Grupo México, S.A.B. de C.V. (BMV:GMEXICO B) is in advanced talks on a potential acquisition of Citigroup Inc.'s Mexican retail bank Banco Nacional de México, S.A. (Banamex), people with knowledge of the matter said. The mining magnate is trying to finalize terms of a potential deal with Citigroup, the people said, asking not to be identified because the information is private. No final agreements have been reached, and talks could still fall apart or another buyer could emerge, the people said.