Ameritrade Holding, the US discount brokerage firm, on Wednesday appeared to have approved a deal to acquire TD Waterhouse USA, a rival, for about $3bn, according to people familiar with the matter.

The company’s board, which had met for two days, was faced with the unusual choice between purchasing the unit of Canada’s Toronto-Dominion Bank, or selling to E*Trade Financial, another rival that had submitted three offers to buy the company in the last month.