The board of the WRU sanctioned the move subject to conditions after a presentation delivered by Regional Rugby Wales and the four regional organisations.
Final approval and confirmation of the amendment to a 12 team Premiership will be granted once the conditions have been considered and agreed.
A 12 team Principality Premiership Division will then be introduced from season 2012/13 if the four regions agree to the terms of acceptance of their appeal.
Under the new plan put forward by the regions Bridgend RFC and Carmarthen Quins RFC will be the two teams added to the reformed Premiership in order to fulfil the talent recruitment strategy requirements of the Ospreys and Scarlets.
The Board of the WRU sanctioned the amended reforms in principle after agreeing there were important strategic and operational rugby reasons put forward to revisit the original reform plans.
If the conditions for the amended Premiership are agreed by the regions the extra costs associated to the inclusion of Bridgend and Carmarthen Quins will be met through the regions and Regional Rugby Wales.
Further conditions are that player quality and age profile standards are met by the two new clubs along with all other criteria set out in the Premiership Participation Agreement.
All the feeder clubs from the Premiership attached to the four regions will have to be treated equally within the requirements of the agreement.
The two clubs to be added to the National Championship Division to replace Bridgend and Carmarthen Quins would be from Division One West.