  Here the effect of rotation up to third order in the angular velocity of a
star on the p, f and g modes is investigated. To do this, the third-order
perturbation formalism presented by Soufi et al. (1998) and revised by Karami
(2008), was used. I quantify by numerical calculations the effect of rotation
on the oscillation frequencies of a uniformly rotating $\beta$-Cephei star with
12 $M_\odot$. For an equatorial velocity of 90 $\rm km s^{-1}$, it is found
that the second- and third-order corrections for $(l,m)=(5,-4)$, for instance,
are of order of 0.07% of the frequency for radial order $n=-3$ and reaches up
to 0.6% for $n=-20$.
