  The Jahn-Teller distortive transition of \lmo is described by a modified
3-state Potts model. The interactions between the three possible orbits depends
both on the orbits and their relative orientation on the lattice. Values of the
two exchange parameters which are chosen to give the correct low temperature
phase and the correct value for the transition temperature are shown to be
consistent with microscopy theory. The model predicts a first order transitions
and also a value for the entropy above the transition in good agreement with
experiment. The theory with the same parameters also predicts the temperature
dependence of the order parameter of orbital ordering agreeing well with
published experimental results. Finally, the type of the transition is shown to
be close to one of the most disordered phases of the generalised Potts model.
The short range order found experimentally above the transition is investigated
by this model.

Strongly Correlated Electrons;Statistical Mechanics