Mitsubishi said that it detected the fraudulent transactions in August, while the employee was absent from work. The Japanese company said that losses from the transactions could increase further.
"Although PDS has already closed the current position and determined how much was lost on the underlying derivatives, we are now investigating the total loss amount," it states.
Mitsubishi said it jumped into action soon after discovering the losses, brought in a lawyer outside and set up an investigative team.
PDS fired the employee two days ago and filed a complaint with police Thursday, Mitsubishi said in the statement.