Sky City Entertainment confirmed it had signed an agreement to sell the Darwin business it has owned for 14 years to the New York-based company.
The purchase agreement is subject to the approval of the Northern Territory Attorney-General, Natasha Fyles.
The deal excludes the beachfront Little Mindil site which it will sell separately.
Earlier this year the Australian Financial Review reported the casino complex could be worth between $200 and $250 million.
New Zealand company Sky City Entertainment is believed to have paid $195 million for the complex in 2004.
Yet Sky City chief executive Graeme Stephens said the sale "is a good outcome for Sky City, the resort's staff, and the city of Darwin".
He said while the resort has been performing better financially over the past 12 months, Sky City's future strategy had the company looking closer to its New Zealand home base and its expanding casino facilities in Adelaide.
"They are a highly respected and well-established hospitality and gaming company and I'm very comfortable handing over the business we have built up over the past 14 years to an operator of this calibre.''He said all the company's 650 staff will be retained once the change of ownership takes effect.
Sky City's association with Darwin will continue for some time, through the ongoing use of the casino's VIP facilities for at least the next two years, subject to availability.
The company also retains the rights to operate an online casino in partnership with Delaware North, should a licence be granted in the future.
It will also continue to own the beachfront Little Mindil site and will run a separate process to sell the site.
With the sale of the Darwin casino still contingent on the new owner gaining regulatory approvals in the Northern Territory, Sky City will continue running the business until regulatory approval is received.