Hit animated children's film "How to Train Your Dragon" is roaring back to the big screen - movie executives are planning a 3-D sequel for 2013.

The DreamWorks picture, which featured characters voiced by Gerard Butler, Jay Baruchel and America Ferrera, fired up the worldwide box office when it was released earlier this year, banking almost $500 million globally.

And studio bosses are hoping to take another swing at the box office takings when the second installment of the Viking tale hits cinemas in three years' time.