  In the present investigation, we consider two new subclasses
N_{{\Sigma}}^{{\mu}}({\alpha},{\lambda}) and
N_{{\Sigma}}^{{\mu}}({\beta},{\lambda}) of bi-univalent functions defined in
the open unit disk U={z:|z|<1}. Besides, we find upper bounds for the second
and third coefficients for functions in these new subclasses.
