SÃO PAULO, May 4, 2018 /PRNewswire/ -- Companhia de Saneamento Básico do Estado de São Paulo – Sabesp ("Company" or "Sabesp"), pursuant to the provisions of Article 157, Paragraph 4, of Law 6.404/76 and to the provisions of CVM Instruction 358/02, informs its shareholders and the market...