Although most analysts were quick to predict that the success of Pirates Of The Caribbean: At World's End virtually guarantees a fourth installment -- and star Johnny Depp has indicated that he would be willing to sign on so that he can explore the character of Jack Sparrow further -- producer Jerry Bruckheimer sounded noncommital when asked about expanding the franchise. "We've been working on this trilogy for 5 1/2 years, and the latest one was just a monster," he told today's (Tuesday) Los Angeles Times. "It's always about making sure you have a great story with interesting plots, themes and characters. There is a possibility-- we'll see what happens."