Boss Pardew said, "We feel we've had good success with Yassin Moutaouakil since he has been here, and Therry is coming from the same division.
"He is a central midfielder with fantastic athletic ability and agility and I like the look of his composure.
"It's an area I felt we needed to strengthen and both he and ZiZi will be strong competition for the likes of Ambrose, Semedo and Matty Holland."
Pardew added: "He's a young player finding his way, but we have high hopes for him."