3Q10 Results Conference Call Economic-Financial Office and Investor Relations Office November/10

This presentation may contain forward-looking statements referring to SABESP’s business outlook. operating and financial results estimates. and growth prospects. These are only projections. and as such. they are exclusively based on SABESP’s management expectation in relation to the future of business and its continuous access to capital to finance the Company’s business plan. These forward-looking statements largely depend on changes in market conditions. governmental rules. industry performance and the Brazilian economy. amongst other factors. in addition to risks exhibited in disclosure documents filed by SABESP. Therefore. they are subject to changes without prior notice. Notice 2

Total billed water and sewage volume, including wholesale (million m³ ) Billed Volume 3 5.6% 4.5% 5.8% 5.4% 5.0% 4.1%

4 Financial Highlights Variation 3Q09 X 3Q10 0.6% 29.6% 43.8% 129.8% 12.7%

Costs and expenses in 3Q09: R$ 1,173.4 Costs and expenses in 3Q10: R$ 1, Costs and Expenses (R$ million) % Net Revenue in 3Q %2.4%2.1%14.5%7.5%9.0%9.9%4.4%0.6% % Net Revenue in 3Q %2.0%1.7%12.1%7.2%9.0%7.9%4.8%0.6% 0,6% (10,5%) (1,8%) (8,1%) (5,4%) (6,4%) 9,0% 13,9% 24,5% 23,9%

Net Income Main variation of the items that affected net income (R$ million) 6 3Q093QT10Var. Net Income 3Q09: R$ million Net Op. Revenue1,629.01, Costs and expenses(1,173.4)(1,180.4)7.0 Other Rev. and Exp Net Financial(157.0) Income Tax and Social Contr.(109.9)(237.6)(127.7) Net Income 3Q10: R$ million 3Q09 Net Income Net Op. Rev.Costs and Expenses Other Rev. and Expenses Net FinancialIncome Tax and Social Contr. 3Q10 Net Income (109.9) (237.6) (127.7) 60.5 (254.4) 4.5 (6.4) (43.3) Operating Result Income Tax and Social Contr. Exchange Var.Net FinancialMonetary Var.

Investment Plan - Financing Company Funds R$ 4 billion = 46.5% Third Party Funds R$ 4.6 billion = 53.5% CEF R$ 1.3 bi BNDES R$ 638 mi BIRD R$ 115 mi BID R$ 958 mi JICA R$ 80 mi Total Financed Investments - Total Amount = R$ 6.1 bi - Total Financed Amount = R$ 4.6 bi - Counterpart = R$ 1.5 bi - Leverage= 75% R$ 3.5 bi 84% 7 JICA CEF BNDES

IR Contacts Mario Azevedo de Arruda Sampaio Angela Beatriz Airoldi (55 11) (55 11)