In Matthius v. Platinum Estates, Inc. (74 AD3d 908, 903 NYS2d 477 [2d Dept 2010]), extrinsic evidence was admissible because the agreement contained a general provision requiring insurance.
"Therefore, evidence of the indemnification agreement, which contained specific provisions regarding the amount of insurance to be provided and the parties to be insured, was admissible to resolve these ambiguities." (Id. at 909.)
However, the court observed that the indemnification agreement also "did not vary, alter, or contradict any terms" of the other agreement and remained enforceable. (Id.)