The chances of the America's Cup being defended in New Zealand appear to be slipping, with an offer worth around $100 million from the Government and Auckland Council apparently rejected.

A team of negotiators appointed by the Crown have been trying since March to thrash out a deal with Team New Zealand, which beat Luna Rossa to retain the Auld Mug on March 17.

The final race of the 36th America's Cup kicked off a three-month period of good faith negotiations, during which Auckland had the first right of refusal to host the next match. That window ends on June 17.

The joint bid by the Government and Auckland Council is believed to have been worth around $100m, made up of a mixture of cash and "in kind" support such as the use of land in Auckland's Viaduct Harbour and other services.

Sources with knowledge of the talks have told the Herald that Team New Zealand informed negotiators in recent days that the bid has been rejected.

Team New Zealand is said to have wanted a package worth in excess of $200m. The board of the syndicate is expected to meet later this week to discuss the matter.

While the negotiation period still has more than a fortnight to run, the source believes the Government has indicated it has tabled its best offer.

Sailor Chris Dickson said the event is "very attractive" and there would be interested parties around the world.

"[The negotiation] is all behind closed doors and we the ratepayers and taxpayers can only wonder what's going on. $100 million sounds like a lot of money to me," he told Newstalk ZB.

Dickson said he thought Team New Zealand would be wise to think about their brand reputation if they took the defence offshore.

"Team New Zealand has built a very strong and valuable brand globally, largely on being New Zealanders. For them to take it somewhere else would go against the grain."

Dickson said the 2021 America's Cup event had been a success, but a lot smaller than initially anticipated due to the Covid-19 pandemic.

"It feels to me we only got half a party, I think we deserve the other half and I hope they can put it together."

Team New Zealand sailors celebrate defending the America's Cup in Auckland in March. (Photo / Photosport)

Team New Zealand earlier this year confirmed they were considering whether to take the world's oldest sporting trophy overseas, warning the foiling monohulls had renewed interest which could see its talent stripped.

Documents showed Team New Zealand had appointed agents to seek international bids, where host cities were invited to offer both a "rights/sanction fee" from the host city to the yachting syndicate, as well as to commit to covering the operating costs of the America's Cup match.

In a statement, a spokeswoman for Economic Development Minister Stuart Nash this week declined to say whether the talks were at an end, or whether the Government might submit an improved offer.

"Discussions and negotiations will be commercial-in-confidence and further information is unable to be released."

Auckland Council referred questions to its economic development and events arm, Auckland Unlimited. It declined to discuss the state of negotiations.

Team New Zealand has been approached for comment.

After the Government and Auckland Council announced a $136m package to defend the America's Cup in 2018, both sides privately acknowledged that to get true value for money, Auckland needed to host at least two defences.