I just saw a trailer for Thor: The Dark World and noticed that it will be released in Germany as Thor - The Dark Kingdom. While movie titles are often changed in localized versions for various reasons (as shown in this more general question), this change from "World" to "Kingdom" seems completely arbitrary to me and I cannot imagine any of the usual reasons to apply here. If there are 10 English words any German understands "world" is one of them, neither do I have any knowledge of "dark world" being used in other contexts.
Additionally, looking at other localized titles it seems that most (if not all?) other countries also use their words for "world" (yet in their own languages, but modern German has always been quite anglophile anyway), and the other countries not listed most probably use the original title. But given that we already had previous instances of seemingly arbitrary title changes that garnered pretty definite and good answers in the end, there might in fact be a known reason behind this oddity. So why was the title of this movie changed in such a minor yet unreasonable way for the German version?