NEW YORK (AFP) - Microsoft founder Bill Gates has recovered his spot at the top of the US money heap, displacing investor Warren Buffett as America's richest person, Forbes magazine's latest list reveals. With 57 billion dollars net worth Gates again leads the list of 400 richest individuals in the world's wealthiest country. He displaced Buffett who briefly held the position this year but who has seen his Berkshire Hathaway investment group's shares slip 15 percent since February and is now worth 50 billion. According to Forbes, whose list was published late Wednesday, the golden 400 have 1.3 billion dollars net worth or more. However, their combined net worth rose only 30 billion dollars, or two percent, to 1.57 trillion dollars. Forbes said that rising oil and dizzy art prices fuelled the entry of 31 new members into the ultra-rich club and the return of eight previous members. A notable arrival was Mark Zuckerberg, 24, founder of the social networking site Facebook. Forbes estimates his worth at 1.5b dollars. Newcomers ranged from fertiliser tycoon Alexander Rovt to Patron tequila founder John Paul DeJoria and Norman Braman, the car dealer and art collector. Biggest gainers were led by New York Mayor Michael Bloomberg who took eighth place with 20 billion dollars worth after a transaction put a new value on his Bloomberg media and financial data network.