When May A Fee Be Divided Under A Fee Sharing Agreement Without Regard To The Proportion Of Services Performed By Each Lawyer?

When each lawyer, by a writing given to the client, assumes joint responsibility for the representation. See, Aiello v. Adar, 193 Misc.2d 649, 750 N.Y.S.2d 457 (Sup. Ct., Bronx Cty, 2002)