Silane-crosslinkable polymeric compositions comprising a polyolefin having hydrolyzable silane groups, an acidic silanol condensation catalyst, and a phenolic antioxidant. The phenolic antioxidant comprises two sulfur-containing radicals, one located at the ortho position and the other located at the para position relative to the hydroxyl group of the phenol. Such crosslinkable polymeric compositions can be employed in various articles of manufacture, such as in the wire and cable industry.