This combination of file images shows Mexican tycoon Carlos Slim(R), Microsoft's Bill Gates(C) and Zara fashion house boss Amancio Ortega of Spain. The three topped the Forbes list of the world's wealthiest billionaires on March 4, 2013. Slim, who controls Latin American telecommunications power America Movil and retail/industrial group Grupo Carso, came in first among the mega-rich for the fourth straight year, with a fortune estimated at $73 billion, up $4 billion from a year ago. Microsoft chairman Gates, a perennial top finisher in the list, placed second with $67 billion, up $8 billion from 2012. Ortega, whose Inditex fashion group includes the popular Zara chain, vaulted from the seventh position into the third spot. His wealth is now estimated at $57 billion, rocketing from $31 billion a year ago. AFP PHOTO / FILES