This is the company set up by Iberdrola to manage its Brazilian investments. Iberdrola holds 39% of Guaraniana, while investment fund 521 Participacoes has 18.3%, and government-owned Banco do Brasil's pension fund, Previ, owns 21.7%. The remaining shares are split between three other investment funds, Bundo Mutuo de Investimentos, BB Banco de Investimentos, and Brasilcap.

Guaraniana was renamed Neoenergia in late 2004.