The 32-year-old's future has been shrouded in doubt for some time as he struggles to play regular first-team football and a move away now looks likely.
Boss Thomas Tuchel has always insisted that he wants to keep the player, and speaking after the win over Lorient in French Cup on Sunday, reiterated that PSG need to keep hold if they wish to win honours.
However he has also said he would not stand in the player's way if he wanted to leave and that now appears to be the case after a transfer request was handed in.
"It's true that today he asked to leave," said PSG sporting director Leonardo after a 1-0 win over Lorient. "We are studying the situation."
Atletico have long been linked and still look to be the frontrunners to do a deal for the Uruguay legend.
He added: "It's also true that there has been an approach from Atletico Madrid."
Now it is out in the open that Cavani has asked to leave, there is sure to be interest from elsewhere.
Manchester United are now reported to have joined the race for his signature following the news that their star striker Marcus Rashford will be on the sidelines for six weeks through injury.
Fellow Premier League sides Arsenal and Chelsea are also said to be in the hunt and could make bids before the window closes.