Reports out of the IRB's Heineken Cup meeting in Dublin suggest the Six Nations competition could be played at the same time of the year as an expanded Tri Nations tournament.
There are also suggestions the top two or top four placed teams in Six Nations and the Tri Nations might play each other as part of the proposed new international window.
The Southern Hemisphere unions could still veto the change in the international schedule but with the Sanzar officials having recently been in Dublin they would have been consulted in the planning process.