’s youth-centric “The O.C.” and NBC’s “Chuck,” is expected to inject a next-gen sensibility into the superhero series, which has collectively earned $1.2 billion worldwide. Fox is keeping quiet on its specific plans for the new project. But the studio has been considering ways to continue its successful series of “X-Men” movies after the third installment, “X-Men: The Last Stand,” helmed by Brett Ratner, collected $459 million in 2006. It’s been leaning toward using the younger characters introduced in the previous pics in future installments –teenagers with powers taught at the Xavier Institute for Higher Learning. The resulting film would likely draw from elements of the Marvel Comic of the same name, launched in 2006, and enlist such characters as Iceman, Rogue, Angel, Colossus, Jubilee and Shadowcat, who have appeared prominently or made cameos in prior pics. Given the penchant for reboots with new actors playing familiar roles, the pic could also reintroduce characters. Lauren Shuler Donner, who produced all three “X-Men” pics, as well as next summer’s “X-Men Origins: Wolverine,” is producing “First Class” alongside “Mr. & Mrs. Smith” scribe Simon Kinberg. Since its dismal summer at the box office, Fox has placed renewed attention on its “X-Men” franchise. The studio, which is actively developing a standalone “Magneto” pic, also is considering creating a “Deadpool” spinoff, based on a character played by Ryan Reynolds in “Wolverine.” Shuler Donner also is producing “Magneto.” Although Schwartz has enjoyed small screen success, he has yet to crack the world of film with a significant project. Tackling a new “X-Men” installment will likely give Schwartz instant credibility within the studio world.