The Otago Rugby Football Union has agreed to let Fuata'i out of his one-year contract with the union to go and join Top 14 club Bordeaux.
Fuata'i (23) will move to the club, which has not renewed the contract of experienced Australian international Adam Ashley-Cooper.
Otago Rugby Football Union general manager Richard Kinley said though it was always disappointing to lose any top line player, it was the job of the union to prepare players to play at the next level and that what they had done with Fuata'i.
Fuata'i came south after impressing in Auckland for King's College.
He has played 28 games for Otago since 2013 and scored eight tries. In 2013, he was a member of the New Zealand under-20 team.
A law student, he just has to sit his professional papers to qualify to be a lawyer. He has trained with the Highlanders on and off this season, but has never made the starting squad for a game.
Kinley said Fuata'i is at the stage of whether he wanted to be a lawyer or try his luck at professional rugby.
Fuata'i, whose father Siro played two games for Otago in 1977, had suffered a couple of serious shoulder injuries when playing in Dunedin which had forced him off the field for lengthy periods.
A left winger, he was selected for the New Zealand Sevens team this season and played in the last two tournaments of the year in Paris and London. Kinley said he played well at the Paris tournament, scoring some nice tries and had been spotted by club bosses.
He has signed a one-year deal with the Top 14 club.
The club also had on its books former Otago back Jayden Spence, who joined the club at the start of last season.
Another Otago back also playing in France is fullback Tony Ensor, who has linked with Paris club Stade Francais. Stade Francais will be coached in the coming season by former Highlanders and Otago coach Greg Cooper.
Kinley said the departure of Fuata'i was a chance for another player to take an opportunity. Outside back options for Otago include Mitchell Scott, Gavin Stark, Jona Nareki, Leroy van Dam and Vilimoni Koroi.
Otago will not be looking outside the province for a replacement.