Oi, Brazil's largest fixed-line phone carrier, and six subsidiaries filed for bankruptcy protection on Monday after Oi failed to win the support of key shareholders for a plan to restructure 65.4 billion reais ($19.3 billion) of debt.
The petition is Brazil's largest ever, according to Thomson Reuters data. It follows Oi's recognition last week that its capital structure was "not sustainable." Without a debt restructuring, Oi estimated that almost 92 percent of existing cash would be depleted by year-end.
In a securities filing, Oi said the petition to seek protection from creditors in a Rio de Janeiro court stemmed from "obstacles confronted by management to finding a viable alternative with creditors." Oi will maintain service quality standards during the process and preserve cash, the filing said.