Billionaire Bill Gates has been knocked off the top of the global rich list by his friend, US investor and philanthropist Warren Buffett.

Mr Buffett's wealth hit £31.2 billion as the price of Berkshire Hathaway stock surged and he topped the list of dollar billionaires.

For the first time, the Forbes' 2008 list revealed that more than 1,000 people made it in to the ultra-rich club which has a combined net worth of £2.2 trillion, with two-thirds classified as self-made.

Among the 1,125 people on this year's list, a record 50 people are under the age of 40.

These include the world's youngest billionaire, 23-year-old Facebook founder Mark Zuckerberg, who ranked 785 with £756 million ($1.5bn).

Microsoft founder Mr Gates, whose fortune rose to £29.2 billion, lost his top spot to Mr Buffet after 13 years and also missed out on second place to Mexican telecoms tycoon Carlos Slim Helu who has £30.2 billion.

Indian steel magnate Lakshmi Mittal was the UK's richest resident with £22.7 billion, putting him fourth on the list behind Mr Gates.

A total of 35 UK citizens are dollar billionaires, but the UK is home to 49, with 36 calling themselves Londoners.

The Duke of Westminster, Gerald Cavendish Grosvenor, is the richest Briton, coming in 46th place with £7.1 billion after making his money through real estate and his family.

Other notable Britons include retailers Philip and Cristina Green in 107th £4.2 billion and Virgin boss Richard Branson in 236th place with £2.2 billion.

Formula One boss Bernie Ecclestone and supermarket owner David Sainsbury are also represented, with £1.9 billion and £856 million respectively.

Harry Potter author JK Rowling is Britain's only woman on the list, coming in 1,062nd with £504 million.

© Independent Television News Limited 2009. All rights reserved.