By Gabriel Araujo SAO PAULO (Reuters) -Brazilian power company Equatorial Energia SA has agreed to acquire local electricity distributor Celg-D, a securities filing showed on Friday, ending the reign of Italy’s Enel SpA over a firm that has long struggled with quality issues. 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, while Enel said it will book a loss of $990 million related to the transaction. Analysts liked the price and Equatorial shares surged as much as 7%, making it the top gainer on Brazil’s Bov…