Bifunctional initiators of group-transfer polymn. (GTP) were prepd. in which two silyl ketene acetal groups are linked by an oligomethylene bridge, either at their C=C double bond or at their alkoxy groups. Their bifunctionality was proven for polymers of Me methacrylate prepd. with initiators of the latter type in THF with Bu4NCN as catalyst. Hydrolysis after complete conversion of monomer yielded chains exhibiting only half of the mol. wt. of the original polymer.