Following a strong share price rally today in his three group companies -- India's most valued firm Reliance Industries, Reliance Petroleum and Reliance Industrial Infrastructure Ltd -- the net worth of Mukesh Ambani rose to 63.2 billion dollars (Rs 2,49,108 crore).

In comparison, 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.

Ambani's wealth of about Rs 2,49,000 crore includes about Rs 2,10,000 crore from RIL (50.98 per cent stake), Rs 37,500 crore from RPL (37.5 per cent) and Rs 2,100 crore from RIIL (46.23 per cent).

Slim's wealth has been calculated on the basis of his stake in companies like America Movil (30 per cent), Carso Global (82 per cent), Grupo Carso (75 per cent), Inbursa (67 per cent), IDEAL (30 per cent) and Saks Inc (10 per cent).