Shareholders on Friday approved Bank of America Corp's takeover of Merrill Lynch & Co.
Bank of America will surpass JPMorgan Chase & Co and Citigroup Inc as the largest bank in the United States, with $US2.7 trillion of assets.
Its brokerage, credit card, investment banking, mortgage and wealth management operations, plus its deposit base, will be the largest in the United States, or close to it.
The purchase values Merrill at about $US21 billion, down from an original $US50 billion on 15 September.
Shareholders of both companies had to approve the transaction, which is expected to close this month.
The takeover ends 94 years of independence for Merrill, in a year when Wall Street's top investment banks all met their demise or changed their stripes.
Bear Stearns Cos was acquired by JPMorgan, Lehman Brothers Holdings Inc filed for bankruptcy, and Goldman Sachs Group Inc and Morgan Stanley converted into bank holding companies.