The bank's third quarter earnings had been impacted already by a towering $17 billion settlement it inked with the Justice Department over mortgage fraud. Wall Street analysts had expected Bank of America to post a loss of $0.09 per share.
With the adjustment, Bank of America posted a loss of 4 cents in the third-quarter, compared to a previously reported loss of 1 cent.
A press release described the bank as being in "separate advanced discussions with certain U.S. banking regulatory agencies to resolve matters related to its foreign exchange business."
Read MoreCiti lowers Q3 results on legal costs
Bank of America is just the latest financial institution to see the forex probe eat away its profits. Citigroup one week earlier adjusted its third-quarter earnings to $2.8 billion—$600 million less than it had previously reported—for the same reason.
In prior earnings releases, Deutsche Bank and JPMorgan Chase & Co. each said they reserved $1.1 billion for the same issues.
On Monday, JPMorgan said in a filing that legal losses could total as much as $5.9 billion from a Department of Justice criminal investigation of its foreign-exchange trading.
Read More JPM estimates legal losses could total $5.9B
—CNBC's Everett Rosenfeld contributed to this report.