We describe here the implementation of methylene-bridged binuclear “constrained geometry catalyst”(μ-CH2-3, 3'){(η5-indenyl)[1-Me2Si (t BuN)](ZrMe2)} 2 (C1-Zr2) to produce high-M w branched polyethylene. In ethylene homopolymerization,~ 70× increases in molecular weight are achieved with (C1-Zr2) vs (μ-CH2CH2-3, 3'){(η5-indenyl)[1-Me2Si (t BuN)](ZrMe2)} 2 (C2-Zr2) under identical polymerization conditions using (Ph3C+) 2 [1, 4- ...