We investigate the correlation between the bulge effective radius (r_e) and disk scale length (r_d), in the near-infrared K band for lenticular galaxies in the field and in clusters. We find markedly different relations between the two parameters as a function of luminosity. Lenticulars with total absolute magnitude fainter than M_T = -24.5 show a positive correlation, in line with predictions of secular formation processes for the pseudo bulges of late-type disk galaxies. But brighter lenticulars with M_T < -24.5 show an anti-correlation, indicating that they formed through a different mechanism. The available data are insufficient to reliably determine the effect of galaxy environment on this correlation.

Accepted for publication in ApJ Letters, 4 pages, 3 figures; minor typos are corrected