Favreau helped create a hugely successful film franchise, starring Robert Downey, Jr. as the comic book superhero, by directing the first two installments and bringing in profits of more than $1 billion.

It was announced earlier this week (begs13Dec10) that the actor/director had walked away from a planned third movie, although no explanation was given for his departure.

Favreau has now opened up about his decision to quit, revealing he wanted to focus on a new project rather than a massively-hyped comic book movie.

He tells the Los Angeles Times, "(I wanted to) find something that lights a fire (inside me and will) blow people away, which is easier to do with a project that isn’t loaded with built-in expectations..."

And it was Favreau's desire to bring Disney attraction the Magic Kingdom to life on the big screen which spurred him on to leave Iron Man 3: "Between the theme parks and the movies, the Disney iconography was probably the first set of archetypes that I was exposed to. Walt was able to expose me as a child to the full array of emotions, including fear and sorrow. Those movies and attractions haunted my dreams and made a deep impression on me as a child."

But Favreau insists he has nothing but good memories of working on the Iron Man films.

He adds, "Marvel and I both came of age together. The years that we shared were a pivotal experience. Kevin (Feige, Marvel Studios president) has a firm grasp on the many franchises and how they all interweave and I am happy that I had the opportunity to establish the world that these characters can now play in... I look forward to seeing what others can do playing in the same world."