The 36-year-old centre left French side Toulon in May after three seasons and said he was "taking a step back" to assess his rugby future.

Nonu, who won 103 international caps and the World Cup in 2011 and 2015, has signed a one-year deal with the Blues, his third stint with the Auckland club.

He will link up with a star-studded backline including All Blacks Rieko Ioane and Sonny Bill Williams.

Nonu will also be working under former All Blacks and Hurricanes team-mate Tana Umaga.

"I have been playing rugby a long time," said Nonu.

"I've known first-hand the highs and the lows of a playing career on and off the field and I am looking forward to giving my best and proving that I can still play at this level."