The Argentine will complete his 42m transfer this week after a deal was struck late Friday night.
"I can officially say that I am a Paris Saint-Germain player," he said on his management's website Dodici Corporation.
"I just need to undergo my medical and define the last details. I can't wait to launch myself into this new adventure.
"PSG are a big club with a great history behind them."
El Flaco spent two seasons at Palermo and had been content to stay on for longer.
"I retain many wonderful memories of Palermo and want to thank my ex-teammates, directors and the fans.
"I'm happy with this new adventure, but at the same time sorry to leave Palermo. I thank everyone! Italy will always be my second home."