Four-wave mixing (FWM) is reported in a multiwavelength laser chip manufactured in an indium phosphide generic technology platform. Measured conversion efficiencies are presented for frequency spacing of 100, 200, and 1700 GHz. The frequencies correspond to pairs of activated channels modulo the free spectral range of the on-chip integrated arrayed waveguide grating-based laser. Observed FWM trends are similar to reported efficiencies in traveling-wave amplifiers.