The infrared absorption spectrum of the NO-Ar complex is measured in the region of the first NO overtone band using a new type of IR-UV double resonance technique which combines IR excitation with (2 + 1) resonance enhanced multiphoton ionization detection. The long lifetime of the complex(greater than or equal to 30 ns) allows the sensitive detection of the vibrationally excited complex itself. Two bands corresponding to Delta P = 0 and Delta P = +1 transitions are observed at 3723.4 and 3727.4 cm(-1) The rotational analysis is based on a rigid rotor model Hamiltonian and yields the rotational constants A' = 1.795(5) cm(-1) B' = 0.0785(2) cm(-1), and C' = 0.0615(1) cm(-1). The observed splitting of rotational lines is consistent with an increased quenching constant zeta' = 4.0(5) cm(-1).