Oi (, Portuguese for "Hi"), formerly known as Telemar, is the largest fixed telephone operator and the fourth mobile telephone operator in Brazil, being the third largest telecommunication company in Latin America. It is headquartered in Rio de Janeiro. In 2013, Oi announced its merger with Portugal Telecom, the largest telecommunication company in Portugal, in order to strengthen the Brazilian firm and simplify its ownership structure. In June 2015 Portugal Telecom was acquired by Altice Group. On June 20, 2016, Oi filed for a 19 billion (65 billion) bankruptcy protection, the largest on record for Brazil. In March 2017, Oi had 63 million revenue generating units (UGRs), including 40 million for personal mobile service, 16.3 million for landline, 6.5 million for B2B (large corporations and microentrepreneurs). Nowadays, it has 2 million hotspots to Oi WIFI network around Brazil. In March 2019, Oi reported a fourth-quarter net loss of 3.359 billion reais ($858 million), widening 66 percent from its year-earlier loss. Total revenue fell 7.9 percent. On February 8, 2023, Oi once again filed for Chapter 15 bankruptcy in the United States. Corporate governance Oi's chief executive officer (as of January 2018) is Eurico Teles, who also serves as the company's chief financial officer and director of investor relations. History Oi (then known as Telemar) was formed as Tele Norte Leste to merge sixteen state-owned incumbent local exchange carriers, during the privatization of Brazilian telecommunications system. Each carrier served a particular Brazilian state in the northern, northeastern and southeastern part of the country. In the break-up of Telebras in 1998 it was sold to a consortium led by the Brazilian construction firm Andrade Gutierrez (21.2%) and Inepar Holdings (20%) as well as other Brazilian corporate and individual investors. The consortium paid 3.434 billion reais. The states that formed the base of Telemar at its inception were Rio de Janeiro, Minas Gerais, Espírito Santo, Bahia, Sergipe, Alagoas, Pernambuco, Paraíba, Rio Grande do Norte, Piauí, Ceará, Maranhão, Pará, Amazonas, Amapá and Roraima, corresponding to 65% of the Brazilian territory and 20 million households. Initially, Telemar was allowed to offer only local voice and data services and interstate long-distance voice services. Today, Telemar and its subsidiaries offer local, long-distance and international voice and data services, besides a growing mobile phone network. In April 2006, it was announced that Telemar would restructure itself, merging its three holding companies into a single company, that would have