Mass-to-Light Ratios of Galaxy Groups from Weak Lensing**Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

We present the findings of our weak-lensing study of a sample of 116 CNOC2 galaxy groups. The lensing signal is used to estimate the mass-to-light ratio of these galaxy groups. The best-fit isothermal sphere model to our lensing data has an Einstein radius of 0.″88 ± 0.″12, which corresponds to a shear-weighted velocity dispersion of 245 ± 18 km s-1. The mean mass-to-light ratio within 1 h-1 Mpc is 185 ± 28 h M☉ L and is independent of radius …