Asymptotic Statistical Properties of Redescending M-estimators in Linear   Models with Increasing Dimension
  This paper deals with the asymptotic statistical properties of a class of redescending M-estimators in linear models with increasing dimension. This class is wide enough to include popular high breakdown point estimators such as S-estimators and MM-estimators, which were not covered by existing results in the literature. We prove consistency assuming only that $p/n \rightarrow 0$ and asymptotic normality essentially if $p^{3}/n \rightarrow 0$, where $p$ is the number of covariates and $n$ is the sample size. 
Ezequiel Smucler
math.ST stat.TH