Sabesp: Notice To The Market

SÃO PAULO, May 30, 2018 /PRNewswire/ — Companhia de Saneamento Básico do Estado de São Paulo – SABESP (B3: SBSP3; NYSE: SBS), one of the largest water and sewage service provider in the world based on the number of customers, hereby announces that on May 30, 2018, it filed Amendment No.1 to its annual report on Form 20F for the fiscal year ended December 31, 2017 (the “2017 Annual Report”) with the Securities and Exchange Commission (the “SEC”). Amendment No. 1 to the 2017 Annual Report can be accessed by visiting either the SEC’s website at www.sec.gov or the Company’s website.