The deal is with Infront, described as a “leading global sports marketing company”.
The proposed Nations Championship, which has also been referred to as the World League and Nations League, would be played in non-Rugby World Cup years.
It would pit the best of the Southern Hemisphere countries against the Six Nations contenders, with Japan and USA reportedly also involved.
The plan is contentious because it was initially thought to exclude the Pacific Nations.
Leading international captains also complained that extra fixtures would have a detrimental impact on player welfare.
To address the latter issue, World Rugby today announced plans to truncate the proposed competition by scrapping the semi-final stage.
In a statement following a meeting in Dublin, the governing body said: “The international federation is undertaking this project in line with the mandate of its unions to secure a strong and sustainable competition and financial platform for unions and a true opportunity for emerging nations to develop and compete at the highest level.”
World Rugby is proposing a three-division format and a system of promotion and relegation. The Six Nations are opposed to the idea of relegation.
The statement added: “The proposed format would be underpinned by a record commercial partnership with leading global sports marketing company Infront, guaranteeing almost £5 billion for investment in the sport over an initial 12-year period (of which more than £1.5 billion is guaranteed incremental revenue for the world game).
“World Rugby also outlined revisions to the original proposal presented to unions in September 2018, following feedback from key stakeholders, including leading players and club competitions:
“World Rugby reduced the schedule by removing the semi-final stage, with player welfare continuing to be a central consideration.
“Players would play 11 Nations Championship matches (and a maximum of 12 matches if their team reaches the final), compared to an average of between 12 and 14 test matches presently.
“Commitment to work with International Rugby Players and the leading domestic club competitions to optimise the model.
“A commitment to invest in a Women’s Nations Championship to accelerate the global competitiveness of the game.”