Mexican billionaire Carlos Slim has emerged the richest person in the world with $53.5 billion in assets, while Indian industrialist Mukesh Ambani, chief of Reliance Industries, ranks fourth with $29 billion in U.S. magazine Forbes' annual list of the world's top billionaires.

Mr. Slim is followed by William Gates III (popularly known as Bill Gates), with a net worth of $53 billion, and Warren Buffet in the third spot with assets worth $47 billion.

NRI billionaire Lakshmi Mittal ranks fifth with a net worth of $28.7 billion, while Mr. Ambani's younger brother Anil Ambani is at the 36th spot with $13.7 billion.

1,011 billionaires

There are 1,011 billionaires in the world now, up from 793 a year ago.

Mr. Gates has held the top spot for 14 of the past 15 years. “The Microsoft founder is now worth $53 billion, up $13 billion from a year ago,” Forbes said.

The U.S. has 403 billionaires — the most in the world — followed by China, which beat Russia to grab the second spot.

Although China has a larger number of billionaires than India, 10 of Asia's top 25 are Indian, while China has one. Hong Kong and Japan each have five.

New York has more billionaires than any other city.

The youngest billionaire — with a net worth of $4 billion — is 25-year-old Mark Zuckerberg, the creator of social networking website Facebook.

The list of Indian billionaires include Mukesh Ambani and Mr. Mittal in the top two, along with Azim Premji ($17 billion), Anil Ambani ($13.7 billion), Shashi and Ravi Ruia ($13 billion), Savitri Jindal ($12.2 billion), Kushal Pal Singh ($9 billion), Kumar Birla ($7.9 billion), Sunil Mittal ($7.8 billion) and Anil Agarwal ($6.4 billion).

Mukesh Ambani has retained the title of being the world's richest Indian for the second consecutive year.

Leading the group of 50 Indians in the list, Mr. Ambani has added over $9.5 billion to his net worth in the past 12 months. Mr. Mittal, who ranks fifth, has gained over $9 billion in the last year.

Mr. Premji, at the 28th place, has seen his rank skyrocket from the 83rd position last year with an addition of over $11.3 billion.

Mr. Ambani's brother Anil, who was ranked at the 34th position in 2009, slipped two positions below to the 36th spot despite an increase of $3.6 billion in his net worth.

Shashi and Ravi Ruia, the promoters of the Essar Group, are ranked at the 40th position, up from 86th last year. The cumulative wealth of Indian billionaires has jumped by $118.9 billion and now stands at about $227.9 billion. The Indian presence has doubled to 50 (from 24 a year ago) in the club