Reliance Industries (RIL) chairman Mukesh Ambani on Monday regained his position as the world's richest Indian with a net worth of $19.6 billion, pushing Sun Pharmaceuticals founder Dilip Shanghvi back to the second place after seven weeks.

With a fall of $100.1 million in his net worth, Ambani slipped from his 39th position in the Forbes 2015 ranking to the 47th position among the world's billionaires, while Shanghvi ($19.3 billion) with a much greater loss of $474.6 million fell to the 48th position from the 44th.

In a 'real time' update, the US business magazine noted that Shanghvi's net worth dip was the third biggest loss among the world's billionaires in its annual rich list.

Ambani and Shanghvi remain the only two Indians among the top 50.

In the annual list released on March 2, Forbes had ranked Ambani as the richest Indian for the eighth consecutive year.

In the global list, Ambani with a net worth of $21 billion was ranked 39th while Shanghvi was at the 44th place with $20 billion, based on share prices and exchange rates as on February 13.

However, Shanghvi overtook Ambani as the richest Indian after two days on March 4 with a sharp rally in the valuation of Sun Pharma.

Globally, Microsoft co-founder Bill Gates continues to top the list with a current net worth of $80.3 billion, up from $79.2 billion in the annual list with Carlos Slim Helu and Warren Buffett retaining their second and third ranking, respectively.

According to Monday's real-time update, Ambani (47) and Shanghvi (48) are followed by Azim Premji (60), Lakshmi Mittal (85), Shiv Nadar (94), Kumar Mangalam Birla (169), Uday Kotak (200), Sunil Mittal (204), Cyrus Poonawala (220) and Gautam Adani (238) among the top 10 richest Indians.