Buffett to give away 85pc of wealth to charity

Most the donations will, ironically, go to a foundation run by Bill Gates, the wealthiest man on the planet.

The investment guru said in a statement that on Monday he would act on letters sent to Gates and other foundations that "that contain irrevocable pledges" to start transferring shares in his Berkshire Hathaway conglomerate to them from July.

He explained the motivation for his gesture in an interview with Fortune magazine, which said the handouts would amount to about 85 percent of his wealth.

"I know what I want to do," he was quoted as saying, "and it makes sense to get going."

Buffett said there were no immediate concerns about his health and that he is still "having fun" working in high finance.

"I feel terrific and when I had my last physical, in October, my doctor gave me a clean bill of health," he said.

But he did make a link to the death of his wife, Susan Buffett, in July 2004.

The two had been living apart but remained close and Buffett said: "She and I always assumed that she would inherit my Berkshire stock and be the one who oversaw the distribution of our wealth to society."

Buffett, 75, made his billions from astute investments that turned him into an world acclaimed operator.

The son of a stock broker and member of Congress, Buffett reportedly bought his first shares on the stock market at the age of 11. Virtually all of the money is concentrated in Berkshire Hathaway, which has interests range from insurance to property, energy and jet leasing.

The shares will go to five foundations. But more than 83 percent of the stock will go to the Bill and Melinda Gates Foundation which already has a kitty of about 30 billion dollars used to pay for medical research and give educational grants.