We study the theory of scattering for a class of Hartree type equations wit
h long range interactions in space dimension n greater than or equal to 3,
including Hartree equations with potential V(x) = lambda\x\(-gamma) with ga
mma < 1. For 1/2 < gamma < 1 we prove the existence of modified wave operat
ors with no size restriction on the data and we determine the asymptotic be
haviour in time of solutions in the range of the wave operators.