  This paper presents a novel method for the reconstruction of interaction
vertices in particle collision data. The algorithm is an agglomerative
clustering technique designed for high-luminosity environments in current and
future proton-proton colliders. Studies are presented in benchmark scenarios
reproducing the LHC data-taking conditions and showing the performance as a
function of the number of interactions per bunch crossing. Particular focus
will be given to the foreseen data-taking conditions at the Run 3 of the LHC.
The proposed algorithm is found to significantly improve the position
resolution on the hard-scatter interaction by limiting the contamination of
tracks from additional interactions in the vertex fit.
