Sky Sports News understands Chelsea have agreed a £25million deal in principle to sign Brazil international Oscar.
The European champions have been chasing the Internacional star for several months, while Tottenham also wanted the 20-year-old.
Chelsea were said to have failed in a previous £20m bid for Oscar, but are now understood to have succeeded with an improved offer.
A transfer could now be finalised, despite the playmaker's agent having previously claimed a move to Stamford Bridge was looking increasingly uncertain.
Internacional president Giovanni Luigi is remaining coy on confirming any deal and told Terra he is waiting for another Chelsea offer.
"I'm waiting for another Chelsea offer this Tuesday. Their offer last Friday didn't match our expectations. Oscar won't leave Internacional for less than 20m Euros, thus they know what they have to offer."
Oscar is expected to arrive in the United Kingdom on Tuesday with the Brazilian Olympic team.
The youngster, capped six times for his country, is regarded as one of the best young talents in Brazil.