The All Blacks have lost their main sponsor, US insurance giant AIG, following their disappointing performance in this year's Rugby World Cup, the team announced on Tuesday.

New Zealand Rugby (NZR) chief executive Mark Robinson said AIG had given early notice that the multi-million-dollar arrangement, in place since 2012, would end next year.

"Lengthy commercial partnerships such as this are unusual, and the lead-in time provided means NZR is very well placed to attract new sponsors," Robinson said.

In a brief statement from AIG, global head of sponsorship Daniel Glantz gave no reason for ending the arrangement. 

But he thanked New Zealand Rugby and the players who have "consistently demonstrated a commitment to excellence on and off the pitch, which has enhanced both of our brands and inspired rugby fans around the world." 

The announcement comes just three months after the All Blacks failed in their bid for an unprecedented third consecutive World Cup and fell from the top of the world rankings for the first time in 10 years.

The AIG sponsorship covered not only the All Blacks and the women's Black Ferns but also the national men's and women's sevens teams, the Maori All Blacks and the New Zealand under-20 side.

During the AIG partnership years, the All Blacks won the 2015 World Cup and the 2017 Women's World Cup, while the men's and women's sevens teams both won gold at the Commonwealth Games and the Sevens World Cup in 2018.

Last October, environmental activists delivered a 35,000 signature petition to NZR urging it to axe its association with AIG after it was revealed that the company was insuring the controversial Adani Carmichael coal mine in Australia.