Rao Chalasani, an IT worker within the bank’s global markets portfolio management group, is alleged to have sent an e-mail to a personal account containing 21 files.
According to the law suit, Mr Chalasani is believed to have sent the message the day before the bank was due to announce 400 redundancies, including his own.
In the court papers, which were quoted by Reuters, the bank said: “The files attached to [the] defendant's email all contain confidential and proprietary, non-public information concerning BofA, including profit and loss figures for different lines of its businesses throughout the world.”
The files are thought to have contained information on the bank’s “current trading positions in numerous securities and the company's assessment of risk”.
BofA discovered the message as part of a security review into large files sent by company employees to outside e-mail addresses.
The bank announced it was to make cuts to its investment banking division in September.