Racing 92 lock Tomas Lavanini has committed to the new Argentina Super Rugby franchise until at least the end of 2018.
The 22-year-old started his professional career at Hindú in the Argentinean capital before moving to Racing at the beginning of this season.
He has been capped 18 times for the Pumas and is currently in Sydney as the squad prepares for the forthcoming Rugby Championship.
"I am very happy with agreeing to terms," he said.
"It will be amazing to play Super Rugby and keep playing in Los Pumas," Lavanini said about this new stage of his career.
In congratulating Lavanini, UAR president Carlos Araujo added, "We continue the process of arming the squad for the important commitments that come as we join Super Rugby.
"The presence of Tomas is important as he is important player for his youth, value and the future years that lie ahead."