Dielectric properties of 0.4PbZn(1/3)Nb(2/3)O(3)-0.3PbSc(1/2)Nb(1/2)O(3)-0.3PbMg(1/3)Nb(2/3)O(3)-(0.4PZN-0.3PSN-0.3PMN) ceramics are presented for 200 < T < 500 K and 20 Hz < nu < 1 MHz. Dielectric constant is very high (more 14000) in the vicinity of the peak. Anomalous broad dielectric relaxation have been observed near the temperature of the maximum permittivity, T-m (at 1 kHz). External bias field considerably lowers the value of dielectric losses at low frequencies due to decrease of polar nano regions contribution to the dielectric permittivity.