BlackRock, the world's biggest money management company, says it holds nearly 7 percent of the Class B stock of Warren Buffett's company.

BlackRock revealed Wednesday that it owns 68.4 million Class B shares of Berkshire Hathaway Inc. The New York-based money manager said in a filing with the Securities and Exchange Commission that it held the shares at the end of 2010.

The stake will likely give BlackRock's investors little say in Berkshire because each of the company's Class B shares carries one-ten-thousandth of the voting rights of a Class A share.

Omaha-based Berkshire owns roughly 80 subsidiaries, including insurance, clothing, utility, furniture, jewelry and corporate jet firms. It also has major investments in such companies as Coca-Cola Co., Washington Post Co. and Wells Fargo & Co.