Billionaire Mukesh Ambani became the richest person in the world, surpassing American software czar Bill Gates, Mexican business tycoon Carlos Slim Helu and investment guru Warren Buffett.

The net worth of Mukesh Ambani rose to 63.2 billion dollars after a strong share price rally in his three group companies — India’s most valued firm Reliance Industries, Reliance Petroleum and Reliance Industrial Infrastructure Ltd.

The net worth of both Gates and Slim is estimated to be slightly lower at around 62.29 billion dollars each, with Slim leading among the two by a narrow margin.

Warren Buffett, earlier the third richest in the world, also dropped one position with a net worth of about 56 billion dollars.