Although it is yet to be decided which country the new franchise will come from, Australia, who currently have one less team than their South African and New Zealand counterparts, are favourites to secure the extra berth.
Melbourne previously made a strong case for inclusion in an expanded tournament, while Australian Rugby Union managing director John O'Neill has suggested that a hybrid Australian team was also a viable option.
South African officials are thought to be pushing for the inclusion of a team from the Eastern Cape to be known as the Southern Kings, while a case could yet be made for New Zealand to increase their quota to six franchises.
"I think a hybrid team with Australians, Pacific Islanders and the odd rugby league player could provide a very competitive team," said O'Neill.
"We would have to be careful to ensure the existing four (Australian) franchises would not be diminished in any way.
"The thing I keep coming back to is that the fifth team will play in the Australian conference.
"It really doesn't make sense for an Eastern Cape to fit into an Australian conference."
Other discussions at the latest SANZAR meeting in Dubai between officials from all three southern hemisphere giants included a new start date and an increase in fixtures.
It was decided that the 2011 tournament would contain one full round of games, plus an extra round of local derbies between sides within each conference.
It was also agreed that the finals, which currently involve the top four sides, would be extended to include six teams.
While all three countries were united on the need for expansion, the timings of the new competition are proving more difficult to agree on. While New Zealand and South Africa are keen to preserve their respective domestic competitions, the Air New Zealand Cup and Currie Cup, the Australians have no such prestigious tournament to protect.
"You've got three quite different perspectives there and that's one of the things we've got to continue to work our way through and discuss and get it sorted out before we go to the broadcasters," said New Zealand Rugby Union chief executive Steve Tew.
"One of the things we are very adamant on is that Super Rugby cannot start any earlier [than its current February start date].
"In fact, we are making a very strong case for it starting in March. We've recently gained support from the Australians in that regard, which is encouraging.
"But these things are all book ended by commitments we can't move. We do have June internationals, there is a Currie Cup, we do need to play the Tri Nations, we have to go and play rugby in the northern hemisphere in November.
"The biggest problem is the 52 weeks is not quite enough in the year. If someone had of designed a 54-week calendar we might be better off."