Gravitational uncertainties from dimension-six operators on supersymmetric GUT predictions.

We consider the gravity-induced dimension-six terms in addition to the dimension-five terms in the SUSY GUT Lagrangian and find that the prediction for {alpha}{sub {ital s}} may be washed out completely in supersymmetric grand unified theories unless the Higgs triplet mass is smaller than 7{times}10{sup 16} GeV.