Cross-linkable polymeric compositions having an ethylene-based polymer, an organic peroxide, and a polyallyl cross-linking coagent, where the polyallyl cross-linking coagent and the organic peroxide are present in amounts sufficient to provide an allyl-to-active oxygen molar ratio of at least 1.6, based on the allyl content of the polyallyl cross-linking coagent and the active oxygen content of the organic peroxide. Such cross-linkable polymeric compositions can be employed in forming coated conductors.