New Zealand Rugby chief executive Steve Tew would not be drawn on what the deal was worth but said both sides were happy.
"We think we've found a nice median between respecting the jersey and making sure they get the exposure and profile for the investment they're making.
"AIG has been a great supporter of our game since coming on board in 2012 and contributed to outstanding results off the field, helping profile our teams throughout the world and showcasing the story and teams of New Zealand rugby to millions of new fans from Chicago to China and further afield."
Preliminary discussions began about 12 months ago, with teams of legal and commercial experts working on it "for months rather than weeks", Tew said.
The AIG logo would retain its central position on the All Blacks jersey and would not be any bigger or smaller than previously.
University of Canterbury Associate Professor of Marketing Ekant Veer said sponsoring the All Blacks was an advertiser's dream.
"It's a phenomenal brand that has dominated rugby for 18 games on the trot and really they've been completely dominant for the last six to eight years."
There was a chance the All Blacks could even become victims their own success, with fans from other rugby-playing nations not watching games because the result seemed inevitable.
"We're seeing a lot of people in Australia just going off rugby in general because they know the result. We know that the All Blacks are going to win so is there any point in watching it?
"So they'll go down in history as one of the most dominant teams in any sport but whether this pays off financially is yet to be seen."
Tew said this had not been the team's experience and they were still pulling the crowds despite a plethora of sporting activity for Chicago this week - the Chicago Cubs winning the World Series for the first time in 108 years, the Chicago Bulls looking for their fourth straight win in the 2016-17 season, the Blackhawks ice hockey team playing, as well as a general election just around the corner.
"Our guys are still getting air time and are still being recognised so I don't think the success of the current team is a negative at all," Tew said.
"You won't find a team that has a better record and I don't see how that can be anything but a positive."
