Shouldn't it be World Trade Centre and not Center?
Well, We wouldn't go around telling the Americans that they have got the spelling wrong! As it is they are pretty upset about what happened on September 11. And we are sure they wouldn't take kindly to others questioning their ability to spell.
Getting back to your question, the word Center has been spelt correctly. That's the way the Americans spell it. A few words, which end in re in British English, the Americans spell it er.
Here are a few examples:
meter, center, and theater
COURTESY : The Hindu (The National News-Paper) - India
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