The 30 year old has played 46 times for the All Blacks, including the 2015 World Cup final, and has represented the Blues in Super Rugby since 2009.
RNZ reports he will still compete in next year's Super Rugby competition before heading to the northern hemisphere in time for the French season according to Sky Sports UK.
Faumuina said it was a difficult decision to leave New Zealand but he was excited by the opportunity in Europe.
