In nonpolar solvents, , -alkaline and -alkaline-earth dicarboxylatopolybutadiene (Mn 4600) leads to gel formation at concentrations as low as 1.5 g dL_1. However, any polar additive, i.e., water or alcohol, has a depressive effect on the metal-carboxylate association and the resulting gelation. The use of group 4 metal ions is an efficient way to overcome this drawback. Cross-linking of the car boxy-telechelic polymer is then promoted by a group 4 metal (Ti, Zr, Ce) alkoxide used in excess vs. the acid end groups. When the unreacted alkoxide groups are hydrolyzed into metal oxoalkoxide groupings, the gelation occurs in the presence of the alcohol formed as a byproduct and the required humidity of the medium. Cross-linking efficiency depends on the size of the group 4 cation just like in the series of alkaline and alkaline-earth cations. The deformation mechanism is controlled by the stability of the metal-carboxylate bonds and by the mean number of chain ends attached to the metal oxide aggregates. In this respect, excess alkoxide is a key parameter to impart to the solutions a broader range of rheological properties. Viscous solutions are observed at a metal-to-chain molar ratio of 0.5, whereas increasing excess of metal alkoxide is responsible for a shear-thickening behavior and finally for elastic gels.