LONDON, England: A group of Credit Suisse investors, claiming billions of dollars in losses during the recent UBS takeover, have sued Swiss financial regulators.

In court, the investors have challenged an order by the Swiss Financial Market Supervisory Authority, or FINMA, that saw the erasure of $17.3 billion in higher-risk Credit Suisse bonds when UBS assumed ownership of the troubled Credit Suisse bank.

The $3.25 billion deal prevented the closing of Switzerland's second-largest bank, Credit Suisse, after customers sought to withdraw deposits after the bank's stock plunged.

"FINMA's decision undermines international confidence in the legal certainty and reliability of the Swiss financial center," said Thomas Werlen, of Quinn Emanuel Urquhart & Sullivan, as quoted by the Associated Press.

"We are committed to rectifying this decision, which is not only in the interests of our clients, but will also strengthen Switzerland's position as a key jurisdiction in the global financial system," Werlen said in a statement.