In this paper we introduce and study two new subclasses \Sigma_{\lambda\mu
mp}(\alpha,\beta)and\Sigma^{+}_{\lambda\mu mp}(\alpha,\beta)ofmeromorphicallymultivalentfunctionswhicharedefinedbymeansofanewdifferentialoperator.Someresultsconnectedtosubordinationproperties,coefficientestimates,convolutionproperties,integralrepresentation,distortiontheoremsareobtained.Wealsoextendthefamiliarconceptof%
(n,\delta)-$neighborhoods of analytic functions to these subclasses of
meromorphically multivalent functions