It's the same the other way around with UK movies and books having different names in North America. Happens for a variety of reasons, from differences in the way people in UK / US speak to simply because the foreign publisher or distributor wants it changed. .. lots of reasons. In this instance though I can't see why giving the movie a title that makes it sound like the latest LEGO release is of benefit lol.
Why must the UK always make things different? What purpose does this serve to the movie?
Avengers Assemble...for a title? Are you serious?!!?
Are The Avengers not that big over there? If not than I can see the reason behind the change. Here The Avengers are huge because Marvel is based here.
i dont know the reason why they are changing it, but they have done that to a lot of movies before, changing titles for some reason.