  We construct a supersymmetric SO(10) model with the asymptotic relation
tan$\beta \simeq m_t/m_b$ automatically arising from its structure. The model
retains the significant Minimal Supersymmetric Standard Model predictions for
$sin^2 \theta_w$ and $\alpha_s$ and contains an automatic $Z_2$ matter parity.
Proton decay through $d=5$ operators is sufficiently suppressed. It is
remarkable that no global symmetries need to be imposed on the model.

High Energy Physics - Phenomenology