The U-L_III EXAFS spectra of colloidal suspensions og hydroxyaluminosilicate (HAS) formed by co-precipitation of silicic acid with dissolved aluminum ions in the presence of added U(VI) are investigated. Data analysis shows the average U-Si distance of 3.3 Å to be comparable to that observed in uranyl-silicate minerals: soddyte or uranophane (3.12-3.2 Å) and boltowoodite (3.5-3.6 Å). Similar to our earlier EXAFS work on Eu(III) incorporation into silica and HAS colloids, strong U-Si interaction is observed, indicated by a relatively large total N(Si) of ~ 3.