Further to the proposed increase from 12 teams to 16, the WRU Board has now also approved a mid-season split of the division with the top eight teams playing against each other in the second half of each season and the bottom eight teams similarly grouped.
The eight/eight split will be determined on league positions based on results from the fixtures already played in the first half of the season.
All the clubs in the expanded division will be subject to the same on and off-field support provided by the Welsh Rugby Union.
As previously agreed and announced the Premiership will be ring-fenced until the end of season 2018/19.
The Board of the WRU has also agreed to a full review of the structure and finances over the first three seasons of the enlarged league.
This review will aim to ensure the Division provides appropriate development opportunities to players and coaches within the WRU’s agreed rugby pathway structure.
These latest changes are in line with the WRU Board’s pledge to continue their consideration of the Competitions Pathway Working Group recommendations.