Morgan Stanley revealed that it has fired a New York based financial adviser who allegedly stole bank account details of 350,000 wealth management clients, and then tried to sell these over the internet.

The Wall Street giant claimed that the former employee had posted the data online, but stated there was no risk any of its high net worth customers could have lost money as a result of the data breach.

While Morgan Stanley declined to name the axed member of staff, but a source cited by Reuters said the fired employee was Galen Marsh, 30, who worked as a financial adviser in one of the bank's New York branches. He joined the bank in April 2008 as a sales assistant.

The source added that Marsh was aiming to profit from the data breach by selling the bank account information through an advertisement on the internet.

However, Reuters reported that Marsh is "devastated by what has occurred and is extremely sorry for his conduct", according to his representative Robert Gottlieb, who works with the law firm Gottlieb & Gordon.

Gottlieb denied that his client posted the information online or tried to sell it.

"This is an employment matter between Mr. Marsh and Morgan Stanley," Gottlieb said.

"He has acknowledged that he should not have obtained the account information and he has been cooperating fully with Morgan Stanley to protect the firm and its customers."