Based on one million reconstructed $\Omgea^- \to \Lambda^0 + K^-$ events
in the Fermilab HyperCP (E871) experiment, we have measured the product of
decay parameters $\alpha_{\Omega}\alpha_{\Lambda}$ and have extracted a
small but not zero value of $\alpha_{\Omega}$. Our result is consistent
with the predictions that the $\Omgea^- \to \Lambda^0 + K^-$ decay is
dominated by the parity-conserving transition.