Capitals in the country's north and northeast suffered electricity supply interruptions on Wednesday.
The monetary authority indicated it will cut the base rate even more.
Mining minister Baldo Prokurica said the state company's corporate governance should be independent from political cycles.
The engineering firm's failure to pay part of the fines included in a corruption-related leniency agreement, could prompt the country's antitrust agency to suspend the agreement, according to a local daily.
With current concessionaire ABV facing major financial problems, investment firm IG4 Capital and debt restructuring company Stardboard are interested in taking over the concession for the Viracopos airport in the Brazilian city of Campinas, according to a local newspaper.