MUMBAI (BLOOMBERG) - India's richest man surged past Silicon Valley tech titan Elon Musk as well as Alphabet co-founders Sergey Brin and Larry Page to become the world's sixth-richest person.

Mukesh Ambani, the chairman of Reliance Industries, whose wealth surpassed Warren Buffett's last week, is now worth US$72.4 billion (S$100.86 billion), according to the Bloomberg Billionaires Index. Shares of the conglomerate have more than doubled from a low in March as its digital unit got billions in investments from companies including Facebook, Silver Lake and, most recently, Qualcomm.

Ambani's energy empire is slowly shifting to e-commerce, with tech giants seeking to take a piece of India's fast-growing digital business. The world's second most-populous nation has seen a spike of foreign interest in its economy, especially from Silicon Valley, and Google said on Monday (July 13) it will spend US$10 billion in the coming years to help accelerate the adoption of digital technologies in the country.

After a drop in US tech shares on Monday, Mr Page's fortune now stands at US$71.6 billion, while Mr Brin's is at US$69.4 billion and Tesla's Mr Musk is worth UIS$68.6 billion. Buffett's net worth dropped last week after he gave away US$2.9 billion to charity.