For spacetimes with the topology R x T2, the action of (2 + 1)-dimensi
onal gravity with negative cosmological constant LAMBDA is written uni
quely in terms of the time-independent traces of holonomies around two
intersecting noncontractible paths on T2. The holonomy parameters are
related to the moduli on slices of constant mean curvature by a time-
dependent canonical transformation which introduces an effective Hamil
tonian. The quantisation of the two classically equivalent formulation
s differs by terms of order O(HBAR3), negligible for small \LAMBDA\.