Innermost disk pairs in least weight normal surfaces

Given transversely intersecting normal surfaces S and S′ in a triangulated 3-manifold M, criteria are given under which inessential intersection curves can be eliminated by a sequence of regular exchanges each of which exchanges a pair of innermost disks. One application is the construction of a G-equivariant, minimal Seifert surface for an oriented link which is invariant under the action of a given finite group G.