Companhia de Saneamento de Minas Gerais : Operating Release - December 2011

Operating Release

December 2011

COPASA: Operating Release - December 2011 Belo Horizonte, January 10th, 2012 - COPASA MG - Companhia de Saneamento de Minas Gerais

(BM&FBOVESPA: CSMG3) hereby announces its operating release for December 2011.

Billed Volume

The increase in billed volume in December 2011, compared to the same period in the previous year, was due to an upturn in the number of water and sewage connections in the period, despite the fact that the consumption period established by the billing schedule was shorter than that of 2010. In comparison with November 2011, the increase in the billed volume was mainly due to an increase in the number of consumption days.

Operating Highlights¹

Indicator ² unit Dec/11 Dec/10 Nov/11
Indicator ² unit Dec/11 Dec/10 Nov/11	Dec/ X Dec/	Dec/11 X Nov/11
NO. OF CONNECTIONS3 un 5,746,049 5,456,679 5,723,089 5.30% 0.40% WATER un 3,634,689 3,500,986 3,623,363 3.82% 0.31% SEWAGE un 2,111,360 1,955,693 2,099,726 7.96% 0.55% NO. OF UNITS4 un 7,110,927 6,784,951 7,086,234 4.80% 0.35% WATER un 4,402,057 4,253,301 4,389,700 3.50% 0.28% SEWAGE un 2,708,870 2,531,650 2,696,534 7.00% 0.46% BILLED VOLUME 1,000 m³ 89,044 87,371 87,534 1.91% 1.72% WATER 1,000 m³ 54,460 54,180 53,579 0.52% 1.64% SEWAGE 1,000 m³ 34,584 33,191 33,956 4.20% 1.85% NO. OF MUNICIPALITIES - WATER CONCESSIONS un 620 615 620 0.81% 0.00% NO. OF MUNICIPALITIES - SEWAGE CONCESSIONS un 225 212 225 6.13% 0.00% NO. OF MUNICIPALITIES - WATER OPERATIONS un 606 603 606 0.50% 0.00% NO. OF MUNICIPALITIES - SEWAGE OPERATIONS un 176 159 176 10.69% 0.00% CONSUMPTION DAYS un 31.40 31.50 30.45 -0.32% 3.12%

1 - Amounts potentially subject to adjustment.

2 - Consolidated data (includes locations operated by the subsidiary COPANOR).

3 - Connections: link between the company's network and the client's building.

4 - Unit: potential subdivisions of the client's building. Ex: a 10-apartment building has one connection and 10 units.

For more information. please contact the IR department.

Tel: [phone]. email: [e-mail]. www.copasa.com.br/ir

About COPASA MG: COPASA MG's main activities comprise the planning. preparation. execution. expansion and operation of sanitation services. It also provides technical cooperation services for several municipalities in the state of Minas Gerais. including those where it does not hold concessions. COPASA MG focuses its activities in Minas Gerais. the third most economically productive state in Brazil. Since February 2006. COPASA MG's shares have been listed under the ticker CSMG3 in the Novo Mercado trading segment of the Brazilian Securities. Commodities and Future Exchange (BM&F Bovespa). which comprises those companies with the highest standards of corporate governance.