In an action on a contract, plaintiff appeals from so much of a judgment of the Supreme Court, Nassau County, entered December 10, 1974, as is in favor of defendants, after a nonjury trial. Judgment affirmed insofar as appealed from, with costs. The agreement between the parties was ambiguous as to whether interest at the rate of 10% should be calculated only on the principal, or on the principal plus the previously accumulated interest. Parol evidence was properly admissible because of this ambiguity. The parol evidence was entirely consistent with the written agreement and supportive of that construction urged by the defendants. Martuscello, Acting P. J., Cohalan, Rabin and Mollen, JJ., concur.