The fee would make Felix the fifth most expensive signing of all time after Neymar, Kylian Mbappe, Philippe Coutinho and Ousmane Dembele.
Three Portuguese sports newspapers – A Bola, Record and O Jogo – claim the 19-year-old has accepted an offer of a five-year contract from Atletico, with a net annual salary worth six million euros.
Joao Felix has been linked with a number of Europe’s leading clubs including Manchester City, Manchester United and Juventus.
Winning the race for his signature would come as a significant boost to Atletico, who are expecting to lose Antoine Griezmann this summer after the Frenchman said he is seeking a new challenge.
Griezmann’s release clause will decrease to 120 million euros on July 1, with his projected sale likely funding Atletico’s sizeable bid for Felix. Griezmann is expected to join Barcelona.
Joao Felix, a forward who can play on either flank or centrally, has just enjoyed a breakthrough season at Benfica, scoring 20 goals in 43 competitive games and helping the club win the Portugese league title.
He also made his debut for Portugal earlier this month, starting alongside Cristiano Ronaldo in their Nations League semi-final win over Switzerland.