ESPN understands that Chelsea have agreed a fee with Internacional for Brazil midfielder Oscar.
Oscar, 20, has been linked with a move to Europe this summer, and both Chelsea and Premier League rivals Tottenham Hotspur have been mooted as interested parties.
The Blues are now closing in on the playmaker's signature after a fee of €25 million was accepted by the player's club Internacional.
An ESPN source said: "Nothing is signed but a deal in principle is agreed for €25 million."
Champions League winners Chelsea have already brought in Eden Hazard from Lille and Werder Bremen's Marko Marin ahead of Roberto Di Matteo's first full season in charge as permanent boss.
Oscar, who will represent his nation at the 2012 Olympics, is highly-rated in his native Brazil, with an arguable career highlight being a hat-trick against Portugal at the 2011 Under-20 World Cup final in Colombia.
Spurs, meanwhile, look set to focus their efforts on landing Porto's Joao Moutinho, who has been lined up as a replacement for Luka Modric, should Real Madrid lodge an acceptable bid for the Croatian.