An extension of the standard model, where the usual scalar doublet is
replaced by a dimension 2N + 1 multiplet, is studied in the limit of l
arge N. We determine the physical mass of the Higgs and the S, T and U
parameters to leading order in this limit. We also consider the scatt
ering of scalar particles and argue that it leads to an attractive int
eraction between scalars whose charge difference is O(N).