New Zealand Rugby's provincial unions have signed off the $200 million Silver Lake deal.

The 26 provincial unions cast 90 votes via secret ballot, with only one vote against the deal, at NZ Rugby's Auckland headquarters.

NZ Rugby chairman Stewart Mitchell said it was a "monumental moment" in the history of NZ rugby.

The deal will see $37m distributed immediately with the 14 NPC teams receiving $1m each, 12 heartland unions $500k each ($6m total), Māori rugby $2m, community clubs $7.5m, Players' Association $5m.

In addition to the $200m deal, there will be an opportunity for NZ institutional investors to raise $62.5m and $100m. If there is insufficient institutional demand, Silver Lake would increase its position to ensure a minimum capital raise of $62.5m.