The Swiss government hastily arranged the takeover of Credit Suisse by UBS on March 19 to prevent a global financial meltdown.
The merger could result in up to 36,000 job cuts worldwide, with up to 11,000 in Switzerland alone.
UBS announced the appointment of former CEO Sergio Ermotti to handle the risks involved in the merger.
Credit Suisse was embroiled in a series of scandals before the merger, including the bankruptcy of Greensill and the implosion of Archegos, a bribery scandal in Mozambique, and a money laundering case linked to a Bulgarian cocaine network.