Mellon lost $7.7 million in foreign exchange trades.

The Pittsburgh-based bank attributed the loss to unauthorized foreign exchange trading by one of its Tokyo-based foreign exchange dealers. The bank did not identify the trader or what actions it took. “The bank has conducted a thorough investigation and has determined that the dealer had circumvented established controls which are considered to be adequate,” the bank said. It said that by doing so, the dealer “knowingly violated the bank’s procedures and exchange trading limits.”