"The case will now be transferred to the Court of Appeals which will hear the trial again in full. This process is expected to take several years," he said in the memo seen by Reuters and confirmed by a bank spokeswoman.

"The superficial nature of the verdict is astounding and does not even pretend to address the arguments we presented during the five weeks of the trial. This will need to be covered by the appeals court," he said.

(Reporting by Oliver Hirt, Angelika Gruber and Michael Shields; Editing by Kirsten Donovan)