A bank and its affiliated broker-dealer (plaintiffs) recently initiated suit in federal district court to enjoin a hedge fund and its manager (defendants) from continuing to pursue a Financial Industry Regulatory Authority, Inc. (FINRA) arbitration claim initiated against them.  Among other things, the plaintiffs contend that the defendants were not “customers” of the broker-dealer affiliate, and were not required to submit to FINRA arbitration.  FINRA Rule 12200 requires FINRA members to arbitrate disputes, in the absence of a written agreement, if requested by “customers.”  The court’s ultimate determination as to who constitutes a “customer” will likely impact the availability of this alternative dispute resolution mechanism for hedge funds and their managers looking to assert legal claims against FINRA members.  This article summarizes the factual allegations, arguments and relief sought by the plaintiffs in their complaint.  See also “How Hedge Fund Managers Can Use Arbitration Provisions to Prevent Investor Class Action Lawsuits,” Hedge Fund Law Report, Vol. 5, No. 26 (Jun. 28, 2012).