The possibility of using a number of bimetallic complexes of germanium (IV) - zinc / cobalt (II) / nickel (II) / cuprum (II) with hydroxycarboxylic acids as modifiers of unsaturated oligoester in the processes of its copolymerization with methyl methacrylate has been investigated. The modification was carried out by adding the corresponding complex to the reaction mixture during the polycondensation of maleic and phthalic anhydride with ethylene glycol at 175 °C. The kinetics of copolymerization at the initial stages was studied by dilatometry at temperatures from 50 °C to 60 °C. It has been shown that the modified polyglycolmalenatephthalate with the studied complexes can significantly increase the rate and reduce the temperature coefficient of the reaction during its copolymerization with methyl methacrylate. The advantages of the studied coordination compounds as modifiers in comparison with unmodified systems and 1,10-phenanthroline have been proved. The effect of the modifier (1,10-phenanthroline), depending on its content in the modified polyglycolmalenatephthalate, on the kinetic characteristics of copolymerization with methylmethacrylate in the range from 0 to 0.5 mol/L was investigated. The calculations of the influence of the temperature coefficient of reaction on the maximum allowable diameter on the example of a spherical sample when reaching a critical temperature of 90 0C for non-isotremic copolymerization processes. Physico-mechanical characteristics have been studied and it has been shown that the addition of a modifier does not significantly change them.  In addition, germanium (IV) compounds retain a higher oxidation state, which makes it possible to use the finished polymer product as a biological material for special purposes. The proposed methods can be used to improve the characteristics of semi-finished products in the industrial production of copolymer products without significant changes in the technological process.