Zero Hora is a Brazilian newspaper based in the city of Porto Alegre, the sixth biggest of the country. It is edited by Grupo RBS.

The RBS Group is being investigated by the practice of oligopoly / monopoly. In 2008, the Federal Prosecutor of Santa Catarina has filed a public civil action (Case No.. 2008.72.00.014043-5) against the company oligopoly Rede Brasil Sul (RBS) in southern Brazil. The MPF requires the company, among other measures, to reducing its number of TV and radion stations in the states of Santa Catarina and Rio Grande do Sul, so that to be in according to the Brazilian law; and the cancellation of the purchase of the newspaper A Notícia from Joinville, consummated in 2006 - which resulted in a virtual monopoly over the relevant newspapers in the state of Santa Catarina.^{[2][3] [4]}

In 2009, the Federal Prosecutor in Canoas (RS), Pedro Antonio Roso, asked the chairman of the RBS Group, Nelson Pacheco Sirotsky, among other informations, the number of TV and radio stations that the company owns in Rio Grande do Sul, "as well as its affiliates, stations and repeaters." The request is part of an administrative proceeding brought by federal prosecutors "to determine possible occurrence of monopolistic practices and irregularities in granting Radio and Television to the RBS Group in Rio Grande do Sul".^[5][6]

• List of newspapers in Brazil
• History of the press in Rio Grande do Sul [pt]