  We explore the dark matter and LHC implications of t-b-tau quasi Yukawa
unification in the framework of supersymmetric models based on the gauge
symmetry G=SU(4)_{c}\times SU(2)_{L}\times SU(2)_{R}. The deviation from exact
Yukawa unification is quantified by a dimensionless parameter C (|C| <~ 0.2),
such that the Yukawa couplings at M_GUT are related by y_t:y_b:y_tau=|1+C| :
|1-C| : |1+3C|. In contrast to earlier studies which focused on universal
gaugino masses, we consider non-universal gaugino masses at M_GUT that are
compatible with the gauge symmetry G. We perform two independent scans of the
fundamental parameter space, one of which employs ISAJET, while the other uses
SoftSusy interfaced with SuperIso. These scans reveal qualitatively similar
allowed regions in the parameter space, and yield a variety of neutralino dark
matter scenarios consistent with the observations. These include stau and
chargino coannihilation scenarios, the A-resonance scenario, as well as
Higgsino dark matter solution which is more readily probed by direct detection
searches. The gluino mass is found to be <~ 4.2 TeV, the stop mass is >~ 2 TeV,
while the first two family squarks and sleptons are of order 4-5 TeV and 3 TeV
respectively.
