SHANGHAI  Flush with cash despite the global economic downturn, China’s sovereign wealth fund quietly bought more than $9 billion worth of shares last year in some of the biggest American corporations, including Morgan Stanley, Bank of America and Citigroup.

Although most of the stakes were small, the China Investment Corporation, the government’s $300 billion investment fund, now owns stock in some of the best-known American brands, including Apple, Coca-Cola, Johnson & Johnson, Motorola and Visa.

The detailed list, which contained holdings totaling $9.6 billion as of Dec. 31, was disclosed Friday in a filing with the Securities and Exchange Commission; it lists stakes only in companies traded in the United States.

The filing offers a glimpse of how China is trying to diversify its more than $2 trillion in foreign currency holdings with stock, rather than investing almost entirely in United States Treasury bonds and other debt securities issued by governments and by government-sponsored enterprises like Fannie Mae.