WELLINGTON • Further expansion of Super Rugby is inevitable, according to New Zealand rugby boss Steve Tew, despite the current model being criticised as unwieldy and difficult to follow.

The premier southern hemisphere championship has grown from 12 sides from New Zealand, Australia and South Africa in 1996 to 18 teams this year, when it spread to Japan and Argentina.

But Tew, the New Zealand Rugby chief executive, said the competition will have to grow more if it is to survive.

"If we want to play professional rugby, we can't just play ourselves - we will go out of business very quickly," he said.

"When we go to the next set of broadcasting deals we've got to be sure we've got a footprint in South America and in Asia and possibly other markets."

In its formative years, Super Rugby was a round-robin competition with the top four teams advancing to the semi-finals. However, from 2011, there has been a conference system which this year has grown to four conferences, with the winners guaranteed the top four places in an eight-team play-off.

Although four New Zealand teams top the overall points tally, because of the conference system they are currently ranked first, fifth, sixth and seventh.

One of the harshest critics of expansion has been former Australia coach Eddie Jones, who is now at the helm of England.

"I watch most of the (Super Rugby) games but some of the games put me to sleep," he said recently. "I don't think the standard's great this year."

The new teams this year - Sunwolves (Japan), Jaguares (Argentina) and Southern Kings (South Africa) - have been placed in the two Africa conferences and among them have won just four of 27 games.

However, Tew said that, while the conference structure was complex and not perfect, it did lay a foundation for the future.

"We've set this conference structure up so that future expansion will be possible and more sensible in terms of travel and workload, but we've got to break into new markets," he said.

AGENCE FRANCE-PRESSE