Abstract: A process for the preparation of substantially linear, highly polymerized polyesters by polycondensing a glycol ester of an aromatic dicarboxylic acid and/or a low molecular weight condensate thereof, the process being characterized by using as a polycondensation catalyst a preformed titanate compound obtained by reacting a titanic acid ester represented by the formula Ti(OR).sub.4, where R is an alkyl group having from 1 to 5 carbon atoms, with an aromatic acid selected from the group consisting of trimellitic acid, trimellitic anhydride, hemimellitic acid, hemimellitic anhydride or a mixture of one or more thereof at a molar ratio of from about 0.5 to about 2.5 mols of the aromatic acid per 1 mol of the titanic acid ester, to thereby form polyesters which have a high softening point and good color tone. SUBACKGROUND OF THE INVENTION1.