Empresas y finanzas
Mexico says Pemex blast caused by gas build-up, not explosives
Attorney General Jesus Murillo said no trace of explosives was found at the site of the explosion, the latest in a string of safety lapses to hit the oil monopoly. New President Enrique Pena Nieto is seeking to push through a major overhaul of Pemex.
(Reporting by Lorena Segura; Writing by Simon Gardner; Editing by Dave Graham)