More than $1.5 billion
Between $1 billion and $1.5 billion
Between $100 million and $1 billion
Archer Daniels Midland Co.
BP (formerly British Petroleum)
Canadian National Railway
Exxon Mobil Corp.
Merck & Co.
Schering Plough Corp.
Tyco International Ltd.
Waste Management Inc.
*May include stocks, bonds and other securities
**Warren E. Buffett committed his first installment of Berkshire Hathaway stock in June 2006.
Sources: Gates tax and SEC filings