Rob Letterman, co-writer and co-director of DreamWorks’ “Shark Tale,” has signed on at Universal to pen his first live-action feature.“The Unprofessionals” is a military comedy in the vein of “Stripes”; “The Fast and the Furious” producer Neal Moritz is in negotiations to produce. U would not comment on negotiations except to confirm they were ongoing. Universal production exec Scott Bernstein will oversee development should a deal be reached. DreamWorks’ “Shark Tale” grossed just shy of $160 million as of Dec. 10. The Sony-based Moritz is producing “Spy Hunter” at U with helmer John Woo; at Sony-based Revolution Studios he is producing “XXX: State of the Union,” helmed by Lee Tamahori.