Appeal by defendant from a judgment of the County Court, Suffolk County, rendered May 10, 1972, convicting him of attempted arson in the third degree, “ as a class A misdemeanor ”, upon a guilty plea, and sentencing him to a prison term of one year. Judgment reversed, on the law and as a matter of discretion in the interests of justice, and case remitted for all purposes to the County Court for further proceedings not inconsistent herewith. The alleged criminal acts took place on January 13, 1972. All parties assumed and still assume that on that date attempted arson in the third degree was a class A misdemeanor. However, on January 13, 1972, and at the time of the sentence, arson in the third degree was a class C felony (Penal Law, § 150.10). An attempt to commit a class C felony was a class D felony (Penal Law, § 110.05). For a class D felony an indeterminate prison sentence of up to seven years could have been imposed (Penal Daw, § 70.00, subd. 2, par. [d]) or an alternative definite prison sentence of one year or less (Penal Law, § 70.05). The parties apparently relied on section 150.05 of the Penal Law as it read prior to. its amendment by section 5 of chapter 961 of the Laws of 1971 (eff. Sept. 1, 1971). Prior to that amendment arson in the third degree was a class E felony, so that an attempt to commit a class E felony was a class A misdemeanor (Penal Law, § 110.05, subd. 6). It is apparent that the plea and sentence were based on the law as it existed prior to the 1971 amendment and not on the substantive law in effect on the date of the alleged crime. The parties thus overlooked the fact that the 1971 amend*659ment had reduced arson in the third degree to arson in the fourth degree and arson in the second degree to arson in the third degree. Under these circumstances, the guilty plea and the sentence should be vacated' and the case remitted for all purposes to the County Court for further proceedings not inconsistent herewith. Hopkins, Acting P. J., Munder, Christ, Brennan and Benjamin, JJ., concur.