He's baack. Arnold Schwarzenegger, 54, will star in "Terminator 3: The Rise of the Machines," now that Sony has paid some $70 million for the international rights to distribute the film, reports Variety (Warner Brothers has the domestic rights). All told, the action-adventure is expected to cost $170 million, which the trade paper calls the most expensive budget ever for a movie. Opening date is planned for the July 4 weekend, 2003. "The Terminator," starring Schwarzenegger as the cyborg from outer space, opened in 1984. Seven years later, its sequel, "Terminator 2: Judgment Day," directed by James Cameron (who went on to do "Titanic"), grossed about $520 million worldwide, including $315 million outside North America. A third installment has long been in discussion, and the storyline for "T3" in part three is expected to pick up a decade after the last sequel, when a twentysomething John Connor (played by Edward Furlong in "T2"; no word on whether he'll reprise his role) reteams with his cyborg protector to battle the TX, an advanced model "female" terminatrix. Meanwhile, Schwarzengger's most current movie, "Collateral Damage," about a veteran firefighter whose family is blown up by Colombian terrorists, was due for release last fall but was put on the shelf in the aftermath of the Sept. 11 attacks on America. The movie, reports the Los Angeles Times, has recently been tested with preview audiences, who found the subject matter palatable. The movie will now be released in February.