:::We do not know that and I cannot find a any reference which would help, which is precisely why the unspecified government ownership (which equals Swedish ägda av staten or i svenska statens ägo), is what is appropriate here. To my knowledge, having studied the English and Swedish sides of such things for over 50 years, when Swedes say "staten äger det" they mean exactly and unmistakably the same thing as Brits, Americans/Canadians, Australians, Nigerians and 100s of millions of others mean when they say "the government owns that", whereas an albeit correct literal tranlation like "the State owns that" is not likely to be perceived by most readers of English as exactly and unmistakably what was meant.  

 :::Whether or not Sweden is designated as a sovereign nation in this context I would have to find irrelevant. If a building is owned by the government of the Bahamas or of Transvaal, which may or may not be considered sovereign nations, it's just owned by the government there. Wouldn't additional and perhaps extensive research to get more details on that be a bit overzealous of us, perhaps even unsoluble?  

 :::I general use, "staten" in Swedish represents exactly the same simple and vague concept as "the government" does in English speaking countries. The same cannot be said of the general perception of a more formal, yet less distinctive/designative, term like "the State" in English.