The rotationally resolved infrared spectrum of the v(3) fundamental band of the long-lived (a) over tilde $ (1)Delta electronic state of the CCO radical has been measured between 1030 and 1105 cm(-1) using a tunable diode laser spectrometer. Metastable CCO was produced in a discharge through a flowing mixture of carbon suboxide and helium. Forty-six rovibrational transitions in the P- and R-branches and the four lowest J-lines in the Q-branch were measured. The band origin was determined to be 1082.03134(19) cm(-1). In addition, 40 rovibrational lines belonging to the 3v(3)-2v(3) band of the ground electronic state were measured. The band origin for 3v(3)-2v(3) was determined to be 1056.97894(94) cm(-1). The measurements in this band together with previously reported frequencies in the C-C and C-O stretching regions were analyzed to determine harmonic frequencies and anharmonicity constants. (C) 2004 Published by Elsevier B.V.