Warren Buffett
Warren Buffett, chairman and CEO of Berkshire Hathaway, takes his seat to speak at the Fortune's Most Powerful Women's Summit in Washington October 13, 2015. Reuters/Kevin Lamarque/File Photo

Billionaire Warren Buffett partly fulfilled his plan to donate his entire wealth to charity. On Thursday, he donated US$2.86 billion (A$3.75 billion) of his holdings in Berkshire Hathaway Inc to the Bill & Melinda Gates Foundation and four family charities.

According to regulatory filing, it is Buffett’s 11th yearly donation to the five charities. The amount is made up of 19.61 million Class “B” shares of Berkshire, reports Reuters. Gates Foundation, which got 14.96 million shares, focuses on improvements on education and health and reduction of poverty.

The four other charities are the Susan Thompson Buffett Foundation, Howard G. Buffett, Sherwood and NoVo Foundations which were named for the billionaire’s first wife, and overseen by his children Howard, Susan and Peter, respectively, according to Fortune.

With his annual donations, the 85-year-old remains the third-richest person in the world. But it has reduced his stake in Berkshire from 32.3 percent in 2006 to 18 percent. Buffett’s net worth before the donation, according to Forbes, was US$68.4 billion (A$89.85 billion).

The richest person is Microsoft co-founder Bill Gates at US$77.6 billion (A$101.92 billion), followed by Spanish retailing magnate Amancio Ortega, valued at US$74 billion (A$97.18 billion).

To finance their activities, the charities often sell the Berkshire share donations. The selected charities reflect the billionaire’s wishes on how his wealth should be spent. There are also smaller charities to whom Buffett also donates.

VIDEO: Why does Warren Buffett give to Charity?