We describe the construction of 2+1-dimensional toplogically massive adS
gravity with N-extended supersymmetry in superspace by means of
introducing a compensating hypermultiplet for the super-Weyl invariance. For
N≥3 the scalar multiplet must be on shell and the potential for
the scalar compensator is completely determined by the geometry. As a
consequence the resulting massive theory has no free parameter for
N≥4. For N=4 we show that this leads to
topologically massive gravity at the chiral point and construct the
corresponding off-shell component action