[en] We report preliminary results of a search for a heavy neutral gauge boson, Z', using the decay channel Z' → ee . The data were collected with the D0 detector at the Fermilab Tevatron during the 1994-1995 p anti p collider run at √s = 1.8 TeV and correspond to an integrated luminosity of ∼ 90 pb^-1. Limits are set on the cross section times branching ratio for the process anti pp → Z' → ee as a function of the Z' mass. We exclude the existence of a heavy neutral gauge boson of mass less than 660 GeV/c² (95% CL), assuming a Z' with the same coupling strengths to quarks and leptons as the standard model Z boson. Combining this analysis with DO's 1992-1993 data set increases the limit to m_Z' > 670 GeV/c²