The richest man in the world is taking over New York.

Mexican mogul Carlos Slim — who already owns a major interest in the New York Times and a major office building in Manhattan — has added a new trophy, the magnificent Duke-Semens mansion across the street from the Metropolitan Museum of Art, The Post has learned.

The deal closed for $44 million cash, when the billionaire swooped in and snatched the prize from the clutches of a mystery Russian buyer whose starting bid was around $37 million, sources said.

If anyone can afford it, Slim can – Forbes reported his family net worth at $53.5 billion.