Whedon told the Los Angeles Times that he has ideas for a potential follow-up, but expressed mixed feelings on developing another project based on "somebody else's story".
He said: "You know, I'm very torn. It's an enormous amount of work telling what is ultimately somebody else's story, even though I feel like I did get to put myself into it. But at the same time, I have a bunch of ideas, and they all seem really cool."
The Avengers debuted in cinemas last month, and has challenged box office records around the world. The film's global takings passed the $1 billion (£623 million) mark earlier this week.
Disney has already confirmed that a sequel to the film is in the planning stages, though new instalments in the Iron Man, Thor and Captain America series will arrive in cinemas first.
Avengers is showing in theatres worldwide now.
> 'The Avengers 2': 5 potential storylines for a sequel - spoilers
Photo gallery - The Avengers in pictures: