NEW YORK — George Lucas says the newest — and final installment — of his "Star Wars" films may get a PG-13 rating.

"I don't think I would take a 5- or a 6-year-old to this. It's way too strong," Lucas says of "Star Wars Episode III — Revenge of the Sith" on CBS' "60 Minutes," to air Sunday.

"My feeling is that it will probably be a PG-13, so it will be the first `Star Wars' that's a PG-13."

"Revenge of the Sith," the third prequel to the "Star Wars" trilogy, will open May 19. The movie features Anakin Skywalker's transformation to Darth Vader, a descent based on Lucas' vision of hell, a mythical planet composed entirely of erupting volcanos.

"We're going to watch him make a pact with the devil," says the director. "The film is more dark ... more emotional. It's much more of a tragedy."

Despite critical pans of Episodes I and II, Lucas says in the interview: "Actually, I am very happy. I'm very pleased with the whole thing."