22 NYCRR Part 1200
New York Rules of Professional Conduct on conflicts of interest
Rule 1.7 · Conflict of Interest: Current Clients
(a) Except as provided in paragraph (b), a lawyer shall not represent a client if a reasonable lawyer would conclude that either:
(1) the representation will involve the lawyer in representing differing interests; or
(2) there is a significant risk that the lawyer's professional judgment on behalf of a client will be adversely affected by the lawyer's own financial, business, property or other personal interests.
(b) Notwithstanding the existence of a concurrent conflict of interest under paragraph (a), a lawyer may represent a client if:
(1) the lawyer reasonably believes that the lawyer will be able to provide competent and diligent representation to each affected client;
(2) the representation is not prohibited by law;
(3) the representation does not involve the assertion of a claim by one client against another client represented by the lawyer in the same litigation or other proceeding before a tribunal; and
(4) each affected client gives informed consent, confirmed in writing.
Source: 22 NYCRR 1200.0, Rule 1.7 (Cornell Legal Information Institute)
Rule 1.9 · Duties to Former Clients
(a) A lawyer who has formerly represented a client in a matter shall not thereafter represent another person in the same or a substantially related matter in which that person's interests are materially adverse to the interests of the former client unless the former client gives informed consent, confirmed in writing.
(b) Unless the former client gives informed consent, confirmed in writing, a lawyer shall not knowingly represent a person in the same or a substantially related matter in which a firm with which the lawyer formerly was associated had previously represented a client:
(1) whose interests are materially adverse to that person; and
(2) about whom the lawyer had acquired information protected by Rules 1.6 or paragraph (c) of this Rule that is material to the matter.
(c) A lawyer who has formerly represented a client in a matter or whose present or former firm has formerly represented a client in a matter shall not thereafter:
(1) use confidential information of the former client protected by Rule 1.6 to the disadvantage of the former client, except as these Rules would permit or require with respect to a current client or when the information has become generally known; or
(2) reveal confidential information of the former client protected by Rule 1.6 except as these Rules would permit or require with respect to a current client.
Source: 22 NYCRR 1200.0, Rule 1.9 (Cornell Legal Information Institute)
Rule 1.10(a) · Imputation of Conflicts of Interest
(a) While lawyers are associated in a firm, none of them shall knowingly represent a client when any one of them practicing alone would be prohibited from doing so by Rule 1.7, 1.8 or 1.9, except as otherwise provided therein, unless:
(1) the prohibition is based on a lawyer's own financial, business, property or other personal interests within the meaning of Rule 1.7(a)(2); and
(2) under the circumstances, a reasonable lawyer would conclude that there is no significant risk that the representation will be materially limited or that the independent professional judgment of the participating lawyers in the firm will be adversely affected.
Source: 22 NYCRR 1200.0, Rule 1.10 (Cornell Legal Information Institute) · Official text: NY Courts, Part 1200 (PDF)