EXCLUSIVE: Men in Black 3 is officially a go, and Columbia Pictures will set a May 25, 2012, release date for a sequel that director Barry Sonnenfeld will shoot in 3D. Will Smith has signed his deal to reunite with director Barry Sonnenfeld, and deals are now being negotiated with Tommy Lee Jones and Josh Brolin. An announcement is imminent.

The project has been in the prep stage for some time, but didn’t become real until Smith chose it over several “next film” candidates. His decision to put on the sunglasses and dark suit gives Sony a killer 2012: the studio previously set a July 3, 2012 release date for its Spider-Man relaunch, which also will be shot in 3D. Walter Parkes and Laurie MacDonald return as MIB3 producers, and Steven Spielberg will be executive producer.

It has long been expected MIB3 would be next for Smith, who last starred in 2008’s Seven Pounds and then took the time to be a very hands on producer in the China-shot Karate Kid remake that stars his son, Jaden (which Columbia releases June 11). Smith then mulled several star vehicles that included City That Sailed, and I hear that he also contemplated Colossus, the scifi remake that Ron Howard wants to direct for Universal and Imagine.

While Smith pondered his choices, Columbia, Sonnenfeld and MIB3 producers Parkes and MacDonald positioned themselves to be ready. I’m told that Rick Baker has been designing and building the creatures, Bo Welch has been designing the sets, and David Koepp had been polishing a script by Etan Cohen that got this whole thing started. Cohen is back and polishing the shooting draft.

The film will use a time travel element that moves the action from contemporary back to 1969. Brolin will play the younger version of Jones’s Agent Kay character. Sony had every reason to be stoked about more MIB, the franchise based on the comic book by Lowell Cunningham. The 1997 original grossed $589 million worldwide, and the 2002 sequel did $442 million in global ticket sales. Those films rank high on Columbia’s all-time gross chart, and the prospect of making an installment that captures the otherworldly creatures in 3D is enticing. Still, many felt another film would be impossible because the gross deals were so prohibitive. I’m told that the principal players showed flexibility. It’s still a big-ticket film, and there is plenty of gross out the door. But the deals have built-in hiatus periods that allow the studio to recoup and make money.

That hurdle was overcome some time ago, and it came down to Smith committing. He showed some flexibility by agreeing to a Memorial Day weekend opening. Since Independence Day, Smith has considered July 4 weekend to be his preferred domain for commercial vehicles, but that slot was already occupied by Spider-Man. Then again, Smith has always been shrewd about choosing projects, and he has positioned himself to keep intact his title as world’s biggest box office star.