We present here results of experiments where low energy electrons are attached to medium-sized benzene clusters. Out of the various fragments observed in the mass spectrometer the most intriguing is the weak albeit unequivocal occurrence of a C6H-6 moiety. Since the gas phase benzene radical anion is not electronically stable, we propose here – based on electronic structure calculation – that this moiety actually corresponds to linear structures formed by opening of the benzene ring via electron attachment.