Lawyers from Switzerland, the United States and UK are talking to a number of Credit Suisse Additional Tier 1 (AT1) bond holders about possible legal action after the state-backed rescue of Credit Suisse by UBS wiped out AT1 bonds, law firm Quinn Emanuel Urquhart & Sullivan said Monday.

Quinn Emanuel said it was in discussions with Credit Suisse AT1 bondholders representing a "significant percentage" of the total notional value the instruments. Quinn Emanuel did not name the bondholders.

Under the UBS-Credit Suisse merger deal, holders of Credit Suisse AT1 bonds will get nothing, while shareholders, who usually rank below bondholders in terms of who gets paid when a bank or company collapses, will receive $3.23 billion.

In Switzerland, the bonds' terms state that in a restructuring, the financial watchdog is under no obligation to adhere to the traditional capital structure hierarchy, which is how Credit Suisse AT1 bondholders lost out.

Funds managed by Lazard Asset Management, PIMCO and GAM Investments were among the most exposed as of end-February to Credit Suisse AT1 debt in terms of portfolio weighting, leaving them potentially vulnerable to losses from the bond write-off, based on Morningstar data seen by Reuters.

PIMCO had 3.49% of its 5.66 billion euro ($6.06 billion) GIS Capital Securities Fund in Credit Suisse AT1 bonds, the Morningstar data showed.

PIMCO did not immediately respond to a request for comment when asked about the AT1 holding and also the potential legal action.

Lazard Asset Management had 7.4% of its 1.45 billion euro Lazard Capital Fi SRI fund allocated to Credit Suisse AT1 debt.

Lazard Asset Management also did not respond to a request for comment on its holding or the possible legal action.

GAM's 1.15 billion euro Star Credit Opportunities fund's exposure to Credit Suisse AT1 debt was 4.81% at the end of last month, based on the Morningstar data.

GAM declined to comment.

A call for bondholders is likely to be convened on Wednesday, March 22, Quinn Emanuel said.

The Credit Suisse rescue has caused turmoil in European markets, with banks' bond prices under pressure as investors focus on the potential risks of holding AT1 bonds.

European regulators said on Monday they would continue to impose losses on shareholders before bondholders in a bid to calm investor nerves following the fallout of the AT1 decision in Switzerland. ($1 = 0.9333 euros)