LOS ANGELES–It's somewhat strange to see Ivan Reitman's name linked to a thriller, since the famed Canadian-raised director (he was born in then-Czechoslovakia) is best known for a long list of comedy hits. However, he says that being an executive producer of the film Disturbia, which opens Friday (April 13), was a journey back to his roots in show business.

"Two of the first films I produced were David Cronenberg's first two films, Shivers and Rabid," he says in a Los Angeles hotel room. "I have always been a fan of the thriller and horror genres. I remember reading David's first script for Shivers, and I wanted to get it made. Frankly, at that time I wanted to get any film made, but I thought it was special.”¦ It turned out to be the start of a very remarkable career for him."

Reitman's career hasn't gone too badly either. After Rabid, he turned his attention to comedy, jump-starting Bill Murray's film career with Meatballs and then casting John Candy and Murray in Stripes. He went from there to producing John Belushi's film debut, Animal House, and directing Ghostbusters and its sequel, Ghostbusters II. His other films as a director include Kindergarten Cop, Twins, and Dave. He says that as the years went by, he gained confidence in his ability to uncover talent.

"I have had a long career of finding good people and working with them," he says, "but part of it was luck. In the first 10 years of my career, I got to meet a lot of people who became stars, and what happens when you do that is you begin to get a sense that it's okay if you cast someone no one knows. I wanted Bill Murray for Meatballs. I had worked with him on [the stage review] The National Lampoon Show and I knew that he was strong and that he would be going on to Saturday Night Live a few months later. Belushi was known to fans of SNL, but no one had heard of him outside of that. But I had seen him on-stage and had confidence he could do the role."

The latest young actor to have Reitman's support is Shia LaBeouf, the star of Disturbia. Reitman had seen him on the Ben Affleck/Matt Damon reality show Project Greenlight and sought him out at the Toronto International Film Festival. "I thought 'This is an up-and-comer.' We had just bought Disturbia, so I arranged to meet him for dinner. He seemed so confident and I just thought he could do almost anything, so I pitched him on Disturbia. I said, 'I think you would be perfect for this movie.' He said, 'Let's go make it, then,' and I came back to L.A. and said, 'I have found the guy. If we ever get the movie made, he would be perfect.'"

In Disturbia, LaBeouf plays Kale, a young man who blames himself for the tragic death of his father. Ordered to spend three months under house arrest, he becomes bored and begins to spy on his neighbours. Eventually, he comes to the conclusion that the quiet man who lives next door is really a serial killer. Reitman developed the screenplay with writers Christopher Landon and Carl Ellsworth before taking it to DreamWorks. Although he had worked with the company before, he had never made a movie with cofounder Steven Spielberg.

"I think we both contributed a lot," he says. "We had a bunch of meetings on the screenplay with [director] D.J. Caruso at Steven's. Casting the lead was easy because I wanted Shia, and Steven had already cast him for Transformers. So there was no argument. He had some good ideas in terms of the frightening stuff, and I had ideas about building the comedy sequences in the first half."

Of course, things don't always work out. Even Reitman has had his failures. The recent Uma Thurman vehicle, My Super Ex-Girlfriend, which Reitman says seemed to have everything going for it, didn't attract an audience.

"My Super Ex-Girlfriend was one of my favourite things, but it has been my least successful film as a director. We could never get the idea of that film across to the audience. We couldn't get them in the door, but once we did they liked it. I know two dozen people who saw it on an airplane and they said it was really good, as though they were surprised it was good. But when you are as fortunate as I am to have the success I have had, there will be a time when things just don't work out."