The new quaternary selenophosphate phases AMP(2)Se(6) (A = Cu, Ag and M = Bi, Sb) were synthesized by ceramic methods at 1023 K. These phases were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX) and a.c. and d.c. electrical conductivity measurements. The phases all show values of electrical conductivity, sigma, of about 10(-4) Omega(-1) cm(-1) at 303 K and photoconductive effect. The conductivity is nearly five orders of magnitude larger than that of related phases. (C) 2003 Elsevier Science Ltd. All rights reserved.