Direct nucleophilic addition of -OH groups on the C(60) skeleton in the basic hydrolysis of ethyl ester of T(h)-symmetric fullerenehexamalonic acid (T(h)-FHMA), leading to the formation of a hybrid with features of T(h)-FHMA and fullerenol, has been observed as an important side reaction. The hydroxylation takes place at considerably milder conditions as those usually used in the synthesis of C(60) fullerenols. UV/Vis and IR spectroscopy were successfully used as a fast monitoring tool which might be of help also in other investigations where additions on C(60) skeleton of molecules with distinct absorption spectra take place.