Companhia de Electricidade de Macau – CEM, S.A. known simply as CEM or Chinese: 澳電 is a private public utility company with a sole concession to transmit, distribute, sell high, medium and low voltage of electricity in Macau.

In November 2010, the Government of Macau and CEM signed the Power Supply Contract Extension for 15 years.

In 2014, Nam Kwong (Group) Company Limited purchased a 90% stake in Sino–French Energy Development Co. from Sino-French Holdings (Hong Kong) Ltd and became CEM's biggest shareholder.

Limited (42%), Energy Asia Consultancy (21%), Polytech Industrial (11%), Asiainvest - Investments (10%), Government of Macau (8%), China Power International Holding (6%) and other investors (2%).

Limited); the remaining 10% stake of Sino-French Energy Development was owned by Hong Kong-Macau billionaire Stanley Ho.

Chinese Central government also owned another shareholder of CEM, China Power International Holding.