The world's richest man, Bill Gates, has urged fellow billionaires to give away most of their wealth, saying sharing brought far more joy than passing on money to descendants.

"I think all billionaires should give away the vast majority of their fortune," the Microsoft co-founder, who has given away a large part of his $49 billion fortune to fight poverty and disease, said at a public debate.

"I'm not saying they shouldn't leave anything for their kids or to have a little bit for themselves but yes, I think they would enjoy it, I think their kids would be better off, and I think the world would be better off.

"I want to share with them how much fun we've had."

Fellow American Warren Buffet, the world's second richest man with a fortune estimated at $46 billion, announced in 2006 that he would leave a part of his wealth to the Bill and Melinda Gates Foundation.

- AFP