  We investigate the properties of the electron spin-transmission through an
Aharonov-Bohm interferometer with an embedded multilevel quantum dot containing
magnetic impurities. A suitable formalism is developed. The amplitude and the
phase of the flip- and nonflip-transmittance are calculated numerically as
function of the magnetic field and the gate potential applied on the dot. The
effects induced by the exchange interaction to spin-dependent
magnetoconductance fluctuations and transmittance phase are shown.
