But the ACCC said it was concerned about competition between Christchurch-Melbourne, Christchurch-Brisbane, Wellington-Brisbane, Queenstown-Brisbane, Auckland-Gold Coast, Dunedin-Sydney, Dunedin-Melbourne and Dunedin Brisbane and wants assurances capacity will be maintained.
The ACCC is now seeking submissions on the draft before making a final decision, it said.
Last month, Air New Zealand lifted its stake in Virgin to about 23 per cent from 19.99 per cent in a series of off-market transactions, while indicating it may seek to hold as much as 26 per cent.
New Zealand's state-controlled airline paid about A$72 million for the shares, with the largest purchase being for 77.4 million shares at 47.68 Australian cents apiece, or A$36.9 million under a forward transaction with Gresham Property Investments.
The New Zealand carrier's shares rose 0.4 per cent to $1.445 on the NZX and have gained 11 per cent this year. Virgin last traded at 45 Australian cents on the ASX.