The expansion of rugby's Super 14 play-off format will have to wait until 2010 after South Africa, New Zealand and Australia were unable to reach an agreement on a planned six-team version.
Next year's Super 14 and Tri-Nations competitions will continue to trial 13 experimental law variations or ELVs, in addition to those that have been on global trial since August.
The Super 14 at present follows a league round robin format - although with only one match between each team rather than the usual home and away series.
The top four then contest the semi-finals in a knockout cup format.
