In EOS Partners v. Levine (NY Slip Op 31853U, Sup Ct, NY County, June 21, 2007, Fried, J., Index No. 601530/05), the court discussed both the attorney-client privilege and the common interest privilege, and the interplay between the two.
Addressing the attorney-client privilege first, the court staetd:
The attorney-client privilege, codified in CPLR § 4503(a), generally prohibits counsel from disclosing confidential communications from a client seeking legal advice.
The party invoking the privilege has the burden of showing that it applies (People v. Osorio, 75 NY2d 80, 84, 549 N.E.2d 1183, 550 N.Y.S.2d 612 1989).
Because the privilege has the effect of withholding relevant information from the fact finder, it applies only where necessary to achieve its purpose and protect from disclosure confidential communications between client and counsel (e.g., Stenovich v. Wachtell, 195 Misc2d 99, 106, 756 N.Y.S.2d 367 Sup Ct NY County 2003).
Courts have recognized that at times "the public interest is served by shielding certain communications ... from litigation, rather than risk stifling them altogether."
The privilege requires that the communications are made for "the purpose of facilitating the rendition of legal advice or services in the course of a professional relationship and have been primarily or predominantly of a legal rather than a commercial nature" (U.S. Bank Natl. Assn. v. APP Intl. Finance Co., 33 AD3d 430, 430, 823 N.Y.S.2d 361 1st Dept 2006).
The court, in EOS, then proceeded to explain the common interest privilege, stating:
New York courts have recognized a "conditional, or qualified, privilege to a communication made by one person to another upon a subject in which both have an interest known as the common interest privilege" (U.S. Bank Natl. Assn., 33 AD3d at 430).
The common interest privilege protects certain communications to third parties who would otherwise waive the attorney-client privilege (See US v. Schwimmer, 892 F2d 237, 243 2nd Cir 1989; Strougo v. Bea Assocs., 199 FRD 515, 520 SD NY, 2001).
The rationale is that as long as "the privilege is not abused, the flow of information between persons sharing a common interest should not be impeded" (Liberman v. Gelstein, 80 NY2d 429, 437, 605 N.E.2d 344, 590 N.Y.S.2d 857 1992).