  We discuss some possible signals of CPT violation in the $B_s$ system that
may be probed at the Large Hadron Collider (LHC). We show how one can construct
combinations ofobservables coming from tagged and untagged decay rates of
$B_s\to D_s^\pm K^\mp$ that can unambiguously differentiate between CPT
violating and CPT conserving new physics (NP) models contributing in $B_s-\bar
B_s$ mixing. We choose this particular mode as an illustrative example for two
reasons: (i) In the Standard Model, there is only one decay amplitude, so it is
easier to untangle any new physics; (ii) $B_s$ being a neutral meson, it is
possible to unambiguously identify any sign of CPT violation that occurs only
in mixing but not in decay. We define an observable which is useful to extract
the CPT violating parameter in $B_s$ decay, and also discuss how far the
results are applicable even if CPT violation is present in both mixing and
decay.
