Paris St Germain last night confirmed that they had agreed a deal with Sao Paulo for the transfer of midfielder Lucas Moura.
The 19-year-old will remain with the Brazilian side until January before linking up with Carlo Ancelotti's side on a four-and-a-half-year deal.
Lucas Moura, had been a target of Manchester United, but the two clubs failed to agree on a fee for the teenager.
Red Devils' manager Sir Alex Ferguson has spoken out about the deal.
"I find it quite amazing that a club can pay €45million for a 19-year-old boy," said the Scot.
"To tell everyone that PSG are here they've signed Thiago Silva and Zlatan Ibrahimovic. They must have spent about £150million in the last month.
"The only deterrent to that is Uefa.
"In the conditions of European football, you don't qualify for Europe by winning the league or coming second - you only get in by invitation.
"That's where, hopefully, Uefa can have some power.
"When somebody's paying €45million for a 19-year-old boy you have to say the game's gone mad."
The playmaker, who is currently in Britain representing Brazil at the Olympics, began his professional career with his hometown club and has made 58 league appearances.
Lucas Moura becomes Carlo Ancelotti's latest signing this summer after already spending €100m on Ezequiel Lavezzi, Thiago Silva, Zlatan Ibrahimovic and Marco Verratti.
PSG have spent over €200m since last summer after they were taken over by the Qatar Investment Authority (QIA). The new owners immediately signalled their intentions to make the Parisian outfit a European giant by breaking the French transfer record with the €42m acquisition of Javier Pastore from Palermo.