The tetrathiane ring of the title compound, C26H4, phenosize S4, has a chair conformation and the molecule has approximate C2 symmetry. Each of the two _uorene ring systems is virtually planar, with the ring planes intersecting at an angle of 67.58 (5)degrees. This novel compound has been formed as a side product from the treatment of 9H-fluorene-9-thione with methyl N-[(benzylidene)phenyl]glycinate in the presence of LiBr and 1,6-diazabicyclo[5.4.0]undecane.