We consider multisoliton patterns in the model of a synchronously pump
ed fiber-loop resonator. An essential difference of this system from i
ts long-line counterpart is that, due to the finite length, dynamical
regimes may be observed that would be unstable in the infinitely long
line. For the case when the effective instability gain, produced by co
mpetition of the modulational instability (MI) of the flat background
and losses, is small, we have consistently derived a special form of t
he complex Ginzburg-Landau equation for a perturbation above the conti
nuous wave (cw) background. It predicts bound states of pulses with a
uniquely determined ratio of the pulse width to the separation between
them. Direct numerical simulations have produced regular soliton latt
ices at small values of the feeding pulse power, and irregular pattern
s at larger powers. Evidence for a phase transition between the lattic
e and gas phases in the model is found numerically. At low power, the
width-to-separation ratio as found numerically proves to be quite clos
e to the analytically predicted value. We also compare our results wit
h recently published experimental observations of MI-stimulated format
ion of a pulse away in a mode-locked fiber laser.