  We study the hadron-quark phase transition in the interior of neutron stars
(NS). For the hadronic sector, we use a microscopic equation of state (EOS)
involving nucleons and hyperons derived within the Brueckner-Bethe-Goldstone
many-body theory, with realistic two-body and three-body forces. For the
description of quark matter, we employ both the MIT bag model with a density
dependent bag constant, and the color dielectric model. We calculate the
structure of NS interiors with the EOS comprising both phases, and we find that
the NS maximum masses are never larger than 1.7 solar masses, no matter the
model chosen for describing the pure quark phase.
