We investigate a supersymmetric extension of the W3 algebra, which is common to a c = 4 free fermion model and to the generic c < 4 supersymmetric coset models based on (A2(1) + A2(1), A2(1) at level (3, m). By using the so-called character technique, we identify a set of eight generating supercurrents of this algebra. For m = 1, corresponding to c = 10/7, the algebra reduces to the "minimal" super W3 algebra, which has been studied previously.