All up, the concessions are worth up to $527 million over the lifetime of the deal, according to analysts' estimates.
Mr Joyce said the deal was "great news" for Auckland and New Zealand.
He claimed it would provide a projected $90 million annual injection into the economy, an estimated 1000 jobs during construction and 800 jobs once it is up and running.
"The New Zealand tourism industry and business sector have been asking for an international-sized convention centre to be built in New Zealand for many years to tap into the growing market of high-value business visitors that we are currently missing out on.
"The Government and SkyCity have completed an agreement that will put New Zealand on the international map as a high-quality convention centre destination."
Labour Leader David Shearer called the agreement a "dodgy deal"
"Over 60 per cent of Kiwis are against National's pokies for convention centre stitch-up. That's no wonder; it's been a dodgy backroom deal from the start.
"John Key has essentially written a blank cheque for SkyCity. It will get more pokies, more gaming tables, ticket in - ticket out systems, cashless gambling and the ability to increase playing limits.
Shearer said the Government was refusing to listen to a finding by the Auditor General that SkyCity had been favoured over other tenderers.
He accused Key of acting as a "broker for vested interests".
"The deal undermines New Zealand's reputation for honesty and transparency.
- nzherald.co.nz