Ameritrade spokeswoman Donna Kush said they got the customer information in an unusable form from AST StockPlan, which administers the accounts and acted as a middleman between NDB and NDB's corporate clients.
"The issue is with the technology and the way it was going to be provided by AST," Kush said. Kush would not say how many accounts were affected or how many institutional customers Ameritrade has.
AST spokeswoman Susan Thomson declined to comment on Thursday and did not return calls on Friday or Monday.
It's only the latest example of data transfer problems in the wake of a merger or sale. After buying CompuBank earlier this year, NetBank found itself overwhelmed with calls from disgruntled customers who had trouble accessing their accounts or whose debit cards it had canceled.
Earlier this month, Ameritrade replaced NDB's Web site with a new site dubbed Ameritrade Plus. Former NDB customers were given accounts and passwords, but cannot monitor and sell stock options and employee stock purchases because of the data transfer problem. The Ameritrade Plus site does not have any message to new customers about the problem; instead, for example, it brings up a FAQ page when someone tries to access their employee stock purchase plan information.
Kush said Ameritrade notified customers in advance that they would no longer be able to trade options and employee stock purchases online. But the notice sent to customers gave a different explanation for the lack of online access.
Employee stock option and stock purchase plan trades "have been executed manually since Sept. 11 due to the tragedy in New York City," Ameritrade said in a note to customers. There is no reference to the switch from NDB to Ameritrade or any data transfer problems with AST StockPlan.
Kush said Monday that Ameritrade has no timetable for fixing the problem. Customers will be notified of any changes via letter or a message on the site.
Additionally, the problem happens in the wake of earnings season--a problem for people attempting to sell stock through an employee stock purchase plan. Employees must act within a 30-day insider trading window after their company has announced earnings.
Ameritrade bought NDB from Deutsche Bank in July in a deal valued at the time at $154 million. Ameritrade said at the time that it would acquire about 316,000 accounts from NDB. But Kush said that number did not include institutional customers.