Progressive Democrat Bill de Blasio has been elected mayor of New York City, replacing billionaire Michael Bloomberg, US media reported Tuesday. "Thank you, New York City," de Blasio's campaign tweeted just after the close of polls, together with a photo showing the presumed winner together with his wife and two children. The 52-year-old will succeed Bloomberg in January at the helm of the United States' largest city. De Blasio promises a new style in a city transformed by 12 years of tough love under Bloomberg, who is stepping down after a record three terms. He is one of the most progressive politicians in the country and left Republican rival Joe Lhota trailing in the dust by tapping into the worries of the economically vulnerable middle class.