Morgan Stanley fired an employee it said stole data, including account numbers, for as many as 350,000 wealth-management clients and posted some of the information online.

The bank alerted law enforcement and found no evidence that clients lost any money, New York-based Morgan Stanley said today in a statement. The firm said it detected account information for about 900 clients on an external website and “promptly” had it removed.

“Morgan Stanley takes extremely seriously its responsibility to safeguard client data, and is working with the appropriate authorities to conduct and conclude a thorough investigation of this incident,” the company said in the statement.

Banks are spending more to protect client data as hacking attacks increase and technology makes dissemination and use of data potentially more widespread. Government agencies and regulators around the world are urging greater vigilance to counter cybercrime after an attack against JPMorgan Chase & Co. last year compromised personal information of about 76 million households.

Morgan Stanley didn’t name the fired employee. The bank said it’s notifying all potentially affected clients, which represent about 10 percent of its wealth-management customers, and enhancing security on those accounts.