The critical behaviour of a spin-I system made up of weakly coupled ch
ains is analyzed by the linear chain approximation, which first uses t
he transfer matrix method to find the exact solution of the linear cha
in and then the Bogolubov variational principle to determine the free
energy of the overall system. The model Hamiltonian is a BEG-like with
dipolar and quadrupolar couplings and a single-ion anisotropy term. T
he system is investigated for several ratios of interchain and intrach
ain interaction terms. A detailed analysis of the role of the intercha
in terms in the reentrant phenomenon is performed.