  We describe a catalogue of gamma-ray source candidates, selected using the
Minimum Spanning Tree (MST) algorithm on the 9-years Fermi-LAT sky (Pass 8) at
energies higher than 10 GeV. The extragalactic sky at absolute Galactic
latitudes above 20 degrees has been investigated using rather restrictive
selection criteria, resulting in a total sample of 1342 sources. Of these, 249
are new detections, not previously associated with gamma-ray catalogues. A
large fraction of them have interesting counterparts, most likely blazars. In
this paper the main results on the catalogue selection and search of
counterparts are reported.
