  The effect of Coulomb and short-range interactions on the spectral properties
of two-dimensional disordered systems with two spinless fermions is
investigated by numerical scaling techniques. The size independent universality
of the critical nearest level-spacing distribution $P(s)$ allows one to find a
delocalization transition at a critical disorder $W_{\rm c}$ for any non-zero
value of the interaction strength. At the critical point the spacings
distribution has a small-$s$ behavior $P_c(s)\propto s$, and a Poisson-like
decay at large spacings.
