Celtic have signed defender Dedryck Boyata from Manchester City on a four-year contract.
The 31-year-old Italy international, who joined PSG from Inter Milan for 10million euros in 2012, has made 29 appearances in all competitions for the Ligue 1 leaders so far this season.
A tweet from the club's official account read: "Paris St Germain are happy to announce the extension of Thiago Motta's contract until 2016."
On Tuesday night Motta played all 90 minutes as PSG beat Bayer Leverkusen 4-0 in the first leg of a last-16 pairing in the Champions League.
The Brazil-born player told psg.fr: "I am very happy that I can play for Paris St Germain until 2016.
"My intention was to continue playing for this team so now everything is fine for me.
"I will keep my feet on the ground and continue to work as I have before, to help PSG to win titles."
Motta, who has been capped 16 times for Italy, also numbers Barcelona, Atletico Madrid and Genoa among his former clubs.