Ainslie said multiple options were explored as to how to continue the project.
The Airport Limited Board supported the formation of a subsidiary company.
Chairman Tony Porter said the board had considered the risks and benefits of various options.
"But ultimately agreed that setting up a subsidiary company to deliver the project was the best solution, especially given Stuart's [Ainslie] experience in overseeing projects of this nature."
Work is getting back under way at the airport.
Ainslie said the site is a construction zone and an active operating terminal so safety is a high priority and they will be relaunching safety measures as soon as the site is up and running.
The project is expected to be completed by mid 2020.