  An exact conformal field theory describing a four dimensional singular string
background is obtained by chiral gauging a $U(1)$ subgroup along with
translations in $R$ of an $SL(2,R)\times R$ Wess-Zumino-Witten model. It is
shown that the target space-time describes a four dimensional black membrane.
Furthermore various duality transformed solutions are constructed. These are
also shown to correspond to various forms of four dimensional black membranes.
