Attendances at matches in the June window have also been falling, as they have in Super Rugby. The backers believe a league in which the top 12 countries play each other in the course of the year, with the Six Nations and Rugby Championship remaining intact but counting towards the ranking for playoffs, would bring greater value to test rugby.
There are plans for Japan and Fiji to be included in the southern hemisphere's Rugby Championship.
The plan also puts forward the move to open up the Six Nations, with a play-off between the country who finish bottom of the championship with the winner of the Europe Rugby
Championship.
One source said that while it is significant that the proposal was not dismissed out of hand in what had been described as a "crunch meeting", there remained many hurdles, not least the impact a new global tournament would have on the club game.
The prospect of playoffs in November would require an extra week in the test window, which would almost certainly be opposed by UK Premiership clubs. There are also lingering concerns that the World Cup, the cash cow of the global game, would be devalued by the proposal, although those behind the new league claim that the World Cup's value to broadcasters would only be enhanced by a new tournament.
There are no plans to stage the global league in World Cup or British and Irish Lions years.
It is understood TRM, the agency hired to sell the concept to broadcasters, has already been able to relate that it would attract a firm offer even at this early stage of negotiations, but the London-based firm will now attempt to increase the value.
The plans will be discussed again at a meeting of the World Rugby executive committee in March and if further progress is made then it could go before the global governing body's council, most likely in November.
"Following positive and productive meetings with union and competition CEOs in Los Angeles, World Rugby has been tasked to continue exploring the viability of potential global competition formats," a World Rugby spokesman said.
"The objective of this exploratory work is to deliver a global competition product and commercial model that will deliver greater value and certainty to all unions by building on the strong foundations of existing competitions and invigorating the July and November windows.
This important project has the potential to enhance the international game."
- Telegraph Group Ltd