Exhaust gas treatment system (ATS) for internal combustion engine

Exhaust gas treatment system (ATS) for internal combustion engine, the system being based on an particulate filter (F) unable to retain all the particulate matter, the treatment system comprising a catalyst (C) of the DOC type upstream of the filter (F) according to a direction of the exhaust gas outflow (EG) and means for controlling the injection (ECU) in order to control a predetermined stoichiometric ratio (lambda) of air/fuel, wherein the injection control means (ECU) comprise means for promoting an enrichment of the stoichiometric ration in order to provoke an active regeneration of the particulate matter filter and means for limiting such enrichment, during the active regeneration procedure, acting as a function of a power/torque required to the internal combustion engine.