The 30-year-old, who featured only sporadically for Tana Umaga's Blues in 2017 as he battled injury and form issues, has agreed to a two-year deal with La Rochelle in the French Top 14 competition.
Ranger, who has made 76 appearances for the Blues, previously played for Montpellier in France from 2013-15, before returning to the Auckland franchise in 2016 in an ill-fated bid to revive his New Zealand career.
The rugged back played six tests for the All Blacks in 2010 and 2013, but made the move to Montpellier just when he appeared to have played his way into the national mix.
He has been beset by injury problems since his return to New Zealand with knee and neck surgeries curtailing his play at both Super Rugby and provincial level.
La Rochelle finished regular season champions in the Top 14 competition, but were eliminated by Toulon in the semifinals.
They have also signed current All Blacks squad halfback Tawera Kerr-Barlow to join a squad that also includes well-performed Kiwis Victor Vito and Jason Eaton.
Photo by: DAVE ROWLAND/GETTY IMAGES (Rene Ranger had limited opportunities for the Blues in 2017.)