Marlborough and Nelson will officially join forces to market the top of the south's tourism attractions to overseas visitors in July.

Unlike the morphing of the provinces' NPC rugby teams into the Tasman Makos, however, the tourism alliance will see each region retain a separate identity.

Tourism New Zealand has encouraged regional tourism organisations to form alliances so that it can sell the country's attractions to foreign trade more easily.

It had originally sought a grouping of Nelson, Marlborough, Christchurch, Canterbury and the West Coast.

Destination Marlborough chief executive Dominic Moran said that was a "big chunk" that offered an enormous amount of diversity in terms of tourism activities and sights.

"It would have been quite hard for Marlborough to put up its hand and say 'look what we've got to offer'," he told a meeting of tourism operators in Blenheim yesterday.

The organisation had since agreed to form a top of the south alliance with its Nelson counterpart and had started to organise its international marketing to trade groups on that basis since last year.

The arrangement means the areas' regional tourism organisations can share resources when it came to marketing the region's internationally.

For example, just one marketing executive from either organisation will be able to represent the top of the south at overseas trade fairs.

Mr Moran said the alliance did not change the funding arrangements for regional tourism organisations. Destination Marlborough is largely funded through local body rates.

Destination Marlborough was previously involved with another alliance called CentreStage, that was involved with joint marketing for Marlborough, Nelson, Wairarapa and Wellington.

It was dissolved in 2004 but Mr Moran said it had been ahead of its time in some respects.

"When Tourism New Zealand is marketing the country offshore it finds it difficult to educate people about the differences between the North Island and the South Island, let alone 30 different regions."

However, he was pleased that Nelson and Marlborough had agreed to form a separate alliance and said Marlborough's wine and Sounds attractions worked well with Nelson's arts and outdoor experiences.

"It doesn't mean Marlborough and Nelson will morph into one. It's not going to be the same thing as has happened with our (NPC) rugby teams - the jury's still out on how that one will work."