By Pablo Mayo Cerqueiro, Chiara Elisei and Davide Barbuscia
LONDON/NEW YORK (Reuters) - Credit Suisse said 16 billion Swiss francs ($17.24 billion) of its Additional Tier 1 debt will be written down to zero on the orders of the Swiss regulator as part of its rescue merger with UBS, angering bondholders on Sunday.
FINMA, the Swiss regulator, said the decision would bolster the bank's capital. The move reflects authorities' desire to see private investors share the pain from Credit Suisse's troubles.
Chair Marlene Amstad said FINMA had stuck to the country's "too-big-to-fail" banking framework in making the decision.
It means AT1 bondholders appear to be left with nothing while shareholders, who sit below bonds in the priority ladder for repayment in a bankruptcy process, will receive $3.23 billion under the UBS deal.
Engineered in the wake of the global financial crisis, AT1 bonds are a form of junior debt that counts towards banks' regulatory capital. They were designed as a way to transfer risks to investors and away from taxpayers if a bank gets into trouble.
The bonds can be converted into equity or written down when a lender's capital buffers are eroded beyond a certain threshold.
"It's stunning and hard to understand how they can reverse the hierarchy between AT1 holders and shareholders," said Jerome Legras, head of research at Axiom Alternative Investments, an investor in Credit Suisse's AT1 debt.
Reuters reported earlier on Sunday that Swiss authorities were considering imposing losses on bondholders as part of the rescue deal.