Let Mn denote the universal covering space of a compact Rie-mannian manifold, Mn, with sectional curvature, -1≤Kmn≤O.We show dependent) conditions, determinesan open dense subset of Mn, at every point of which, there exists a local isometric splitting with nontrivial flat factor. Such a coolection, which we call an abelian structure, also gives rise factor. Such a collectionk, which we call an abelian structure, also gives rise to an essentially canonical Cr-stucture in the sense of Buyalo, i.e. an atalas to an essentially canonical Cr-stucture in the sense of Buyalo, i.e an atlas for an injective F-STUCTURE, for which additional conditions hold, It follows in particular that the minimal volume of Mn vanishes. We show that an abelian structure exists if the injectivity radius at all points of Mn is less than ε(n)>O.This yields a conjecture of Buyalo as well as a strength-ened version of the conclusion of Gromov's gap conjecture in our special ituation. In addition, we observe that abelian stuructures on nonpositively curved manifolds have certain stability properties under suitably controlled changes of metric.