Endesa is engaged in the production, transmission, distribution, and supply of electricity, through hydroelectric, fossil fuel, and nuclear generation. Co. is also engaged in the mining of coal for use in its fossil-fuel electric plants; mining research; land restoration, and environmental monitoring and control.

Iberdrola is a holding company. Through its subsidiaries, Co. operates in four segments: network business, which includes all the energy transmission and distribution activities, and other regulated activity originated in Spain, the U.K., the U.S. and Brazil; deregulated business, which includes electricity generation and sales businesses as well as gas trading and storage businesses carried on by Co. in Spain, Portugal, the U.K. and North America; renewable business, with activities related to renewable energies in Spain, the U.K., the U.S. and the rest of the world; and other businesses, including the engineering and construction businesses and the non-power businesses.

Red Electrica is engaged in the transmission of electrical energy, the operation of the system and the management of the transmission network in the Spanish electricity system. In addition, through its subsidiaries, Co. is engaged in the acquisition, holding and management of foreign securities, co-ordination of international exchanges, provision of telecommunications services for third parties, provision of consultancy, engineering and construction services outside the Spanish electricity system, securing of funds, carrying out of financial transactions and provision of financial services.