Bill Gates retains America's richest person slot: Forbes

Microsoft co-founder Bill Gates has retained his position as the richest person in America for the 19th year in a row this year, according to Forbes' annual ranking of the nation's 400 super rich people who have a combined net worth of USD 1.7 trillion dollars.

With a net worth of USD 66 billion, Gates not only remained the richest person in America but is also "the planet's most generous person", thanks to his countless philanthropic endeavours in developing nations, including India, Forbes said.

The 56-year old Harvard drop out has given away USD 28 billion to philanthropic causes so far, with his new obsession being building better toilets for those without water or sewage systems, it added.

Every year 1.5 million children die from food and water tainted with fecal matter, more than the  annual deaths from AIDS and malaria combined, Forbes said.

The Bill and Melinda Gates Foundation is also spearheading a malaria vaccine that is showing promise in clinical trials.

The non-profit Global Alliance for Vaccines and Immunisation (GAVI) founded by Gates has raised USD 4.3 billion in pledges from various countries to provide life-saving vaccines against a range of deadly infections.

"Gates and his good friend Warren Buffett continue to recruit new members to their Giving Pledge, in which the very wealthy promise to give away at least half of their net worth during their lifetime or after they die," Forbes said.

Gates' net worth rose USD 7 billion since last August on the back of Microsoft shares, which climbed 20 per cent and on gains from investments in private equity, bonds and stocks, Forbes said.

In addition, Gates continues to sell shares of Microsoft and now just one-fifth of his net  worth stems from the software company he co-founded 37 years ago.

On the second spot with a USD 46 billion networth is 82- year old Buffett, chairman of Berkshire Hathaway, who recently completed radiation treatment for prostate cancer.

Earlier this year, Buffett said he had picked his CEO replacement but has declined to give a name.

Among the names of possible successors making the rounds is Berkshire's head of reinsurance business India-born Ajit Jain.

Buffett is not too far behind Gates when it comes to philanthropy. He gave USD 1.5 billion to the Gates Foundation in July, bringing his total contribution to USD 17.25 billion.

On his birthday in August he pledged USD 3 billion Of stock to his children's foundations.

His fortune grew USD 7 billion as class A shares jumped more than 20 per cent since last year.