American tech giant Apple was granted Overseas Investment Office approval to buy PowerbyProxi for more than $100 million.

The change in ownership of the New Zealand wireless power developer was confirmed by Apple last month, but the world's biggest technology company refused to provide any details or the terms of the agreement.

However, a summary of the OIO approval released on Thursday shows the deal needed sign-off because it crossed the $100 million threshold to be considered significant business assets.

The exact figure has been withheld.

At the time of the sale, 74 per cent of the company was owned by New Zealand- based investors.

PowerbyProxi was spun out of the University of Auckland.

In 2013, it attracted $4m in funding from Samsung's venture capital arm, along with $5m from New York-listed TE Connectivity and Wellington-based investment fund Movac.

TE Connectivity held 12.3 per cent and Samsung Electronics had 10.8 per cent when PowerbyProxi was sold, the OIO approval shows.

Two UK-based shareholders were also mentioned: Eric Tracey, who held 1.2 per cent, and Mark Jaffray, who had 0.7 per cent.

The October 11 approval falls within the time of caretaker government, with NZ First leader Winston Peters signing a coalition agreement with Labour on October 19 and ministers sworn in a week later.

The Overseas Investment Act has been targeted by the new government early, with changes flagged to effectively ban the sale of existing residential property to foreign buyers and ministers this week issuing a directive to the OIO over the sale of sensitive and rural land