Marvel Comics characters are all over cinema screens this year, from Captain America to Spider-Man to the forthcoming X-Men and Guardians of the Galaxy. But after The Avengers united several characters, fans are wondering why there isn't more crossover. For example, why isn't Spider-man in the Avengers?

The Amazing Spider-ManAndrew Garfield as 'The Amazing Spider-Man'

The answer is pretty boring: it's down to business. Disney owns the Avengers and the Guardians (and Marvel itself), but Sony owns the rights to Spider-man and the Fantastic Four, while Fox owns the X-men.

As The Amazing Spider-Man 2 stormed the UK box office, people have been asking producer Matt Tolmach whether there might be some crossover in the future. "We'll see," he teases. "Once you decide to open up the universe, the rules go out of the window and you get to have fun. We talk about everything all the time, but Disney and Sony are obviously two very different companies. So as great as it would be, the truth is no. Right now, we are working with the characters in the Spider-man universe, and there are tons of them."

More: Check out our review for The Amazing Spider-Man 2

Indeed, Sony is planning its own spin-off movies, creating a sort of sub-universe with movies centred around the anti-hero Venom and the super-villain team The Sinister Six. 

But none of this has stopped people from asking whether Spider-man might one day show up in an Avengers movie. "That's what everyone asks," Tolmach says. "But right now, the truth about Spider-man is that he swings along. That's his plight, so it's not happening anytime soon."

Watch the trailer for The Amazing Spider-Man 2: