SkyCity is working though the implications for its 4000 workers, as its Hamilton, Queenstown and Auckland establishments close immediately in light of the new Covid-19 regulations.
Its Auckland hotels will remain open temporarily to accommodate guests already staying.
Chief executive Graeme Stephens said it was working through the financial implications of the closures and would update the market when it could.
"SkyCity is fully complying with the government's instruction to shut down all non-essential services. This nationwide closure is an unprecedented change for everyone and we are very focused on the implications for our employees."
Its Adelaide casino closed earlier today following similar restrictions mandated by the Australian government.
"We respect the Australian government's decision to close the Adelaide Casino in order to combat the spread of Covid-19. We are now very focused on addressing the welfare of our 1000 employees in Adelaide."
Stephens said SkyCity had started consultation with the unions in South Australia and expected to finalise a plan for its employees over the next week.
It has withdrawn its earnings guidance for the year ending 30 June 2020, which was released last week.