A study of ethene solution polymerization with the rac-dimethylsilylbis(indenyl)-zirconium dichloride/methylaluminoxane catalyst system in a high-temperature (140 degreesC), continuously stirred tank reactor system was carried out. C-13 NMR, gel permeation chromatography, Fourier transform infrared, and rheological measurements were used for polymer analyses. Polyethylenes with low molecular weights (weight-average molecular weight approximate to 35-55 kg/mol) and small amounts of methyl, ethyl, and long-chain branching were produced. 13 C NMR measurements showed that the long-chain and methyl branches increased and that the ethyl branch contents decreased with decreasing monomer concentrations. At high monomer concentrations, the chain transfer to the coordinated monomer was concluded to be the predominant chain termination mechanism, whereas the chain transfer to aluminum was dominant at low monomer concentrations, which was evidenced by the fact that the selectivity of end groups was reduced to about 50%.