The trigger system of the ALICE dimuon arm is based on Resistive Plate Cham
bers (RPC). Besides a short description of the trigger system, the test res
ults of a RPC prototype with electrodes made of low resistivity bakelite (s
imilar or equal to 3.10(9) Omega.cm) are presented. Rate capability, time r
esolution and cluster size have been measured for the RPC operated both in
streamer and in avalanche mode. Although the rate capability is obviously h
igher in avalanche mode (few kHz/cm(2)), remarkable results have been achie
ved even in streamer mode (several hundreds of Hz/cm(2)).