  We have studied the modulation instability of obliquely propagating ion
acoustic waves in a collisionless magnetized warm plasma consisting of warm
adiabatic ions and two different species of electrons at different
temperatures. We have derived a nonlinear Schr{\"o}dinger equation using the
standard reductive perturbation method to describe the nonlinear amplitude
modulation of ion acoustic wave satisfying the dispersion relation of ion
acoustic wave propagating at an arbitrary angle to the direction of the
external uniform static magnetic field. We have investigated the correspondence
between two nonlinear Schr{\"o}dinger equations $-$ one describes the amplitude
modulation of ion acoustic waves propagating along any arbitrary direction to
the direction of the magnetic field and other describes the amplitude
modulation of ion acoustic waves propagating along the direction of the
magnetic field. We have derived the instability condition and the maximum
growth rate of instability of the modulated ion acoustic wave. We have seen
that the region of existence of maximum growth rate of instability decreases
with increasing values of the magnetic field intensity whereas the region of
existence of the maximum growth rate of instability increases with increasing
$\cos \theta$, where $\theta$ is the angle of propagation of the ion acoustic
wave with the external uniform static magnetic field. Again, the maximum growth
rate of instability increases with increasing $\cos \theta$ and also this
maximum growth rate of instability increases with increasing $\beta_{e}$ upto a
critical value of the wave number, where $\beta_{e}$ is the parameter
associated with the nonthermal distribution of hotter electron species.
