Argentina winger Mateo Carreras will leave Newcastle Falcons at the end of the season to join French Top-14 club Bayonne.
Carreras is in his third season at Kingston Park where he has scored 16 tries in 37 appearances.
The 23-year-old, who has 17 caps for Los Pumas, scored three tries in the World Cup.
The Falcons are bottom of the Premiership with five defeats from five matches.
Carreras grabbed 13 tries in last season's Premiership, second only to Cadan Murley of Harlequins, who scored 15.
However, the diminutive winger has only played one game so far this season after helping Argentina reach the semi-finals in France.
Falcons head coach Alex Codling told the club's website: "We are naturally disappointed to be losing such a fantastic player and we will always do our best to retain our top talent, but Mateo has been professional and transparent throughout the entire process.
"He still has a massive role to play for the Falcons between now and the end of the season, and I know he will approach it with his usual diligence and positivity."