Representing the Republican Party, the campaign -- funded to the tune of $50m -- was Bloomberg's first foray into politics.
He will now need all his wits to lead a city still coming to terms with the atrocities of September 11 and mourning the imminent departure of much-loved-of-late mayor Rudolph Giuliani.
Last night in a speech to supporters, Bloomberg said, "Tonight is not about Republicans and Democrats, it's about New Yorkers."
Bloomberg set up his information network in 1981 after leaving Salomon Brothers. It now offers services such as Bloomberg News and Bloomberg Television and has expanded into Europe.
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