GENEVA (AP) - Swiss bank UBS AG said Thursday it has discovered that unauthorized trading by one of its staff has caused an estimated loss of $2 billion, and warned it could result in a loss for the entire third quarter.
The announcement caused UBS shares to plummet 6.3 percent to 10.24 Swiss francs ($11.68) in early trading on the Zurich exchange.
The Zurich-based bank provided little information on the incident, saying it was still under investigation. But it said no customer money was affected.
"UBS has discovered a loss due to unauthorized trading by a trader in its investment bank," it said.
"UBS's current estimate of the loss on the trades is in the range of $2 billion," the bank said. "It is possible that this could lead UBS to report a loss for the third quarter of 2011."