All Black Fekitoa signs with Toulon
Speculation about the 25-year-old's future began when he was left out of the All Blacks' squad for the recent series against the British and Irish Lions.
While he earned a late recall for the third Test as an injury replacement it was clear Fekitoa had slipped down the pecking order with New Zealand selectors.
"It has been the hardest decision of my life to leave New Zealand," the Tongan-born player said in a social media post.
"But after looking at all the things that are important to me, I feel this is the right time for me personally and for my career."
New Zealand has a policy of not selecting overseas-based players for the All Blacks, although Fekitoa did not rule out the prospect of returning later in his career.
"Doesn't matter where I go to work. We still have a lot more to do," he said.
"I hope to return one day with more experience and success."
Fekitoa made his international debut in June 2014 after a sensational season for the Highlanders and has scored eight tries in the black jersey.
While strong on defence, a perceived lack of threat in attack is believed to have led to him being dropped.
All Blacks coach Steve Hansen, speaking Thursday before the move was confirmed, said Fekitoa had to make a decision "based on what's right for him".
"Like all of the guys that go overseas, we don't want him to go, but if he goes we'll support him," Hansen told Radio Sport.
Agence France-Presse
