We studied the α-relaxation in ortho-terphenyl (OTP) by photon correlation spectroscopy (PCS) at temperatures (250 K < T <270 K) below the crossover temperature T_c. We found the following. Contrary to the mode-coupling theory prediction, the non-ergodicity parameter f_c is temperature independent, which might be due to a strong orientational scattering in OTP. The stretched exponent β_k decreases as temperature decreases, and the relaxation time τ(T) obeys the Vogel-Fulcher law. In the short-time limit of PCS measurement (t ~ 0.1 µs), no decaying process (neither the Johari-Goldstein β-relaxation nor the critical decay) was observed.