Spain's Naturgy said last November it had agreed to sell 96% of Chilean unit CGE to China's State Grid for 2.57 billion euros ($3 billion), amid rising investment from the world's second largest economy in South America.
Chile, the world's top copper producer, counts China as its most important trade partner.
Chile's Fiscalía Nacional Económica (FNE), the country's antitrust authority, said in a statement that it had given its unconditional approval for the deal, saying that it did not substantially affect competition in the power sector.
CGE is mainly engaged in the transmission and distribution of electric power and owns distribution concessions in 11regions of the Andean country.
(Reporting by Fabian Cambero; Writing by Adam Jourdan; Editing by Jonathan Oatis)