Oi
Oi, 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. Oi‘s major subsidiaries include Telemar and Brasil Telecom.
Oi SA engages in providing telecommunications services. The company was founded on November 27, 1963 and is headquartered in Rio de Janeiro, Brazil.
