The 20-year-old moved to the Paris club last summer from Pescara, but he has been heavily linked with a move back to Serie A in recent weeks.
The highly-rated youngster, who is already a full Italy international, has admitted that he would like to join Juventus one day. However, his agent, Donato di Campli, has revealed that United and Barca are looking to sign the player.
"I have been contacted by many clubs," Di Campli told Le 10 Sport.
"Barcelona and Manchester United are interested. Sir Alex Ferguson really likes Marco."
Verratti has made 17 appearances in Ligue 1 this season for PSG.