Status report on the development of the primary vertex fast reconstruction

97-04 Fast vertex search algorithm is proposed and described. It relyes upon the geometry of detecting system which surrounds the mean interaction region of LHC proton-proton beams in a barrel region. The detector is simulated and performance of the algorithm has been studied. Vertex resolution can be as good as 150 microns with a finding efficiency above 90Possible hardware implementation is discussed. The decision latency is estimated to be 550 ns.