SINGAPORE (Sept 20): Mitsubishi Corp unit Petro-Diamond Singapore expects to book a loss of about US$320 million ($440 million) from unauthorised oil trades, the parent company said in a statement.

An employee hired locally by Petro-Diamond to handle its oil trading with China repeatedly engaged in “unauthorised derivatives transactions” and disguised “them to look like hedge transactions” since January, Mitsubishi said in the statement.

The unit has closed the positions and determined how much was lost in the underlying derivatives but is still examining the total losses, it said.

How the unauthorised trades will impact Mitsubishi’s earnings is under investigation and will be announced if and when a performance review is necessary, the company said.

The employee, who wasn’t identified, was terminated on Sept 18 and reported to police the next day.