Van Tilborg, who is also a Blues director, thinks there may be an opportunity for New Zealand to field six franchises in a revamped Super competition after 2010.
He has recently been elected to the board of the New Zealand Rugby Union but has stressed his comments on the future of the Highlanders are made purely from a personal perspective and not on behalf of the NZRU.
There should "absolutely'' be two franchises in Auckland, van Tilborg told the Otago Daily Times yesterday.
"From a population base point of view, and from the point of view of the whole Blues structure, there should be another team up here,'' he said.
"I think there are a number of kids from Auckland and Harbour who would potentially be represented in another franchise in the region. Across all the unions, we're producing more players up here.''
Van Tilborg is originally from Timaru and says he has an empathy for the Highlanders, the smallest franchise in the Super 14.
It should not be taken as read that if there was to be a second franchise established in Auckland, the Highlanders would have to go, he said.
"Obviously the Highlanders franchise has been under some pressure in terms of support and the rest of it. But I'm not interested in trying to deny the Highlanders. The franchise has got a magnificent heritage in terms of its image and what it does for rugby in the south.
"I'm a supporter of the Highlanders. I personally believe there should be two South Island franchises. And I'd like to see ways the Highlanders can be strengthened.
"I would like to see another franchise available in New Zealand. That's my personal point of view. I just think that up north, there is enough population and other things to support a second Auckland franchise.''
North Harbour had not lobbied the NZRU to become a franchise base, van Tilborg said. But it had suggested the provincial union had players who were missing out.
There have been suggestions of a possible franchise-sharing arrangement between Otago and North Harbour, and van Tilborg did not discount the idea.
"I have, off the record and on a very casual basis, spoken to people over last couple of years within the Highlanders region about whether there could be options around that.
"Vested interests would have to be accommodated.
"Clearly, we would see that up north would be a better training place. But I also understand the parochialism in the south and the need to try to keep their identity.
"There would be a lot of logistical issues. One that I have talked about before is assisting the Highlanders with some of our non-Blues players, but making sure they come back.
"It's hard to support when you've got guys who go down to the Highlanders and a year later they transfer to Otago. We're trying to foster growth and a pathway that's closer to home.''
North Harbour players have occasionally felt marginalised by the Auckland-dominated Blues but van Tilborg said the unions had a healthy relationship.
