Measurement of the decay probability K"L -> 2π^o

Using the 180-liter ITEP liquid xenon bubble chamber we have measured the branching ratio Γ(K"L -> 2 π^o)/Γ(K"L -> 3 π^o) to be (3.7 +/- 0.8) x 10^-^3. We find η"o"o to be (2.02 +/- 0.23) x 10^-^3.