(Geneva) A group of holders of high-risk Credit Suisse bonds whose debts were erased during the takeover by its rival UBS is suing the Swiss stock market policeman, their lawyers revealed on Friday.

Swiss authorities demanded that 16 billion Swiss francs ($17.9 billion) of bonds be written off in the mega-merger of the country’s two largest banks, announced in March.

The order of the Swiss Financial Market Supervisory Authority (Finma) has angered bondholders, who are in principle better protected than shareholders.

The latter did not lose everything in the case, although they saw the value of their assets fall. They will receive around three billion Swiss francs, or 0.76 francs per share, compared to a last closing price of 1.86 francs before the announcement of the agreement.

The group of Swiss and international investors who sued Finma collectively bear more than a quarter of the erased debt, or 4.5 billion Swiss francs.

Law firm Quinn Emanuel filed a formal complaint on Tuesday at the Federal Administrative Court in St. Gallen, in northeastern Switzerland, a spokesperson told AFP.

“Finma’s decision undermines international confidence in the legal certainty and reliability of the Swiss financial center,” said Thomas Werlen, the firm’s managing partner in Switzerland.

This filing is only “the first in a series of steps we will take to seek redress for our clients who have been unlawfully deprived of their property rights,” said Richard East, senior partner at Quinn Emanuel’s office. in London.

Other lawsuits for the same reason are also underway in Switzerland and other countries.

The relevant securities, called “AT1 bonds”, were created after the 2008 global financial crisis to place the burden of losses on investors rather than taxpayers.