Topological conformal field theories based on superconformal current algebras
are constructed. The models thus obtained are the supersymmetric version of the
G/G coset theories. Their topological conformal algebra is generated by
operators of dimensions 1, 2 and 3 and can be regarded as an extension of
the twisted N=2 superconformal algebra. These models possess an extended
supersymmetry whose generators are exact in the topological BRST cohomology.Comment: 16 pages, phyzzx, US-FT-11/9