The present invention relates to a specific functionalized diene elastomer. This functionalized elastomer exhibits a reduced cold flow without, however, damaging the properties of a reinforced rubber composition in which it is present, in particular the processing properties and the hysteresis properties. This functionalized diene elastomer carries, at the chain end, a silanol functional group or a polysiloxane block having a silanol end and is partially coupled by or star-branched by tin.