  The existence of an additional body around a binary system can be detected by
the help of the light-travel time effect. Due to the motions of binary and the
companion stars around the common mass center of the ternary system, the
light-time effect produces an irregularity on the eclipse timings. Monitoring
the variations in these timings, sub-stellar or planet companions orbiting
around the binary system can be identified. In this paper, additional bodies
orbiting the Algol type binary DI Peg are examined by using the archival
eclipse timings including our CCD data observed at the Ankara University
Kreiken Observatory. More than five hundred minimum times equivalent to around
nine decades are employed to identify the orbital behavior of the binary
system. The best fit to the timings shows that the orbital period of DI Peg has
variation due to an integration of two sinusoids with the periods of $P_3 =
49.50\pm0.36$ yr and $P_4 = 27.40\pm0.24$ yr. The orbital change is thought to
be most likely due to the existence of two M-type red dwarf companions with the
masses of $M_3 =0.213 \pm 0.021$ M$_\odot$ and $M_4 = 0.151 \pm 0.008$
M$_\odot$, assuming that the orbits of additional bodies are co-planar with the
orbit of the binary system. Also, the residuals of two sinusoidal fits still
seem to show another modulation with the period of roughly $P = 19.5$ yr. The
origin of this modulation is not clear and more observational data are required
to reveal if the periodicity is caused by another object gravitationally
bounded to the system.
