N = 8 supergravity breaks down to N = 1

The field equations of N = 1 supergravity in d = 11 dimensions admit a spontaneous compactification on the seven-sphere to an N = 8 theory in d = 4 with local SO(8) invariance. A spontaneously broken version of this theory is provided by another solution of the field equations for which the metric on S/sup 7/ is distorted. The isometry group of this new solution is SO(5)xSU(2), the relevant holonomy group is G/sub 2/, and the N = 8 supersymmetry is broken down to N = 1 at the Planck scale. The implications for grand unified theories are briefly discussed.