NEW YORK, (AFP) – Warren Buffett, the world’s second richest man, on Sunday announced plans to give away an estimated 85 per cent or just over $37 billion of his estimated 44 billion dollar wealth to charity.

Most of 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 he would act on letters sent to Gates and other foundations “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 per cent 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 a 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 per cent 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.

Buffett and the Gates’ are close friends.

Fortune magazine estimated earlier this year that Buffett has about 44 billion dollars. It said Gates is now worth about 50 billion dollars.

According to Fortune, Buffett plans to eventually become a trustee of the Gates foundation. Bill Gates this month announced plans to withdraw from day-to-day control of Microsoft by July 2008 to concentrate on the foundation.

Buffett said in his statement that the value of the first gift to the Gates foundation would enable it to increase spending by about 1.5 billion dollars.

“I greatly admire what the Bill and Melinda Gates Foundation (BMG) is accomplishing and want to materially expand its future capabilities,” he said.

“In the future I expect the value of my annual gifts to trend higher in an irregular, but eventually substantially manner,” he added.

Shares will also be given to the Susan Thompson Buffett Foundation, the Howard G Buffett Foundation, Susan A Buffett Foundation and NoVo Foundation (Peter A Buffett) run in the name of his late wife and by other members of his family.

Buffett said he would set aside 10 million shares of class B common stock for the foundation, and award five per cent of the balance of those shares once a year. On Friday, a Berkshire Hathaway class B share was worth 3,071 dollars on the New York Stock Exchange.

Buffett’s wife died at age 72 after suffering a stroke. Buffett said that his wife had always wanted to give away their money faster.