At the same time, the OIO is expanding its team to 14 from nine.
The office has been working closely with local law firms to get them on board, particularly those with multiple rejections, to raise the standard of applications before they are lodged, she said.
The OIO aims to assess 90 per cent of applications within a certain timeframe, based on the way it classifies the transaction.
The office is often criticised for the time it takes to process applications, most recently by NZX-listed industrial automation firm Scott Technology over a more than six-month wait for Brazilian meat processor JBS to buy a controlling stake. And ASX-listed Broadspectrum's board cited it earlier this year as a reason its shareholders should reject a takeover offer from Spain's Ferrovial.