A process for producing a silane-crosslinked polyolefin which comprises exposing a polyolefin containing at least one [1,3,2]-dioxasilinane ring structure to moisture in the presence of an organic carboxylic acid, which is used as a hydrolysis and condensation catalyst and does not contain tin, thereby producing the silane-crosslinked polyolefin, wherein the polyolefin containing at least one [1,3,2]-dioxasilinane ring structure is made by the process of grafting an olefinically unsaturated [1,3,2]-dioxasilinane to a polyolefin in the presence of a free radical initiator. There is also provided the resulting silane-crosslinked polyolefin and the graftable silane composition used in the process.