Small‐signal gains as high as 1.5&percent; cm−1have been measured in a TEA‐CO2amplifier on the 00°2‐ (1001, 0201)I,IIsequence bands. The ratio of the gain coefficient of the sequence bands over the gain coefficient of the regular bands has been observed to be independent of either the CO2or He proportion in the gas mixture. It has also been found to increase with the electrical energy dumped into the active medium and to reach a value of 1/3 at an excitation density of 140 J/l. Gain on the sequence bands has been found to be responsible for the anomalously high gain coefficient that is measured at low J values of theRbranch of the regular 9.4‐&mgr;m transition in TEA amplifiers.