(Reuters) - Some holders of Credit Suisse Group AG's so-called additional tier 1 (AT1) bonds have approached a law firm to assess whether they have a case against the Swiss authorities' decision to wipe out their holdings as part of the UBS Group AG deal.

George Zelcs and Chris Burke, partners at Korein Tillery, a boutique law firm specializing in complex litigation, said fewer than a dozen non-U.S. bondholders had approached them to discuss options. The firm has not yet been hired.

Their discussions come after law firm Quinn Emanuel Urquhart & Sullivan separately said on Monday it was in discussions with Credit Suisse AT1 bondholders representing a "significant percentage" of the total notional value of the instruments.

Neither firm named the bondholders.

Switzerland's Federal Department of Finance said it would not comment on a hypothetical situation.

Korein lawyers are examining the language of the AT1 bond contracts and whether regulators have the authority to wipe out the bonds without first doing the same for equities, the lawyers said.

(Reporting by Laura Matthews; additional reporting by Noele Illien; Editing by Chizu Nomiyama)

By Laura Matthews