A novel approach to metallocene catalyst heterogenization is presented. Supported metallocenes are obtained by metallation of indenyl-modified silica produced by a nonhydrolytic sol-gel process. The catalytic activities for ethylene polymerization are rather high for supported systems and may reach 190 grams of polyethylene per gram of catalyst per hour per bar. The influence of the preparation and composition of these supported metallocene systems on ethylene polymerizaiton and polyethylene characteristics are reported.