Warren Buffett's annual donation of stock to five foundations is worth around $3.4 billion this year.

In a news release, Berkshire Hathaway said Buffett converted 11,867 of his Class A shares into around 17.8 million Class B shares to make the contributions.

Based on the schedule established in 2006, when Buffett pledged to give away the bulk of his fortune in the coming decades, the Bill and Melinda Gates Foundation will be getting a large majority of the shares.

At Monday's closing price of $192, the 13.5 million shares going to the Gates Foundation are worth around $2.6 billion.

While the number of shares donated declines each year, a 12.8 percent increase in price of Class B shares from last year's $170.25 means the the value of the gift will have increased by about 7.1 percent from $2.42 billion.

Including this year, Buffett will have donated 243.3 million Class B shares to the Gates Foundation, just under 49 percent of the 500 million shares pledged. Next year's gift will bring the total percentage to 51 percent.

The total value of the gifts, using the market price at the time of the gifts, will be $24.5 billion, an average of $100.61 per share.

The total value using the current stock price would be $46.7 billion.

Along with the Gates Foundation, four family foundations are also receiving stock: the Susan Thompson Buffett Foundation, Sherwood Foundation, Howard G. Buffett Foundation and NoVo Foundation.

Berkshire said that including this year's gifts, the five foundations have received about 43 percent of Buffett's 2006 holdings with a market value of about $31 billion at the time of the contributions.

At the 2007 Berkshire shareholder meeting, Buffett explained why he decided to "farm out" his philanthropy by donating to foundations run by family members and his friend Bill Gates.

"When I have money to give away, I believe in turning it over to people who are ... energized, working hard at it, smart ... doing it with their own money, the whole thing. And I get to keep doing what I like doing. So as far as I’m concerned, I haven’t given away a penny."