At a time when the power of movie stars is fading, Tom Cruise, whose own bankability remained a question mark through the middling successes of “Valkyrie” and “Knight and Day,” is proving he’s once again a major player in the tentpole business.

Cruise has agreed to star in Warner Bros.’ sci-fi tentpole “All You Need Is Kill,” and his third major booking in as many months assures that he’ll be working steadily for at least the next year — and keeping his name on marquees for the foreseeable future.

“All You Need Is Kill” had been wallowing in development hell for months, but with Cruise committed, Warner Bros. and director Doug Liman are expected to fast-track the project. Based on the graphic novel, the story is in the vein of “Groundhog Day,” with a twist: A soldier in a war against aliens finds himself reliving his last day over and overafter he’s killed. Through the training and battles he experiences in these time loops, he becomes a better soldier.

Dante Harper penned the script, with Joby Harold doing a rewrite. Sources said Cruise liked the script so much that Liman traveled to Pittsburgh, where the thesp was shooting Paramount and Skydance’s “One Shot,” to meet with the actor about the role.

Erwin Stoff, Tom Lassally and Jason Hoffs are producing through 3 Arts Entertainment. Harold is exec producing.

Another important development: Liman, who’s been onboard to direct “Kill” for some time, has lined it up as his next project. For months, Liman had been weighing whether to do “Kill” or the Paramount space adventure “Luna,” which struggled to assemble financing and saw David Ellison’s Skydance Prods. drop out — forcing Liman to turn to “Kill” for now.

Cruise’s busy schedule could enable Liman to do both. Production on “Kill” will begin in the late third/early fourth quarter of 2012, though no start date is yet set.

Though studio sources expressed concern that Cruise may be wary of doing back-to-back sci-fi pics, people close to the thesp tell Variety that he agreed after Liman’s insistence that the films would be completely different.

Cruise certainly has a whirlwind of work cut out for him: After a worldwide promo tour for this winter’s “Mission: Impossible Ghost Protocol” and finishing up “One Shot,” Cruise will begin to shoot the Universal sci-fier “Oblivion” in March, promote the summer musical “Rock of Ages” and likely hop right into “Kill.”

Though Cruise’s deal with Warners isn’t officially signed, his commitment should pave the way for a fast greenlight — proving that he’s still one of the handful of actors whose clout can get a project moving.

Cruise is repped by CAA.