We consider the inverse problem of determining, the possibly anisotropic, conductivity of a body \Omega ⊂Rn, n ≥3, by means of the so-called local Neumann-to-Dirichlet map on a curved portion \Sigma of its boundary ∂\Omega . Motivated by the uniqueness result for piecewise constant anisotropic conductivities proved in Inverse Problems 33 (2018), 125013, we provide a Hölder stability estimate on \Sigma when the conductivity is a-priori known to be a constant matrix near \Sigma .