The merger between banks Credit Suisse and UBS could cut up to 36,000 jobs worldwide, the SonntagsZeitung weekly reported Sunday.

The Swiss government hastily arranged the takeover by UBS of Credit Suisse on March 19 to prevent a global financial meltdown, following fears of contagion from the collapse of banks in the United States.

UBS announced Wednesday it would bring back former chief executive Sergio Ermotti to handle the enormous risks involved in the Swiss banking giant's controversial absorption of its troubled rival Credit Suisse.

On Sunday, citing anonymous internal sources, SonntagsZeitung said management was mulling cutting between 20% and 30% of the workforce, meaning between 25,000 and 36,000 jobs.

According to the weekly, up to 11,000 jobs could be cut in Switzerland alone, which did not provide details of which posts could be targeted.

Before the merger, UBS and Credit Suisse had employed slightly over 72,000 and 50,000 people, respectively.

UBS and Credit Suisse, the second-biggest bank in Switzerland, were among the select banks worldwide considered global systemically important financial institutions (G-SIFIs) and therefore deemed too big to fail.

UBS chairperson Colm Kelleher said this week: "There's a huge amount of risk in integrating these businesses."

Credit Suisse was embroiled in a series of scandals leading up to a March 15 share price collapse when investor confidence plunged following two bank failures in the U.S.

Among these were the bankruptcy of the British financial company Greensill and the implosion of the U.S. hedge fund Archegos.

It was also caught up in a bribery scandal involving loans to state-owned companies in Mozambique. In addition, it was fined $2 million in a money laundering case linked to a Bulgarian cocaine network.

Boardroom shake-up

Meanwhile, Norges Bank Investment Management will vote against the re-election of Credit Suisse Chair Axel Lehmann and six other directors at the Swiss lender's annual general meeting on Tuesday, the Norwegian wealth fund said on its website.

"Shareholders should have the right to seek changes to the board when it does not act in their best interest," the Norges wealth fund said ahead of the April 4 meeting.

Besides Lehmann, Norges opposes the re-election of Credit Suisse directors Iris Bohnet, Christian Gellerstad, Shan Li, Seraina Macia, Richard Meddings and Ana Pessoa.

Credit Suisse declined to comment, and UBS did not immediately respond to a request for comment.