New Zealand now also looking at Northern Hemisphere
NZR Chief Executive Steve Tew said the deal was "new territory" for his organisation and would help it tap into commercial opportunities among London's large expatriate Kiwi community.
"This alignment will create significant opportunities for both sides, with players, coaches and staff able to learn from different environments with different people, challenges and cultures," Tew said in a statement.
The statement said NZR would cooperate on "playing and coaching resources", as well as leveraging commercial opportunities, but offered scant detail on how the deal would work in practice.
The New Zealand Herald reported that All Blacks taking a break from the rigours of international rugby could turn out for Harlequins.
Sabbaticals have become standard for top All Blacks looking to freshen up in recent years as NZR attempts to stop cashed-up overseas clubs poaching its talent.
The likes of Dan Carter, Richie McCaw and Sonny Bill Williams all had sabbaticals built into their contracts designed to keep them with the All Blacks long term.
The issue of player retention has become more pressing for the world champions as those in the prime of their career such as Lima Sopoaga, Steven Luatua and Aaron Cruden opt to take the club cash on offer in Europe.
The deal is also likely to see Harlequins coaches and players heading to New Zealand to gain experience playing Southern Hemisphere rugby.
"The All Blacks are the benchmark of excellence for all teams, so to be able to align with them both on and off the pitch will be of significant benefit to the club," Harlequins Chief Executive David Ellis said.
Agence France-Presse
