By Agence France-Presse
The Los Angeles-based company said it will take a majority stake in Rock in Rio in 2019, although a representative for the festival in Brazil said that the arrangement would be a 50-50 split.
The festival's Brazilian founder, Roberto Medina, will maintain a key role in organizing the festival, Live Nation said.
"The partnership will generate a number of synergies that will enable the realization of even greater ambitions for Rock in Rio," Medina said in a statement.
Rock in Rio has its roots in the fall of Brazil's military dictatorship in 1985 when a total of nearly 1.4 million people came out for 10 days of music that included Queen, Rod Stewart, AC/DC and Yes.
With a seventh edition taking place last year, Rock in Rio has become South America's best-known music festival.
It has also expanded overseas with editions in Lisbon, Madrid and, in 2015, a first US version in Las Vegas that starred some of the top names in pop music including Taylor Swift and Bruno Mars.
Live Nation is the largest live entertainment company, promoting tours and handling sales through Ticketmaster.
Like its rivals, it has increasingly set its sights on festivals and has acquired major events such as Lollapalooza, Bonnaroo and Austin City Limits in the United States and the Leeds and Reading festivals in England.
Festivals have grown sharply in number, attendance and profitability since the turn of the century, becoming a rite of passage for many young people in the Western world.
With their growth, festivals have also turned into one of the music industry's major money generators, and companies such as Live Nation look set to maximize efficiency by running multiple events.