Equatorial will pay 1.58 billion reais ($309 million) for Celg-D in a deal that also includes a 5.71 billion-real debt restructuring, it said.
Reuters had reported earlier this year, citing sources, that Enel was in talks to sell Celg-D, which distributes power to 3.3 million customers in Brazil's center-west state of Goias.
Enel paid 2.1 billion reais to buy Celg-D from the state and Eletrobras in a privatization in 2016.
Celg-D said in a separate filing on Friday that Equatorial aims to expand its footprint in power distribution and diversify its portfolio.
The deal still requires approval from Brazil's antitrust watchdog CADE and power regulator Aneel, the firms said.
($1 = 5.1171 reais)
(Reporting by Gabriel Araujo; editing by Jason Neely)
