  The symmetry algebra of asymptotically flat spacetimes at null infinity in
four dimensions in the sense of Newman and Unti is revisited. As in the
Bondi-Metzner-Sachs gauge, it is shown to be isomorphic to the direct sum of
the abelian algebra of infinitesimal conformal rescalings with bms4. The latter
algebra is the semi-direct sum of infinitesimal supertranslations with the
conformal Killing vectors of the Riemann sphere. Infinitesimal local conformal
transformations can then consistently be included. We work out the local
conformal properties of the relevant Newman-Penrose coefficients, construct the
surface charges and derive their algebra.
