TD Bank Financial Group and Ameritrade Holding Corp. are in discussions about a potential transaction involving TD Waterhouse USA.

Through duplicative statements at the companies' Web sites, officials said the will make no further comment over the online brokerage until an agreement is reached. They also made no assurances that a transaction will take place.

As one of the world's largest brokerages houses, TD Waterhouse serves more than three million customers in the U.S., Canada and Britain. It is a unit of the Canadian banking giant Toronto Dominion Bank.

Ameritrade is a multi-faceted broker that serves both the individual and institutional investors. This latest news comes on the heels of an unsuccessful takeover of Omaha, Neb.-based Ameritrade by online rival E-Trade Financial. The merger attempt prompted a May 12 statement from Ameritrade's board of directors indicating that the company was not for sale.

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