A series of 400 nm thick metal-insulator films of compositions (Co50Fe50)x(Al2O3(100-x) (7 ≤ x ≤ 52; x is in vol.%) are deposited on glass substrates using dual electron beam evaporation technique. The films are nanocrystalline with crystallite sizes of 1-3 nm. Resistivity of the films varies as a function of (I/T)0.5 showing a tunneling type behaviour. The films show isotropic and negative magnetoresistance (GMR). A film of composition (Co50Fe50)82.5(Al2O3)17.5 show maximum tunneling magnetoresistance (TMR) of 7.2% at room temperature and in a magnetic field of 8.2 kOe.