This marked the tenth annual donation, and as has become customary for Buffett. However, he surpassed himself by making it his largest gift so far. It totalled 20.64m Class “B” shares of Berkshire, meaning the billionaire has now given more than $21.5bn to charity.

Buffett, now aged 84, is left with about 18.8 per cent of Berkshire’s stock, which Forbes estimated still leaves him third richest man in the world with a net worth of over $67.2bn. As well as being one of the wealthiest, Buffett is also regarded as one of the most generous business people with his consistent contributions to a range of charities. Bill Gates – currently ranked the wealthiest person in the world at $78.7bn – is also committed to utilising his financial health for philanthropic endeavours.

Buffett has been a long-term vocal supporter of the work the Microsoft founder and his wife do – he has previously given significant donations to help them carry on with their efforts, and was also on hand to honour them with the Forbes 400 Lifetime Achievement Award for Philanthropy earlier in 2015.

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He said that compared to other founders of foundations “in no case” did they “remotely pour the personal time and effort and brainpower into their foundations that Bill and Melinda have”. He added that “they have been spending – and I’ve observed it – certainly 50 hours a week, maybe averaging 60 hours a week”.

The Gates Foundation has focused on improving healthcare while reducing poverty, and expand educational opportunities as well as access to information technology. Buffett is one of the foundation’s trustees and has been a key driver in establishing the foundation as one of the leaders in venture philanthropy. This time round, Buffett gave the foundation around 15.76m shares, which would equate to 76 per cent of the total he donated.

The Berkshire CEO has run the company since 1965, which has more than 80 businesses across a variety of sectors, with interests in railroads, energy and insurance.

Learnings from Warren Buffett after 50 years of Berkshire Hathaway investing

He gave further donations to the charity named after his late wife – the Susan Thompson Buffett Foundation, as well as the Howard G Buffett, Sherwood and NoVo Foundations – overseen by his three children.

Buffett has taken to making his annual donations in July, tending to reduce the number of shares by five per cent from the prior year. Charities often sell the donated shares to finance their projects and initiatives – following Buffett’s desire that the money be spent. The gift is donated under the terms it must be spent currently for operations, rather than added to endowment funds. 

By Rebecca Smith