US investment bank Morgan Stanley on Monday said it had fired an employee for stealing the personal data of hundreds of thousands of wealth management customers.

Some account information for about 900 of the clients, including account numbers and names, was briefly posted on the Internet and, once detected, was “promptly removed,”the bank said in a statement.

No passwords or social security numbers were stolen, the company said, adding: “There is no evidence of any economic loss to any client.”

Morgan Stanley did not identify the alleged thief by name but said the person worked in its wealth management business, without providing further details.

The employee stole data on about 10 percent of its wealth management customers, or about 350,000 people, it said.

The New York-based global financial services firm, which has offices in more than 43 countries, said it had informed law enforcement and regulatory authorities and was working with authorities to investigate the incident.

Shares in Morgan Stanley dived 3.4 percent to $37.39 amid a broad US stock market rout.