An expanded Super Rugby series looks set to include the first side from Argentina and a sixth team from South Africa after bosses approved a "preferred model" on Thursday.

The changes got the nod at a meeting of the South African, New Zealand and Australian Rugby (SANZAR) executive committee in Sydney, and will now be taken to national unions for approval.

"Today's meeting was another important step in deciding the future of Super rugby," SANZAR CEO Greg Peters said in a statement.

"Encouraging progress was made and we now have a preferred model that involves six teams from South Africa and a new team from Argentina.

"The model will now be taken to the national unions for approval before SANZAR presents its final position to broadcasters and fans in due course."

The southern hemisphere provincial competition currently includes five teams from each of Australia, New Zealand and South Africa.

In 2012, SANZAR expanded the former Tri-Nations competition to include Argentina and rebranded it as the Rugby Championship.

Previous reports have said the Super rugby competition was at risk of splintering if South Africa, who currently run a promotion-relegation system, were not allowed a sixth team.

AFP