The deal, which will run until May 2018, is believed to be the second-most valuable sponsorship agreement in world rugby - trailing only the NZRU's current partnership with adidas.
With the pair of corporate giants now boosting the NZRU coffers, Tew believed the benefits of selling advertising space on the black jersey outweighed any concerns over tradition.
"We are in a challenging time, in this world we live in,'' he said. ``We have a business that has roughly $100 million turnover a year - it needs to be significantly more than that if we're going to survive, if we're going to grow the game at the community level and if we're going to retain players.
"It's a challenge for us, and we need some money.''
While the exact amount of money remained under wraps, AIG executive vice president Peter Hancock said the company's contribution was considerable.
"We really are placing our faith in the continued success and values of [New Zealand rugby],'' he said. "This is the largest commitment that we are making to any sport anywhere in the world.''
It is safe to say, though, the agreement will fall some way short of the $28 million a year the insurers paid Manchester United to appear on the red shirt from 2006-2010 - a deal which went unrenewed after AIG fell victim to the global financial crisis and had to be bailed out by the US Government.
Critics of their involvement in New Zealand rugby may hope for a similar turn of events, but Tew hoped the financial sense of the decision would eventually prevail over the inevitable backlash.
"We think there will be a balanced analysis of this. People who consider very carefully what is in behind this for New Zealand rugby - the way we have respected the jersey, the fact we have chosen a truly global partner with New Zealand interests - hopefully will celebrate it the way we are.''
In addition to the All Blacks jersey, which will make its debut next weekend in the Rugby Championship match against the Wallabies in Brisbane, AIG will also appear on the shirt and shorts of five other New Zealand teams - the Black Ferns, the Maori All Blacks, the men's and women's sevens teams and the under-20 men's side.
Unlike those teams, however, the logo on the All Blacks' playing kit will be without its border and will be smaller in size. Tew said the sizing was one third of that allowed by IRB regulations, a decision which was intended as a ``sign of respect'' to tradition.
For those who remained unimpressed, Tew had a simple answer.
"We respect people who decide that it's not a good idea, but we're the ones in charge of the legacy at the moment and we'll make the decisions we need to make.''