The sources said the investigation is over, and that prosecutors are expected to bring charges and request a trial.

The sources said 23 people including the former head of UBS in Italy, Fabio Innocenzi, had been probed, as well as UBS Europe and Sofia SGR. Under Italian law the two companies can be held responsible for the actions of their employees.

Innocenzi said he had learned only on Thursday that he was under investigation as an official of the bank and was unaware of the details of the investigation.

UBS said in a statement it did not comment on ongoing legal proceedings.

Prosecutors have looked into whether Sofia committed fraud by applying higher-than-average fees to 117 clients and by failing to disclose conflicts of interest on deals that generated losses for customers.

UBS Europe, part of UBS Group AG, was under investigation because Sofia SGR negotiated its products through the bank.

Sofia SGR has been liquidated and some of its assets taken over by Italian asset manager Azimut Holding SpA. Azimut said the activities it acquired were not among those that were subject to the investigation.

(Reporting by Emilio Parodi in Milan; Writing by Valentina Za; Editing by Matthew Lewis and Louise Heavens)