(Bloomberg) - Credit Suisse Securities LLC sued to block a Financial Industry Regulatory Authority arbitration, arguing that the investors who initiated the claim don’t fit the Finra definition of “customer” required for the dispute- resolution process.

The investors named in the complaint bought exchange traded notes underwritten by Credit Suisse called TVIX, on the secondary market, “through accounts or advisers unaffiliated with Credit Suisse” Credit Suisse said in a complaint filed yesterday in federal court in Baltimore.

Finra rules act “as an agreement to arbitrate only between Finra members and their ‘customers’” and defendants “have never been customers of Credit Suisse,” according to the complaint.

VLS Securities LLC, of Darien, Connecticut, a marketing agent for TVIX, also is a plaintiff in the suit and a respondent, with Credit Suisse, in the arbitration claim.

“The individual investors sued by Credit Suisse and VLS have already received a Finra ruling denying a motion to move their cases outside of Finra,” said Cynthia Moulton, of Moulton & Arney LLP, an attorney for the investors. “We intend to contest Credit Suisse and VLS’s efforts to obtain a different result in federal court.”