The attenuation of 720 MHz transverse acoustic waves has been studied in the metallic glass Pd//0//. //7//7//5Si//0//. //1//6//5Cu//0//. //0//6 at low temperatures. At 0. 062 K the attenuation is found to be intensity-dependent, a behavior already observed in amorphous insulators and explained by the existence of a broad distribution of two-level systems. The temperature variation of the attenuation was measured between 0. 062 K and 1. 5 K at low and high acoustic intensities. It is described by a resonant interaction with two-level sytems plus a relaxation contribution.