Despite a spirited fightback by the side from 2-0 down to earn a 2-2 draw against Avai on Wednesday night, Renato"s agent announced via Twitter that the 48-year-old had left his post.
“He"s resigned and will say farewell to the squad this [Thursday] afternoon," said agent Gerson Oldenburg.
Renato is considered one of the Gremio"s greatest ever players, helping the club to win the Copa Libertadores and Intercontinental Cup in 1983, and had been in charge of the side since last August.
He leaves the team in 12th place in the table with eight points from seven games, and is already the third manager to vacate his position since the 2011 Brasileirão season began in May.