Measurement of the branching ratio Γ(K L -->π + π - )Γ(K L -->all)

We have measured the branching ratio GAMMA (K/sub L/ ..-->.. ..pi../sup +/..pi../sup -/)/GAMMA (K/sub L/ ..-->.. all) to be (2.01 +- 0.09) x 10/sup -3/. This value is in good agreement with other recent determinations of this branching ratio and yields a value for the CP-violating parameter eta/sub + -/ of (2.25 +- 0.05) x 10/sup -3/.